Metro Riyadh

Temporary Traffic Management of Major Construction Projects Case Study: Metro Riyadh

Author: Bishoy M. Kelleny

First Supervisor: Prof. Dr.-Ing. Markus Friedrich Second Supervisor: Prof. Dr. Ibrahim A Alhammad Advisor: AOR Dipl.-Ing. Manfred Wacker

October 2014

Universität Stuttgart Institut für Straßen- und Verkehrswesen Lehrstuhl für Verkehrsplanung und Verkehrsleittechnik

Abstract

Abstract Major Construction Projects are currently running in different areas of the world, triggering significant impacts on road networks as well as road users. International codes of practice were developed in North America and Europe in order to locally address the issue of major projects’ temporary traffic management. However, in most developing and transitional countries, even in some developed countries, the issue is not yet clearly addressed. The primary purpose of this M.Sc. Thesis is to investigate the available standards and codes of practice for temporary traffic management of major construction projects in order to synthesize the best practice in one self-explanatory study. Secondary purpose is to debrief the key tasks performed for the temporary traffic management schemes of outstanding international projects. Last milestone of the thesis is to transfer and apply the knowledge acquired from the international codes of practice and the lessons learned from the investigated outstanding projects to the case study of Metro Riyadh in Saudi Arabia. The key results of this thesis are highlighted in the recommended comprehensive temporary traffic management approach that considers the safety, mobility, environment and society in the elaboration phase. The adopted method of work, planning tools and evaluation scheme in the case study emphasize on this inclusionary approach in planning the temporary traffic management of major construction projects. The thesis strives at integrating the temporary traffic management concept in the early stages of the project’s preliminary engineering design, planning, management and scheduling in order to mitigate the traffic related impacts and enhance sustainable construction.

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Author’s Statement

Author’s Statement I hereby certify that I have prepared this Master’s Thesis independently, and that only those sources, aids and advisors that are duly noted herein have been used and/or consulted. Stuttgart, 24.10.2014

Bishoy M. Kelleny

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Table of Contents Lists of Tables and Figures List of Abbreviations

v xiii

INTRODUCTION

1

1

4

CHAPTER 1: LITERATURE REVIEW

1.1

Conception of Temporary Traffic Management of Major Construction Projects 4

1.1.1

Traffic Management

4

1.1.2

Temporary Traffic Management

4

1.1.3

Need for Temporary Traffic Management

5

1.1.4

Major Construction Projects

6

1.2

Elaboration of TTM Plans for Major Construction Projects

8

1.2.1

Temporary Traffic Management Responsibilities

8

1.2.2

Development Process of Temporary Traffic Management Plans

8

1.3

Strategic Planning of Temporary Traffic Management

14

1.3.1

Work Zone Impacts Assessment

14

1.3.2

Temporary Traffic Control (TTC) Strategies

17

1.3.3

Transportation Operation (TO) Strategies

19

1.3.4

Public Information (PI) Strategies

20

1.4

Work Zone Dissection and TTC Devices Review

22

1.4.1

Work Zone Dissection According to “MUTCD”

22

1.4.2

Work Zone Dissection According to the “Traffic Signs Manual”

26

1.4.3

TTC Devices (MUTCD- USA)

31

1.4.4

TTC Devices (Traffic Signs Manual- UK)

33

1.5 1.5.1 1.6

Temporary Traffic Management- ITS Review

38

Conceptual Framework of Work Zone ITS

38

Evaluation of Temporary Traffic Management Alternatives

41

1.6.1

Evaluation Criteria

41

1.6.2

Quantification of Evaluation Criteria

46

1.6.3

Cost Effectiveness Evaluation

49

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1.7 2

Comprehensive Temporary Traffic Management Plans CTTMP CHAPTER 2: CASES ANALYSIS

2.1

Case Analysis 1: Dulles Corridor Metrorail

54 56 56

2.1.1

Project Background

56

2.1.2

Work Zone Impacts

61

2.1.3

TTM Strategies

72

2.2

Case Analysis 2: London Crossrail

80

2.2.1

Project Background

80

2.2.2


82

2.2.3

TTM Strategies

90

2.3

Case Analysis 3: Stuttgart 21

103

2.3.1

Project Background

103

2.3.2

Work Zone Impacts

106

2.3.3

TTM Strategies

110

3

CHAPTER 3: CASE STUDY- METRO RIYADH

3.1

118

Project Background

119

3.1.1

City of Riyadh

119

3.1.2

Riyadh Traffic Conditions

119

3.1.3

Project Overview

122

3.2

Work Zone Impact Assessment

125

3.2.1

Construction Data

125

3.2.2

Implementation Area Data

131

3.2.3

Assessment of the Impacts on the Mobility

133

3.3

Temporary Traffic Management Strategic Planning

136

3.3.1

Baseline Condition Analysis

136

3.3.2

Worksite Traffic Layout

146

3.3.3

Potential TTM Strategies Elaboration

147

3.3.4

TTM Strategies Effectiveness Assessment

151

3.4

Recommended TTM Plan for Zayd Ibn Al Khatab Rd.

172

3.4.1

Strengths and Weaknesses (SW) Analysis

174

3.4.2

Mitigation Measures

175

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4

Conclusion

177

5

Appendices:

182

5.1

Appendix 1: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Morning Peak Hour at the Baseline Condition 182

5.2

Appendix 2: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Evening Peak Hour at the Baseline Condition 183

5.3

Appendix 3: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Morning Peak Hour for TTM Alternative No.1 184

5.4

Appendix 4: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Evening Peak Hour for TTM Alternative No.1 185

5.5

Appendix 5: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Morning Peak Hour for TTM Alternative No.2 186

5.6

Appendix 6: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Evening Peak Hour for TTM Alternative No.2 187

5.7

Appendix 7: Total Delays Calculation for the TTM Alternatives In Comparison To the Baseline Condition at the Morning Peak Hour 188

5.8

Appendix 8: Total Delays Calculation for the TTM Alternatives In Comparison To the Baseline Condition at the Evening Peak Hour 189

5.9

Appendix 9: Queue Lengths Calculation Sheet for TTM Alternative No.1 during Morning Peak Hour 190

5.10

Appendix 10: Queue Lengths Calculation Sheet for TTM Alternative No.1 during Evening Peak Hour 191

5.11

Appendix 11: Queue Lengths Calculation Sheet for TTM Alternative No.2 during Morning Peak Hour 192

5.12

Appendix 12: Queue Lengths Calculation Sheet for TTM Alternative No.1 during Evening Peak Hour 193

5.13

Appendix 13: Emission Calculation Steps for TTM Alternatives during Morning Peak Hour 194

5.14

Appendix 14: Emission Calculation Steps for TTM Alternatives during Evening Peak Hour 196

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6

iv

List of References

198

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Lists of Tables and Figures List of Figures Figure 1: TMP Development Process (Source: U.S DOT, FHWA (2005), RULE ON WORK ZONE SAFETY AND MOBILITY- Developing and Implementing Transportation Management Plans for Work Zones, P.2-2) ................................................................... 10 Figure 2: TTM Strategies- Level of Influence. ................................................................ 21 Figure 3: Components of Temporary Traffic Control Zone (Source: MUTCD 2009, P.553). ............................................................................................................................. 23 Figure 4: Types of Tapers and Buffer Spaces (MUTCD 2009, P.556). ......................... 24 Figure 5: Work Zone Dissection in Single Carriageway Road (Source: Safety at Street Works and Road Works, a Code of Practice, P.21). ...................................................... 27 Figure 6: Work Zone Dissection in Dual Carriageway Road (Source: Traffic Signs Manual, Ch.8, Part 1, P. 168) ......................................................................................... 27 Figure 7: Typical Site Layout (Source: Traffic Signs Manual, Ch.8, Part 1: Design, P.19). ............................................................................................................................... 30 Figure 8: Priority sign method on a two lane single carriageway road (Source: Traffic Signs Manual, Ch.8, Part 1, P.126). ............................................................................... 35 Figure 9: Stop/Go method on a two lane single carriageway road (Traffic Signs Manual, Ch.8, Part 1, P.130). ....................................................................................................... 36 Figure 10: Comprehensive Temporary Traffic Management Plans- Development Scheme. .......................................................................................................................... 54 Figure 11: Dulles Metrorail Project Map (Source: Dulles Corridor Metrorail Project Website) .......................................................................................................................... 57 Figure 12: Tysons Corner Detailed Map (source: Dulles Corridor Metrorail Project Webpage) ........................................................................................................................ 58 Figure 13: Aerial Photo of Dulles Metrorail Project in the Area of Tysons Corner (source: Google Earth 2014, 38°55ʹ35.78ʺN 77°13ʹ29.56ʺW, elevation 436 ft., Europa Technologies, Google. 13 October 2012). ..................................................................... 59 Figure 14: Project Alignment by Operation Area (source: Project Management Plan, P.54). ............................................................................................................................... 60 Figure 15: At-Grade Intersection No.1-1 between Route 123, Colshire Rd. (South) and Scott Crossing R. (North) After Construction (source: Google Earth 2014, 38°55ʹ29.34ʺN 77°12ʹ29.91ʺW, elevation 314 ft., Google, Europa Technologies. 13 October 2012). ................................................................................................................ 61 Figure 16: At-Grade Intersection No.1-2 between Route 123 and Old Meadow Rd. After Construction (source: Google Earth 2014, 38°55ʹ26.65ʺN 77°12ʹ37.89ʺW, elevation 327 ft., Google, Europa Technologies. 13 October 2012)..................................................... 62 Figure 17: At-Grade Intersection No.1-3 between Route 123 and Tyson Blvd. After Construction (source: Google Earth 2014, 38°55ʹ12.97ʺN 77°13ʹ17.33ʺW, elevation 421 ft., Google, Europa Technologies. 13 October 2012)..................................................... 62

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Figure 18: I-495 HOT Lanes Intersection with Dulles Metrorail Track (source: Google Earth 2014, 38°55ʹ20.84ʺN 77°12ʹ58.18ʺW, elevation 375 ft., Europa Technologies, Google. 2012). ................................................................................................................ 63 Figure 19: Overall View of the Method of Construction for Construction Zone 1 (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 123 Tysons). ........... 64 Figure 20: Intersection 2-1; Route 7 (Leesburg Pike), Westpark Dr. and Gosnell Rd. After Construction (source: Google Earth 2014, 38°55ʹ25.41ʺN 77°14ʹ12.05ʺW, elevation 438 ft., Europa Technologies, Google. 13 October 2012).............................. 65 Figure 21: Intersection 2-2; Route 7 (Leesburg Pike) and Spring Hill Rd. After Construction (source: Google Earth 2014, 38°55ʹ20.84ʺN 77°14ʹ28.37ʺW, elevation 403 ft., Europa Technologies, Google. 13 October 2012). ................................................... 65 Figure 22: Intersection 2-3 Route 7 (Leesburg Pike), Tyco Rd. and Westwood Center Dr. After Construction (source: Google Earth 2014, 38°55ʹ48.12ʺN 77°14ʹ34.41ʺW, elevation 389 ft., Europa Technologies, Google. 13 October 2012).............................. 66 Figure 23: Route 7 (Leesburg Pike) - Lane Shift (source: Virginia Mega Projects Webpage, Lane shift makes way for rail station construction along Route 7) ............... 67 Figure 24: Right Lane Closure along Route 123 (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 123 Tysons). .................................................... 68 Figure 25: One Carriageway, two directions Scott Crossing Rd. (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 123, Changes to Scott Crossing Rd.) .................................................................................................................. 69 Figure 26:Traffic Patterns Change (Route 7/Route123) (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 7, Major Changes Coming to Route 7/Route 123 Interchange). .............................................................................................. 70 Figure 27: Eastbound Route 7 Traffic Stream Shift to International Dr. (source: Google Earth 2014, 38°55ʹ02.44ʺN 77°13ʹ38.19ʺW, elevation 506 ft., Europa Technologies, Google. 13 October 2012). ............................................................................................. 70 Figure 28: Construction Dumpsite and Construction Fleet Route (source: Google Earth 2014, 38°57ʹ13.47ʺN 77°20ʹ13.72ʺW, elevation 371 ft., Google, Europa Technologies. 13 October 2012). ........................................................................................................... 71 Figure 29: Work Zone Pull-off Area (source: Virginia Department of Transportation VDOT 2011, Virginia Work Protection Manual- Standards and Guidelines for Temporary Traffic Control, P.6H-23) .............................................................................. 77 Figure 30: Relation between London Crossrail and London Underground Network (source: Transitized 2014) .............................................................................................. 80 Figure 31: Central Section Tunnels Alignment (Proposed Work Plan for the Tunnel Boring Machine-TBM) (source: Crossrail.co.uk 2014). .................................................. 81 Figure 32: Eastbourne Terrace Main Worksite (source: Google Earth 2014, 51°30ʹ58.88ʺN 0°10ʹ38.05ʺW, elevation 102 ft., Google, The GeoInformation Group. 19 July 2013). ....................................................................................................................... 84 Figure 33: Eastbourne Terrace Worksite Strategic Location (source: Paddington Bus Diversion Assessment) ................................................................................................... 85

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Figure 34: Implementation Area Signal Groups of Controlled Intersections (source: Traffic Modeling Review- Transport Consultant Brief). .................................................. 85 Figure 35: Cross-sectional View of Crossrail Paddington Station- Excavation Works Proceedings (source: Crossrail Information Sheet July 2013) ....................................... 87 Figure 36: Departure Rd. Taxi Rank, Along With Eastbourne Terrace- Baseline Condition (source: Google Earth 2014, 51°31ʹ03.59ʺN 0°10ʹ46.88ʺW, elevation 115 ft., Google, GeoBasis-DE/BLG). .......................................................................................... 88 Figure 37: Development Process of TTM Plans for Crossrail Paddington Station. ....... 92 Figure 38: Performance Index (PI) of the Network Links for each Scenario (source: Perret, P., et al. 2011) ..................................................................................................... 93 Figure 39: Eastbourne Terrace Worksite during Construction (source: Crossrail.co.uk 2014) ............................................................................................................................... 95 Figure 40: Proposed Operating Scenarios for the Relocated Taxi Rank at Red Star Deck- (source: Google Earth 2014, 51°31ʹ07.37ʺN 0°10ʹ44.11ʺW, elevation 96 ft., Google, The GeoInformation Group, Europa Technologies. 19 July 2013) .................. 97 Figure 41: Existing Bus Stops and Stand along Eastbourne Terrace (source: Google Earth 2014, 51°30ʹ59.87ʺN 0°10ʹ37.99ʺW, elevation 103 ft., Google, The GeoInformation Group. 19 July 2013) ............................................................................ 98 Figure 42: Yellow Box Junction (source: gov.uk 2014) ................................................ 102 Figure 43: Existing Trains Maneuvering at Stuttgart Main Station (source: Google Earth 2014, 48°47ʹ52.83ʺN 9°12ʹ20.19ʺW, elevation 754 ft., 2009 GeoBasis-DE/BKG, Google, Europa Technologies. 16 September 2012). .................................................. 104 Figure 44: Stuttgart 21 Construction Zones Overview (source: Bahnprojekt-StuttgartUlm.de 2014). ................................................................................................................ 105 Figure 45: Main Construction Zone PFA 1.1 at the Main Station of Stuttgart (source: Bahnprojekt-Stuttgart-Ulm.de 2014). ............................................................................ 106 Figure 46: Planned Works Layout of Stuttgart New Main Station (source: BahnprojektStuttgart-Ulm.de 2014).................................................................................................. 107 Figure 47: Combined Planned Works of the New Main Station and the Light Rail U12 Modification (source: Bahnprojekt-Stuttgart-Ulm.de 2014). ......................................... 108 Figure 48: Worksites No. 1 and 2 Conflict with the Existing Blood Bank Facility at Jäger St. (source: Google Earth 2014, 48°47ʹ05.19ʺN 9°10ʹ34.34ʺW, elevation 826 ft., Google, 2009 GeoBasis-DE/BKG. 16 September 2012). ............................................ 110 Figure 49: Worksites no. 3 and 8 at Heilbronner St. (source: Google Earth 2014, 48°47ʹ06.99ʺN 9°10ʹ45.38ʺW, elevation 826 ft., 2009 GeoBasis-DE/BKG, Google. 16 September 2012). ......................................................................................................... 111 Figure 50: Construction Element 1, Worksites 3 and 8 Section (source: DB Projekt GmbH Stuttgart 21). ...................................................................................................... 112 Figure 51: Construction Element 2, Worksites 3 and 8 Section (source: DB Projekt GmbH Stuttgart 21). ...................................................................................................... 112 Figure 52: Construction Element 3, Worksites 3 and 8 Section (source: DB Projekt GmbH Stuttgart 21). ...................................................................................................... 113

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Figure 53: Construction Element 4, Worksites 3 and 8 Section (source: DB Projekt GmbH Stuttgart 21). ...................................................................................................... 113 Figure 54: Light Rail Tunnel Worksite at Kurt Georg Kiesinger Platz (source: Google Earth 2014, 48°47ʹ04.10ʺN 9°10ʹ49.37ʺW, elevation 809 ft., 2009 GeoBasis-DE/BKG, Google. 16 September 2012). ...................................................................................... 114 Figure 55: Light Rail Worksite TTM Construction Elements (Final Layout) - (source DB Projekt GmbH Stuttgart 21). ......................................................................................... 115 Figure 56: Permanent Road Closure between Schlossgarten and Existing Main Station (source: Google Earth 2014, 48°47ʹ01.89ʺN 9°11ʹ11.61ʺW, elevation 785 ft., 16 September 2012). ......................................................................................................... 116 Figure 57: Riyadh City Road Network (source: Google Earth 2014, 24°42ʹ42.34ʺN 46°44ʹ58.14ʺE, elevation 2079 ft., DigitalGlobe, Google. 29 July 2014). .................... 120 Figure 58: City of Riyadh Modal Split (source: Arriyadh.com 2014) ............................ 121 Figure 59: Trip Purpose Distribution in Riyadh (source: Alqhatani, M. et al. 2012) .... 121 Figure 60: Metro Riyadh Route Scheme (source: Arriyadh.com 2014). ...................... 123 Figure 61: 3F2 Station Worksite (source: Google Earth 2014, 24°39ʹ40.29ʺN 46°44ʹ42.27ʺE, elevation 1964 ft., Google, DigitalGlobe. 7 March 2014). ................... 124 Figure 62: Schematic Plan of Metro Line 3 (Orange line) - Station 3F2 (Source: Dornier Consulting GmbH Report). ........................................................................................... 126 Figure 63: Station 3F2 Construction Footprint (source: Dornier Consulting GmbH Report). ......................................................................................................................... 127 Figure 64: Station 3F2 Construction Zone- Construction Phases (source: Dornier Consulting GmbH Report). ........................................................................................... 128 Figure 65: Structural Precast Concrete Elements of the Tunnel Segment (source: Dornier Consulting GmbH Report). .............................................................................. 129 Figure 66: Soil Removal Trucks Route from 3F2 Station Worksite to the Dump Site (source: Google Earth 2014, 24°38ʹ02.54ʺN 46°45ʹ58.02ʺE, elevation 1986 ft., Google, DigitalGlobe. 4 July 2014). ............................................................................................ 131 Figure 67: 4-Legs Signalized Intersection In the Implementation Are (source: Google Earth 2014, 24°39ʹ40.41ʺN 46°44ʹ38.95ʺE, elevation 1956 ft., DigitalGlobe. 7 March 2014). ............................................................................................................................ 132 Figure 68: Parking facilities along right-turn lane off-Zayd Ibn Al Khatab Road (source: Dornier Consulting GmbH Report). .............................................................................. 133 Figure 69: Impacts on Mobility along Zayd Ibn Al Khatab Rd. (source: Google Earth 2014, 24°39ʹ37.19ʺN 46°44ʹ42.26ʺE, elevation 1962 ft., DigitalGlobe. 7 March 2014). ....................................................................................................................................... 134 Figure 70: Convergence Point between the Transitional Ramp and the Station Worksite. ....................................................................................................................... 135 Figure 71: Intersection Summarized Traffic Volumes (source: Traffic Counts- Dornier Consulting GmbH Report). ........................................................................................... 137 Figure 72: Geometry and Signal Phase Sequence of the Intersection in the Implementation Area (source: Dornier Consulting GmbH Report). ............................. 138

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Figure 73: Lane Groups of the Intersection in the Implementation Area (source: Dornier Consulting GmbH Report)............................................................................................. 141 Figure 74: Example of Two Lane Groups with Shared Lane Traffic. ........................... 143 Figure 75: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Morning Peak Hour- Baseline Condition. ..................................................................... 146 Figure 76: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Evening Peak Hour- Baseline Condition. ..................................................................... 146 Figure 77: Soil Removal Trucks Route To/From the Dumpsite Along Dharan St., and Maneuvering Inside the Worksite (source: Google Earth 2014, 24°39ʹ34.65ʺN 46°44ʹ18.26ʺE, elevation 1957 ft., DigitalGlobe. 7 March 2014). ................................. 147 Figure 78: TTM Alternative No. 1 at Zayd Ibn Al Khatab Rd. (source: Dornier Consulting GmbH Report)............................................................................................. 149 Figure 79: TTM Alternative No. 2 at Zayd Ibn Al Khatab Rd. (source: Dornier Consulting GmbH Report)............................................................................................. 149 Figure 80: Transitional Ramp Worksite at Salah Ad Din Rd., Construction Element No.1 ....................................................................................................................................... 150 Figure 81: Transitional Ramp Worksite at Salah Ad Din Rd., Construction Element No.2 ....................................................................................................................................... 151 Figure 82: The Intersection Geometry and Traffic Volumes (Morning Peak) for TTM Alternative No.1 (source: Dornier Consulting GmbH Report). ..................................... 153 Figure 83: Intersection Lane groups for TTM Alternative No.1. ................................... 154 Figure 84: Lane Grouping of Northbound Direction for TTM Alternative No.1 at Zayd Ibn Al Khatab Rd. .......................................................................................................... 154 Figure 85: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Morning Peak- TTM Alternative No.1. .......................................................................... 155 Figure 86: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Evening Peak- TTM Alternative No.1. .......................................................................... 155 Figure 87: The Intersection Geometry and Traffic Volumes (Morning Peak) for TTM Alternative No.2 (source: Dornier Consulting GmbH Report). ..................................... 156 Figure 88: Intersection Lane groups for TTM Alternative No.2 (source:...................... 157 Figure 89: Lane Grouping of Northbound Direction for TTM Alternative No.2 at Zayd Ibn Al Khatab Rd. (Morning Peak). ............................................................................... 157 Figure 90: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Morning Peak- TTM Alternative No.2. .......................................................................... 158 Figure 91: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Evening Peak- TTM Alternative No.2. .......................................................................... 158 Figure 92: Potential Detour for Zayd Ibn Al Khatab Southbound Direction (source: ... 159 Figure 93: Total Delays at the Intersection- Morning Peak. ......................................... 160 Figure 94: Total Delays at the Intersection- Evening Peak. ......................................... 160 Figure 95: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.1Morning Peak Hour. ...................................................................................................... 165 Figure 96: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.1Evening Peak Hour. ...................................................................................................... 165

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Figure 97: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.2Morning Peak Hour. ...................................................................................................... 166 Figure 98: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.2Evening Peak Hour. ...................................................................................................... 166 Figure 99: Comparison between the Two TTM Alternatives for Emissions Produced at Morning Peak Hour. ...................................................................................................... 168 Figure 100: Comparison between the Two TTM Alternatives for Emissions Produced at Evening Peak Hour. ...................................................................................................... 168 Figure 101: Recommended TTC Plan for Zayd Ibn Al Khatab Rd. ............................. 173

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List of Tables Table 1: Recommended Advance Warning Signs Minimum Spacing (derived from the MUTCD 2009) ................................................................................................................. 23 Table 2: Criteria Determining Taper Length (Source: MUTCD 2009, P.557) ................ 25 Table 3: Approach Zone Characteristics (Source: Safety at Street Works and Road Works - A Code of Practice, P.105)................................................................................ 28 Table 4: Lead in taper length (Source: Safety at Street Works and Road Works - A Code of Practice, P.105) ................................................................................................. 29 Table 5: Minimum and desirable longitudinal clearance (Source: Traffic Signs Manual, Ch.8, Part 1: Design, P.23) ............................................................................................. 29 Table 6: Work methods for TTC (Safety at Street Works and Road Works- a code of practice, 54)..................................................................................................................... 34 Table 7: TTM Strategies Adopted in Dulles Corridor Metrorail Project (source(s): Dulles Metrorail Transportation Management Plan, P. 14-16, Developing and Implementing Transportation Management Plans for Work Zones, P.4-2,4-3, PE Design Refinement Environmental Assessment, Ch.3, P.3-32, Dulles Corridor Metrorail Project Webpage) ......................................................................................................................................... 75 Table 8: TTM Mitigation Measures Proposed for Eastbourne Terrace Full Closure Scenario (source: Perret, P., et al. 2011, P.9)................................................................ 95 Table 9: Assessment Criteria for Bus Diversion Options (Derived from: Paddington Bus Diversion Assessment, P.24).......................................................................................... 99 Table 10: Riyadh City Demographic Structure 2012 (source: Arriyadh.com 2014) .... 119 Table 11: Morning and Evening Peak Hourly Volumes of the Signalized Intersection for the Different Traffic Streams (source: Dornier Consulting GmbH Report). ................. 136 Table 12: Signal Program- Morning Peak Hour (source: Dornier Consulting GmbH Report). ......................................................................................................................... 139 Table 13: Signal Program- Evening Peak Hour (source: Dornier Consulting GmbH Report). ......................................................................................................................... 139 Table 14: LOS Criteria for Signalized Intersections (source HCM 2000, Ch.16, P.16-2) ....................................................................................................................................... 140 Table 15: Saturation Flow Rate per Lane Group, Calculation Parameters (source: HCM 2000, P.16-11) .............................................................................................................. 142 Table 16: Example of Lane Group Allocated Volumes ................................................ 144 Table 17: Northbound Approach Control Delays and LOS for TTM Alternative No.1Morning Peak ................................................................................................................ 161 Table 18: Northbound Approach Control Delays and LOS for TTM Alternative No.1Evening Peak ................................................................................................................ 161 Table 19: Northbound Approach Control Delays and LOS for TTM Alternative No.2Morning Peak ................................................................................................................ 162 Table 20: Northbound Approach Control Delays and LOS for TTM Alternative No.2Evening Peak ................................................................................................................ 162

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Table 21: Emissions Rates for TTM Alternatives Assessment (source: Rouphail, et. Al, 2000, and Abu-Allaban, M., et al, 2007) ....................................................................... 167 Table 22: Emissions Values during Morning Peak Hour for the Two TTM Alternatives ....................................................................................................................................... 167 Table 23: Emissions Values during Evening Peak Hour for the Two TTM Alternatives ....................................................................................................................................... 168 Table 24: TTM Alternatives- Summarized Evaluation Criteria ..................................... 172 Table 25: TTM Integrative Mitigation Measures and Strategies (source: RULE ON WORK ZONE SAFETY AND MOBILITY- Developing and Implementing Transportation Management Plans for Work Zones, P.4-2 and P.4-3) ................................................ 176

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List of Abbreviations Abbreviation

Meaning

TTM


CTTMP

Comprehensive Temporary Traffic Management Plans

AASHTO

American Association of State Highway and Transportation Officials

MUTCD

Manual on Uniform Traffic Control Devices

U.S. DOT

U.S. Department of Transportation

FHWA

Federal Highway Administration

TMP

Transportation Management Plan

TTC

Temporary Traffic Control

TO

Transportation Operations

PI

Public Information

TA

Transport Assessment

WZIA


SM

Slow Modes

TMC

Traffic Management Center

ITS

Intelligent Transportation Systems

CCTV

Closed Circuit Television

SSD

Stopping Sight Distance

m

Meter

Ft.

Feet

mph

Mile Per Hour

Km

Kilometer

sec

Second(s)

VMS

Variable Message Signs

VA

Vehicle-Actuated

CBA

Cost-Benefit Analysis

LOS

Level of Service

HC

Hydrocarbons

CO

Carbon Monoxide

NOx

Nitrogen Oxide

VMT

Vehicles Miles Travelled

MEV

Million Entering Vehicles

CMF

Crash Modification Factor

RUC

Road User Cost

CTTMP

Comprehensive Temporary Traffic Management Plan

SW

Strengths and Weaknesses

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Dr.

Drive

Blvd

Boulevard

Rd.

Road

HOT

High Occupancy Toll Road

EIS

Environmental Impact Statement

EA

Environmental Assessment

SOV

Single Occupancy Vehicle

HOV 2

High Occupancy Vehicle of two persons

HOV 3+

High Occupancy Vehicle of three persons and more

PuT

Public Transport

MOT

Maintenance Of Traffic

GRH

Guaranteed Ride Home

TBM

Tunnel Boring Machine

VPH

Vehicles Per Hour

PrT

Private Transport

PCU

Passenger Car Unit

PI

Performance Index

RAG Assessment

Red-Amber-Green Assessment

HGV

Heavy Goods Vehicles

HCDA

High Commission for the Development of Arriyadh

ANM

ArRiyadh New Mobility Consortium-

HCM

Highway Capacity Manual

RTOR

Right-Turn On Red

s/veh

Seconds per Vehicle

Km/h

Kilometer per Hour

CEI

Cost Effectiveness Index

RQ

Queue Storage Ratio

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INTRODUCTION

INTRODUCTION Traffic management strategies were developed and reformed by international and local agencies in Europe and North America as an indispensable action in order to mitigate the pressure on the network due to the remarkable increment in the number of vehicles between 1960 and 19801. Traffic management is the context of how to operate the traffic flow at the most favorable conditions, maximizing the individual’s benefit and minimizing the social cost. Thus, on one hand; it aims at minimizing parameters like: travel time, vehicles emissions, state of congestion and social exclusion, on the other hand maximizing the reliability, safety, operational capacity and resilience under various conditions of operating. The application area of traffic management is broad, it encompasses: freeways, arterials and local urban roads. Therefore, each category of the roads hierarchy is characterized by its own applications of traffic management in order to achieve the objectives in accordance with the intended function of the road segment. As a matter of fact, the applications of the traffic management became a necessity, since it is the very prime approach for a sustainable operation of the existing roads networks, which is a global aim now with an increasing population (road users) and scarce resources (material and lands). One worthwhile area of traffic management applications is the Temporary Traffic Management (TTM). As per understood from the terminology, the time parameter plays a crucial role in this area of application. It is brought up to execution as mitigation or precautionary measures against irregular upcoming circumstances or unusual conditions of operation within specified time interval. The critical need for this measures rises from deteriorated operational capacity, predicted congestion and arisen safety concerns in specific cases like running construction activities. These measures are planned, elaborated, executed and monitored on basis of the nature of the event; therefore a sub-categorization was developed in order to clearly define each area of application. This lead to the core theme of the thesis; “Temporary Traffic Management of Major Construction Projects”. Major Construction Projects that have a profound influence on the traffic flow in road networks and persist for a considerable duration of time. Therefore, the thesis addresses this specific sub-category of traffic Management, in order to provide an investigative study of the international standards and its various applications within this are of practice (TTM). Although the international standards were developed through decades in order to provide a guiding reference for TTM plans elaboration, these standards were conceptualized very broadly in order to be used flexibly in accordance with the preliminary conditions and the circumstances of every individual case. For example, the elaborated plans during the construction of major railway project would be radically different from the plans elaborated for road maintenance works due to the difference in the size and duration of impacts on safety and traffic flow streamlining. Therefore, the TTM standards provide the general framework, subsequently each agency, authority or

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INTRODUCTION

city council has to introduce their own plans based on the attributes of the implementation area and the nature of the planned works. Although these standards and guiding references can provide the elementary understanding of the TTM framework, there is still a need to investigate on the link between the context and the application in the different outstanding construction projects, which is the area of interest of the Thesis. Therefore; the work plan of the thesis is to investigate and analyze the TTM approaches that could be valid for different areas of major construction applications based on the available international standards. Furthermore, a couple of already-established and ongoing projects from the countries of the investigated standards, and similar in conditions to the planned case study will be reviewed and analyzed. Finally, in the case study chapter, there will be an elaboration of a TTM plans from scratch in order to apply the investigated tools and methodologies in a real project; Metro Riyadh. The work flow of the Thesis, as could be understood from the previous paragraphs, comes in a logical sequence that starts with investigating on the published TTM standards including the utilized strategies, the elaboration process and the evaluation criteria of different alternatives. This work flow shall lead to conceptualize what is so called “Comprehensive Temporary Traffic Management Plans”- (CTTMP). Thereafter, a revealing cases analysis will be conducted in the second chapter for cases from USA, UK and Germany in order to provide robust understanding of the published standard in light of their areas of application. London Crossrail, Dulles Corridor Metrorail and Stuttgart 21 projects are going to be investigated and evaluated in terms of TTM. In order to conduct such an approach, there will be a brief description of each project background, the adopted planning and practice of TTM elaboration, and a review of the adopted TTM plans. The main objective of these two milestones of the thesis; the literature review and the case analysis, is to engineer the base for the case study: Metro Riyadh. The project “Metro Riyadh” is a running Metro system project in Riyadh; the capital of Saudi Arabia. The city already suffers from severe traffic flow issues; therefore a considerable aspect to tackle when adopting the project was the traffic Management during the construction time. The case study is conducted in cooperation with “Dornier Consulting GmbH”, a German Consulting Firm that is undertaking the TTM planning for one of the major worksites in Metro Riyadh Project. The assigned worksite for the case study comprises two construction elements (metro station box and transitional ramp) that are in direct conflict with a major signalized intersection in the implementation area. On the basis of the literature reviewed, and the lessons learned from the analyzed cases; TTM for this implementation area is going to be strategically planned. Thereafter, different alternatives of TTM solutions are going to be proposed, and assessed in accordance with the practice revealed in the literature review. The alternative assessment will utilize quantitative as well as qualitative

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INTRODUCTION

measures for evaluation. Final fully elaborated TTM plan is going to be developed for the implementation area, satisfying the recommendations and the dimensions of the used standard. Subsequent to the plan development and prior to the winding up, strengths-weaknesses (SW) analysis shall be conducted for the recommended plan in order to justify the selection in terms of strengths and include appropriate mitigation measures for the weaknesses.

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1 CHAPTER 1: LITERATURE REVIEW 1.1

Conception of Temporary Traffic Management of Major Construction Projects

The notion of Temporary Traffic Management (TTM) in this section will be conceptualized based on the codes of practice and the standards from USA and UK. The standards for TTM applied in USA and accomplished by the (American Association of State Highway and Transportation Officials-AASHTO) were published in (PART 6) of the “Manual on Uniform Traffic Control Devices for Streets and Highways- MUTCD”2, besides other publications and research projects sponsored by the U.S. Department of Transportation (U.S. DOT) and Federal Highway Administration (FHWA) that will be referred to regularly. In UK, the provision for the TTM is published in “Traffic Signs Manual”3. The “Traffic Signs Manual” has two parts, first part is for the design and the second is for the operation. Besides the “Traffic Signs Manual” in UK, there is another provision published under the title “Safety at Street Works and Road Works - A Code of Practice”4, published in 2013, and legally binding regulations for the “Traffic Management Act 2004”. In the following section, the thesis will attempt to conceptualize an understanding of the TTM concept in light of the aforementioned international provisions in order to establish a good foundation for the subject-matter.

1.1.1

Traffic Management

According to the Traffic Engineering Handbook, the main objective of traffic management is “The utilization of personnel, materials, and equipment along freeway, city street, and rural highways to achieve safe and efficient movement of people, services, and goods”1 (Herman W. 1992; P.360). Accordingly, the “Traffic Signs Manual” emphasizes on the same concept, since it identifies the traffic management objectives as: “to maximize the safety” and “to keep traffic flowing as freely as possible” (Traffic Signs Manual, Ch.8, Part 1. 2009; P.11). It could be concluded that the safety parameter is amongst the priorities of the traffic management, thereafter comes the traffic efficiency. It is worth mentioning here that the safety concerns become more critical when it comes to construction zones, since it involves two components of safety; the safety of the road users and the safety of the construction workers. This could highlight at this early stage of the thesis the significance of the traffic management for construction zones.

1.1.2


Temporary Traffic Management (TTM) could be primarily interpreted as provisional measures introduced to specific traffic zones in order to mitigate the impacts of specific emerged circumstances influencing the traffic flow and the safety of the road users. TTM regulations proposed in the MUTCD and Traffic Engineering Hand book, may

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apply to either work zones or zones exposed to especial events or incidents (maintenance work or rehabilitation). Whilst the “Traffic Signs Manual” categorizes the regulations into two main schemes: “Standard” and “Relaxation Schemes” (Traffic Signs Manual 2009, Chapter 8, Part 1, P. 9), “standard schemes” apply to work zones in all expected conditions, whilst the “relaxation schemes” refer to short-term work zones with reasonable conditions of visibility, topography and low traffic volumes. Consequently, the “Traffic Signs Manual” recommends fully detailed plans of TTM for the work zones exposed to relatively long-term construction activities. TTM should be distinguished from regular and long-term traffic management measures and plans. TTM basically endeavors to achieve similar objectives to the long-term traffic management plans as per aforementioned, but it must perform these objectives within limited timeframes and under intensified unfavorable operational conditions of deteriorated roadway capacity and serious safety concerns, without compromising the time schedule of the work zone’s activities. On the contrary, long-term traffic management measures and actions usually are planned at agency level based on roadway full capacity, in order to reform the traffic flow streamlining with less severe safety concerns. This initial understanding of TTM paves the way for the theme of the next section (the need for TTM).

1.1.3

Need for Temporary Traffic Management

The previous paragraphs briefly conceptualize the framework of the TTM; this indeed imposes the questioning of the need for TTM. As per aforementioned, the work zones impacts on the roadways urge the need for traffic management measures that could intensify the effectiveness of the infrastructure exploitation in order to enable the impacted part of the network from overcoming the deteriorated capacity besides the emerging safety concerns. This deteriorated capacity triggered by the work zone should be subjected to optimization process within the framework of TTM; otherwise it will result in successive impacts of the work zones. These successive impacts start with the state of congestion and queue forming, consequently, other safety and environmental concerns start to arise. Another crucial function of the TTM is to coordinate the work zones, since the concurrent conflict between works zones within the same traffic zone would result in accumulated impacts on the network and the surroundings. The need for TTM escalates increasingly with the significance of the running activities within the work zone, especially when it involves highly urbanized areas with tremendous traffic volumes. This typically applies to major construction projects, since they (major projects) are usually implemented within urban and capital areas in order to enhance the mobility or the economic activities within this area of implementation. Moreover, the construction duration of such project tends to be relatively long. Considering the anticipated impacts on the traffic conditions, business activities, environment and the society for this remarkable construction period, thus the TTM of

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major construction projects should be perceived as a project in its own right. It tackles issues like regulating the traffic volumes entering to the work zone either by diverting the fleet, or by other means of controlling (e.g. intersection optimization), providing safe corridors for pedestrians and cyclists and preparing comprehensive traffic plans for the zone during the construction period. Once again, the degree of thoroughness of TTM elaboration pertains primarily to the significance of the planned works. Therefore, in the next section, there will be further clarification for the notion of major construction project and its work zones.

1.1.4

Major Construction Projects

The recognition of major construction projects is categorical for determining the TTM workflow. Since the thesis is tackling the TTM of major construction projects, it would be appropriate to detect at this early stage of the thesis the attributes of this category of projects. Thus, the TTM measures, solutions and strategies can be readily explained in the forthcoming stages of the thesis within this context of major construction projects. The work zone connotation should be understood prior to the recognition of major construction projects, thus the significance of the work zone could be detected. Work zones in the MUTCD include all zones exposed to activities running on, within or adjacent to the carriageway such as: construction, maintenance or rehabilitation that may be considered as temporary obstacles. The concept of a work zone does not vary in the “Traffic Signs Manual” of the UK. Road infrastructure projects, tunnels and bridges projects comprises these kinds of activities which form what is so called “work zones”. This category of work zones (roads, bridges and tunnels) is distinguished from other construction worksites due to its direct conflict with the roadway and the traffic flow. On the contrary, other construction projects, where the construction activities are limited to the construction site, whilst the main impact on the road network is limited to managing the impacts from the construction fleet. Within this category of work zones, the “WORK ZONE MOBILITY AND SAFETY PROGRAM”, adopted by the U.S. DOT and FHWA, provides a scheme for identifying the significance of construction projects and its associated work zones 5. The idea behind this scheme is to enable the concerned parties of traffic planning in the implementation area from assessing the significance of the project, consequently estimating the extent of the work zones impacts and providing the adequate TTM strategies and measures. The project significance identification process is not performed once, rather, it is an iterative process during the elaboration of the TTM plans, so that the project significance could be firmly identified. The iteration of this process is recommended, since the project available data at the planning stage is not sufficient to perceive the project significance. Thus this process shall be repeated during the design and the implementation phases in order to validate the project significance in light of the actually performed activities.

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A major project (significant project) according to U.S. DOT and FHWA “is defined as one that, alone or in combination with other concurrent projects nearby, is anticipated to cause sustained work zone impacts that are greater than what is considered tolerable based on State policy and/or engineering judgment” (WORK ZONE MOBILITY AND SAFETY PROGRAM 2013 5). Referring to the “engineering judgment” draws the attention to the importance of identifying the project significance within the context of the implementation area, since it is for some specific areas a project may be considered “major”, while for other may not. Therefore, the “WORK ZONE MOBILITIY AND SAFETY PROGRAM” proposes three main criteria that address both parameters (the project and the implementation area), in order to identify the project significance. The three criteria are: “Project characteristics”, “Traffic characteristics” and “Work zone characteristics” (WORK ZONE MOBILITY AND SAFETY PROGRAM 2013 5), synthesizing the norms of these three criteria would develop an effective tool to track the project significance. At the very beginning of the planning process, data concerning to traffic characteristics (traffic volumes, streams, traffic composition and transport modes) could be easily collected for the implementation area. As regards the project characteristics, a preliminary analysis should be conducted in order to prepare a perception for the project duration, size and length of works, possibility for construction phasing and the surrounding conditions. The integrating of TTM strategies at this early stage of project planning may not be feasible before assessing the work zone impacts; however some TTM indispensable strategies, like lane closure due to open tunneling (cut-and-cover) could be detected, consequently tackled as a project characteristic. Work zone characteristics encompass all issues and concerns related to safety, mobility and social costs in the vicinity of the work activities. The work zone impacts assessment will be extensively discussed within the context of TTM strategic planning. The identification of the project significance constitutes the base for further TTM development and elaboration. As per the following in the section of TTM plans elaboration, the project significance identification is always a turning point in the development process of TTM. It forecasts the impact domain of the project; whether it is limited to urban corridors, or it is extended to influence the network level, consequently provide a preliminary understanding of the TTM trend. Moreover, it forms with the work zone impact assessment the framework of the TTM strategies.

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1.2

Elaboration of Temporary Traffic Management (TTM) Plans of Major Construction Projects

The understanding of the TTM concept and the notion of major construction projects serves as backdrop for the elaboration of TTM plans of these projects. The elaboration of TTM plans should undergo several stages of sieving and refinement in order to be consistent with the project and area of implementation nature, as well as the TTM key objectives. Hereinafter, the thesis will tackle the TTM elaboration process recommended in the investigated standards, starting from the responsibilities distribution, thereafter; the workflow of the development process according to the different trends available in the literature.

1.2.1

Temporary Traffic Management Responsibilities

The MUTCD states clearly that the elaboration of such plans and the erection of the corresponding devices fall under the responsibility of the public regulatory authority of which the project or the implementation area belongs toi. This responsibility may, under special contractual agreement, refer to the issuance or the approval of proposed plans. Thus, for major projects that engage non-governmental parties, the regulatory authority obliges the developer to propose TTM plans covers the project duration, thereafter, this authority is responsible for reviewing such proposals and assuring its compliance with the published standard specification and other legally binding legislation. The “Traffic Signs Manual"ii adopts another approach, since it assigns the traffic management task to a specialized traffic management designer, no matter whether it is an independent designer, or a part of the project design team (joint venture or consortium). It must be borne in mind that in case of carrying out the design tasks of the traffic management and control for the project by another designer through approaches like joint-ventures or subcontracting, it is still the sole responsibility of the project designer to deliver the temporary traffic control plans of the project included in the design brief to the concerned authority and to seek the approval.

1.2.2

Development Process of Temporary Traffic Management Plans

According to the “RULE ON WORK ZONE SAFETY AND MOBILITY- Developing and Implementing Transportation Management Plans for Work Zones”, the U.S DOT and the FHWA introduce the plans for TTM of wok zones as “Transportation Management Plans (TMP)”6. The TMP is the tool used for managing the traffic within the work zone, maintaining the safety and mobility at the most acceptable conditions, and minimizing the social cost of the disrupted traffic flow. A TMP therefore, is basically the same as

i

MUTCD, 547

ii

Traffic Signs Manual, Chapter 8, Part 1,13

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TTM plan discussed in this thesis. Accordingly, the TTM plan shall be referred to as TMP only in this section, in consistence with the terminology used in the investigated literature; however, it will be addressed as TTM in the full body of the thesis. For a significant project, the U.S DOT and FHWA identify three main components for a TMP. These components will be discussed in detail in the following section. The main point of focus here will be the development workflow. The development process of TMPs should be launched since the very beginning of the project planning, and it goes ahead during the design and implementation of the project. The TMPs development in the U.S practice provides more comprehensive understanding of the elaboration process, starting at the system planning level, until it reaches to post-project evaluation, and the upgrading of TMPs. Thus, it would be beneficial to analyze the U.S practice for developing TMPs, subsequently fill in the gaps, if there is any, throughout reviewing the plans elaboration according to the “Traffic Signs Manual” from UK. The elaboration of TMPs according to the U.S Department of Transportation and FHWA encompasses three development stagesi; the planning and design stage, the construction stage and the performance assessment stage. Each stage has to be conducted in accordance with the main aim of the TTM in order to minimize the anticipated impacts of the project. In reference to the major projects conception, a decisive parameter has to be sorted out is to determine the project significance, since this will consequently influence the provided TMPs. For a project classified as major (significant) project, the TMP shall comprise three main components; namely, the temporary traffic control (TTC), Transportation Operations (TO) and Public Information (PI)6. The three components will be extensively demonstrated and analyzed in the following section. For this section, the thesis focuses on the development process of TMPs. Figure 1 demonstrates this process of TMPs development, obtained from the U.S. DOT and FHWA, it reveals the main inputs for each development stage. In the planning and design stage, the decision concerning to the TMPs components is made subsequent to the project significance determination. Moreover, the involved stakeholders shall be identified in the stage. Identifying the stakeholders as early as possible is essential, since they are a part and a parcel of the PI strategies. As per aforementioned, in this early stage of the TMPs development, materials concerning to project characteristics, implementation area traffic characteristics and work zone characteristics shall be analyzed and investigated. In accordance with the project identification as a major (significant) project, work zone impact analysis shall be conducted in order to recognize the main impacts of the work zone on the safety and mobility. Based on the key findings of the work zone impact assessment, proposals for

i

RULE ON WORK ZONE SAFETY AND MOBILITY- Developing and Implementing

Transportation Management Plans for Work Zones, P.2-2. Available from: [6 June 2014]

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TTM strategies should be initiated for mitigating the anticipated impacts of the work zone. This particular step in the planning and design stage will be henceforth referred to as “strategic planning”, since it engages the evaluation of the proposed TTM strategies’ alternatives on basis of the effectiveness assessment and the costeffectiveness. The work zone impacts assessment will be explained and linked to the TTM strategies in the following section. The TTM strategies evaluation scheme shall be tackled after perceiving a comprehensive understanding of the notions of work zones impacts, and the TTM strategies, within the context of major construction projects.

Figure 1: TMP Development Process (Source: U.S DOT, FHWA (2005), RULE ON WORK ZONE SAFETY AND MOBILITY- Developing and Implementing Transportation Management Plans for Work Zones, P.2-2)

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Upon the completion of the design, and prior to the launching of the construction phase, a decisive parameter for the TTM, which is the construction phasing plan, has to be clarified. The construction phasing plan identifies the possible segmentation of the project or the construction element in order to mitigate the work zone impacts. Moreover, construction phasing plan would effectively coordinate the planned works with other running worksites in the vicinity of the implementation are in order to refrain from the cumulative impacts on the road network, triggered by adjacent work zones. The construction phase refers to the realization of TTM strategies set forth in the issued for construction TMP. Noteworthy is that the TMP execution is advised to be launched prior to the commencement of the construction activities of the project, so that the traffic disruption impacts could be dampened before the pressure of the project is added. During the construction phase, the TMPs objectives shall be strictly monitored and regularly assessed in order to keep the plans on the track. There is always a possibility to modify the plans if the TMP is found to be deviated from the objectives, or in case of observed deficit in the design. The post project evaluation is a very useful tool to improve the TTM strategies and measures at the agency level, as well as for TTM designers and engineers. It facilitates the TTM guidelines updating and reforming based on a comprehensive assessment of the implemented measures and plans. Within this context, Scriba, T. (FHWA), et al., indicate in the research results report for “Assessing the Effectiveness of Transportation Management Plan (TMP) Strategies- Feasibility, Usefulness, and Possible Approaches”7 that California Department of Transportation has already invested in monitoring and evaluation programs in order to investigate the TMP during construction and there is endeavors to legislate the monitoring and the assessment as a contractual commitment (Scriba, T., et al. 2012, P.9). The U.S DOT and FHWA recommend a template for the TMP that comprises the “Potential TMP Components”. The complete set of components provides a brief description for each development stage. Components that pertinent to case study in chapter 3 will be highlighted and provided. The complete set of TMP components are shown hereinafter, according to the U.S DOT and FHWA.           

“The Introductory Material; The Executive Summary; TMP Roles and Responsibilities; Project Description; Existing and Future Conditions; Work Zone Impacts Assessment; Work Zone Impacts Management Strategies; TMP Monitoring Requirements; Contingency Plans; TMP Implementation Cost; Special Considerations;

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 Attachments.” (U.S DOT, FHWA (2005), RULE ON WORK ZONE SAFETY AND MOBILITY- Developing and Implementing Transportation Management Plans for Work Zones, P.3-2) As per mentioned before, the provision for TTM plans according the “Traffic Signs Manual” from UK shall be reviewed subsequent to the U.S DOT provisions in order to synthesize both understandings in one comprehensive approach. Thus, the UK provision for TTM plans elaboration shall be tackled here in a selective manner, in order to refrain from redundancy. Similarly to the work zone impacts assessment, the UK local regulatory authorities impose what is so called “Transport Assessment- TA”8 for any planned development. Two levels of assessment were stated in the “Guidance on Transport Assessment”; namely “Transport Assessment” and “Transport Statement”, dependently on the significance of the project’s impacts on transport. As per could readily interpreted, the TA is pertinent to major construction projects, hence, a brief description of the TA preparation will be highlighted. The recommended “Road map and contents of a transport assessment report” (Guidance on Transport Assessment 2007, P.19), depicts similar approach to the one adopted by the U.S. DOT and FHWA for the development process of the TMPs. One item is worthy to highlight here is the analysis of the “Baseline transport data” (Guidance on Transport Assessment 2007, P.20), since this baseline condition would be an asset in understanding the traffic-related issues in the implementation area, consequently could precisely highlight the anticipated impacts of the proposed work zone. Furthermore, the baseline condition is an excellent reference line to assess the effectiveness of proposed TTM alternatives, as will be observed later. Another interesting key tool that the “Traffic Signs Manual” is emphasizing on is the risk assessment, since it is stated clearly that “It is vital that risk assessments are carried out at all stages of the development of the project, bearing in mind the potential hazards to the workforce and the public.” (Traffic Signs Manual 2009, Ch. 8, Part 1, P.11). This enhancing of the role of the risk assessment is recommended for major construction projects, especially these projects that involve deep and open excavation, whereas concerns about slope stability may arise. The “Traffic Signs Manual” identifies the end product of the development process of the TTM plans as “the design brief”, which was referred to in the section of the responsibilities towards TTM. Basically, the design brief functions as a project directory, it shall comprise all the conducted studies concerning to traffic-related safety and mobility, including the TA, besides the adopted strategies for mitigating the impacts of the works, and further recommendation and clarification concerning to the traffic management during the construction period. The “Traffic Signs Manual” compiles all the design prerequisites in a way that figure out the key objectives of the TTM plans, which were primarily safety operation and mobility efficiency. Moreover, the minimized social cost as an objective could be extracted from the last required site information “needs of local residents and businesses” (Traffic

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Signs Manual, Ch.8, Part 1, P. 15). For major construction projects, upon the completion of the design and prior to the installation of the TTM measures, the manual imposes a “POST-DESIGN REVIEW”, which is advised to involve an “independent road safety audit” ((Traffic Signs Manual, Ch.8, Part 1, P. 17). This kind of approach reflects the high safety concerns at the side of the manual. Finally, the “Traffic Signs Manual” instructs the designer or who is acting on behalf, to deliver the TTM scheme in a self-explanatory documentation, adhered to the rules and recommendations set forth in the manual and other legally binding regulations. With this brief description of the development process of TTM plans according to the literature and the published standard, the thesis shall proceed to further explanation of some concepts and terms were mentioned in this section without interpretation. This explanation shall be provided in the following section for the work zone impacts assessment, consequently the strategies to mitigate these impacts.

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1.3

Strategic Planning of Temporary Traffic Management

Strategic planning is the process, in which the agency or the planning body employs specific analysis tools in order to identify their priorities, objectives and limitations, consequently determine the appropriate strategies to be adopted and effected. In the previous section, the TTM strategic planning was a part and a parcel of the planning and design stage in TTM development process. For TTM, and according to this definition of the strategic planning, an analysis for the work zone is supposed to be conducted in order to identify all the anticipated impacts on the safety, mobility, and may extend to address the impacts on the socioeconomic structure of the implementation area. This analysis from now on shall be called “Work Zone Impacts Assessment”9 (WZIA), which is considered as the main tool for the TTM strategic planning. Based on the key findings of the WZIA, the agency (TTM designer) should be able to determine the appropriate TTM strategies. As per aforementioned in the TMPs section, for a major construction project, the TTM strategies could be categorized in three categories: temporary traffic control (TTC), transportation operation (TO) and public information (PI). They are all strategies that need to be formulated comprehensively in traffic management plans and schemes in order to mitigate the work zone impacts. The following sections will tackle the conceptions of WZIA and the TTM strategies based on this understanding of the TTM strategic planning, and in light of the provided literature. Although the evaluation of the TTM strategies is considered as a strategic planning tool, it will be tackled separately in an individual section since it engages prolonged procedures that were found too much to be concluded here in this section.

1.3.1


The definition and the need for WZIA can be better understood within the context of the TTM strategic planning, as per aforementioned. WZIA for a major construction project shall comprehensively recognize all the anticipated threats and impacts within the context of safety, mobility and social cost. Moreover, it helps detecting the extent of the impacts, thus it enables the coordination with other projects or work zone in the vicinity of the implementation area. The U.S DOT and FHWA conducted a study to provide better understanding of WZIA process, it is published under the title “Work Zone Impacts Assessment: An Approach to Assess and Manage Work Zone Safety and Mobility Impacts of Road Projects”. According to this study, the WZIA functions as a planning aid tool at different levels of traffic management policy. The thesis is primarily concerned about the TTM of major construction projects; in that respect, only WZIA at the project level shall be demonstrated. Conforming to the previous findings, the project significance identification and the WZIA at planning and design stage determine together the TTM strategies that shall be adopted.

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At project level, according to the understanding of the TTM strategic planning, the assessment of the work zone impacts should be performed on two levels or scales. First level is the WZIA during the planning stage, where the preliminary construction method could be compiled with the implementation area profile, so that the potential TTM strategies could be highlighted. Thereafter, an advanced level of WZIA should be undertaken at the design delivery stage in order to determine the adopted TTM strategies. However, this second level of WZIA, where the anticipated impacts are assessed, whilst the TTM solutions are taken into account, will be addressed as TTM effectiveness assessment. In other words, the second level of WZIA is usually performed to assess the performance of specific TTM solutions, in order to prioritize one on the expense of the other. The U.S DOT and the FHWA describes this sequence of WZIA as “Work Zone Impacts Assessment During Preliminary Engineering” and “Work Zone Impacts Assessment During Design” (Work Zone Impacts Assessment: An Approach to Assess and Manage Work Zone Safety and Mobility Impacts of Road Projects, P.5-1, P.6-1). Thus, in this section the thesis will tackle the WZIA during what is so called “preliminary engineering”, whilst the second level of the WZIA will be tackled in the section of TTM performance effectiveness evaluation. The U.S DOT and FHWA elaborate 7 steps for WZIA development in the preliminary engineering and identify the issues to address during WZIA “safety, traffic capacity and demand, community impacts and combined impacts with nearby, concurrent projects” (Work Zone Impacts Assessment: An Approach to Assess and Manage Work Zone Safety and Mobility Impacts of Road Projects, P.5-5). The thesis highlights here the distinct procedures which were found pertinent to the context of major construction projects. At first; the project materials (description, dimensions, plans, duration, method of work statements and construction phasing plan) and the data from the implementation area (urban/rural area, socioeconomic structure, traffic volumes, traffic streams, transport modes, concurrent projects in proximity to the proposed projects and the traffic capacity analysis) should be incorporated, so that the work zone impacts could be identified whether it is extended to the network level or it is limited to the urban corridor level. Upon the completion of this data collection and analysis, the WZIA shall be conducted on basis of “qualitative assessment” (U.S DOT and FHWA, 5-10) for the issues mentioned before (safety, traffic capacity and demand, community impacts and combined impacts with nearby or concurrent projects). The qualitative assessment is recommended for this step due to the fact that the TMM plan is still in the strategic planning phase; therefore, detailed TTM strategies may not be available to perform a quantitative assessment. Therefore, qualitative assessment for the impacts on the safety, mobility and community could be feasible at this stage in light of the proposed method of construction and the other project and implementation area data. It is worth mentioning here that for specific impacts (e.g., impacts on traffic efficiency); it may be useful to utilize quantitative assessment using tools like microscopic simulation. This approach may be utilized at this early stage in order to detect significant impacts that

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can be diminished if the adopted method of construction is replaced. Significant impacts could be intolerable delayed travel times due to lane closure, drastically reduced speed on the alternate route due to the detour or other impacts that must be detected as early as possible. As regards the community impacts issues, this categorically depends on the area of implementation and its socioeconomic structure. As regards the Transport Assessment (TA), it encompasses a preliminary design of the TTM measures with the step of “Identification of impacts and mitigation measures” (Guidance on Transport Assessment 2007, P.19). This highlights the importance of integrating the TTM planning at the very early stage of the project preliminary engineering. The guidance as well as the “Traffic Signs Manual” emphasize on the site existing conditions (Baseline transport data), and its role in the TA, consequently the TTM strategic planning. The site conditions include all traffic parameters that may be relevant to the TTM systems and strategies; these parameters could be traffic volumes and streams, traffic compositions, travel behavior, geometry of the roads, construction site logistics and accessibility and finally the risk analysis. Furthermore, the “Traffic Signs Manual” introduces a distinctive tool to the TTM strategic planning; namely, the risk assessment (Traffic Signs Manual, Ch.8, Part 1, P.11). A duly performed risk assessment should follow the development procedures set forth in “Five steps to risk assessment”10 , published by (Health and Safety Execution- HSE). This leaflet describes five basic steps of performing risk assessment; it states that the risk assessment should comprise: “Step 1: Identify the hazards, Step 2: Decide who might be harmed and how, Step 3: Evaluate the risks and decide on precautions, Step 4: Record your findings and implement them, Step 5: Review your assessment and update if necessary” (HSE, 2). Therefore, in light of these findings, the UK Department for Transport adopts the TA and the risk assessment as the key tool for the TTM strategic planning, whilst the U.S DOT and FHWA comprehend both tools in what is so called “WZIA”. Therefore, it could be concluded that the U.S practice tends to provide more holistic approach that integrates safety, mobility and social cost to investigate the anticipated impacts of the work zone. Moreover, the U.S provision is traffic management-oriented. In light of the key findings of the WZIA and the proposed methods of construction, the traffic management designer should be able to select the appropriate TTM strategies. For example, a strategy of prioritizing slow mode (SM) streams utilizing signage may be a rational choice based on WZIA findings of highly involved (SM) traffic streams within the implementation area. Other indispensable traffic management strategies could be the lane closure and detours based on the proposed method of construction, or remarkably observed safety concerns. The U.S DOT and FHWA refer to this step as “Identify Preliminary Work Zone Management Strategies” (U.S DOT and FHWA, 5-16), similarly to the preliminary design of mitigation measures defined in the U.K “Transport Assessment Guidance”. It is referred to as “preliminary” since it is supposed to undergo

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further refinement and effectiveness evaluation, as will be studied in the section of the TTM effectiveness evaluation. In the following section, an overview of TTM strategies will be displayed, thus the concept of TTM strategic planning can be perceived.

1.3.2

Temporary Traffic Control (TTC) Strategies

In reference to the “Developing and Implementing Transportation Management Plans for Work Zones”6, the traffic management plan comprises three main components (TTC, TO and PI); subsequently each component has its underlying strategies. The key objective of this section and the next two sections is to reveal the widely spread strategies employed in the international standards and codes of practice, and to provide rigorous understanding of these strategies, hence, they could be easily analyzed in the cases analysis chapter and applied in the case study chapter. At first, TTC is the sub-category of TTM strategies that are primarily concerned about controlling the traffic locally, within, adjacent or around the work zone. It must be borne in mind that the level of TTC is the local traffic zone accommodating the work zone (worksite). This concept is important, since each TTM category is concerned about specific level of influence, as will be revealed for each category. The U.S DOT and FHWA in their publication provide a collective guidance framework regarding to the TTC strategies development and exploitation, whilst the provision of the UK Department for Transport “The Traffic Signs Manual” concerns primarily about the usage of TTC devices. Hereinafter, the U.S. provisions will be highlighted, whilst the UK provision will be included in the section of TTC devices review. The MUTDC defines some “fundamental principles” (MUTCD, 549) in order to regulate the development process of TTC. It emphasizes on the comprehensive approach of the design that should take into account all the road users, and the refraining from significant changes in the road network geometry in order to provide operational conditions as similar as to regular situations. TTC strategies according to the U.S DOT and FHWA are grouped into three sets: “control strategies”, “traffic control devices”, “project coordination, contracting and innovative construction strategies” (Developing and Implementing Transportation Management Plans for Work Zones, P.4-1 and P.42). The control strategies endeavor to mitigate the work zone impacts based on two main measures; the roadway regulation and the work conditions regulation. The regulation of the roadway according to the U.S DOT and FHWA can be performed via “full road closure, lane shift or lane closure”. Selecting the roadway regulatory control strategy(s) depends primarily on the WZIA findings concerning to roadway capacity, road hierarchy, traffic volumes and composition, and the capacity reserves of the potential alternative routes. In regard to the regulatory work conditions measures; it exhibits methods for scheduling and time framing the critical work activities in a way that conform with the traffic and mobility efficiency. Night work, off-peak hours work,

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construction phasing plan; they are all could be utilized in regulating the works, consequently act within the TTC framework. Nevertheless; the cost effectiveness and the impacts on the surrounded area shall be taken into account when proposing such strategies. Traffic control devices will be extensively tackled within the context of the work zone dissection. As regards the project coordination; contracting and innovative construction strategies, they shall be explored in order to provide full and clear understanding of TTC strategies. Project coordination shall be performed as early as possible with other projects in the vicinity of the implementation area, or with any other administrative body or stakeholders in order to avoid any escalating conflicts during construction. This approach is considered as an effective tool to compact the cost of the TTM and minimize the cumulative impacts of work zones. As regards the contracting strategies which could function efficiently in the TTC of major construction projects, the U.S DOT and FHWA recommends 4 contractual approaches that proved to be effective in TTM of major construction projects. The approaches are: “Design-Build, A+B Bidding, Incentives/Disincentives Clauses and Lane rental” (Developing and Implementing Transportation Management Plans for Work Zones, P.4-8, and P.4-9). It is noteworthy that these contractual approaches are recommended for the project itself in order to minimize the work zone impacts and the other needed TTM measures. Design-Build approach assigns the tasks of design and execution, including measures of TTC to one firm or organization11. With the help of this approach, the contractor is expected to strive to integrate the traffic management considerations since the very beginning of the planning and design, deliver an integrated design that takes into account the work zone impacts and plan the construction in a way that minimize these impacts. One of the merits of this approach is the high level of coordination of planning, design and implementation which may primarily contribute to compact the cost, enhance the efficiency and reduce the construction duration, consequently minimize the work zone impacts. Moreover, Design-Build contracting enhances the role of the “Accelerated Construction Technology Transfer- ACTT, a “strategic process that uses various innovative techniques, strategies and technologies to minimize actual construction time, while enhancing quality and safety on today’s large, complex multiphase projects.” (Warne, T., 2011)12. A+B Bidding is an innovative approach of considering the awarded tenderer, where A refers to the itemized cost and B refers to the road user incurred cost during the construction duration. Therefore, the bidders are incentivized to program the project in a sequence that minimizes B in order to be considered for the bid (Developing and Implementing Transportation Management Plans for Work Zones, P.4-8). The road user cost shall be estimated by the traffic management designer or other planning body; it will be tackled in the section of cost effectiveness evaluation.

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Concerning to the other contractual approaches (Incentives/ Disincentives clauses and lane rental); they may be used to encourage the contractor to minimize the construction duration, or to minimize the extents of the work zone (e.g., lane rental to charge the contractor for lane closure). However, these two approaches shall undergo specific condition, since they may burden the client, the developer or the planning body with massive costs. As regards the innovative construction strategies, it is among the most effective TTC strategies, since it contributes to accelerating the construction process, thus it minimize the mobility and safety impacts triggered by the work zone. These strategies encompass all pre-manufactured components or employing advanced technology in construction (e.g., tunnel boring machine TBM). Another trend of innovative construction strategies could be the trend leveraged in the project of “Stuttgart 21”, as will be demonstrated in the cases analysis chapter. In Stuttgart 21 work zones, intelligent construction solutions were utilized in order to maintain the capacity and number of lanes of major roads at the baseline conditions during construction.

1.3.3

Transportation Operation (TO) Strategies

Whilst the TTC strategies strive to regulate the traffic locally within work zones and maintain the traffic condition at satisfactory level of safety and efficiency, the TO strategies provides a broader perspective towards the transportation level, in the urban corridor or in the network level. Transportation operation here should be distinguished from the traffic control of the work zone in terms of the level of influence, as per referred to when tackling the TTC. For example, if the TTC strategy is concerned to convey a road closure message to the road users via TTC devices, the TO is supposed to manage the detoured traffic streams due to this road closure, and to minimize its impacts on the corridor/network level. The U.S DOT and FHWA identify four categories of TO strategies: “Demand Management Strategies, Corridor/ Network Management Strategies, Work Zone Safety Management Strategies and Traffic/ Incidents Management and Enforcement Strategies” (Developing and Implementing Transportation Management Plans for Work Zones, P.4-3). The demand management plays a crucial role on the level of transportation operation. In order to understand this role of demand management in TO strategies, it should be discussed within the context of transport supply. The transport supply is the provision of transport services13 to meet the needs of the travel demand, since it is a service, thus its infrastructure has been designed to accommodate the forecasted demand. In light of this understanding, an alarming issue may arise due to reduced capacity of the roadways/networks triggered by work zones, since it influences the level of supply. The demand management strategies provide solutions for this supply issue by controlling and reducing the demand instead of investing in more supply infrastructures. The strategy adjusts the transport demand with the help of methods like: modal shift, SM promotion and public transport prioritization, in order to utilize the existing infrastructure

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of the transport supply with no extra investment cost. Moreover, the transport demand adjustment substantially contributes to parking management solutions, since it minimizes the vehicular commuting. The WZIA determine the extent of the work zone impacts whether it is limited to an urban corridor, or it extends to the level of the network, based on this finding, the TO strategies sets the appropriate measures to manage and mitigate these impacts. According the U.S DOT and the FHWA, the corridor/network management and the work zone safety management strategies provide technical and methodological solutions in order to guarantee resilient, efficient and safe operational for the road users. Corridor/network management solutions could be “signal timing/coordination improvement”, “street/intersections improvement”, “turn restrictions”, “trucks/heavy vehicle restrictions” and “reversible lanes”, as well as the “coordination with adjacent construction sites” (Developing and Implementing Transportation Management Plans for Work Zones, P.4-16). As regards the work zone safety, it utilizes strategies similar to the TTC devices to perform similar task on the level of transportation operation. Moreover, it may impose speed limits in order to enhance the safety on the level of the corridor/network. Before concluding the TO section, it is worth mentioning that in both provisions (USA and UK), there were recommendations regarding the leverage of what is so called “Traffic Management Center- TMC”, and the applications of “Intelligent Transportation Systems- ITS” and the traffic surveillance using “Closed Circuit Television- CCTV” in the temporary traffic management and transportation operation of urban corridors and road networks during the construction of major construction projects. There will be an ITS review for TTM application in a later stage of the literature review.

1.3.4

Public Information (PI) Strategies

The public participation is enhanced in the TTM plans development process since the very beginning of the planning and design stage; the stakeholders are a part and a parcel of the WZIA in order to settle issues like the right of way obtaining or to avoid the conflict of interest during the construction. Though, the PI is meant to keep the road users notified of the running construction/development activities, the associated TTM measures and strategies as well its impacts. Hence, the road users could possibly adjust their travel behavior to avoid the disruption, or exhibit rational driving behavior within the impacted zones to mitigate the risk. Thus, the level of influence of PI could be perceived as state or regional level. The U.S DOT and the FHWA recognize two approaches of PI strategies; “Public Awareness Strategies” and “Motorist Information Strategies” (Developing and Implementing Transportation Management Plans for Work Zones, P.4-10, and P.4-12). On one hand, the U.S DOT and the FHWA define the public awareness strategies as approaches to familiarize and acquaint the public about the work zones and its

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impacts. It utilizes published notifications, like “Brochures and mailers”, Press releases” or “Paid advertisements”, audible and visual alerting, like “Telephone hotline”, “Planned lane closure web site”, “Project web site” or the recent social media “Facebook and Twitter”. The other conventional social inclusion and public participation tools like “Public meetings/hearings” or “Work zone education and safety campaigns” may be still effective for certain age groups of society within the implementation area. On the other hand, the objective of the motorist information strategies is to “provide current and/or real-time information to road users regarding the project work zone”, (Developing and Implementing Transportation Management Plans for Work Zones, P.4-12). In order to provide real time information, the work zone and its impact area should be coordinated with a traffic management center. Devices like the changeable message signs or other changeable traffic signs may be utilized to convey this information to the road users. Traffic radio and recently smart phone application may contribute to improve the strategy performance. In order to conclude this section with highlighting the key findings concerning to TTM strategies, Figure 2 depicts the reviewed TTM strategies and the corresponding level of influence. This section was a brief orientation to the TTM strategies formulating the main trend of TTM plans elaboration. Subsequent to this review of TTM strategies, it would be appropriate to conduct a kind of investigative analysis of the work zone dissection and the deployment of TTC devices, so that the TTM understanding can be enhanced to an advanced level of details.

Figure 2: TTM Strategies- Level of Influence.

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1.4

Work Zone Dissection and Temporary Traffic Control (TTC) Devices Review

The interdependencies between the work zone segments and the TTC devices utilized for each segment can’t be overlooked. The different functions of the TTC devices can be better understood out of its spatial location in the work zone. Therefore, it would be appropriate to analyze the dissection of a typical work zone prior to the tackling of the exploited devices and in light of the conception of the TTM strategies and objectives perceived in the previous section. In the following sections, the thesis will depict the work zone different segments and will analyze the attributes of each segment in terms of function, dimensions, decisive parameters and integration in the TTM objectives. International standards from USA “Manual on Uniform Traffic Control Devices- MUTCD, PART 6: TEMPORARY TRAFFIC CONTROL”, and from UK “Traffic Signs Manual, CHAPTER 8: Traffic Safety Measures and Signs for Road Works and Temporary Situation”, will be comprehensively investigated in order to establish an overall understanding of this crucial strategy of TTM.

1.4.1

Work Zone Dissection According to the MUTCD-USA

The dissection of a work zone is an analysis of the work zone components based on the geometry, characteristic features and traffic-related attributes. A typical work zone according to the “MUTCD” comprises four main sections. These sections are “Advance Warning Area”, “Transition Area”, “Activity Area” and “Termination Area” (MUTCD, P.552:555). Each section of the work zone has a particular function that integrates with the main objectives of the TTM (the enhancement of the safety and the mobility) and contributes to the streamlining of the traffic flow. Figure 3 demonstrates the allocation of each section accordingly with the traffic flow direction and the actual working zone. The sections were established in a sequence that enables the TTM plan from delivering the traffic streams seamlessly and maintains the work activities running safely. The advance warning section, subsequently A, B, and C, which are the sub-dividing distances between the restriction point, first sign, second sign and the third sign respectively (MUTCD 2009, P.554) has no change in the carriageway width. The main function of this section is to calm down the traffic flow in the upstream via conveying a clear warning messages to the road users concerning to the forthcoming work zone. The “MUTCD” recommends specific values for the sub-dividing distances A, B and C according to the road hierarchy, the traffic volume and definitely the speed limit. Table 1 demonstrates the recommended distances in meters, derived from the MUTCD provision which was supplied in feet (MUTCD 2009, P.554), whereas 1 ft. = 0.3048 m.

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Figure 3: Components of Temporary Traffic Control Zone (Source: MUTCD 2009, P.553). Table 1: Recommended Advance Warning Signs Minimum Spacing (derived from the MUTCD 2009)

Road Type

Distance Between Signs (m) A

B

C

Urban (low speed)

30.48

30.48

30.48

Urban (high speed)

106.68

106.68

106.68

The transition area is the second section in the work zone, comes subsequently to the advance warning area. The transition area is supposed to gradually merge the traffic streams that coming from the upstream. The roadway within the transition area encounters a change in the dimension from the initial dimensions at the upstream to the constringed dimensions at the downstream. The length of the transition area is governed by the taper length. The taper is the terminology describing the geometry changing of the carriageway. The taper length according to the MUTCD is determined

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based on the taper type and governed by the offset width and the road speed. The taper types according to the MUTCD are:     

“Merging taper; Shifting taper; Shoulder taper; One Lane, Two-Way traffic taper; Downstream taper” (MUTCD 2009, P.557).

The merging taper is similar to the case demonstrated in the transition area in Figure 3. The shifting taper is another type of tapers whereas the road course fully shifted to avoid work zone with no change in the carriageway dimensions (see Figure 4). Shoulder taper and downstream taper (see Figure 3 and Figure 4) are auxiliary tapers since they have no direct conflict with the traffic flow. The one lane, two-way traffic taper is strategy of TTM; in which, one lane is utilized by two opposite traffic streams, thus the taper is exploited in order to merge the two-lanes-two-way traffic into one lane, two-way traffic.

Figure 4: Types of Tapers and Buffer Spaces (MUTCD 2009, P.556).

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The length of each type of taper shall be determined based on two main decisive factors; the offset width and the road speed, as per illustrated in Table 2. The road offset [W] is the transversal offset in feet that the approaching traffic stream is enforced to it. The MUTCD defines the speed [S] as the “posted speed limit or off-peak 85thpercentile speed prior to work starting, or the anticipated operating speed in mph” (MUTCD 2009, P.557). The (Speed Concepts: Informational Guide) published by the U.S Department of Transportation defines the off-peak 85th-percentile speed as “the speed at or below which 85 percent of vehicles travel.”14 Table 2: Criteria Determining Taper Length (Source: MUTCD 2009, P.557) Taper Length Criteria

Speed Criteria

Type of Taper

Taper Length

Merging Taper

at least L

Shifting Taper

at least 0.5 L

Shoulder Taper

at least 0.33 L

One-Lane, Two-Way Traffic Taper

50 feet min, 100 feet max

Downstream Taper

50 feet min, 100 feet max

40 mph or less

𝐿=

𝑊𝑆² 60

45 mph or more

𝐿 = 𝑊𝑆

The activity area is the critical section of the work zone, since it is the segment of which the road course is in a direct conflict with the work activities. It is usually accompanied with high safety concerns regarding both of the road users and the workers. Thus, the “MUTCD” imposes certain surrounding buffering spaces in order to provide safe area of operation. These buffering spaces are prohibited for any work activities, it is provided as safety measure in order to minimize the possibility of causalities. The buffering spaces are established in both longitudinal and lateral directions, with specific minimum distances governing the buffering space (see Figure 4). According to the “MUTCD”, the longitudinal buffering space is identified as “Stopping Sight Distance”. Stopping Sight Distance SSD in the “MUTCD” is obtained from the AASHTO model for calculating the SSD (Equation 1): 𝑆𝑆𝐷 = 1.47 𝑉𝑡 + 1.075

𝑉² 𝑎

(U.S Customary)

Equation 1

(Source: Layton R., Dixon K. (2012), P.17)15 Where,  SSD: Stop Sighting Distance.  V: Speed in mph (mile per hour)i.  t: is the perception- reaction time PRT, 2.5 sec according to 2005 AASHTO Policy (MUTCD 2009, 108).

i

1 Mile = 1.60934 Km.

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 a: deceleration rate ft./sec², 11.2 ft./sec² according to 2005 AASHTO Policy. As regards the lateral buffer space, the “MUTCD” states that “The width of a lateral buffer space should be determined by engineering judgment” (MUTCD 2009, P.555). The engineering judgment shall be understood accordingly with the MUTCD definition (MUTCD 2009, P.14) as an objective action or measure, completely based on the fundamentals of engineering with no rigid preset stereotype. There is no standard specification for the lateral buffering space due to the fact that such a parameter can’t be quantified and unified for all circumstances. For example, the required lateral buffering engaged in deep excavation works, involves a good number of influencing factors; (excavation stability, retaining works, soil classification ….etc.) shall be radically different from the lateral buffering space required for road rehabilitation works, whereas a minimum lateral buffer would be sufficient to guarantee the safety of the workers.

1.4.2

Work Zone Dissection According to the Traffic Signs Manual- UK

The word "works" here in this section refers to the category “Standard schemes” which was discussed in an earlier stage of this chapter, referring to work zones with relatively longer duration. The dissection of standard work zones in this section is based on the provision of the UK standard published by the UK Department for Transport in the “Traffic Signs Manual, Chapter 8: Traffic Safety Measures and Signs for Road Works and Temporary Situation, Part 1: Design” and the “Safety at Street Works and Road Works, a Code of Practice”. The UK provisions always address two categories of roadways; single carriageway and dual carriageway. Figure 5 demonstrates a basic layout of work zone in single carriageway road. The “Safety at Street Works and Road Works, a Code of Practice” identifies the elementary components of this basic layout, in order to pave the way for more sophisticated cases in the dual carriageway and other cases. These elementary components are: “approach zone D”, “lead in taper T”, “safety clearances L and S”, “working space”, “exit taper” and “end of works zone” (Department for Transport (2013), Safety at Street Works and Road Works, a Code of Practice, P. 22).

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Figure 5: Work Zone Dissection in Single Carriageway Road (Source: Safety at Street Works and Road Works, a Code of Practice, P.21). Whilst for dual carriageway roads, according to the “Traffic Signs Manual”, a typical work zone shall comprise of five zones (see Figure 6): “approach zone”, “lane-change zone”, “lead-in zone”, “works zone” and “end-of-works zone”. (Traffic Signs Manual, Ch.8, Part 1, P.168).

Figure 6: Work Zone Dissection in Dual Carriageway Road (Source: Traffic Signs Manual, Ch.8, Part 1, P. 168) In order to refrain from redundancy, there is no need to redefine notions that have been already defined and discussed, like the approach zone, tapers and safety clearances. Hence, the thesis will move forward to the regulations governing these parameters, since it is worthwhile to highlight the trend of the “Traffic Signs Manual” for determining them. In accordance with the previous findings, the distances (D), (T) and (E) are determined on basis of the road hierarchy and characteristics, and the speed limits.

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The internal details of the working space are out of the context in this particular section of the thesis, thus the parameter C will be neglected for these elementary considerations. Table 3 demonstrates the minimum values for the distances governing the allocation of the approach zone (advance warning zone in the U.S provision) for roads with permanent speed limits 40 to 50 mph or less, according to the code of practice for safety at street works and road works. For roads with permanent speed limits beyond these thresholds, the “Traffic Signs Manual” provides 1 to 2 miles for advance signing. Table 3: Approach Zone Characteristics (Source: Safety at Street Works and Road Works - A Code of Practice, P.105) Type of road

Minimum visibility distance to first sign (m)

(D) Distance from first sign to start of lead in taper (m)

60

20 to 45

60

45 to 110

Single carriageway – speed limit 50 mph or more

75

275 to 450

All-purpose dual carriageway – speed limit 40 mph or less

60

110 to 275

Single carriageway – speed limit 30 mph or less Single carriageway – speed limit 40 mph

The taper layout in the “Traffic Signs Manual” is considered as a decisive parameter for the safety of traffic flow. Thus, this issue of the taper is addressed delicately in terms of length and position. In regard to the taper position, the “Traffic Signs Manual” emphasizes on the compatibility with vertical and horizontal “sight lines”, since they are essential for safe and seamless operation within the work zone. The “Traffic Signs Manual” provides some standardized positions for the tapers in relation to different locations of works (junctions, shoulders …etc.); however, they are just a guiding reference for the actual design. This indeed is subjected to the engineering judgment and based on the “risk assessment”. As for the lead in taper length, Table 4 provides certain values recommended by the “Traffic Signs Manual” for the taper length, on basis of the road hierarchy, characteristics and the speed limit. As concerns the exit taper, it follows a simplified rule; it shall be allocated at 45° to the edge of the carriageway.

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Table 4: Lead in taper length (Source: Safety at Street Works and Road Works - A Code of Practice, P.105) Type of road

Lead in Taper Length T (m) Width of works including sideways safety zone 1m

2m

3m

4m

5m

6m

7m

13

26

39

52

65

78

91

20

40

60

80

100

120

100

Single carriageway – speed limit 50 mph or more

25

50

75

100

125

150

175

All-purpose dual carriageway- speed limit 40 mph or less

25

50

75

100

125

150

175

Single carriageway – speed limit 30 mph or less Single carriageway – speed limit 40 mph

Figure 7 demonstrates a typical site layout indicating the work space and its auxiliary safety clearance L and S (the required clearance around the actual working space). The “Traffic Signs Manual” recommends minimum longitudinal clearance, minimum lateral clearance and minimum longitudinal exit clearance. Table 5 shows the minimum and desirable longitudinal clearance values in light of the speed limit. Table 5: Minimum and desirable longitudinal clearance (Source: Traffic Signs Manual, Ch.8, Part 1: Design, P.23) Permanent speed limit (mph)

Minimum longitudinal clearance L (m)

Desirable longitudinal clearance L (m)

Minimum longitudinal exit clearance (m)

Desirable longitudinal exit clearance (m)

30 or less

0.5

10

0.5

9

40

15

30

3

9

50

30

50

3

9

60

60

100

9

9

70

100

200

9

9

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Figure 7: Typical Site Layout (Source: Traffic Signs Manual, Ch.8, Part 1: Design, P.19). The “Safety at Street Works and Road Works - A Code of Practice” provides as well minimum values for the minimum width of sideways safety zone ranges from 0.5 to 1.2 m; however, this value of the lateral clearance shall be reviewed in light of the engineering practice on basis of the works types and the associated risks. In reference to Figure 5; it is timely to tackle the remaining segment of the work zone, which is the end of works zone (E). The function of this segment is to notify the road users of the works termination. The “Traffic Signs Manual” determines a range from (10

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to 30 m) for single carriageway road with speed limit 30 mph or less, up to 90 m for dual carriageway road with the national speed limit. At this point, the work zone dissection according to the international standards comes to an end. In the following section, the exploitation of the different TTC devices shall be analyzed in light of the perceived dissection of the work zones. Following the same sequence, at first the “MUTCD” from USA shall be investigated for the TTC devices exploitation, followed by the provision of UK “The Traffic Signs Manual”.

1.4.3

TTC Devices (MUTCD- USA)

The MUTCD introduces two approaches for the deployment of TTC devices within work zones. The first approach is the “Flagger Control” (MUTCD 2009, P.566) utilizing “hand signaling devices” or “automated flagger assistance devices”, this approach is more appropriate to short term work activities, for example potholes repairs, due to the fact that the deployment of the traffic management personnel seem to be more adequate for such short term situations. The second approach is to provide TTM plans and strategies equipped with physically installed devices “signs, signals, markings and other devices” (MUTCD 2009, P.576). This approach seems to be more appropriate for situations with relatively longer durations. Since the focal point of the thesis is the major construction projects, characterized by long construction periods, therefore, the second approach has been selected to be tackled in this section. The first type of TTC devices is the signs. The exploitation of signs within work zone could be easily observed in the advance warning area and the termination area (see Figure 3), which were discussed in the previous section. The main function of the TTC signs in the advance warning area is to warn the road users to the forthcoming work zone and to declare the end of the work zone (exit). However, it could be utilized in some other particular situations as regulator for prioritizing some traffic streams (e.g., public transport or the fleet of the constructions truck). The “MUTCD” defines three main functional categories of TTC signs deployed in work zones:  “Regulatory;  Warning;  Guide” (MUTCD 2009, P.576), [including exit and detour guiding signs]. Although, the TTC signs provide an economic solutions for TTM, since it has relatively low investment cost, and it has minimal operation and maintenance cost, there are some limitations of its utilization. One limitation is the static approach of the TTC signs; hence it conveys static message without any considerations to the time factor or other changeable factors (traffic volumes, weather conditions …etc.). Another limitation could be the misinterpretation of a sign when providing complex messages. Therefore, it is highly recommended when using TTC signs to exploit it for conveying straightforward messages and deploy it strategically at specific points in the work zone, where there is

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no crucial influence of changeable factors. The “MUTCD” provides full detailed description, dimensions, and work method statement of each TTC sign set forth in the three main functional categories. Another type of signs according to the “MUTCD” is the “Portable Changeable Message signs” (MUTCD 2009, P.598). For this TTM solution, the limitation of the static approach has been concluded, since this kind of signs provide responsive messages and instructions depending on the de-facto operational conditions within work zones. In comparison to the ordinary TTC signs, the changeable ones have relatively higher investment cost, since it involves “control systems” and “power sources”. Therefore, the “MUTCD” defines a specific area of application, for work zones on “high density urban freeways” where high traffic volumes are expected. The Portable Changeable Message signs may be considered as a good asset for TTM plan of a major construction project that is expected to have a relatively long construction period, thus the investment cost could be reimbursed over the project duration. The aforementioned two kinds of TTC devices are usually allocated at the sections of advance warning and termination in the TTM plans. Another major TTC device which has a crucial role in the transition area is the “Arrow Boards” (MUTCD 2009, P.601). Arrow boards are equipped with evenly distributed LED (Light-emitting diode) lights in order to be able to show different arrow messages and to display the arrows either in flashing mode or in sequential mode. The arrow signs are allocated in a sequence that indicates a merging lanes or lane closure in the transition area as well as the advance warning area. It is recommended for arrow signs to be erected on the shoulder, at the end of the shoulder taper and optionally at the end of the taper length (end of the transition area). Though, the arrow signs involve source of power, a solar cells could be integrated with the sign in order to minimize the investment cost. It is worth mentioning that the arrow signs are strictly prohibited for lane shift indication, since the flashing or sequential mode of display may not convey the intended message properly. Work zones impacts may extend to engage intersections with high volumes; hence, a portable traffic signal is indispensable. The “MUTCD” in the guidance regulations states that for a temporary traffic control signal “should not operate longer than 30 days unless associated with a longer-term temporary traffic control zone project” (MUTCD 2009, P.493). This applies to major construction projects with long term duration. Thus, temporary signals are recommended, on basis of engineering studies and measurements, for long term applications which involve intersections or conflicting traffic streams in the work zone, in order to improve the level of service and the safety at the intersections. The decision on utilizing TTC signal shall be made based on several factors; like the traffic volumes at the intersections, the nature of the traffic streams (vehicular, cyclists and pedestrians) and the cost of installation, operation and dismantling. The “MUTCD” imposes that the technical and operational specification of

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conventional traffic signals shall apply to the TTC signals. The recommended point of allocation is “within 200 feet of a grade crossing” (MUTCD 2009, P.616). A part from the warning and instructive devices, the TTM plan should deploy barriers that control the traffic flow within the work zone by directing the vehicular or other kinds of traffic streams, through or around the working space in a way that guarantees the safety of the road users as well as the workers. These barriers are typically the channelizing devices, which are considered as the backbone of TTC devices, since it is supposed to perform this task of controlling the traffic in the work zone, besides its safety-enhancing function. On one hand, it functions as a physical barrier that prevent any deviating vehicle from penetrating it in case of loss of control, thus it guarantees the safety of the workers. On the other hand, it prevents the road users from starring at the running activities which may dissipate their attention and result in road accidents. The channelizing devices shall be deployed and erected in a self-explanatory arrangement, taking into account a sufficient buffering space around the actual working space. The “MUTCD” provides regulatory framework for the exploitation of channelizing device indicating the dimensions, the color, the method of installation, and the recommended area of application.

1.4.4

TTC Devices (Traffic Signs Manual- UK)

The TTC devices deployed in the work zones are described within the context of TTM strategies and measures set forth in the “Traffic Signs Manual, Chapter 8: Traffic Safety Measures and Signs for Road Works and Temporary Situations, Part 1: Design”. Although the manual does not recognize distinct classification for the devices based on the placement section nor the function, but this classification could be readily performed in light of the manual organizational framework of TTM. The devices in the “Traffic Signs Manual” could be classified as per following:    

TTC Signs. TTC portable signals. TTC barrier and delineation devices. TTC monitoring devices (CCTV).

The TTC signs according to the “Traffic Signs Manual” have the same conventional functions of traffic control within the work zone. They are utilized for: advance warning, regulating, controlling, diverting and conveying messages to the road users. They are delivered either in static forms or in forms of “variable message signs (VMS)” (Traffic Signs Manual 2009, Ch.8, Part 1, P.81), thus it could convey dynamic messages. Regarding to the exploitation of the signs within the work zone, it is remarkably utilized in the approach zone and the end of works zone. The approach zone starts with the “road works sign”, which alarm the driver to the forthcoming road works, followed by the “road narrows sign”.

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It is worth mentioning that the “Safety at Street Works and Road Works- a code of practice” introduces two main trends for traffic control during the temporary situations; passive traffic control and positive traffic control. The work zone attributes (maximum speed limit, the maximum available coned area length and the maximum traffic flow) determines which approach to be adopted. The work method of TTC identifies the TTC signs and devices that should be exploited. Thus, it is worthwhile to review the TTC work methods provided in the “Traffic Signs Manual” whilst tackling the exploitation of the TTC devices. Table 6 demonstrates the different approaches for traffic control and its corresponding wok methods in light of their decisive parameters. Table 6: Work methods for TTC (Safety at Street Works and Road Works- a code of practice, 54) Method

Max speed limit (mph)

Coned area length

Traffic flow (maximum)

Give and take

30

50 m maximum

20 vehicles over 3 minutes and 20 HGVs per hour

Priority sign

60

80 m maximum

42 vehicles over 3 minutes

Stop/Go boards

60

Up to 100 m Up to 200 m Up to 300 m Up to 400 m Up to 500 m

70 vehicles/3 minutes 63 vehicles/3 minutes 53 vehicles/3 minutes 47 vehicles/3 minutes 42 vehicles/3 minutes

Portable traffic signals

60

300 m maximum

No Limit

Speed reduction

60

Not Applicable

Not Applicable

Convoy working

Temporary limit of 10 mph

Not Applicable

Not Applicable

Road closure or one way traffic

60

Not Applicable

Not Applicable

‘Stop- works’ sign

60

Not Applicable

Not Applicable

‘Temporary obstruction’ sign

60

Not Applicable

Not Applicable

Passive Traffic Control

Positive Traffic Control

There are always two areas of application in the “Traffic Signs Manual”; single carriageway roads and dual carriageway roads. On one hand, the TTC of single carriageway road according to the “Traffic Signs Manual” encompasses five principal methods of controlling the traffic:    

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“Give and take; Priority signs; Stop/Go signs; Stop-Works;

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 Portable traffic signals” (Traffic Signs Manual 2009, Ch.8, Part 1, P.113) On the other hand, for the case of dual carriageway roads; the TTC work methods tend to be more subjected to engineering judgment, since the operational conditions at dual carriageway roads tend to be less critical than the ones at single carriageway roads. In reference to Figure 6 (Work Zone Dissection in Dual Carriageway Road), it shows the deployment of TTC signs within a typical dual carriageway work zone. Hence, the prescribed methods of controlling the traffic in temporary situations at the single carriageway roads will be briefly described here, with highlighting the devices exploitation. The manual identify the “Give and Take” method as a “system of shuttle working” (Traffic Signs Manual 2009, Ch.8, Part 1, 120); the shuttling operates in between the two points whereas the single carriageway road is narrowed to one lane. It has a fundamental signage system; starts with the road works sign, followed by a road narrow sign, same as Figure 5. The priority sign method utilizes three advance warning signs instead of two, they are respectively the road works sign, road narrows sign and then the priority sign which prioritize one traffic stream on the expense of the other. (See Figure 8).

Figure 8: Priority sign method on a two lane single carriageway road (Source: Traffic Signs Manual, Ch.8, Part 1, P.126).

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The second trend of positive traffic control shall come into effect in case of high traffic volumes work zone (e.g., Stop/Go boards and Portable traffic signals), or when the works construction method imposes the need for full or partial road closure and traffic rerouting (e.g., Convoy working, Road closure or one way traffic or Stop- works sign). The work method of Stop/Go sign utilizes an extra rotating sign operated either manually or remotely controlled, showing the message to stop or to go. It is allocated at the end of series of advance signs that warn the road user of the forthcoming road works, then to the change of the carriageway dimensions (merge) and finally to the expected traffic control sign prior to the Stop/Go sign itself. This method is appropriate under certain conditions of good visibility and within the recommended coned area. Figure 9 shows the location of the Stop/Go sign within the approach zone, and the auxiliary supplementary plates.

Figure 9: Stop/Go method on a two lane single carriageway road (Traffic Signs Manual, Ch.8, Part 1, P.130). A “STOP- WORKS” sign becomes essential when the road can’t be any more accessible due to the works construction method. The “STOP- WORKS” sign restricts the traffic flow for a certain time period until the risk is removed. This method is utilized on a small scale for short periods of complete road closure. The last method for the positive traffic control is the portable traffic signals. This method is more likely to be used for controlling the traffic within work zones of major constructions projects, since it could provide vehicle-actuated (VA) technique for traffic control. VA portable traffic signals maximize the efficiency for the road users by means of adjusting the green time in accordance with the actual demand (traffic volumes)16.

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The remainder of this section is the TTC barrier and delineation devices, and the TTC monitoring devices (CCTV). Traffic cones, cylinders and traffic posts are the basic elements of traffic delineation. Other devices shall be utilized in accordance with specific site needs and traffic conditions. The term (site needs) reflect specific site conditions such as excavation, which triggers higher work associated risks. As for the traffic conditions, the work zone may be conflicting with mixed traffic streams, such as pedestrians and cyclists, thus a special measures are mandatory to provide safe routes within or around the work zone. According to the “Traffic Signs Manual”, the category of TTC barriers and delineation devices includes, besides the traffic cones and posts, a wide range of barriers that could be utilized as: pedestrian safety barriers, vehicle restraints barriers or delineation barriers. As concerns the TTC monitoring devices (CCTV), the “Traffic Signs Manual” recommends using post-design monitoring system for the proposed TTM plans, in which a CCTV surveillance system is utilized. This measure is strongly advised for TTM of major construction projects in order to make sure that the plans have been elaborated accordingly with the design objectives, and to enable the planners from intervening whenever is needed to modify and reform the introduced measures. In this section, the TTC devices were discussed in light of the work zone dissection, and according to the provisions of the international standards. The TTC devices strategy, considered among the TTM strategies, was selected to be extensively analyzed since it is the key tool for TTC and TTM. In the following section, there will be a brief analysis of another trend of devices that is recently introduced to traffic management solutions, which is the Intelligent Transportation Systems.

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1.5

Temporary Traffic Management- Intelligent Transportation Systems (ITS) Review

The role if “Intelligent Transportation Systems- ITS” in traffic management and transportation operation has been evolving through the last decade. In late nineties, ITS was identified as “young discipline”17. Recently, it is among the widely used tools at the agency level for traffic management and operation. Chen, K., Miles, J. define the ITS as “a generic term for the integrated application of communications, control and information processing technologies to the transportation system. The resultant benefits save lives, time, money, energy and the environment.” (Chen, K., Miles, J. (1999), Sec.1, P.1.1). This definition highlights two main decisive factors of the ITS use; first is the technical feasibility of the non-recurring investment cost induced by integrating such applications (communications, control and information processing) into transportation systems, and second is the repay of this cost throughout considerable period of utilization and traffic externalities mitigation. These two factors indeed conform to the frame work of the TTM of major construction projects, since this kind of projects is characterized by relatively long implementation time, as per concluded before, and the traffic-related impacts of these projects are more likely to induce significant fiscal and social cost. Therefore, the introducing of the ITS technologies to TTM strategies could be an asset and cost-efficient measure for TTM of major construction projects. Work zone ITS usually consists of four components; “sensors”, “communications links”, “software” and “electronic equipment”18 for conveying the intended message to the road users. These components should not be expensive in order to be consistent with its desired benefits of minimizing the direct and the indirect cost. For a major construction projects, the ITS deployed in the work zones are primarily utilized as a TTM strategy, aims at similar objectives of other strategies for traffic management; mitigating the work zone impacts on the safety, mobility and other socioeconomic values. Ullman et al. (2014) point to another aim of work zone ITS that is related to the construction management, referred to as “improve work productivity and durability” (Ullman, et al. (2014), P.04). The work mentioned here stands for the construction activities in the work zone, since the enhanced mobility and safety should consequently minimize the works disruptions and enhance the mobility of the construction fleet to and from the worksite. In addition to its crucial role in managing and mitigating the traffic impacts of work zones, the ITS could be an effective tool for traffic surveillance and monitoring during the project implementation, consequently in the post-project evaluation.

1.5.1

Conceptual Framework of Work Zone (ITS)

Ullman, et al. (2014) elaborate a development scheme for work zone ITS. This scheme tends to be comparable to the TTM plans development process (see ‎1.2.2 Development Process of Temporary Traffic Management Plans), since it starts with

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compiling information about the project, referred to as “Assessment of needs” (Ullman, et al. 2014, P.7), until it reaches to provide a detailed system plan, deployment and installation, and finally monitoring and evaluation. In this section, the thesis will highlight the main notions that constitute the conceptual framework of work zone ITS according to Ullman, et al. (2014). As per aforementioned, the work zone ITS is a TTM strategy, thus the adoption of such strategy shall be based on particular findings (threats) of the WZIA and specific needs for mitigation measures recommended by the TTM strategic planning (WZIA). Significant and severe impacts of the work zones primarily stimulate the potential for work zone ITS strategy. Moreover, existing TMC for the area of the project implementation, or already established ITS system nearby the work zone may support the decision making for the work zone ITS deployment. The extent of the work zone impacts, consequently the required influence area of the ITS system should be borne in mind when planning ITS for a work zone. Based on these elementary decision support data concerning to the work zone impacts significance, existence of TMC or already established ITS, and preliminarily identifying the ITS influence area, the TTM designer shall be able to decide whether to take the ITS strategy for further design step, or to discard it from the TTM strategic planning process. Ullman, et al. (2014) identify this further step as “concept development and feasibility” (Ullman, et al. 2014, P.15), where the ITS strategy should be put on the table for discussion in light of the pre-determined needs. At this point, the traffic management designer and the involved stakeholders shall investigate the strategy’s strengths and weaknesses (SW analysis) in order to determine its applicability. Ullman, et al. (2014) introduce a score-based scheme to determine the ITS feasibility, total score greater than 30 indicates to cost-effectiveness of ITS deployment in the work zone. Major construction projects characterized by complex nature and relatively long construction duration tend to achieve score above 30 on this scale. After the work zone’s ITS feasibility determining, the traffic management designer should commence the design of the required ITS system, in line with the general TTM plan design. Therefore, it could be clearly noted that the ITS concept development and feasibility shall be a sub-task of the TTM strategic planning. The ITS system design, similarly to other TTM strategies may propose different scenarios, so that different alternatives could be evaluated in the effectiveness assessment stage. Upon completion of the design, the work zone ITS system shall undergo strict costeffectiveness assessment, cost-benefit analysis (CBA) can be used here. Ullman, et al. (2014) points to that the U.S DOT, Research and Innovative Technology Administration has developed a database scheme for obtaining the benefits and costs of several ITS solutions19. This database scheme can be useful for preliminary assessment and investigation, prior to duly conducted CBA.

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Procurement, installation and commissioning procedures shall be launched immediately upon the evaluation conclude to a positive result. The procurement method primarily depends on the project nature, ITS category, organizational framework and the required area of expertise. It is strongly advised to issue highly detailed specification for the works in order to avoid any conflicts or delays in the procurement and installation. Ullman, et al. (2014) emphasizes on scheduling the installation in a way that leave a timing margin for “deployment”, “calibration” and “unexpected occurrences”, so that the system could be fully installed and operating prior to the commencement of the work zone activities (Ullman, et al. (2014), P.52). In the post-project (post-installation) monitoring stage, all the TTM strategies and components (including the ITS solutions) shall undergo a regular and comprehensive evaluation in order to guarantee the conformity to the plan objectives, observe any deviation or deficiencies and to intervene to fix these deficiencies. Here, this point highlights the role of the ITS deployment in monitoring and evaluating other TTM strategies and components. Apart from the evaluation of the ITS itself as a TTM strategy, utilizing the ITS for TTM monitoring and evaluation can provide high quality data base about the traffic conditions of the work zone. This data may be employed in the strategic planning process for further projects. Bushman, R. et al20, and the lesson learned outlined in the U.S DOT “Intelligent Transportation Systems for Work Zones”21 highlight the potential of ITS for work zones on two major scales; the scale of urban freeways and the scale of Highways. Besides the ITS paradigms described in (Ullman, et al. (2014), P.03), the TTM designer should decide about the ITS solution that is appropriate to the area of application and can achieve cost efficient performance within the TTM framework. Amongst the strongly recommended ITS paradigms for work zone is the “real time traveler information” that could be integrated into the PI strategies.

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1.6

Evaluation of Temporary Traffic Management Alternatives

Effectiveness evaluation is a categorical part of the TTM refinement process. The effectiveness of the strategic planning is always questionable at the level of stakeholders, unless it undergoes a transparent assessment scheme. If the TTM evaluation is strongly recommended in the post-project (monitoring) phase, it is indispensable in the early planning and design phase. This necessity comes out of the fact that the TTM plans elaboration process is usually carried out with the help of multicriteria decision analysis methodology; whereas different alternatives are assessed on basis of effectiveness. At this point, the role of evaluation is clear as planning and design tool, as well as an assessment and refinement tool. In light of these findings, the literature identifies two types of evaluation indicators:  TTM Design evaluation indicators for the strategic planning phase.  TTM Effectiveness assessment indicators for the post-installation (monitoring) phase. The first type of indicators is prognosticated using traffic analysis and modeling tools, as regards the second type; it is field-collected and processed data using manual or electronic methods. The literature exhaustively tackles both types, however; the following sections will outline only limited number of indicators, which were found pertaining to the context of designing and planning the traffic management of major construction projects work zones. The criteria of assessment are profoundly correlated to the WZIA development, since the WZIA reveals the threats to the safety, mobility and other aspects of social cost, and the evaluation indicators should investigate the effectiveness of the adopted mitigation strategies within the same context. Therefore, the effectiveness evaluation indicators shall analyze the TTM performance either qualitatively or quantitatively on this scale collaboratively with the WZIA. This illuminates another key role of the WZIA, which is to identify the appropriate indicators for assessing the TTM strategies in the pre- and post-design phase22. However, it must be borne in mind that at this level of assessment, only the project level is considered, since the post-installation evaluation process may reach to the agency level, as per mentioned in the WZIA section, but this is not the case here.

1.6.1

Evaluation Criteria

In this section, the thesis will address the relevant criteria of TTM evaluation indicators in light of the lessons learned from the practice and the literature review. A guiding study “A primer on work zone safety and mobility performance measurement”23, conducted by Ullman G., Lomax T., and Scriba T. for the U.S DOT and FHWA, reveals the TTM evaluation criteria in the U.S practice. It emphasizes on three main measures; “safety measures”, “mobility measures” and “exposure measures” (Ullman G., et al. 2011, P.V). Mobility and safety measures were always present in the context of transport evaluation, as concerns exposure measures; it is a special attribute of a work

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zone, since it is crucial criterion that is derived from the temporal (duration) and the physical dimensions (length, width and extents) of the work zone activities, so that the severity of safety issues and the mobility performance indicators could be properly interpreted and judged. In other words, the crash statistics, which is the most common safety measure, is meaningless if it is described outside the time-exposure context, the same for a mobility indicator (control delays or queue length due to lane closure for example), it can’t be quantified, nor understood without perceiving the dimensions of the closed lane in relation to the available carriageway capacity and the available storage distances for the queues. The study provides wide range of indicators for each measure, however, the planner, designer or whoever may be interested in evaluating the TTM performance, shall select the evaluation indicators based on: the project (work) nature, site conditions, the WZIA and its findings, consequently the TTC and TO adopted strategies. In another study from the Imperial College London; Kaparias, I., Bell, M. et al. 24 introduced four main notions for evaluating the urban traffic management and ITS, they are: traffic efficiency, traffic safety, pollution reduction and social inclusion considering land use. Although this study isn’t exclusively conducted in respect of work zones traffic management and control, but it provides a comprehensive evaluation scheme of traffic management issues, since it takes into consideration the social and environmental aspects. With appropriate interpretation and understanding, the study could be utilized as an efficient tool to identify and quantify descriptive indicators for TTM strategies performance assessment. In light of the two approaches provided in both studies, there could be an aggregation of the evaluation criteria relevant to major construction projects as follows:    

Safety. Mobility. Pollution reduction. Social inclusion (land use. 1) Safety:

Safety performance assessment tends to be addressed primarily based on crash statistics. In such a way, the TTM safety evaluation may be exclusively conducted during the project implementation or post-project evaluation. Comparing the different crash and accident rates, classifying its severity and detecting TTM strategies that tend to have better safety performance could be very useful tool at the agency level to refine and improve the TTM practice. Scriba, T., et al identify some indicators for post-project evaluation, which may be used to assess the performance during the implementation as well. Number and severity of crashes as well as the crash rates (Scriba, T. et al., P.6) are on top of these indicators, which may be an asset for agency level evaluation. Within the same context, the UK “Traffic Signs Manual” advises an evaluation scheme for signs' condition in order to maintain the signs and the devices at reasonable

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condition, which contributes to an enhanced safety performance in the work zone (see Traffic Signs Manual, Ch.8, Part 2: Operation , Appendix 4.3). Whilst for the project level, specifically at the planning and design stage, which is the thesis area of interest, it is necessary to include the safety considerations in the design. Actually, all the standards and codes of practices that provides measures for TTC and TO are based on engineering interpretation for the safety parameter (e.g., minimum taper lengths and alignments, design of the advance warning zone, the safety clearances around the activity areas, …. etc.). However, the need to address the direct safety impacts of work zones, which is the traffic crashes and accident, may arise, especially for major construction projects characterized by significant construction duration. At the project level, in the planning and design stage, the main safety indicator is the crash rates, as per aforementioned. However, forecasting the TTM strategies’ impacts on crash or accident rates is not an effortless task. There are two main trends for work zone potential risk detection; qualitative approach and quantitative approach (Shane, J., et al, 2012)25. In quantitative approaches, the data concerning to crash rates and crash severity shall be collected and statistically processed in light of their proximity to the work zone components. In such a way, the work zone component, strategy or element that is statistically more likely to trigger crashes shall be detected and subjected to further analysis (Shane, J. et al, xiii). This approach is consistent to the recommendation of Kaparias, I., et al26 based on (Elvik R., et al., The handbook of road safety measures), to take into account the crash (accident) impacts, and not to depend only on the crash counts, since there are minor crashes that don’t provide fair perception of the safety evaluation at the work zone. The qualitative approach concerns more about the crash or the accident conditions and the main contribution factors, it utilizes interviews or surveys. Bourne, J.S., et al recognize a hybrid of qualitative and quantitative safety measure; “Inspections scores” (Bourne, J., S., et al. 2010, P.2-1, P.2-4), whereas all the TTM safety measures and devices are assessed regularly on an inspection sheet, each safety component is assigned to a certain score, thus the overall safety indicator of the work zone could be figured and compared on the agency scale. This evaluation scheme is usually utilized for evaluation the safety performance of the work zone during the project implementation; however. 2) Mobility: Bourne, J.S., et al, (2010) and Ullman G., et al. (2011) have similar approaches for assessing the mobility performance of work zones, indicators like delay per vehicle, queue length, duration of queue, volume/capacity ratio and level of service (LOS) of signalized intersections are utilized to assess the effectiveness of the TTM strategies in mitigating the work zone impacts on the mobility. On another hand, Kaparias, I., et al introduce for the same context of mobility performance another approach entitled

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“traffic efficiency”; comprises “four sub-categories: mobility, reliability, operational efficiency, and system condition and performance” (Kaparias, I., Bell, M. et al. (2011), P.20), however, it must be borne in mind that these sub-categories were synthesized in order to assess the overall effectiveness of traffic management and ITS at the agency level, therefore it must be refined and elected when applying it to the area of temporary traffic management at the level of projects (major construction projects). Yet, the delay indicator is still falling under two categories; the reliability and the operational efficiency. Mobility and operational efficiency indicators can be utilized in evaluating TTM alternatives prior to the implementation phase, as well as assessing the effectiveness of the TTC and TO strategies in the post-project (monitoring) phase. 3) Pollution reduction: Traffic emissions are amongst the environmental concerns all over the world that were found to have serious impacts on the human well-being and the environmental quality. Generally speaking, traffic and transport sectors have a considerable contribution to air pollutants like Hydrocarbons (HC), Carbon Monoxide (CO), Nitrogen Oxide (NOx)27, besides another serious incurred social cost, which is the noise emission. The work zones operational conditions are more likely to aggravate the traffic-related emission rates due to several factors, like the reduced speeds and the prolonged driving routes. The impeded movement of traffic within the work zones may force congestion and other unfavorable operational conditions like stop-and-go traffic, which will consequently produce more emission rates. Moreover, the critical nature of the major projects neighborhood (high dense urban areas or central business districts) boosts the severity of the traffic emissions issue, and urges the need to prioritize TTM solutions and strategies that contribute to the pollution reduction. The link between the traffic management strategies and the pollution reduction can be better understood out of two traffic-management-related factors; namely, the “traffic conditions” and the “driving route” (Kaparias, I., et al. 2011, P.35). These two factors characterizing potential TTM alternatives are primarily correlated to the pollution reduction evaluation criterion. In other words, TTM strategy that optimizes the traffic flow (reduced vehicles delays and stop-and-go) within the work zones will consequently enhance the pollution reduction. In a similar concept, TTM strategy that encompasses shorter length of driving route within the work zone will certainly generate fewer emissions. Pollution reduction evaluation process shall investigate the emission rates triggered by the work zone traffic management strategies, which is basically the compound product of the aforementioned factors, besides other factors that shall not be overlooked (e.g., vehicle type, fuel, weather condition,… etc.). 4) Social inclusion: Due to the fact that the thesis is addressing the temporary traffic management of major construction projects, the social inclusion may not sound relevant to evaluate such strategies, since it is not permanent actions or measures. However, the previous

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conclusion of the major projects potential for urban areas highlights the significant impacts that work zones might breed on the society and the notable value of social inclusion as an evaluation criteria for proposed TTM alternatives. The social inclusion term for TTM alternatives can be interpreted as the level of social acceptance towards specific TTM strategy or solution. The effectiveness assessment of the work zones traffic management on basis of social inclusion should be distinguished from the social inclusion assessment of the construction project itself. Kaparias, I., Bell, M. et al., recognize the interdependencies between traffic management strategies and social inclusion as following; “social inclusion through traffic management and ITS involves the facilitation of the participation of individuals in economic, social and cultural life” (Kaparias, I., et al. 2011, 38). TTM should be consistent with the same objectives. This definition reflects the importance of conducting an exhaustive socioeconomic analysis for the implementation area within the context of TTM strategic planning. Hence, TTM of major construction projects shall prioritize the individuals’ accessibility to their residential places, work places, school places and other infrastructural facilities, without compromising the traffic efficiency, mobility and other considerations. Sensitive infrastructural facilities in the vicinity of the work zone should be taken into account since the early planning and design phase of TTM; therefore, accessibility to such facilities could be prioritized and maintained. Among the planning tools that have been proved to be effective for social inclusion assessment is social participation. Social participation may be performed via surveys, questionnaires or public meetings with the identified stakeholder groups. Conducting such kinds of public meetings shall be preceded with rigorous socioeconomic analysis of the implementation area in order to reveal the potential conflict of intersects and clearly identify the appropriate stakeholders. In the same aforementioned study, Kaparias, I., Bell, M. et al., point out to another aspect of the traffic management social impacts, which is the land use. Within the context of temporary traffic management, land use refers to the temporarily consumed land due to traffic management adopted strategies of the work zones. In light of this understanding, land use cannot be separated from social inclusion assessment, since the temporarily occupied land due to traffic management measures would impair the quality of life of one or more social group, either pedestrians, business (shops) owners, dwellers or the road users themselves. Therefore, what sets the priority of traffic management strategies’ alternatives is the minimized occupied land, besides the other social acceptance of the strategy.

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1.6.2

Quantification of Evaluation Criteria

1) Safety In light of the previous findings concerning to the safety as an evaluation criteria, it has been concluded that the forecasting of the TTM strategies’ impacts on crash or accident rates and the detection of the risk triggered by the work zones require a high quality data record for the crash rates and severity prior to the TTM installation. Usually the preliminary design of major projects could provide an idea about the method of construction (work method statement), so that the potential risk could be detected, analyzed and addressed. Work method statement indicates the general geometry of the project, the extents, besides the methods of construction, which represent the main safety concerns towards the road users as well as the workers. On basis of the data available in the early planning stage, and the findings of the WZIA, TTM strategies’ alternatives should be brought to discussion. Thereafter, the safety performance of TTM strategies shall be assessed and quantified. As per indicated in (Bourne, J.S., et al., 2010, P.4-7), the role of data management systems for crash analysis database is crucial in obtaining and analyzing the safety performance of proposed TTM strategies. Maze, T., et al. indicates to an effective tool of performing this analysis adopted by the U.S DOT, which is the “Traffic and Criminal Software- TraCS”28. With the help of this application, full detailed description of the crash or accident and its consequences is recorded, respectively with the spatial location within the work zone. This high quality data enables the planners or the traffic management designers from assessing the risk associated with the proposed TTM strategies. For a major construction project, it is advised to pursue this kind of data regarding to the work zones crash analysis within the area of implementation or in similar areas with similar conditions. This recommendation is based on the fact that the risk analysis of work zones is obtained via statistical modeling; therefore, parameters like drivers’ behavior, climatic conditions, topography and roadway geometry may influence the validity of this models whenever applying to disparate conditions. Crash rates obtained for specific work zone shall be described in terms of roadway length and duration of observation, in order to be comparable to other zones’ crash rates. “Crash rate typically is expressed as “crashes per VMT” (Vehicles Miles Travelled) or “crashes per million VMT (MVMT)” for roadway sections and “crashes per million entering vehicles (MEV)” for intersection locations.” (Mallela, J., Sadasivam, S. 2011, P.36). These units are indeed derived from what is so called “exposure measures”, which were discussed in the evaluation criteria as a temporal or physical attributes of the work zone that helps to describe the safety and mobility indicators. Mallela and Sadasivam introduced what is so called “CMF- Crash Modification Factor”; which is an adjustment factor that can be applied to the historical recorded crash rates in order to foresee the increment in the crash rates that would be associated with the

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work zone. FHWA-Office of Safety provides guiding values for the crash modification factors on the “CMF Clearinghouse website”i. It is worth mentioning here that these values of the crash modification factor have been calibrated for a good number of influencing factors, including but not limited to length and location of works and traffic volumes; therefore, these site-based considerations have to be taken into account for the exploitation of these values elsewhere. Hence, before concluding the safety criterion quantification it should be clear that the foreseen work zone triggered crash rate is the multiplication of the concurrent crash rate and the crash modification factor (CMF). 2) Mobility (traffic efficiency) Depending on the evaluation situation, whether it is design alternatives evaluation, or it is post-project evaluation, the quantification methodology of the work zone mobility performance assessment differs. For post project evaluation, it is quite a systematic procedures to monitor, record and process indicators concerning to the mobility and traffic efficiency. According to (Bourne, J.S., et al., 2010), parameters like travel time, speeds, queue lengths can be manually or electronically collected, and recorded. Surveys could be an effective approach to qualitatively investigate the road users’ satisfaction with the work zone travel condition. Ullman G., et al., 2011, propose intersections level of service as a compound indicator of the mobility and traffic efficiency, which addresses a good number of traffic characteristics “volumes, delays and signal timing” (Ullman G., et al., 2011, P. 22). It is worth mentioning here that the electronic monitoring of work zones may not be the best economic solution, thus the exploitation of already established TMC could be efficient solution for TTM monitoring and evaluation. As for design alternatives evaluation, Bourne, J.S., et al., 2010, refers again to the utilization of data management systems. Bourne, J.S., et al., introduces a good example of this tool utilized at the agency level, which is the lane closure systems, in which, the information about previous applications of lane closure are stored, and utilized for forecasting the traffic impacts of using such strategy in other projects. Lane closure database system led to the establishing of “the freeway performance management system (PeMS)” (Bourne, J.S., et al., 2010, P.4-9), which adds a crucial value to the lane closure database system, since it provides real time estimation for the proposed lane closure in relation to other planned lane closure within the area of implementation. These forecasting tools were developed at the agency level in order for the agency to be able to assess and quantify the impacts of lane closure. It could be utilized at the project level by the traffic management designer in order to assess the design alternatives prior to the project is taken to the agency for approval.

i

CMF Clearinghouse: http://www.cmfclearinghouse.org/index.cfm

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For major construction projects, that may be planned for areas do not utilize data management systems, other solution like traffic microscopic or macroscopic simulation (e.g., PTV VISSIM, Synchro) or “Sketch-Planning Tools (e.g., QuickZone)” (U.S DOT, FHWA (2006), Work Zone Impacts Assessment: An Approach to Assess and Manage Work Zone Safety and Mobility Impacts of Road Projects, P.5-14) and (Samdi, A., Baker, J.29), could be a very good option to estimate and quantify the mobility performance indicators of a work zone. Sketch planning tools that utilizes volume/capacity ratio and spreadsheet-based capacity analysis tools can quantify the mobility performance of a major project work zone and provide parameters like the travel times, queue lengths, control delays and intersections level of service. 3) Pollution reduction In order to assess the effectiveness of a TTM alternatives in minimizing the pollution triggered by a work zone, the evaluation process shall investigate the emission rates triggered by the work zone for each alternative, which is basically the compound product of the aforementioned factors (traffic conditions and driving routes), besides other factors that govern the emission rates under the regular operational conditions “driver characteristics”, “vehicles characteristics” and “weather characteristics” (Mallela, J., Sadasivam, S. (2011), P. 45). More specifically, TTM strategies of work zones may impose certain operational conditions (e.g., start-stop traffic, queue, detour …etc.). The additional traffic emissions triggered by major construction projects work zones are considered as a byproduct of these exceptional operational conditions imposed by work zone TTM strategies. The evaluation therefore, should consider the excess in traffic-related emissions due to the introducing of specific TTM strategy or measure. Mallela and Sadasivam recognize the two approaches of estimating the traffic emission rates; first approach is the “Static Emission Factor Models”. It could be readily interpreted from the designation that the first model approach estimates the traffic emission for the predominant conditions of traffic and vehicle type. Indeed, this approach may not be effective to use for TTM, since the traffic flow disruption and the worsened traffic operational conditions are not taken into account. The second approach is the “Dynamic Instantaneous Models”, the term “dynamic” points the ability of the models to capture and process changes in the speed and acceleration in order to provide accurate estimation of the emission rates at the “micro-scale” level. In order to apply this level of instantaneous-performance models for work zones emission rates estimation, the input data concerning to the stop-and-go, idling and acceleration shall be exhaustively detailed. For this reason, Mallela and Sadasivam mentioned that there are many traffic simulation software have incorporated this dynamic models within their domain of use. In “Kaparias, I. et al, (2011), Development and application of the CONDUITS Decision Support Tool for predictive assessment of pollution impacts”, further findings are introduced concerning to the application of the developed TTM performance indicators

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in terms of emission and pollution reduction. In this study, it is referred to “CONDUITS_DST” (Kaparias, I. et al, 2011, P.13), a software tool was developed in cooperation with “Kapsch TrafficCom”i. The CONDUITS_DST software tool synthesize the developed index for emissions from motor vehicles and a micro-simulation model within its framework in order to estimate the emission rates for a given traffic management solution, or to compare between different traffic management scenarios 30. In case of unavailability of microscopic and modeling tools, classic methodology for estimating the traffic-related emissions as a function of the traveled kilometers, or vehicles delays can be leveraged in order to assess the effectiveness of TTM alternatives in minimizing the work zone traffic-related emissions. 4) Social inclusion

The purpose of quantifying the TTM evaluation criteria (safety, traffic efficiency and pollution reduction) is to elaborate a comprehensive and unified evaluation scheme for the TTM potential strategies. However, performing this task for the social inclusion criterion seems not to be feasible, since it primarily depends on the implementation area attributes and socioeconomic structure, since each socioeconomic structure stimulates its own social inclusion indicators. Hence, it is strongly recommended to address each implementation area individually with respect to its own values, landmarks and socioeconomic structure. An effective approach to quantify the TTM performance from social inclusion perspective is to strive at measuring the level of social acceptance and satisfaction with the TTM proposed solution or strategy. A quantifiable indicator could be the land used for TTM tool to assess the TTM alternatives and prioritize the strategy that tends to minimize the occupied land. Moreover, the social cost incurred due to the application of specific TTM alternative could be another tool that measures the level of public acceptance. For cases like the diverting of specific traffic fleet to a calm residential road, or the relocation of public transport facility adjacent to a luxurious hotel or restaurant, the social inclusion criterion would be a value-added for assessing such kinds of TTM decisions.

1.6.3

Cost Effectiveness Evaluation

In the last section, cost-effectiveness evaluation wasn’t included in the evaluation criteria; though, it is an assessment tool, for it is considered either as a further assessment stage, or a stand-alone assessment tool. With the help of the Cost-Benefit Analysis (CBA), the cost effectiveness of TTM strategies are assessed based on their monetary benefits obtained from the mitigation of the work zone impacts on the road user, versus their associated fiscal costs of implementation. Cost-benefit analysis

i

https://www.kapsch.net/ktc

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(CBA) has been always an effective tool to evaluate and prioritize alternatives based on their cost-effectiveness, especially for major projects that involve massive fiscal and social costs. In the CBA of TTM measure, the road user cost plays a crucial role in the analysis procedure. Road user costs (RUC) cannot be separated from the WZIA, which was discussed in an earlier section of this thesis; indeed most of the anticipated impacts induced by a work zone have an influence, in a way or another on the road user. In the previously explained TTM effectiveness assessment procedures, the tendency was to address the performance technically in terms of mobility and traffic efficiency, traffic emissions, as well as safety performance in order to conduct the TTM strategic planning. Whilst for the cost effectiveness evaluation, the methodology is to compare the implementation cost of specific TTM strategy or measure against the RUC incurred by the road users in case of no-option alternative. The “no-option alternative” in the TTM context will be used to address the full closure solution. This assessment approach may be very useful to assess the feasibility of introducing specific TTM solutions (High-tech, ITS or Innovative Construction) solutions that involves high investment cost, in some particular cases where the other available option is the full closure (no-option alternative). In this assessment approach, the RUC is transformed into monetary units in order to integrate it in the CBA evaluation of the TTM strategy effectiveness. In the U.S practice, RUC is defined as “the additional costs borne by motorists and the community at-large as a result of work zone activity” (Mallela, J., Sadasivam, S. (2011), P.5). Besides the non-recurring cost of establishing the TTM strategy, Mallela and Sadasivam identified the work zone monetized impacts on a road user as following: “travel delay cost” (derived from mobility and traffic efficiency), “vehicle operating costs” (mobility), “crash costs” (safety), “emission costs” (pollution reduction) and finally the “impacts of nearby projects” (Mallela, J., Sadasivam, S. (2011), P.5) . The last impact cost (the impacts of nearby projects) is crucial when adopting the project phases scheduling as a TTM strategy, since the CBA of the incurred cost of coordination or scheduling versus the work zone impacts mitigation benefits determines the validity of the proposed strategy, or recommends further optimization for the project scheduling. This brings to the discussion another crucial parameter that should be a part and a parcel of the TTM cost effectiveness evaluation, which is the impact on the construction duration. As per highlighted before, the exposure time is necessary for understanding and interpreting the severity of certain work zone impacts, hence it is a deterministic factor for the adopted TTM measure or strategy. The same applies to the cost effectiveness, since the impact of specific TTM strategy on the construction duration; consequently the exposure time should be taken into account when calculating the corresponding RUC for both alternatives (TTM solution and the no-option alternative). For example, introducing a high-tech or innovative construction method as a TTM solution can profoundly minimize the RUC, but on another hand it may prolong the

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construction duration significantly, thus even this minimized RUC when it is multiplied by the exposure time it exceeds the RUC of the no-option solution. This is apart from the cost of the prolonged construction duration. Based on the analysis of the TTM strategy benefits from the RUC mitigation against its incurred costs of implementation, the traffic management designer can be in a better position of deciding whether this specific traffic management strategy of a major construction project is economically feasible or not. In light of this revealed trend of cost-effectiveness evaluation, there will be a brief review of monetizing methodologies, taking into account that only road user costs/benefits seem to be pertinent to major construction projects shall be exhibited. 1) Work zone travel delay cost It is the road user monetized cost, incurred due to the excess in the travel time caused by work zone TTM measure or no-option alternative. Mallela and Sadasivam introduce the following formula (Equation 2) in order to estimate the work zone travel delay cost. Traffic volumes and traffic composition are necessary parameters to apply the formula; therefore an accurate record shall be preserved and kept updated from the WZIA stage. As regards the work zone delay time, it is a characteristic value of each TTM alternative, obtained from the pre-design evaluation phase, with the help of the tools that have been discussed before. 𝑊𝑜𝑟𝑘 𝑧𝑜𝑛𝑒 𝑡𝑟𝑎𝑣𝑒𝑙 𝑑𝑒𝑙𝑎𝑦 𝑐𝑜𝑠𝑡 = 𝑤𝑜𝑟𝑘 𝑧𝑜𝑛𝑒 𝑑𝑒𝑙𝑎𝑦 𝑡𝑖𝑚𝑒 $ 𝑣𝑎𝑙𝑢𝑒 𝑜𝑓 𝑝𝑒𝑟𝑠𝑜𝑛𝑎𝑙 𝑡𝑟𝑎𝑣𝑒𝑙 (𝑝𝑎𝑠𝑠𝑒𝑛𝑔𝑒𝑟 𝑐𝑎𝑟𝑠) ℎ𝑟 $ 𝑣𝑎𝑙𝑢𝑒 𝑜𝑓 𝑏𝑢𝑠𝑖𝑛𝑒𝑠𝑠 𝑡𝑟𝑎𝑣𝑒𝑙 (𝑝𝑎𝑠𝑠𝑒𝑛𝑔𝑒𝑟 𝑐𝑎𝑟𝑠) ℎ𝑟 $ × 𝑣𝑎𝑙𝑢𝑒 𝑜𝑓 𝑡𝑟𝑢𝑐𝑘 𝑡𝑟𝑎𝑣𝑒𝑙(𝑇𝑟𝑢𝑐𝑘𝑠) ℎ𝑟 $ 𝑣𝑎𝑙𝑢𝑒 𝑜𝑓 𝑡𝑖𝑚𝑒 − 𝑟𝑒𝑙𝑎𝑡𝑒𝑑 𝑑𝑒𝑝𝑟𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛 𝑏𝑦 𝑣𝑒ℎ𝑖𝑐𝑙𝑒 𝑡𝑦𝑝𝑒 ℎ𝑟 $ [ ℎ𝑟 𝑣𝑎𝑙𝑢𝑒 𝑜𝑓 𝑓𝑟𝑒𝑖𝑔ℎ𝑡 𝑖𝑛𝑣𝑒𝑛𝑡𝑜𝑟𝑦 − 𝑓𝑜𝑟 𝑙𝑜𝑎𝑑𝑒𝑑 𝑡𝑟𝑢𝑐𝑘𝑠 ] 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑠𝑠𝑒𝑛𝑔𝑒𝑟 𝑐𝑎𝑟𝑠 𝑜𝑛 𝑝𝑒𝑟𝑠𝑜𝑛𝑎𝑙 𝑡𝑟𝑎𝑣𝑒𝑙 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑎𝑠𝑠𝑒𝑛𝑔𝑒𝑟 𝑐𝑎𝑟𝑠 𝑜𝑛 𝑏𝑢𝑠𝑖𝑛𝑒𝑠𝑠 𝑡𝑟𝑎𝑣𝑒𝑙 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑟𝑢𝑐𝑘𝑠 × 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑣𝑒ℎ𝑖𝑐𝑙𝑒𝑠 𝑏𝑦 𝑣𝑒ℎ𝑖𝑐𝑙𝑒 𝑡𝑦𝑝𝑒 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑙𝑜𝑎𝑑𝑒𝑑 𝑡𝑟𝑢𝑐𝑘𝑠 [ ]

Equation 2

(Source: Mallela and Sadasivam (2012), Work Zone Road User Costs- Concepts and Applications, P. 7)

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2) Work zone vehicle Operating Cost According to Mallela and Sadasivam, the work zone vehicle operating cost is the additional cost incurred by road users due to the exceptional operational conditions within the work zone. These exceptional operational conditions comprise “speed change”, “stopping”, “queue idling” and “detour” (Mallela and Sadasivam (2012), P.25). The additional cost includes “fuel consumption”, “engine oil consumption”, “tire-wear”, “repair and maintenance”, and “mileage related depreciation” (Mallela and Sadasivam (2012), P.26). Thus, the work zone vehicle operating cost can be obtained from the multiplication of the additional consumption costs per vehicle and the number of vehicles (Equation 3). This additional consumption of fuel, engine oil and other vehicle components can be observed for each TTM alternative as a function of the travelled mileage (kilometer), depending on the vehicle type. 𝑊𝑜𝑟𝑘 𝑧𝑜𝑛𝑒 𝑣𝑒ℎ𝑖𝑐𝑙𝑒 𝑜𝑝𝑒𝑟𝑡𝑎𝑖𝑛𝑔 𝑐𝑜𝑠𝑡 = 𝑎𝑑𝑑𝑖𝑡𝑖𝑜𝑛𝑎𝑙 𝑐𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛 𝑢𝑛𝑖𝑡 × 𝑢𝑛𝑖𝑡 𝑐𝑜𝑠𝑡 × 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑣𝑒ℎ𝑖𝑐𝑙𝑒𝑠

Equation 3

(Source: Mallela and Sadasivam (2012), Work Zone Road User Costs- Concepts and Applications, P. 26) 3) Work zone crash costs Mallela and Sadasivam identified the work zone crash costs as the monetary value of the crashes triggered by the work zone, thus, analytical records of crash rates, frequency and severity shall be preserved prior to works commencement (3 years), for the analysis zone, in order to detect the alteration in the crash statistical behavior. The foreseen work zone associated crash rates is the cornerstone for estimating the crash cost. Mallela and Sadasivam refer to the two trends of obtaining such cost, first trend is the “Human capital cost”, and the second is “Comprehensive cost” (Mallela and Sadasivam 2011, 40), the FHWA report “Crash Cost Estimates by Maximum PoliceReported Injury Severity Within Selected Crash Geometries”31 provides an approximation for both trends. This crash cost estimation accounts for, besides the crash geometry, other crucial parameters; like the crash severity and speed limit. As a conclusion, estimating the work zone associated crash rate, consequently crash cost reckon on statistical process. This estimation takes into consideration site-based factors that may radically vary from area to another. In order to estimate the crash cost triggered by a major construction project, or to assess the effectiveness of specific traffic management strategy in mitigating certain crash cost, the historical crash record of the analysis area has to be investigated in light of the area characteristics (e.g., traffic volumes, location and crash severity), and with respect to the project nature (e.g., work length and duration, TTM strategy, work times).

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4) Work Zone Emission cost Traffic externalities, particularly vehicles emissions and noise are byproducts of road transport. These externalities are not limited to the road users; rather it is influencing the society as a whole. The first step to compute this social cost is to estimate the emission rates triggered by the work zone adopted strategies, as per discussed in the quantification section. Thereafter, these emission rates are processed in certain estimation schemes for the health and social influences, and converted into monetary values. Examples for these schemes were adduced in (Mallela and Sadasivam (2011), P.48:49) and (Segal, L. (1999), P.24, P.35)32. Mallela and Sadasivam (2011) emphasize on the fact that these monetary costs were estimated based on specific area of implementation characteristics; therefore, it may radically be changed due to different socioeconomic considerations in other areas of implementation. At the end of this section, it is worth highlight the tool developed by the World Bank, helps to compute the road user costs based on the fleet composition and the road characteristics, namely “The HDM-4 Road User Costs Model Version 2.00 (HDM-4 RUC)”33. The tool is user friendly and applicable to different areas of implementation. It provides RUC concerning to most of the parameters which were discussed in this literature review (e.g. accident costs and emission costs).

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1.7

Comprehensive Temporary Traffic Management Plans CTTMP

In light of the investigated trends of TTM at the different scales, a comprehensive approach for developing TTM plans of major construction projects could be comprehended based on the understanding of the literature review. This comprehensive scheme takes into account the TTM influencing factors (safety, mobility, environment and society), besides it integrates the cost-efficiency as an assessment tool. Figure 10 depicts the development scheme of what is so called “Comprehensive Temporary Traffic Management Plans” of major construction projects.

Figure 10: Comprehensive Temporary Traffic Management Plans- Development Scheme. Logical steps commences with the project identification, thereafter the compiled project data and the implementation area data are taken to the TTM strategic planning. In the strategic planning; the WZIA is performed in light of the proposed construction method and the analysis of the implementation area. This analysis comprises traffic analysis, socioeconmoic analysis and risk analysis. Upon the completion of the WZIA, the impacts on the mobility and the safety are highlighted, and can be forwarded to the second step of the strategic planning, which is the alternatives elabortion. The potential TTM solutions and measures are synthesized in several alternatives in order to be assessed in terms of their effectiveness in the third step of the strategic planning. This assessment is performed based on multi-criteria evaluation. In some particular cases, where the TTM alternatives are limited to the no-option solution and one specific TTM solution, hence the cost-effectiveness evaluation is strongly recommended to assess

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such situation. Noteworth here is that the cost-effectiveness evaluation takes into account the parameters used for the multi-criteria evaluation in form of monetized road user cost (RUC). Upon the assessment is performed, using quantitative, qualitative or CBA tools, the decision for the recommended TTM alternative can be concluded. At this point, and before the implementation stage, a strengths-weaknesses (SW) analysis is advised in order to analyze the selected TTM alternative in terms of its strengthes and weknesses, so that the selection can be justified based on the strengths on one hand, and mitigation measures can be prposed for the weaknesses on another hand. Finally, the TTM alternative can be implemented, and hence starts the monitoring and post-installation evaluation phase. In this phase, rigorous monitoring, and step-back evaluation is necessary in order to assure the quality of the TTM performance, and the conformity of the outcomes to the objectives. In the monitoring/evaluation phase, the proposed mitigation measures from the SW analysis can be appropriate intervention tools in case of any emerging defects in the TTM performance, otherwise the arisen defect should be escalated to the strategic planning loop iteratively.

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CHAPTER 2: CASES ANALYSIS

2 CHAPTER 2: CASES ANALYSIS Three major construction projects will be analyzed in this chapter in light of the literature reviewed in the previous chapter and the TTM code of practice in each area of implementation. The analysis will comprise a brief introduction to each project and its background, a discussion about the work zone impacts on the safety, mobility and the socioeconomic structure of the surrounding neighborhood, and finally illuminating the adopted TTM strategies. The lesson learned from these cases analysis, in addition to the literature review would formulate a solid basis for the case study chapter. The projects that will be tackled in this chapter are respectively: Dulles Metrorail Corridor from Virginia-USA, London Crossrail from UK and Stuttgart 21 from Germany. Noteworthy, the three selected projects are transportation-oriented projects which are implemented within medium- to high-density urban areas. This is consistent with the early presumption in the literature review that considers the tendency of major construction project for the highly urbanized areas. Moreover, the relevance of the selected projects as cases analysis and the investigated standards from USA, UK and EU in the literature review would better explain the link between the standard theory and the practice, which will consequently reflect in the robustness of the thesis methodology.

2.1 2.1.1

Case Analysis 1: Dulles Corridor Metrorail Project Background

The first case analysis is from USA. The project is a Metrorail extension (23 Miles) 34, located administratively within the state of Virginia, operating from East Falls Church to Dulles International Airport. The project is falling under the category of “Virginia Mega Projects”35, aiming at improving the mobility in north Virginia, enhancing the capacity and the quality of public transport and providing a good access to certain points of interest (Dulles International Airport). Besides the project contribution to the overall mobility improvements in the implementation area, the project has other positive impacts on the environment and the society due to the expected environmental friendly travel behavior36. In consistent to what was discussed in the literature review concerning to the need for this kind of major construction projects within urban and capital areas for some reasons related to mobility improvements and business enhancement; the project will be of great asset to two main capital areas; namely “Tysons Corner, Virginia's largest employment center, and the Reston/Herndon area, the state's second largest employment concentration” (Dulles Corridor Metrorail Project 2012). This reveals the economic value of the project, and highlights as well the anticipated work zones’ impacts on the surrounding neighborhood and the traffic network.

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The project comprises two phases (see Figure 11). Phase 1, extends from the East Falls Church until Wiehle Avenue, encompassing five stations, planned from 2009 until 2013. Whilst the second phase continues until the East of Loudoun County after the International Airport of Dulles, encompasses 6 stations, planned from 2014 until 2016. Thus the total number of the planned stations is 11 stations. The project is managed by the Metropolitan Washington Airports Authority (a public bodyi), which is responsible for the planning, design and implementation of the project and its contractual agreements, consequently the TTM of the project work zones.

Figure 11: Dulles Metrorail Project Map (Source: Dulles Corridor Metrorail Project Websiteii) The thesis in this section will be more focusing on the first phase due to the fact that the phase is already completed, so that the analysis can be readily conducted. Moreover, the Tysons area is considered as a good example for the work zone challenges that may be encountered within TTM framework, since it is the central business district of the Fairfax County, assumes the major share of the County’s business activities with 26.6 million square feet of office space37, and a considerable

i

Metropolitan Washington Airports Authority http://www.mwaa.com/267.htm

ii

Dulles Corridor Metrorail Project

http://www.dullesmetro.com/pdfs/Dulles-Metrorail-Project-Program_map-6-7-12.pdf

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two retail centers. A quick look at the area profile, infrastructural facilities, the business trends and the area working places shows the potential for Home-Work, HomeShopping and Home-School trips. A study conducted by the Fairfax Department of Transportation and Cambridge Systematics concluded to findings concerning to the work trips from Dulles corridor to Tysons corner, support these potential for workrelated trips attracting38. Figure 12 shows the project alignment within the area of Tysons Corner. Four stations were implemented along the course of the project in this area, namely Mclean (Tysons East), Tysons Corner (Tysons Central 123), Greensboro (Tysons Central 7) and Spring Hill (Tysons West). Two stations (Mclean and Tysons Central 123) were constructed on the shoulder of Virginia State Route 123, whilst the other two stations (Greensboro and Spring Hill) were constructed in the median of the Virginia State Route 7. The metro tracks are elevated on series of aerial Pier-Supported Bridges, except for the segment between Tysons Corner and Greensboro, for which a tunnel section was constructed to accommodate the Metrorail system in order to avoid the conflict with the grade separated intersection between route 7 and route 123, and other unfavorable topographical conditions (see Figure 12 and Figure 13).

Figure 12: Tysons Corner Detailed Map (source: Dulles Corridor Metrorail Project Webpage)

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Figure 13: Aerial Photo of Dulles Metrorail Project in the Area of Tysons Corner (source: Google Earth 2014, 38°55ʹ35.78ʺN 77°13ʹ29.56ʺW, elevation 436 ft., Europa Technologies, Google. 13 October 2012)39. The project was identified as a major project (“Mega Project” according to Titunik, S., Virginia Department of Transportation), characterized by a cost exceeding the threshold of $1 Billion, since the total budget of the first phase is $2.916 Billion (Project Management Plan 2008, P.56). This early significance identification of the project was a main driving factor for a good number of measures and decisions were made during the planning and design phase, throughout the preliminary engineering stage. One remarkable measure was the contract awarding strategy, which was Design-Build approach. As per discussed before in the literature review, this Design-Build contractual approach is preferable for major construction projects triggering significant TTM issues. The approach enables early integration of TTM in the design concept, utilizes the construction phasing plan as an effective TTM strategy and minimizes the conflict of interests during the implementation. In regards the TTM issues related to the project, the Project Management Plan identified the roles and responsibilities distribution. Primarily, the project impacts assessment (including the work zone impacts assessment) were conducted by Airports Authority, whilst performing the design, construction management and all the required safety and mobility quality assurance were conducted by the Design-Build Contractor. In this case of Dulles Metrorail Project, the Design-Build contract was awarded to a Joint-Venture consortium called Dulles Transit Partners DTP. Noteworthy here is that the Project Management Plan states that the TTM plan of Dulles Metrorail Project shall be implemented by the Virginia Department of Transportation based on a memorandum of understanding signed with the other project partners. This indeed

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enhances the coordination with other major projects in the vicinity, and facilitates procedures like utility relocation and public outreach. One major product of the Project Management Plan was the project division by operation areas (see Figure 14). This provision reveals the Design-Build Consortium and other project partners’ perception of the project’s first phase internal division. As per aforementioned, in the project analysis, Tysons Corner will be the focal point. Tysons Corner comprises two main construction zones: zone 1 along Route 123 and zone 2 along Route 7i. These two construction zones are the main elements that shall be investigated and analyzed in terms of construction methods, work zone impacts, TTM strategies and finally the lesson learned.

Figure 14: Project Alignment by Operation Area (source: Project Management Plan, P.54).

i

Dulles Corridor Metrorail Project (2012), Construction. Available from:

[29 June 2014]

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2.1.2


The understanding of the construction activities of the investigated segment of the project (Tysons Corner) would facilitate the assessing of the work zone impacts. As per stated in the previous section, the construction of this project segment engages two construction zones along route 123 and 7. In the following paragraph, the project elements and its construction method used for each construction zone will be briefly demonstrated, so that the work zone impacts could be perceived within the context of the method of construction. Dulles Metrorail line is elevated along the north side of route 123. The construction had to cross over two grade separated intersection (intersection with the Capital Beltway and intersection with Westpark Dr.), and it had to cross over three at-grade intersections, they are respectively intersection no.1-1: Colshire Dr. /Scott Crossing Rd., intersection no.1-2: Old Meadow Rd. and intersection no.1-3: Tyson Blvd.i (see Figure 15, Figure 16 and Figure 17). Two stations were constructed in this construction zone, Mclean Station and Tysons Central 123. Both stations are elevated at approximately 16 m and 9 m respectively, since the line elevation starts to decline in order to be accommodated in the tunnel section 200 m right after Tysons Central 123 station.

Figure 15: At-Grade Intersection No.1-1 between Route 123, Colshire Rd. (South) and Scott Crossing R. (North) After Construction (source: Google Earth 2014, 38°55ʹ29.34ʺN 77°12ʹ29.91ʺW, elevation 314 ft., Google, Europa Technologies. 13 October 2012).

i

The intersections are coded based on the sequence of the construction zone (1 or 2) and the

sequence of the intersection (1, 2 and 3).

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Figure 16: At-Grade Intersection No.1-2 between Route 123 and Old Meadow Rd. After Construction (source: Google Earth 2014, 38°55ʹ26.65ʺN 77°12ʹ37.89ʺW, elevation 327 ft., Google, Europa Technologies. 13 October 2012).

Figure 17: At-Grade Intersection No.1-3 between Route 123 and Tyson Blvd. After Construction (source: Google Earth 2014, 38°55ʹ12.97ʺN 77°13ʹ17.33ʺW, elevation 421 ft., Google, Europa Technologies. 13 October 2012).

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An exceptional attention had to be paid to other running construction activities in the vicinity of the project. In particular, the I-495 Capital Beltway HOT Lanes (HOT: High Occupancy Toll Road), which is another major project not only lying in the vicinity of the project, yet intersecting with Dulles Corridor Metrorail Project (see Figure 18).

Figure 18: I-495 HOT Lanes Intersection with Dulles Metrorail Track (source: Google Earth 2014, 38°55ʹ20.84ʺN 77°12ʹ58.18ʺW, elevation 375 ft., Europa Technologies, Google. 2012). The overall work zone impacts on the mobility, triggered by constriction zone no.1 shall be addressed as the cumulative effects of Dulles Corridor Metrorail Project and I-495 Capital Beltway HOT Lanes. Figure 19 depicts an overall view of the construction zone no.1, indicating the different locations of the project elements.

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Figure 19: Overall View of the Method of Construction for Construction Zone 1 (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 123 Tysons). As regards the construction zone No.2, the same methodology of understanding the work zone impacts within the context of the method of construction applies. Besides a tunnel segments, construction zone 2 (along Route 7) encompasses the construction of two stations (Tysons Central 7 and Tysons West), and conflicts with 3 at-grade intersections (see Figure 20, Figure 21 and Figure 22). These intersections are respectively intersection no.2-1 Westpark Dr. and Gosnell Rd., intersection no.2-2 Spring Hill Rd. and Leesburg Pike, and intersection no.2-3 Tyco Rd. and Westwood Center Dr. For this segment of the project, there was no direct conflict with other major project like the first zone, however, the extended impacts of the running construction activities of the major project in the vicinity still needed to be taken into consideration.

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Figure 20: Intersection 2-1; Route 7 (Leesburg Pike), Westpark Dr. and Gosnell Rd. After Construction (source: Google Earth 2014, 38°55ʹ25.41ʺN 77°14ʹ12.05ʺW, elevation 438 ft., Europa Technologies, Google. 13 October 2012).

Figure 21: Intersection 2-2; Route 7 (Leesburg Pike) and Spring Hill Rd. After Construction (source: Google Earth 2014, 38°55ʹ20.84ʺN 77°14ʹ28.37ʺW, elevation 403 ft., Europa Technologies, Google. 13 October 2012).

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Figure 22: Intersection 2-3 Route 7 (Leesburg Pike), Tyco Rd. and Westwood Center Dr. After Construction (source: Google Earth 2014, 38°55ʹ48.12ʺN 77°14ʹ34.41ʺW, elevation 389 ft., Europa Technologies, Google. 13 October 2012). Since Tysons Central 7 Station is the end of the underground construction (the tunnel section) in Tysons Corner, the station platform level is almost at-grade (± 0.3048 m), regardless the mezzanine floor. Afterwards, the line continues to be elevated again on series of pier bridges until the next following station (Tysons West). The end of construction zone no.2 is the intersection point with Dulles Toll Road (Dulles Access Road). An expansion for Route 7 (Leesburg Pike) from 6 traffic lanes to be 8 traffic lanes (4 lanes per each direction) was carried out as a pivotal part of the Metrorail project in order for the roadway to be able to accommodate the newly established almost-at-grade station (Tysons Central 7). The construction of the station besides this expansion required lane shift in the median course (see Figure 23), in addition to other traffic patterns change in the area, that will be discussed as part of the work zone impacts on mobility. Besides these changes in the traffic patterns, the service roads along Route 7 (at intersections 2-1, 2-2 and 2-3) in the eastbound direction underwent full closure due to the expansion works; however, access points to the business activities were maintained.

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Figure 23: Route 7 (Leesburg Pike) - Lane Shift (source: Virginia Mega Projects Webpage40, Lane shift makes way for rail station construction along Route 7) In light of these briefly described construction methods, the work zone impacts can be analyzed in terms of mobility, safety, environment and society as per aforementioned. Thus, the TTM measures and strategies could be perceived as a mitigation tools and strategies for these impacts. These work zone impacts studies were conducted and refined as a part of the final Environmental Impact Statement (EIS) of the project; they were identified as “Construction Effects”. In the following paragraphs, these impacts will be addressed individually in order to highlight how they were detected during the early planning and design stage and considered during the preliminary engineering stage. 1) Impacts on Mobility: The work zone impacts on mobility can be explained based on assessing the baseline traffic conditions (LOS and delays); thereafter, analyzing the situation taking into consideration the potential changes in the traffic patterns, induced by the work zone. These changes, including the construction-related measures (e.g., lane shift, road closure) and definitely added traffic volume from the construction fleet, constitute the major impacts that need to be tackled in the TTM strategic planning. The first significant impact on mobility in construction zone no.1 is the closure of the southbound right-turn lane on Route 123 due to the piers foundation work and to provide safe buffering distance for the construction crew of Mclean Station (Tysons

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East Station) (see Figure 24), for two years started from February, 2010. This lane closure moved the right-turn traffic volumes to the remaining lanes, thus the rightturners had been able to make the turn just at the exit, that means the right-turn and the straight traffic streams were sharing the lanes until the exit during the period of the right-turn lane closure.

Figure 24: Right Lane Closure along Route 123 (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 123 Tysons). Another significant impact in construction zone no.1 was the change in the traffic pattern at Intersection No.1-1, particularly, the long term full closure of one road direction adjacent to the Tysons East Station construction area, and shifting two direction traffic streams to one carriageway at Scott Crossing Rd. (see Figure 25).

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Figure 25: One Carriageway, two directions Scott Crossing Rd. (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 123, Changes to Scott Crossing Rd.) The significant mobility impact in construction zone no.2 was triggered by the necessary expansion of the roadway along Route 7, associated with other changes in the traffic patterns. The changes in the traffic patterns triggered by the construction of new lanes41 and the temporarily lane closure of the service roads, in addition to the major change in Route 7/Route 123 interchange. For this interchange, the westbound traffic stream coming from Route 123 was shifted to use the intermediate lane which was assigned before (at baseline condition) to the eastbound stream, accessing Route 7 (see Figure 26). Southbound traffic stream coming from Route 7 has no change in its traffic pattern, whilst eastbound traffic stream coming from Route 7 accessing Route 123 has a significant change (1.1 Km detour), since it has to make the turn at the International Dr. (see Figure 27).

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Figure 26:Traffic Patterns Change (Route 7/Route123) (source: Dulles Corridor Metrorail Project Webpage, Construction, Route 7, Major Changes Coming to Route 7/Route 123 Interchange).

Figure 27: Eastbound Route 7 Traffic Stream Shift to International Dr. (source: Google Earth 2014, 38°55ʹ02.44ʺN 77°13ʹ38.19ʺW, elevation 506 ft., Europa Technologies, Google. 13 October 2012).

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These pointed out traffic disruptions and traffic patterns change were the significant impacts on the mobility triggered by the project work zones. Other minor impacts on mobility were recognized, like the loss of parking stalls and maneuvering areas for some existing business facilities, in the properties of “Wendy’s” at Route 7/Route 123 interchange, and “Cherner Kia Izusu” at Route 7 and Spring Hill Rd. (Environmental Assessment 2006, Ch.3 Environmental Effects, P.3-5). Another crucial matter that was part of the work zones impacts assessment is the construction fleet management and coordination. In addition to material delivery trucks, the tunnel section in Tysons Corners required a considerable number of dump trucks on daily basis. Preliminary studies were conducted in order to identify the fleet routes (to/from the dumpsite), the fleet size and its anticipated impacts. The dumpsite was early determined near to Dulles International Airport. The fleet size was estimated as 50 trucks/day entering and exiting the dumpsite (Environmental Assessent 2006, Ch.3, P.3-32). This traffic volume needed to be delivered throughout Dulles Access Rd., Route 28 and Route 606 (see Figure 28) until it reaches the dumpsite. Therefore, appropriate traffic managemnt measures were necessary to mitigate the impacts of this added volume to the network.

Figure 28: Construction Dumpsite and Construction Fleet Route (source: Google Earth 2014, 38°57ʹ13.47ʺN 77°20ʹ13.72ʺW, elevation 371 ft., Google, Europa Technologies. 13 October 2012). 2) Traffic-related Impacts on Safety: The EIS generally emphasizes on the safety concerns triggered by the temporal roads/lanes closure and other traffic patterns changes due to the construction42. An example of such safety concerns is the one arises from the imposed changes in the

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Route7/Route 123 interchange, since the southbound traffic stream at Rout 7 weaving to Route 123 southbound need to make a very sharp turn (see Figure 26). Therefore, appropriate TTM (in this case would be TTC) measures needed to be implemented in order to mitigate the risk triggered by such sharp turn. 3) Traffic-related Impacts on Environment: The EIS highlights two main traffic-related impacts of Dulles Corridor Metrorail work zones on the environment. These two impacts, particularly air quality impacts are the construction trucks emissions and the aggravated vehicles’ emissions due to the expected traffic operational conditions (congestion, stop-and-go, acceleration and deceleration). 4) Traffic-related Impacts on Society: The EIS outlined the potential societal impacts that possibly would have been encountered from the traffic externalities (particularly noise emissions) triggered by the work zone traffic conditions, and imposed detours. Noteworthy here is that the EIS findings concluded to that there would not be remarkable impacts from these work zone traffic-related externalities influencing the neighborhood due to the indirect adjacency and the sufficient buffering distances (Final Environmental Impact Statement. Chapter 3, 3-39). At this point, the WZIA can come to a conclusion that the main work zone impacts is primarily linked in a way or another to the traffic operational conditions and the impacts on mobility. In the following section, the adopted TTM strategic plan will be extensively discussed and analyzed in light of the discussed work zone impacts and the mitigation recommendation from the EA and the EIS.

2.1.3

Temporary Traffic Managmenet Strategies

The main input for the TTM strategic planning is the WZIA that should be analyzed along with the baseline traffic volumes and traffic operational conditions within the implementation area. Daily traffic volumes estimates from Virginia Department of Transportation43 for the baseline yeari indicate to traffic volumes between 59,000 AADT along Route 7 (Leesburg Pike Rd.) and 30,000 AADT along Route 123 (Chain Bridge Rd.) within the work zones of Dulles Corridor Metrorail Project. The WZIA studies for Dulles project weren’t conducted individually, since it was a part of the environmental assessment (EA) and the environmental impact assessment (EIS), therefore, the mitigation recommendations concerning to the construction effects set forth in the final EIS were substantial input for the TTM strategic planning.

i

Baseline year is 2009, prior to the launching of the construction.

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A study about the transportation analysis of Dulles Corridor 44 reveals some facts concerning to the travel behavior for Tysons Center and along Dulles Corridor prior to the project. It indicates for Tysons Corner area work trips a high dependence on Single Occupancy Vehicle (SOV) (approximately 75%), whilst the High Occupancy Vehicle of two persons (HOV 2), High Occupancy Vehicle of three persons and more (HOV 3+) and the Public Transport (PuT) account for the remaining share. This modal split provides an initial understanding of the travel behavior and the traffic composition along the corridor, consequently the potential TTM strategies. Consistent with these findings, the project management plan, issued for construction in 2008 indicated that the main objective of the project TTM plan (TMP) was to manage the travel demand, so as to “reduce reliance on single-occupancy vehicle travel” and “decrease the amount of vehicular travel to and from the construction zone” (Project Management Plan 2008, P.85). In Dulles Corridor Metrorail Project, the TTM adopted strategies were refined, synthesized, coordinated and integrated in what is so called “Transportation Management Plan-TMP”. In reference to what was concluded in the literature review, the TMP for a major construction project necessarily comprises three main components (strategies); namely, the temporary traffic control (TTC), the transportation operation (TO) and the public information (PI). In some states, the TTC plans is referred to as maintenance of traffic (MOT) plans i, likewise the state of Virginia. Within the context of these three trends of TTM, all the construction-related traffic measures were regulated and engineered in a way that guarantees the safety of the workers and the road users, and maintain the streamlining of the traffic as much as possible. Construction related traffic measures are the procedures of closing partially or fully, shifting or modifying a part or a segment of the roadway due to the intended construction activities, or to keep safety buffering spaces for the construction crew. Although the three strategic trends of the TTM are meant to integrate in the comprehensive TTM plan, however, the TTC tends to address the impacts of the work zone on the local scale. In other words, the TTC strategies primarily concerns about the safety and the mobility of the workers and the road users locally within the extent of the work zone, as per discussed in the literature review. Whilst the TO and the PI strategic trends address the demand for commuting in order to mitigate the work zone impacts throughout minimizing the exposed travelers. As per aforementioned, for Dulles Corridor Project, the corner stone of the TMM plan was the travel demand management. This could be explained in terms of the remarkable reliance on the SOV in commuting along the corridor.

i

U.S Department of Transportation, Federal Highway Administration (2013). Transportation Management Plans (TMPs) for Work Zones. Available from:

[3 July 2014]

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On one hand, the adopted demand management strategies were issued and effected based on a research conducted in 2005 for 8 focus groups (Small Tysons businesses2 groups, Tysons Retail shoppers- 2 groups, Tysons Pass-Through Commuters- 2 groups and Tysons Destination Commuters- 2 groups), in addition to 1000+ Telephone Interview conducted in 200645. On another hand, the anticipated congestion triggers along the corridor were another decisive parameter for the TTM. Robey, C., McAllister, M., 2007 highlight the main influencing factors for the potential congestion along the corridor as following: Bottlenecks (40%), Traffic Incidents (25%) and Work Zones (20%). Therefore, the strategies were elaborated in a way that addresses demand management as well as the congestion influencing factors. Table 7 lists the TTM strategies deployed and exploited in Dulles Corridor Project 46, classified according to the U.S DOT and FHWA provision (Developing and Implementing Transportation Management Plans for Work Zones, P.4-2, and P.4-3). The TTM strategies stated in the table include the strategies explicitly mentioned in the TMP presented to Virginia Department of Transportation (Vigliotti, P., 2008), in addition to other TTM measures and strategies extrapolated from the project website, the traffic management plan, Preliminary Engineering EA and the Final EIS.

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CHAPTER 2: CASES ANALYSIS Table 7: TTM Strategies Adopted in Dulles Corridor Metrorail Project (source(s): Dulles Metrorail Transportation Management Plan, P. 14-16, Developing and Implementing Transportation Management Plans for Work Zones, P.4-2,4-3, PE Design Refinement Environmental Assessment, Ch.3, P.3-32, Dulles Corridor Metrorail Project Webpage) Temporary Traffic Control (TTC)

Public Information (PI)

Transportation Operation

Control Strategies

Traffic Control Devices

Project Coordination, Contracting and Innovative Construction

Public Awareness Strategies

Motorists Information Strategies

Demand Management Strategies

Corridor/ Network Management Strategies

Work Zone Safety Management Strategies

Traffic/ Incident Management and Enforcement Strategies

Construction Phasing (1, 2)

Temporary Signs

Coordination with other VDOT Mega Projects.

Public Outreach

Changeable Message Signs

Communication (Public and Employer Outreach)

Coordination with adjacent construction site(s)

“Move-It” signs

Safety service patrols.

Business Access Improvement

Channelizing Devices

Coordination with Other Local Agencies

Project Website

511 System

Increase Transit Services (PuT)

Temporary Traffic Signals

Ramp or Lane Closure/ relocation

Temporary Traffic Signals

D-B Contracting Approach

24 Hour Hotline

Smart Traffic Center

Van Pool/Car Pool

Tyson's Corner Circulator

Increase coordinated police presence

Surveillance cameras

Innovative Construction Methods

Coordination with Major Employers

Guaranteed Ride Home

Acceleration and Deceleration Lanes

(Route 7)

Work hour restriction for peak travel

Variable Work Hours

Detours

Compressed Work Week

pull-off areas

Tele-Working

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Smart Traffic Center


In reference to the adopted TTM strategies, it is noted that the Dulles Corridor Project TMP working group has introduced some distinctive strategies, particularly for the demand management and for the potential congestion management. In the following paragraphs, some of these adopted strategies that sound distinct for TTM will be tackled for much more understanding. 1) Pull-off areas. This strategy is recommended for highly recommended for highways or expressway (controlled or limited access highway) exposed to shoulder closure for long distances (> 0.5 mile = 0.8 Km) along the course of the road way (the case of Route 123, construction of Mclean Tysons East Station and Tysons Central 123 Station), and for a considerable duration (30 days or more)47. Pull-off areas strategy enables motorists who ought to for one reason or another to evacuate the roadway (crash, mechanical problem, law enforcement check or any other disruption), from finding a refuge within the work zone closed shoulder. This strategy primarily addresses major congestion influencing factor, which is the bottleneck (considered for 40% of the congestion factors), since the stopped vehicles within the course of the roadway is among the main triggers of the bottleneck. Virginia Department of Transportation VDOT identifies the required distance between two successive pull-off based on the length of the work zone activity area, for activity areas with lengths greater than 1 mile and less than 2 miles, the recommended distance between two successive pull-off areas is 0.5-0.75 mile, whilst for activity areas lengths greater than 2 miles, the recommended distance is 1 mile.

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Figure 29: Work Zone Pull-off Area (source: Virginia Department of Transportation VDOT 2011, Virginia Work Protection Manual- Standards and Guidelines for Temporary Traffic Control, P.6H-23) 2) Guaranteed ride home. The Guaranteed Ride Home (GRH) is a demand management approach that addresses directly the psychological motivation for using the SOV in commuting. Workbased commuters tend to rely on their owned SOV in order to have the freedom of determining their departure time, with no adherence to the PuT schedule or the unreliable service at late hours of the day. Work-oriented commuter, who rely on nonSOV travel modes in their work trips for certain times per week (one to three times a week) are offered an immediate cheap (sometimes free) guaranteed ride to home in case that they may need to leave work early for emergency, or for unexpected extra working hours. This GRH is valid for specific number of use per year. It is obvious that GRH strategy endeavor to manage the travel demand through diminishing the reliance on SOV commuting. Although the strategy may require much efforts in coordinating the different involved parties (employees, transit (PuT) agencies,

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taxi or car rental agencies), it seems to be promising according to findings from Benczer, W. (2006). The study states that despite the facts that there was no concrete estimation of the strategy influence on the commuter’s modal shift, the conducted survey reveals its public acceptance and tendency to influence the mode choice 48. 3) Variable work hours/ compressed work week. Variable work hours and compressed work week strategies are considered among the demand management strategies; particularly they are used for shifting the work-based travel demand outside the peak periods. Both strategies entail flexibility in work schedule49. The strategy of variable work hours can be understood as assigning different work shifts to the employees in order to avoid intersecting departure time with other working place within the implementation area. Compressed work week strategy aims at dividing the total week working hours by less working days, this would result in minimizing the daily work-based trips, and shifting the departure time beyond the evening peak. It is worth mentioning that the benefits of these two strategies are not limited to the mobility enhancement or demand management, yet extended to business performance boosting. 4) Tele-working. Teleworking is a form of performing work’s tasks from home, so that the need to commute to work could be reduced. For adopting such a strategy in order to manage the demand within an implementation area, consequently improve the network performance, the business structure of the area should be massively analyzed in order to investigate its capacity for this paradigm shift. Lister, K. and Harnish, T. (2011) revealed the potential of management, professional, services sales and office job families for working from home50. However, this strategy cannot be instantly introduced to an implementation area as a TTM strategy, rather it should have been integrated within the area transport policy, thereafter could be emphasized for TTM strategic planning and application. 5) Acceleration and Deceleration Lanes. This strategy was introduced as a specific measure for managing the effects of the construction fleet on one hand, and on the other hand to minimize the bottleneck effect, which was detected as a main trigger of congestion along Dulles corridro. The potential bottleneck phenomena here for the construction traffic is called “Moving” or “Active” bottleneck, where the congestion or the queue is observed within limited section of the roadway due to remarkable difference in the speeds51. This typically applies to the construction fleet, therefore this strategy was introduced along the proposed construction fleet route in order to provide the dump trucks with dedicated lanes enabling streamline deceleration and non-disruptive acceleration. Acceleration and Deceleration strategy has proved effectiveness not only for remedying the bottleneck

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(moving bottleneck), but even for enhancing the roadway capacity to accommodate more traffic volume (10%), like the case of “IH 394 Freeway, Minneapolis”52. 6) Move-it signs (Fender Bender) Regulatory signs were tackled in the “MUTCD” (section 2B.65, P.101); aim primarily at adjusting the driver behavior and mitigate the congestion during minor incidents. It takes the form of static signs conveying a message to the road users to “move their vehicles out of the roadway and onto the shoulders until enforcement officials arrive so as not to obstruct traffic lanes” (Cottrell, B. 2005, P,38)53.

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2.2 2.2.1

Case Analysis 2: London Crossrail Project Background

London Crossrail is considered as “Europe’s largest construction project”54 with total funds of 14.8 billion British Bounds. The project was adopted for enhancing the rail network capacity of London by 10%. The overview map of the project in relation to the existing London Underground Rail Network (see Figure 30) illustrates the concept of the design. The project aims at improving the level of service at the interchanges between the existing stations (40 stations connected) by means of minimizing the number of transfers. London Crossrail establishes an efficient link between London east, central and west in a way that integrates the already established stations with the new development vision.

Figure 30: Relation between London Crossrail and London Underground Network (source: Transitized 2014)55 The project centroid is located in Central London, identified by “Forbes” in 2005 among the World’s Most Economically Powerful Cities, and expected by 2020 to be Europe’s richest city56. The launching of the construction works was in May 2009 from Canary Wharf; “one of Europe’s major business districts (...) with a working population of approximately 65,000 people”57 indicates the economic value of the project for London. The total length of the project is 118 Km, including 23 Km of twin-bore tunnels

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considered as the major civil works of the project. Apart from the project tunnel works, the surface sections were recognized as: 1. Western section: operates between Paddington to Reading over Heathrow Airport via small tunnel section. 2. North-east section: operates between Stratford and Shenfield. 3. South-east section: the shortest surface section starts right after the Central Tunnel Sections ends at Woolwich to Abbey Wood. As per aforementioned, the project major works are located in the central section due to the underground tunnel works and the planned future stations, whilst the work zones in the other surface sections of the project involve expansion and renovating works for the existing rail lines and stations, considered non-significant from TTM perspective. Therefore, the traffic management challenges encountered in the central section seemed to be the significant due to the planned heavy construction and the nature of central London (socioeconomic structure). Figure 31 depicts the central section alignment and the tunneling work plan. The central section is planned to be in operation in 2018.

Figure 31: Central Section Tunnels Alignment (Proposed Work Plan for the Tunnel Boring Machine-TBM) (source: Crossrail.co.uk 2014). London Crossrail central section has 7 new planned stations; they are respectively from west to east: Paddington, Bond Street, Tottenham Court Road, Farringdon,

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Liverpool Street, Whitechapel and Canary Wharf (Isle of Dogs) station. Although the central section is primarily planned as underground construction and tunnel section, it encompasses surface access points and ventilation shafts in the very middle of central London. Besides the underground mined stations, the central section comprises two cut-and-cover stations (Paddington and Canary Wharf) and one surface station (the new Custom House Station)58. Therefore, major surface construction works and activities were expected and taken into account during the early planning and design stage, so that its impacts on mobility and safety could be effectively mitigated by means of TTM strategies. Another aspect has to be highlighted in this early stage of the project configuration is the project programming, since the work for the central section was planned to start simultaneously at several construction sites long the section, the aggregated effect of these work zones had to be considered and managed. Due to the discussed several factors of the works complexity and the sophisticated structure of central London, the central section would be an excellent case analysis from TTM perspective. Particularly the construction zone “C2- Paddington Station”, recommended by Mr. Greg Limna, Head of Logistics, Crossrail Ltd.59, as the best example to address the TTM strategic planning performed for Crossrail Project. In the next section, the construction method and the induced impacts of the construction zone (C2- Paddington Station) will be revealed and analyzed, therefore the adopted TMM plans could be linked to the impacts and help to better understand the UK practice of TTM for the case of major construction projects.

2.2.2


As per discussed before, the work zone impacts are fundamentally imposed by the construction methods and the socioeconomic characteristics of the implementation area. The Crossrail central section is characterized by two main elements; namely they are the tunnels and the stations. For the tunnels, the work has been divided into five segments (see Figure 31) assigned to 8 high technologized tunnel boring machines (TBM). As regards the stations, the newly planned stations are 7 stations, constructed by means of cut-and-cover or mining. However, for both methods of construction, surface works are involved. In addition to the local impacts entailed by the construction works, there are extended impacts triggered by the construction fleet. The “non-road transport” were promoted in removing the excavated soil (approximately 6 million tons), like using rail transport for removing the excavated soil along the section from Paddington until Whitechapel60. However, the material delivery trucks and demolishing/construction waste removal trucks besides the stations excavated soil removal trucks along the same route (Paddington to Whitechapel) were still critical issues that needed to be addressed decently. Specific lorry routes and holding areas were planned and decided at early stage of the project planning in order to assess the anticipated impacts, consequently consider it in the TTM planning.

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For the central section, the impacts on mobility, safety, environment and society were extensively tackled in the project Environmental Statement volume 8b. In this statement, the central section is divided into 13 construction zones, of each is assigned to coding system (C1:C13) in order to facilitate the impacts identification in light of the specific characteristics of each zone. The preliminary investigations outlined the anticipated impacts within the context of delays (for public and private transport), loss of parking spaces and general safety concerns. In this section, the construction zone at Paddington station, coded as (C2) will be extensively analyzed in terms of the impacts on mobility, safety, environment and society. The existing historical Paddington station date back to 19th century is a “central London railway terminus and London Underground Station complex served by four underground lines” (crossrail.co.uk). This historical station was identified as “English Heritage Grade A”, that refers to a highly prioritized historical building. Therefore, the Crossrail station at Paddington was designed as a newly separate box station, established by means of cut-and-cover technique, parallel to the existing station. The newly planned Crossrail station will be integrated with the existing station througout proposed entrances connecting the existing platforms with the planned Crossrail platform in order to minimize the transfer (interchange) time and improve the overall level of service. According to the Crossrail Environmental Statement, the construction zone C2 comprises besides the main worksite at Eastbourne Terrace, four worksites. Among these four worksites, there are three (Paddington Central worksite, Platform 1a worksite and Red Star Deck worksite) were planned to provide supplementary and supporting services (offices, storage … etc.) and were identified for no significant impacts. The construction activities along Eastbourne Terrace, between Bishop’s Bridge Rd. and Praed St. (see Figure 32), are considered the main triggers of Paddington Station work zone impacts. Aggravating impacts on the mobility and the traffic efficiency were expected from this worksite due to the adopted method of construction (cut-and-cover), besides the impacts from the excavated soil removing Lorries, estimated at 130 lorry trips/day for peak construction duration of 31 weeks Crossrail Environmental Statement, Volume 8b, Ch.3, P.7). The remaining worksite among the identified four worksites constituting the construction zone C2 is the Circle Line Linki worksite at the intersection between Praed St. and Spring St., where interchanging entrances were planned to integrate the new Crossrail line with the existing Underground Lines (Circle Line at Paddington).

i

Circle Line Link is an existing London Underground line that passes perpendicularly to

Paddington Station, and is planned to be integrated in Crossrail Paddington Station.

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Figure 32: Eastbourne Terrace Main Worksite (source: Google Earth 2014, 51°30ʹ58.88ʺN 0°10ʹ38.05ʺW, elevation 102 ft., Google, The GeoInformation Group. 19 July 2013). Prior to the planned works description and analysis of its impacts, it is necessary to reveal the strategic importance of the location on the local and regional scale. The worksite is surrounded by two London’s major roads (Transport for London Road Network- TLRNi) shown in green in Figure 33, in addition to another crucial road links in adjacency of the worksite, Bishop’s Bridge Road and Praed St., exposed to high levels of traffic. This crucial strategic location in north-west Central London, besides the massive intended construction works point out to what extent the work zone impacts could be significant.

i

Transport for London Road Network TLRN is a road network in the city of London, whereas the

stops are restricted as a part of congestion management plan for the city.

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Figure 33: Eastbourne Terrace Worksite Strategic Location (source: Paddington Bus Diversion Assessment) In light of the displayed spatial location and the strategic functionality of the implementation area (see Figure 32 and Figure 33 respectively), herein is highlighted the major traffic elements which are in conflict with the worksite. The worksite is in direct conflict with two signal groups of signalized intersections (see Figure 34). The signal groups coding numbers and the signal heads numbers were maintained the same as the “Traffic Modeling Review”61 in order to facilitate the results tracking.

Figure 34: Implementation Area Signal Groups of Controlled Intersections (source: Traffic Modeling Review- Transport Consultant Brief).

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The main works at Eastbourne Terrace, besides the twin bored tunnels, comprise the construction of the new Crossrail Station including two new northern and southern ticket halls and two ventilation shafts. “The Crossrail Paddington Station will take the form of an underground box measuring 260m long, 25m wide and 23m deep, and located directly under Departures Road and Eastbourne Terrace” (crossrail.co.uk 2014). The station box structurally comprises four main elements; northern and southern diaphragm walls (approximately 25 m) and the western and eastern long diaphragm walls (approximately 260 m), in addition to intermediate supporting columns that were designed to be erected in the middle of the short span parallel to the long diaphragm walls. The description of the structural elements of the station is necessary to understand the proposed methods of construction, since it (the method of construction) had the major influence on the traffic flow and it was the key issue of the TTM. The initially proposed method of construction was to execute the works in a sequence that avoids the full closure of Eastbourne Terrace. The Crossrail Environmental Statement (2005) Volume 262, and Paddington Station and Environs, London W2Planning Brief63 describe the initial method of construction in the following sequence:  First to establish the northern and southern diaphragms walls.  Second to establish the western diaphragm wall and the intermediate supporting columns (whilst the traffic is shifted to the eastern side of the roadway), so that half of the span of the at-street-level slab could be structurally supported and constructed on the diaphragm wall and the intermediate columns.  The traffic can be shifted to the executed part of the station’s box, in order to establish the eastern diaphragm wall, consequently the remaining part of the slab span.  After the completion of the station’s box construction, the excavation works shall proceed until it reaches to the foundation level beneath the twin bored tunnels in order to construct two storeys at the concourse level and at the platform level. Figure 35 shows a cross-sectional view throughout the long diaphragm walls (western and eastern walls), and the intermediate supporting columns, the figure illustrates as well the excavation works methodology for the worksite. The latest stage of the construction involves the establishment of the subway from Crossrail box station to the existing Circle Line platform at Paddington (worksite number 4 in the construction zone C2), this subway was planned to be established by means of cut-and-cover along Praed St., which would necessitate the partial closure of the street for 6 to 8 monthsi.

i

Crossrail Supplementary Environmental Statement 2 (2006), Ch.3, P.19. Available from:

[23 July 2014]

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Figure 35: Cross-sectional View of Crossrail Paddington Station- Excavation Works Proceedings (source: Crossrail Information Sheet July 2013i) This preliminary designed construction method had undergone major changes due to the escalation of “number of concerns” (City of Wetminister 2011)64 regarding the safety of the road users and the construction workers; these major changes imposed the full closure of Eastbourne Terrace (and Departure Road) for two years, except for the section between Bishop’s Bridge and Cleveland Terrace. The adopted full closure would allow constructing both of the diaphragm walls at the same time; this in turn would certainly minimize the construction duration and its associated impacts. Therefore, upon the completion of the activities at the western perimeter, it was possible to open one lane in February 2014. In light of this changed construction method, it is noteworthy to point out that the UK practice of TTM strategic planning conduct another approach for the TTM risk assessment rather than the U.S practice, as per discussed in an earlier stage of the thesis (see Development Process of Temporary Traffic Management Plans , ‎1.2.2).

i

Crossrail.co.uk 2014, Crossrail Paddington station main excavation works. Available from:

[19 October 2014]

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The risk assessment in the UK practice functions as an independent refining tool that is taken into effect upon the completion of the preliminary design/method of construction and prior to the final issuance of the design brief and its appendices (TTM plan). In other words, whilst the risk assessment is an integrated measure in the process of TTM development according to the US practice, it is an iterative measure used for the work zone impacts identification and assessment in the UK practice. This approach is clearly illustrated in the case of the Crossrail project. In the following few paragraphs, the work zone impacts will be briefly described in light of the finally adopted method of construction, so that the TTM plans and strategies elaborated by Crossrail Company, City of Westminister and other planning bodies could be understood within the context of the adopted construction method. The major impacts of the finally adopted method of construction are incurred by Eastbourne Terrace as well as the parallel Departures Road (see Figure 36), since they are considered as important transport hub in Central London (Planning Brief of Paddington station and Environs, P.6). Eastbourne Terrace is a dual “public highway” carrying around 1000 vehicles per hour (VPH) at peak, considering the baseline condition, whilst Departures Road is a two lane road giving access for taxis and private cars to Paddington’s existing station (Crossrail Environmental Statement, Volume 8b, Ch.3, P.3.) carrying around 500 VPH at peak.

Figure 36: Departure Rd. Taxi Rank, Along With Eastbourne Terrace- Baseline Condition (source: Google Earth 2014, 51°31ʹ03.59ʺN 0°10ʹ46.88ʺW, elevation 115 ft., Google, GeoBasis-DE/BLG).

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These traffic volumes (1000 + 500 VPH) can explain the public concerns of the “rat runs”i (Executive Summary and Recommendations 2011, P.9) and its consequences on safety and traffic capacity in the case of the full closure and traffic diversion. These concerns were raised in the undertaken neighborhood consultations during the TTM strategic planning stage. This approach of public participation illuminates the UK practice in TTM strategic planning concerning to measuring the public acceptance and assessing the TTM alternatives in terms of social inclusion. Coming back to the WZIA, particularly the baseline condition analysis, these peak traffic volumes, besides the pedestrian phase (in the signal program) lead into approximately full capacity utilization at the peak periods of the intersection no. 127 between Eastbourne Terrace (and Departures Road), Praed St., Spring St. and Craven Road (see Figure 34). For the baseline condition, there were parking stalls provision along Eastbourne Terrace (on-street parking), 200 NCPii parking at the end of platform 1 and motorcycles parking between platform 10 and 11. For the on-street parking, it was eliminated during the construction, and regarding to the other parking facilities, there were some expected deterioration in the accessibility, that needed to be addressed in the TTM. The functionality for mobility of Eastbourne Terrace is not limited to private transport (PrT) (including taxis) traffic streams; yet the roadway was used to accommodate several bus lines’ stops and stands, therefore the TTM strategic planning needed to consider not only the detour of the vehicular streams and the relocation of the taxi rank, yet the relocation of the bus stops and stands. Considerable pedestrian streams were recognized during the impacts assessment, particularly at the pedestrian access to the station from Departures Road and at the intersection. As regards the other work zone impacts concerning to the society, they are, as per aforementioned crucially related to the socioeconomic structure of the implementation area. The worksite lies in a major development location. The predominant land use is for residential units and small businesses (shops, restaurants and hotels). As a part and a parcel of the impacts on the society, the sensitive activities within the implementation area were identified in the planning brief of Paddington station in order to provide safe TTM measures for these activities. These sensitive activities included besides the residential units, St Mary Hospital and Medical School at Praed St., London Pharmacy Education and Training at 50 Eastbourne Terrace, Paddington Fire Station at Harrow Road and North Westminster Community School. These locations were identified as sensitive due to the nature of commuting groups (patients or pupils), or the nature of the produced trips (emergency vehicles or fire trucks).

i

Rat Runs is the phenomenon of vehicular traffic streams to use residential or local roads.

ii

National Car Park. Available from:

[23 July 2014]

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Finally, traffic-related environmental impacts triggered by the work zone traffic diversion and construction fleet were limited to the associated noise, dust and vehicles emissions due to traffic diversion into calm area. In light of the previously picked out highlights, the planning brief of Paddington station summarizes the initially anticipated work zone impacts triggered by the proposed works at the main Eastbourne worksite and Praed St. as following:  The full closure of Eastbourne Terrace (Impacts on mobility).  Closure of Chilworth St. for through traffic.  Relocation of the bus stops and stands along Eastbourne Terrace (Impacts on mobility and society; noise and anti-social behavior).  Relocation of the taxi rank in Departures Road (Impacts on mobility).  Diversion of the vehicular streams, bus routes and other SM streams (Impacts on mobility and society).  Reduction in the roadway of Praed St. (Impacts on mobility).  Impacts on mobility, safety, society and environment from the construction fleet.  Impacts (on society) on the existing sensitive activities within the worksite (hospitals and schools).  Loss of parking stalls along Eastbourne Terrace. The mitigation measures and TTM strategies concerning to these anticipated impacts will be described and analyzed in the TTM Strategies section in order to comprehensively perceive the UK practice of TTM for a major construction project like the Crossrail, in a highly urbanized area with sensitive facilities.

2.2.3

Temporary Traffic Management Strategies

The TTM plans of Crossrail Paddington Station main worksite at Eastbourne Terrace underwent several stages of elaboration and refinement until it was finally issued for implementation. These several stages could be similar in practice to what is so called strategic planning. The TTM general framework of the Crossrail was conceived in the information papers “D06 Construction Traffic”, “D19 Highway and Traffic during Construction” and “D20 Traffic Management during Construction” i. These three guiding references clarify the methodology of identifying the potential impacts that may be triggered by the construction fleet or the worksites, and briefly describe the appropriate actions and TTM strategies that should be adopted in response. Further stage of TTM plans development was the recommended mitigation measures set forth in the Crossrail Environmental Assessment (ES) and its supplementary, for example the proposed relocation of the taxi rank at Departures Road, or the proposed

i

Crossrail Information Papers. Available from:

[26 July 2014]

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diversion of the bus routes to Westbourne Terrace. These initial recommendations were subjected to further analysis and assessment based on their technical constructability, and the public acceptance with respect to their traffic-related social and environmental impacts. This assessment was addressed extensively in the Transport Assessment (TA) submitted by the Crossrail traffic Consultant (Mott MacDonaldi) to the City Council of Westminster. In this TA, the main structure of the TTM plans concerning to the main issue of the Paddington Crossrail Station worksite (the full closure of Eastbourne Terrace and its consequences) was addressed, analyzed and designed. One eminent procedure in the development of TTM plans and strategies of Paddington Crossrail Station was the public participation. The stakeholders were included in the elaboration process by means of neighborhood consultations in order to highlight their main concerns and comments regarding the proposed TTM measures. Finally, the proposed TTM plans and strategies, TA and the concerns and comments raised by the stakeholders were assigned to an independent consultant (Arupii) (Executive Summary and Recommendations, P.9) in order to validate the TA prepared by the Crossrail traffic Consultant, and advise for further mitigation measures or recommendations. Figure 37 summarizes the development process of TTM plans for Crossrail Paddington Station and indicates to the changed method of construction due to risk assessment results. In this section, the thesis will focus on the methodology adopted by both consultants for elaborating and validating the TTM plans and strategies. Furthermore, the utilized assessment criteria for the TTM alternatives and the recommended mitigation measures will be revealed and highlighted, hence the UK approach for TTM can be better understood out of the real practice.

i

[19 October 2014]

ii

[19 October 2014]

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Figure 37: Development Process of TTM Plans for Crossrail Paddington Station. The TTM plans of Crossrail Paddington Station worksite at Eastbourne Terrace primarily had to verify that the full closure of Eastbourne Terrace and Departure’s Road would not impose intolerable operational conditions or severe impacts on the surrounding environment and society. Upon the recognition of the necessity to fully close Eastbourne Terrace, a traffic model of the implementation area was established in order to compare between three different scenarios; the baseline scenario, the partial closure scenario and the full closure scenario 65. This model was prepared by the Crossrail traffic consultant and reviewed by an independent consultant in order to check its validity. At first, the cycle time, intergreen times and the method of control (actuated or pretimed) for each signalized intersection was “reviewed and optimised” (Perret, P., et al. 2011, P.51) for each traffic scenario. As regards the operational condition of the network road links, “the mean maximum queue- MMQ” “the degree of saturation” and the “delay” (Perret, P., et al. 2011, P.21) were computed for each scenario as well as for the baseline condition. Indeed, these traffic measures were useful for two reasons, first is to assess each TTM alternative comparatively with the baseline condition, and the second reason is to check the capacity performance of the road links for each scenario after considering the diverted traffic volumes due to the closure (full or partial). Therefore, indicators like the saturation level (volume-to-capacity ratio) and the queue

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lengths were necessary to obtain for such assessment, whilst the delays per each passenger car unit (PCU) represent a crucial indication of the impacts on the motorists (RUC) for the proposed scenarios in relation to the baseline situation. Finally, the mobility performance statistics (total distance travelled- , total time spent and mean journey speed) of all the observed network links were summarized for the three scenarios. Besides these traffic-related performance indicators, an interesting cost-effectiveness assessment tool was utilized; namely, the performance index (PI) that was integrated in the modeling software and calculated based on thess summarized mobility performance statistics, so that the monetized cost of congestion for each scenario can be obtained. As could be readily observed from the results demonstrated in Figure 38, the inevitable congestion cost of the partial and full closure proposals have no remarkable differences. 2000 1800 1600

1400 1200 Performance 1000 Index (£/hr) 800

AM Peak PM Peak

600 400 200 0 Baseline

Partial Closure

Full Closure

Figure 38: Performance Index (PI) of the Network Links for each Scenario (source: Perret, P., et al. 2011) Another assessment criterion that had a crucial role in the TTM strategic planning is the time factor. The time factor has been interpreted here into two terms, one the exposure time of each scenario and the other is the impact of each scenario on the construction time. The exposure time is an indication to the aggregated incurred cost (congestion cost, social cost …etc.) due to introducing a specific TTM measure or strategy for a certain time period. As regards the second term, which is the impact on the construction time, it can be better understood out of the Crossrail Paddington Station case, where the TTM strategy of Eastbourne Terrace full closure could compact the construction time by two years. Indeed, these two assessment criterion are correlated, since the prolonged construction duration would necessarily add extra cost, besides the construction cost itself. On this basis of assessment criteria, the full closure

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scenario was identified as preferable, and its impacts were identified as manageable. Similar findings concerning to the preferred alternative were concluded to in the model validation performed by the second traffic consultant (Arup). In order for the TTM Plans of Crossrail Paddington Station to manage the full closure of Eastbourne Terrace for two years, three main tasks needed to be undertaken; the diversion of the mixed traffic streams (primarily the bus routes), the relocation of the taxi rank and the relocation of bus stops and stands existed along Eastbourne Terrace. For each tasks, a number of concerns and limitations were present and had to be tackled decently. Each task was addressed in the TTM plans in a sequence that minimizes the traffic flow disruptions, maximizes the safety of the road users and the workers and triggers the least social cost of noise and traffic emissions. Of course there were inevitable impacts or unfavorable operational conditions, therefore appropriate TTM strategies and mitigation measures were developed and synthesized. The TTM strategies of the full closure were illustrated in the mechanism imposed by the regulating authority in order to mitigate the anticipated impacts and respond to the concerns raised in the neighborhood consultations. This mechanism contained in the “Executive summary and Recommendations- City of Westminster” can be summarized as follows:  Adopting multi-tiered coordination with Transport for London, City Council of Westminster and other planning and regulatory agencies via forming planning and coordinating groups on different scales in order to mitigate and diminish the cumulative impacts of several worksites in the vicinity of the implementation area (forming groups and holding regular meetings).  Elaborating Comprehensive TTM strategic plans that address the local impacts of Eastbourne closure and consider as well the concerns raised by the businesses and the stakeholders in the implementation area.  Implementing appropriate TTM measure for pedestrians at the intersection between Eastbourne Terrace and Praed St. (intersection no. 127) in order to provide safe and adequate walkway for this prolonged walking route due to the closure of the pedestrian access at Eastbourne Terrace/ Departure’s Road (see Figure 39) and the relocation of the bus stop.  Establishing an effective monitoring system that utilizes the “Environmental Minimum Requirements- EMR”i in order to maintain the operational condition during the closure at acceptable environmental and social levels, particularly the noise and other traffic emissions shall be within the allowed limits.

i

Environmental Minimum Requirements- EMR is the provision that determines the allowed

thresholds during the Crossrail construction, regarding to the environment and the heritage. Available from: [19 October 2014]

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Figure 39: Eastbourne Terrace Worksite during Construction (source: Crossrail.co.uk 2014) As regards the mitigation measures; Perret, P., et al. 2011 briefly stated the TTM measures that were introduced to the TTM alternatives in order to mitigate the impacts. These impacts will be grouped hereinafter according to literature review debriefing. This grouping of the TTM measures adopted in Crossrail is made in order to get more acquaintance to the commonalities between the UK TTM practice, extrapolated from the Crossrail, and the U.S. practice that primarily constituted the literature review. Table 8 demonstrates the grouped TTM mitigation measures, recommended in the traffic modeling report prepared by the first consultant. It is worth highlighting here that the TTM measures and strategies of a major construction project have the same trends, even if the terminology is different. In other words, a rigorous TTM plan of a major construction project should address the impacts of the work zone on the local level (TTC), on the corridor or network level (TO) and on the state level (PI), which is clear here in Crossrail project. Table 8: TTM Mitigation Measures Proposed for Eastbourne Terrace Full Closure Scenario (source: Perret, P., et al. 2011, P.9) TTC Measures

TO Measures

PI Measures

“Banning/permitting certain movements for certain vehicles”

“Making modifications to traffic signals”

“Provision of statuary notices of road closure in the Paddington and surrounding areas”

“Lane markings” “Kerb realignment” “Relocating stop line”-at intersection.

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Subsequent to identifying the measures of managing the full closure of Eastbourne Terrace, the TTM three sub-tasks had to be addresses. The first task was the relocation of the taxi rank existed at Departure’s Road. In the Crossrail ES, it was recommended to relocate the taxi rank at Red Star Deck since the early worksite impacts assessment conducted in Crossrail ES 2005. Indeed this was the most feasible location since the taxi rank has to be adjacent to the station in order to serve the passenger on one hand, and on the other hand to refrain from allocating additional taxis traffic to the heavily trafficked Praed St. and the surrounding residential roads south of the station, according to Westminster City Council objectivesi. Since this proposal concerning to the taxis rank relocation was made in 2005, several impact studies and modelled scenarios were conducted in order to provide optimized operational conditions at the intersection between the proposed taxi rank at Red Star Deck and Bishop’s Bridge Road. “Red Star Taxi Deck Traffic Modelling Report” 66 demonstrates the proposed two scenarios of managing the traffic pattern at the intersection between the proposed taxi rank and Bishop’s Bridge Road (see Figure 40). First scenario was to assign the two exit lanes at Bishop’s Bridge Road for right turning only, whilst the second scenario was to assign on exit lane for each direction. The first scenario was found to impose extra detour on the motorists share heading towards westbound direction. Based on the monitored intersection between Departure’s Road and Praed St. for the existed taxi rank, the second scenario was preferred since the turning tendency was found inclined towards the left direction. At the same time, some adjustment in the turning behavior was expected in reality due to the eastbound (right turn) operation. Therefore, the second scenario allowing both turnings was adopted.

i

Westminster City Council identified the key development issues in Paddington Station and

Environs, London W2- Planning Brief, P.8.

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Figure 40: Proposed Operating Scenarios for the Relocated Taxi Rank at Red Star Deck- (source: Google Earth 2014, 51°31ʹ07.37ʺN 0°10ʹ44.11ʺW, elevation 96 ft., Google, The GeoInformation Group, Europa Technologies. 19 July 2013) Coming to the second major task that was supposed to be performed by the TTM plans of Crossrail Paddington station, which was to divert the existing bus routes and relocate the bus stops. Eastbourne Terrace used to accommodate 9 routes at baseline condition; of which, five lines were operating for 24 hours67. Two bus stops at Eastbourne Terrace-Paddington Station and Eastbourne Terrace-Cleveland Terrace were existed in addition to one bus stand at Cleveland Terrace (see Figure 41). This resulted in bus traffic of 77 buses per hour during weak days operating along Eastbourne Terrace. Hence, there was a need to relocate these two bus stops and their corresponding bus routes (6 bus lines), and the bus stand and its corresponding terminating bus lines (three bus lines), in order to enable the full closure of Eastbourne Terrace.

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Figure 41: Existing Bus Stops and Stand along Eastbourne Terrace (source: Google Earth 2014, 51°30ʹ59.87ʺN 0°10ʹ37.99ʺW, elevation 103 ft., Google, The GeoInformation Group. 19 July 2013) The main objective of this particular section of the thesis is to address the lessons learnt from the methodology adopted in Crossrail Paddington station to divert the bus routes and to relocate the existed bus stops and stand. After the comprehensive analysis of the bus routes network in Paddington area conducted in “Paddington Bus Diversion Assessment” report, shifting the routes along with the two bus stops to Westbourne Terrace was the most feasible solution. Nevertheless, the TTM plan still needed only to introduce a new buses routes plan that seamlessly integrates the diverted routes and the relocated stops within the buses routes overall plan of Paddington area. This integration should be performed in a way that achieves the most favorable operational conditions and minimize the traffic impacts and the other impacts on the society and environment. Within this context, 6 options were prepared, so that the most appropriate option could be selected based on assessment criteria configured in light of the aforementioned TTM main assessment criteria (mobility, safety and minimized social and environmental cost). The assessment criteria used for “Paddington Bus Diversion Assessment” are categorized as follows (see Table 9), in order to identify them within the context of the assessment criteria scheme elaborated in the literature review.

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Table 9: Assessment Criteria for Bus Diversion Options (Derived from: Paddington Bus Diversion Assessment, P.24) Mobility

Safety

Environment

Society

Increase in bus journey time.

Impact on cyclists.

Additional distance travelled by buses.

Impact on bus passengers.

Bus stop removal.

Impact on pedestrians.

Walking distance from bus to station.

Impact on the road network.

Additional bus stop required.

Change to signal control.

Impact on the local residents.

Infrastructure changes.

Impact on loading.

Changes in traffic regulations. Opposed right turns. Impact on parking.

Each assessment criteria for each bus diversion option was calibrated on either quantitative or qualitative scale and allocated to another descriptive scale: good (green), moderate (amber) and poor (red), which is so called “RAG Assessment” (Skupinska, E., et al. 2011, P.23). Each category on this “RAG” scale is assigned to certain number of points (Red= 0 points, Amber= 3 points and Green= 5 points), so that the assessment criteria points could be aggregated for each diversion option in order to identify the most appropriate one. After completing this assessment of diversion options, the preferred option underwent to further impacts assessment in order to recognize the potential triggered impacts and introduce mitigation measures for it in the TTM plans. Indeed, this sequence is typically consistent with the pointed out TTM strategic planning depicted in Figure 37. The option referred to as “the preferred option” was option no.6, “identified as the most advantageous with least operational complexity, least additional travel time for passengers and shortest additional diversion distance for the buses” (Skupinska, E. et al. 2011, P.26). The impacts assessment performed for the preferred option utilized similar criteria to the ones used in the diversion options assessment. It was concluded that the preferred option’s impacts on the bus schedule, journey time and safety, predominantly were not significant. As regards the impacts that were found remarkable, they were the ones on the local residents and on parking and loading facilities. These highlighted impacts were recommended to be mitigated by means of the proposed “Route Management Strategy”, which will be described and analyzed in the last section of this cases analysis due to its prime function and distinct role. Here, the thesis comes to address the last major task performed by the TTM plans of Crossrail Paddington station, which is to relocate the bus stand along with the three terminating bus routes. The bus stands should be distinguished from the bus stop due

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to its different operating characteristics, consequently the anticipated impacts. Bus stand functions as a depot for the terminating bus lines to park for relatively longer waiting times, moreover, the required length is greater since it needs to accommodate three buses at some specific periods. Besides the facility dimensions which have a direct impact on the visual quality, other concerns were recognized during the neighborhood consultations regarding “noise and anti-social behavior from bus stand activity” (Skupinska, E. et al. 2011, P.30). These factors of the dimensions, the impacts on the visual quality and local residents were taken into consideration whilst introducing the potential locations for the stand and the diverted routes of the terminating routes as well. 17 proposals for the bus stand were made in light of the above revealed influencing factors. Again, a number of assessment criteria were utilized in order to evaluate the proposed locations. It is worth mentioning here that the assessment criteria for the proposed locations of the bus stand were made up to minimize the impacts on the surrounding neighborhood, even if it is on the expense of the trip time, on the contrary from the case of the bus routes diversion where the trip time factor was prioritized. Assessment criteria addressing the impact on the residents, impacts on parking and loading, impacts on non-motorized road users and the available space were utilized to evaluate the proposed locations by the same methodology of “RAG Assessment”. Three different locations were selected to accommodate each terminating bus route individually. This indeed mitigated massively the potential impacts that would be associated with one location combining the three routes together. Nevertheless, the preferred options for the bus stand locations were subjected to further impacts assessment as per constituted under the Crossrail Paddington station TTM strategic planning. The investigated further assessment criteria concluded to the same observation of no significant impact on buses operation, local road network, or the road safety. Although there were some lost parking spaces, they were not expected to impact the parking demand within the area. At this point, Paddington station main worksite TTM tasks relevant to the full closure of Eastbourne Terrace were revealed, highlighted and analyzed. Furthermore, the individual classic TTM measures (TTC, TO and PI) were revealed. However, there is still the “Route Management Strategy” yet have not been discussed. “Traffic DiversionRoute Management Strategy” was introduced as a comprehensive TTM strategy in order to address the significant impacts that were found pertaining to the full closure of Eastbourne Terrace, and its consequences (buses routes diversion and buses stops and bus stand relocation. “Traffic Diversion- Route Management Strategy”68 This document entitled “Route Management Strategy”, to which was referred to as a TTM comprehensive mitigation strategy, adopted upon the decision was made regarding the full closure of Eastbourne Terrace. In this document, which was called as

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“Live”, all the TTM measures that would mitigate the full closure and diversion impacts, particularly on the local residents and the parking and loading facilities, were synthesized in order to form a kind of management framework. The route management strategy primarily sets the actions for intervention in case of exceptional operational conditions. These exceptional conditions include unexpected congestion or queue length beyond the capacity, deviation from the TTM objectives (efficient traffic flow, enhances safety, minimized social cost), as well as the impacts of planned events (sport events or festivals). In order to enhance the efficiency of the route management strategy, a public outreach campaign has been launched in order to get the stakeholders, road users and PuT passengers acquainted with the planned activities. This campaign included emails, flyers, information on the website and on bus announcements. One crucial issue was addressed in the route management strategy is the incident management; “Route Management for Emergencies and Events” (Selema, I. et al 2011, P.12). For incident or planned events during the construction period, a short term road/lane closure may be required; hence the strategy provides the actions and measures that would minimize the impacts of such events. The route management strategy provides traffic management solutions for each individual possible closure of road links considered major within the implementation area. Moreover, the route management strategy determines the monitoring strategies to detect such conditions, as weel as the contact persons for receiving notifications and the enforcement strategies. Concerning to the monitoring strategies, they vary from internal monitoring systems managed by the bus service provider, to the level of “strategic traffic monitoring” managed by “London Streets Traffic Control Centre and the Metropolitan Police Traffic Operation Control Centre” (Selema, I. et al 2011, P.20). This highlights the crucial role of traffic management center (TMC) as an efficient TTM tool, as per revealed before in the literature review. As concerns the enforcement, the strategy introduced “on-street enforcement” as well as deployed CCTV for controlling, particularly at the “yellow box junctions”, where the entering is restricted unless the exit is clear in order to avoid gridlocks (see Figure 42).

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Figure 42: Yellow Box Junction (source: gov.uk 2014)69 Upon the issuance of this route management strategy, then the full component of the area TTM plan was completed, including all the strategies and measures that were found effective to mitigate the anticipated impacts. However, it is worth mentioning here before concluding the case analysis that the impacts from the construction fleet were minimzed by means of restricting the soil removal trucks to specific working hours, outside the peak hours. This is actually was between “6pm to 4am Monday to Friday and between 8am to 1pm on Saturdays” (crossrail.co.uk 2014).

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2.3 2.3.1

Case Analysis 3: Stuttgart 21 Project Background

Stuttgart City is the capital of Baden Wuertemberg state in Germany, characterized by major economic and industrial activities, particularly in the field of high technology and automotive industry. Besides its leading contributing role to the state and the nation economy, Stuttgart is considered as “one of Europe’s innovation hubs” (Zeiner, H. 2012)70. On this basis of leading economic activities and densely populated capital area, mobility and transport became a major issue in the city. This early finding would explain the close relation between the city socioeconomic structure, the planned project Stuttgart 21 and later on the TTM corresponding issues. Stuttgart 21 is another urban development project, primarily aiming at improving the trains movement and connection, not only on the local or the national level, yet on the regional (European) level. The project has been identified amongst “largest urban renewal projects” in Germany as well as Europe (Ward, J. 2010)71. The project significance could be recognized from three main parameters; the massive estimated cost of implementation (approximately 6.5 Billion Euros), the remarkable duration of realization (approximately 11 years) and the project influence on the local and regional level. On one hand, Stuttgart 21 derives its significance on the national level from the fact that the project encompasses the link Stuttgart-Wendlingen, which is the crucial component of the project “Stuttgart-Augsburg Line” proposed in the (Federal Transport Infrastructure Plan 2003)72. On the other hand, the regional significance of the project comes out of the crucial role assumed by Stuttgart-Ulm link in the proposed high speed train axis “Paris–Strasbourg–Stuttgart–Vienna–Bratislava”73. The existing main train station in Stuttgart is above-ground terminus station, with 17 tracks. Terminus stations do not allow trains through traffic, therefore the train movement from east to west and vice versa has to undertake a certain maneuvering at Stuttgart main station (see Figure 43). This maneuvering necessarily triggers extra trip time and occupied land that could be reclaimed if the terminus station turned into through station. This leads to the project conceptual design, since the newly planned system is primarily based on an underground through main station, equipped with 8 tracks only74. This design concept will allow the trains to run directly through the station with no need for any kind of maneuvering, which will minimize the trip time and intensify the station capacity. In addition to the anticipated reformed station operational conditions, the reclaimed space occupied by the existing station is planned for an extensive urban development.

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Figure 43: Existing Trains Maneuvering at Stuttgart Main Station (source: Google Earth 2014, 48°47ʹ52.83ʺN 9°12ʹ20.19ʺW, elevation 754 ft., 2009 GeoBasisDE/BKG, Google, Europa Technologies. 16 September 2012). The project comprises 6 main construction zones. The planned works (total 57 Km in length) in these zones comprises tunneling (33 Km), rail tracks upgrading or extension, new planned stations at the Airport, Mittnach St. (Stadtquartier Rosentein), siding (passing tracks) at Untertuerkheim, besides the major works of the main station in construction zone PFA 1.1i (see Figure 44). Following the same approach adopted in the cases analysis, one construction zone should be picked out and analyzed, so that the predominant trend adopted for TTM could be revealed and highlighted. For Stuttgart 21, the main station worksite was found to be ideal to perform this task due to several factors, on top of them the extremely critical location of the worksite in the city center of Stuttgart and the kind of heavy and remarkable civil works involved.

i

PFA: Planfeststellungsabschnitt: Zoning Section (Construction Zone)

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Figure 44: Stuttgart 21 Construction Zones Overview (source: Bahnprojekt-Stuttgart-Ulm.de 2014).     

Neubaustrecke: New Line. Neubaustrecke, Tunnel: New Line in Tunnel. Bestandsstrecke: Existing Line. Bestandsstrecke, Tunnel: Existing Line in Tunnel. Neubaustrecke Wendlingen-Ulm: New Planned Line Wendlingen-Ulm.  Neubau Stadtbahn im Tunnel: New Planned Light Rail in Tunnel.

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 Fern-/Regionalbahnhof, Bestand: Existing (Rural/ Regional Train) Station.  Fern-/Regionalbahnhof, Neubau: New Planned (Rural/ Regional Train) Station.  S-Bahn-Station, Neubau: New Planned Sub-urban Rail Station.  Eisenbahnbrücke: Railway Bridge.  Straßenbrücke: Road Bridge.

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Figure 45 demonstrates the spatial location and extents of the main construction zone of the new planned main station. The construction zone has been sub-divided into 8 construction phases in order to mitigate the anticipated impacts on this critical part of Stuttgart road network. Among these 8 phases, there are specific worksites that have the direct conflict with the major links (Willy Brandt St., Heilbronner St. - Türlen St. and Schiller St.). In the following section of the work zone impacts, these worksites will be highlighted and analyzed in terms of their anticipated impacts and on basis of the adopted method of construction, as per conducted in the previous cases analysis.

Figure 45: Main Construction Zone PFA 1.1 at the Main Station of Stuttgart (source: Bahnprojekt-Stuttgart-Ulm.de 2014).

2.3.2


In reference to the layout of the main construction zone PFA 1.1 shown in Figure 45, the main work zone impacts are incurred by Willy Brandt St., Heilbronner St. - Türlen St. and Schiller St. This particular fraction of Stuttgart road network is exposed to daily traffic of approximately 60,000 PCU/day75. Indeed, the state of traffic in Stuttgart City prior to the launching of the construction works was at the stake. The inevitable construction method of cut-and-cover was expected to breed unfavorable operational conditions that may be intolerable at some points, since this construction method is usually associated with partial or full road closure. The spots that were found to be severely exposed to impacts triggered by the planned works can be summarized as follows:  Worksite at Jäger St.  Worksite at Heilbronner St. - Türlen St.  Worksite at Kurt Georg Kiesinger Platz.

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 Worksite at Schiller St. and Gebhard Müller Platz.  Worksite at Willy Brandt St. A brief description of the planned works and the method of construction for each worksite will be provided in this section, prior to highlighting the adopted TTM strategies in the following section. Figure 46 depicts the general layout of the new main station and its auxiliary tunnels in relation to the three road network links (Willy Brandt St., Heilbronner St. - Türlen St. and Schiller St.). The works encompasses three milestones; the northern tunnel head, the southern tunnel head and the train tunnelsmain station concourse. In addition to these works, directly related to the new development (Stuttgart 21), there is another modification was to be introduced to the light rail system infrastructure (shown in light blue color) at the area of implementation due to levels conflict. This modification extends the work zone impacts to the extension of Heilbronner St. at Türlen St. and to Willy Brandt St.–Schillerstr- Gebhard Müller Platz (see Figure 47). Moreover, this will necessitate the relocation of the light rail station (Staatsgalerie).

Figure 46: Planned Works Layout of Stuttgart New Main Station (source: BahnprojektStuttgart-Ulm.de 2014).  DB- Tunnel Nordkopf: German Railway North Tunnel Head (227 m).  Fernbahntunnel mit Bahnhofshalle: Main Station and Train Tunnels Concourse (447 m).  DB- Tunnel Südkopf: German Railway South Tunnel Head (200 m).  Grenze PFA 1.1/1.5: Construction zones 1.1/1.5 Boundary.  Grenze PFA 1.1/1.2: Construction zones 1.1/1.2 Boundary.  Nördliches Bahnhofsgebäude: Main Station Northern Building.

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Figure 47: Combined Planned Works of the New Main Station and the Light Rail U12 Modification (source: Bahnprojekt-Stuttgart-Ulm.de 2014). Figure 47 demonstrates the sub-division of construction zone PFA 1.1. The construction zone was sub-divided into 25 worksites. The proposed works in these worksites are all planned to be performed by means of cut-and-cover method of construction. Therefore, remarkable work zone impacts were expected from the planned works and its duration. The light rail infrastructure modification at worksite 3 at Kurt Georg Kiesinger Platz, Heilbronner St. and Türlen St. is planned for duration of 3 to 3.5 years. The construction of the northern tunnel head at worksite 3, besides dewatering works running at the moment at worksites 1 and 2 at Jägerstraße besides worksite 8 at Heilbronner St. are planned for cumulative duration of approximately 4

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years. The construction works related to the relocation of the light rail station (Staatsgalerie) at Willy Brandt St., Schillerstr and Gebhard Müller Platz are planned for duration of 3 years. The construction of the southern tunnel head at worksites 23 and 24 (Willy Brandt St.) is planned for duration of 3 years as well. Traffic-related impacts from the described works should be addressed in the WZIA, besides the permnant impact from the lasting closure of the link between Schlossgarten and the old main station at worksite 14. The aforementioned worksites were the ones expected to breed significant trafficrelated impacts on the mobility, safety, environment and social cost. Other works involved in this construction zone, yet not in direct conflict with the road network (e.g., worksites falling inside Schlossgarten or the existing main station), were excluded from the work zone impact analysis, since they were not expected to influence the mobility and traffic efficiency. Though, the planned works at Schlossgarten on one side were a subject of societal and political conflict (due to ecological and hydrological considerations) prior to and during the project launching. On the other side, the planned woks inside the existing main train station may be considered significant in terms of train safety and railway operation. However, considering the fact that the thesis is primarily concerned about studying temporary vehicular traffic management, only these highlighted worksites were therefore selected to be analyzed. Noteworthy, the construction phasing plan’s activities were not elaborated as end-start relationships, since there are overlaps between the planned activities. Consequently, cumulative work zone impacts are present at certain periods. In addition to these works, there are many utility relocation works were (have to be) initiated prior to the cut-and-cover works. Besides the direct conflict with mobility and traffic, other trafficrelated societal aspects were part of the work zone impact analysis. This could be clearly understood from the existence of sensitive social facilities like Koeningn Katharina high school at Schiller St. More crucial is the existence of critical trips generated from and attracted to the “Blood Bank” in Katharinin Hospital (Stuttgart Clinic) which was delicately tackled when analyzing and planning the TTM of worksite 1 and 2 at Jäger St. (see Figure 48). Based on this scrutinizing analysis of the work zone impacts, the existing traffic operational conditions and the socioeconomic structure of the implementation area, the Construction Department of the Municipality of Stuttgart (Stadtverwaltung Stuttgart Tiefbauamt) was in a good position of understanding the domain of the work zone impacts and assessing the proposed measures and plans to manage the traffic during the construction. These measures will be revealed and explained briefly in the following section, so that the lessons of TTM from case analysis Stuttgart 21 can be concluded.

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Figure 48: Worksites No. 1 and 2 Conflict with the Existing Blood Bank Facility at Jäger St. (source: Google Earth 2014, 48°47ʹ05.19ʺN 9°10ʹ34.34ʺW, elevation 826 ft., Google, 2009 GeoBasis-DE/BKG. 16 September 2012).

2.3.3

Temporary Traffic Management Strategies

The key issue of Stuttgart 21 TTM was how to realize the planned construction works while the traffic operational conditions are preserved. As per aforementioned in the work zone impacts analysis, the state of traffic is Stuttgart was at the stake, thus “any deterioration in the capacity was not open to debate”, says Mr. Härterich, from the Construction Department, Municipality of Stuttgart. Therefore, any full or partial closure of the major roads within the implementation area was not part of the TTM strategic planning. One important lesson learned from this case analysis is that the early identification of the implementation area traffic characteristics could help to consider the TTM issues in the preliminary engineering and planning of the project and consequently take it into account for the TTM strategic planning. This is consistent with the recommendation for TTM development process highlighted in in the literature review (see ‎1.2.2 Development Process of Temporary Traffic Management Plans ). This early identification is shown clearly in the sub-division of the construction zone PFA 1.1, since the phasing plan was elaborated in a sequence that preserve the traffic conditions during the construction, as will be explained in the following paragraphs. In Stuttgart 21, there is an extensive exploitation of the “Innovative Construction Strategies” as TTM strategies, particularly in construction zone PFA 1.1. Innovative Construction strategies were referred to in the literature review (see ‎1.3.2 Temporary Traffic Control (TTC) Strategies) as a temporary traffic control strategy. At this early

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stage in the literature review, the innovative construction strategies were briefly described as the exploitation of pre-fabricated elements, or the high-tech equipment in order to accelerate the construction procedures, consequently compact the exposure time and its associated impacts. In Stuttgart 21, another trend of intelligent construction solutions was utilized, which was disassembling the construction zone’s sub-divisions into finite construction elements. These construction elements can be realized without disrupting the traffic significantly. In other words, the number of lanes for major roads is maintained the same, and shifted respectively with every construction element, with compacting the lane size, hence the work zone impacts on the road capacity are minimized. A good example of this strategy can be the worksites no. 3 and 8, for the northern tunnel head at Heilbronner St. Figure 49 depicts the entire works area that needed to be executed for the northern tunnel head of the new main station (worksites no. 3 and 8). Accordingly with the adopted TTM strategy of utilizing innovative approaches of construction, this area was disassembled into four finite construction elements. The major road Heilbronner St. lanes therefore were maintained at the same number (3 lanes in the eastbound direction and four lanes including one bus lane in the westbound direction) during the construction elements realization. Figure 50, Figure 51, Figure 52 and Figure 53 illustrate the four construction elements with the respective lanes geometry of each element.

Figure 49: Worksites no. 3 and 8 at Heilbronner St. (source: Google Earth 2014, 48°47ʹ06.99ʺN 9°10ʹ45.38ʺW, elevation 826 ft., 2009 GeoBasis-DE/BKG, Google. 16 September 2012).

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Figure 50: Construction Element 1, Worksites 3 and 8 Section (source: DB Projekt GmbH Stuttgart 21).


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This strategy is adopted as well for TTM of the light rail worksites at Kurt Georg Kiesinger Platz (see Figure 54 and Figure 55) and at Schiller St., Gebhard Müller Platz, and for the TTM of the southern tunnel head worksite at Willy Brandt St. The intelligence of this strategy lies in identifying the size and dimensions of the construction elements, taking into account the required lane sizes, taper lengths, work zone dissection (components), so that the traffic flow can be maintained while the works development is on the track. This perception of the elaboration considerations of innovative construction strategy leads to the conclusion that this strategy (innovative construction methods) is not a stand-alone strategy, yet it is a set of compound TTM/TTC strategies that integrate into the main strategy framework. The interview with Mr. Härterich, from the Municipality of Stuttgart revealed some of these auxiliary TTM/TTC strategies referred to in the previous paragraph. As a matter of self-evident, there was extensive deployment of TTC devices (tabular markers, cones and barricades) in order to guarantee safety and efficiency in traffic control within and in between the construction elements. This strategy of TTC devices was introduced in accordance with the principles, instructions and guidance set forth in “Richtlinien für die Sicherung von Arbeitsstellen an Straßen- RSA” (The German Guidelines of Safety for Road Works).

Figure 54: Light Rail Tunnel Worksite at Kurt Georg Kiesinger Platz (source: Google Earth 2014, 48°47ʹ04.10ʺN 9°10ʹ49.37ʺW, elevation 809 ft., 2009 GeoBasis-DE/BKG, Google. 16 September 2012).

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Figure 55: Light Rail Worksite TTM Construction Elements (Final Layout) - (source DB Projekt GmbH Stuttgart 21). Besides this application of integrated TTM strategies in Stuttgart 21, the Integrated Traffic Management Center Stuttgart (IVLZ) plays a crucial role in the TTM strategies monitoring and intervention. As per aforementioned, the backbone strategy of Stuttgart 21 TTM is the utilization of innovative construction methods. These methods require high standard safety performance. Therefore, Stuttgart TMC monitors the traffic operational conditions as well as the safety performance throughout the work zones by means of CCTV and traffic counts. Although the TMC is highly involved in the TTM of Stuttgart 21, this involvement does not encompass deployment of variable message signs connected to the center. Actually this exclusion of VMS aligns with the strategy conceptual framework of controlling the same traffic volumes locally throughout the work zones by means of conventional TTC devices and static signs, since there are no expected long-term traffic diversions. However, “Deployment of VMS could be an appropriate solution whenever arise a need for large scale detours”, says Mr. Härterich. It is worth mentioning here that the permanent closure of the link lies in between Schlossgarten and the existing (old) main station results in significant impacts on the traffic operational conditions, particularly at Gebhard Müller Platz signalized intersection (see Figure 56). Although the impacts triggered by this change in the traffic pattern are falling under the category of permanent impacts, they were tackled in the TTM strategic planning. This changed traffic pattern besides other simultaneous running worksites could impose intolerable cumulative impacts at this critical fraction of

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Stuttgart road network. Figure 56 depicts the closed road, and the changed traffic pattern resulting in diverting considerable traffic volumes to Gebhard Müller Platz. Traffic Microscopic Simulation planning tools were utilized to assess the newly added volumes, consequently adjust the signal program at the intersection in order to accommodate the new volumes and provide convenient level of service. Other intersection improvement strategies are planned to be introduced to this particular intersection due to the massive works planned. One intersecting strategy is the utilization of temporary traffic barricades to minimize the conflict points between the traffic streams, so that the signal phases can be decreased.

Figure 56: Permanent Road Closure between Schlossgarten and Existing Main Station (source: Google Earth 2014, 48°47ʹ01.89ʺN 9°11ʹ11.61ʺW, elevation 785 ft., 16 September 2012). As previously noted, Stuttgart 21 was confronted by opposition and public rejection due to ecological and social considerations. In light of this societal uneasiness towards the project, the public outreach as an initiative strategy for the project’s TTM is supposed to perform a crucial role in mitigating this rejection, at least from traffic operation perspective. An extensive utilization of Public Information (PI) strategies was conducted via the website of Stuttgart current traffic conditions (Aktuelle Verkehrslage Stuttgarti), “press release”, the project website (Bahnprojekt-Stuttgart-Ulm 2014) and other strategies like flyers or postal mails for residents in the impact areas. This approach would acquaint the residents with the planned and proposed activities, so

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that they can either adjust their travel behavior (route choice and departure time) or drive more carefully throughout the declared work zones. Finally, before concluding this case analysis of Stuttgart 21, it would be timely to highlight briefly the TTM adopted strategy towards the construction fleet. The excavated soil and construction material removal and delivery is carried out from the central worksite PFA 1.1 by trucks to the northern train station (Nord Bahnhof) in order to be delivered to the dumpsite by trains. The construction fleet route is assigned to a route formerly used by heavy goods vehicles (HGV) from (Stuttgart Goods Station) to the northern train station76, hence, no significant additional volumes from the construction fleet are incurred by the network.

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3 CHAPTER 3: CASE STUDY- METRO RIYADH In this chapter of the thesis, a real case study is going to be tackled in light of the international standard reviewed in chapter 1, and with the help of the lessons learned from the analyzed cases in chapter 2. The case study is the TTM of the major construction project “Metro Riyadh” from Saudi Arabia. Following the main trend of major construction project, the project is a transportation-oriented project planned for a highly urbanized and vast growing city (Riyadh [Arriyadh]). In this case study, one station construction site recommended by Dornier Consulting GmbH is going to be fully analyzed, planned and designed for the TTM, in a similar approach to the one conducted in the cases analysis. Although the case study is primarily addressing the aspect of the TTM of the project selected work zone, understanding other aspects regarding Riyadh City and its traffic conditions and travel behavior would give the case study a robust background. Moreover, the road network operational conditions and the socioeconomic structure of the implementation area are decisive parameters for the TTM strategic planning, as revealed before. Therefore, the case study chapter commences here with the project background, in terms of the city governing, demographic and socioeconomic structure, the link to the road network operational conditions and finally the project overview.

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3.1

Project Background

3.1.1

City of Riyadh

Riyadh is the capital of Saudi Arabia, one of the world growing cities with 5.7 million inhabitants (High Commission for the Development of Arriyadh- HCDA 2012)77. The demographic structure of this population is going to be described here in this inauguration, since it may explain and reveal some major aspects in the travel behavior of the city in later sections. Among these demographic considerations is the remarkable share of expatriates (39%) in Riyadh City (see Table 10). Table 10: Riyadh City Demographic Structure 2012 (source: Arriyadh.com 2014) Population

Percentage

Census

Total

100%

5,700,000

Saudi

61%

3,477,000

Saudi (Age group < 15 years)

35%

1,995,000

Saudi (Age group 15-60 years)

60%

3,420,000

Saudi (Age group > 60)

5%

285,000

Saudi (Males)

52%

2,964,000

Saudi (Females)

48%

2,736,000

Saudi (Males- Age group 15-60 years)

19%

1,083,000

Non- Saudi

39%

2,223,000

Non- Saudi (Males)

27%

1,539,000

The city have witnessed a massive growth during its modernization era (1953- 1975)78. The establishment of Saudi ministries and other governmental agencies headquarters in Riyadh over decades enhanced the political and social role of the city on the local and regional scale. Moreover, there are existing 1581 factories in Riyadh (37% of Saudi factories) (Arriyadh.com 2014). The economy of Riyadh is primarily based on productive sectors, including, besides industry, construction and real estate, banking and commercial, and agricultural. These business trends extensively influences the travel behavior and tends to produce more work-related trips.

3.1.2

Riyadh Traffic Conditions

This brief inauguration of the political and socioeconomic structure highlights the role of the road-based transportation mode for Riyadh as a growing city, since the road transport is the primary means for goods transport to and from the city (Arriyadh.com 2014), as well as for the individuals commuting. The road network of the city has been implemented in its recent “grid pattern” since 1953 (Elsheshtawy, Y. 2008, P.124). The total network length is 540.18 Km, of which the vast majority is local roads. However

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the road hierarchy is characterized by the key function of the expressways and the principal arterial roads (particularly King Fahd Rd., and the Ring Roads) in enhancing the mobility within the city and to other areas of Saudi Arabia. Figure 57 demonstrates the hierarchical system of the city grid road network and highlights the Ring Roads.

Figure 57: Riyadh City Road Network (source: Google Earth 2014, 24°42ʹ42.34ʺN 46°44ʹ58.14ʺE, elevation 2079 ft., DigitalGlobe, Google. 29 July 2014). The travel behavior of the city can be better understood out of two main indicators, the modal split and the car ownership. Figure 58 shows the modal split for the trips in the city, whilst Figure 59 identifies the trip purpose distribution 79. Alqhatani, M. et al. 2012 indicates that the number of Riyadh’s vehicles in 2008 reached 1,916,314. Taking into account the fact that there are among those who are authorized to drive, there are 1,539,000 of non-Saudi, “most of whom are workers who are less able to afford a car” (Alqhatani, M. et al. 2012). This number of expatriates can be assumed for the 8% private buses mode share, since this kind of transport mode is mostly adopted by the companies and factories for their workers. The number of vehicles in Riyadh, along with the legal capacity of vehicle driving in Riyadh and the modal split indicate significant dependency on the private mode of transport.

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2% 5% 8%

PrT PrT Buses

Taxis PuT Buses

85%

Figure 58: City of Riyadh Modal Split (source: Arriyadh.com 2014)

6%

19%

Work/ business Shopping Social/recreational 56%

10%

School Other

9%

Figure 59: Trip Purpose Distribution in Riyadh (source: Alqhatani, M. et al. 2012) Alqhatani, M. et al. indicated in this study that the increasing vehicles ownership as well as the lack for an efficient public transport system have significantly contributed to the encountered congestion problems, from which the city chronically suffers. The same study highlighted in the abstract that one of the congestion influencing factors is the mixed land use in the vicinity of the principal arterial roads of the city. Indeed, this conclusion superbly paves the way for the following section of Metro Riyadh Project’s overview.

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3.1.3

Project Overview

In response to these congestion problems referred to in the previous section, the HCDA has included the transportation into the framework of the “Comprehensive Riyadh City Strategic Development Plan”. This comprehensive plan introduces an integrated public transportation master plan in order to reduce the dependency on private mode of transport in commuting, besides other adopted measures and actions aim at enhancing the existing road network efficiency. Metro Riyadh and the planned Bus Network system formulate the top of the network hierarchy in this master plan. On one hand, Metro Riyadh route scheme is characterized by two major lines: the blue line (Al Aliaa- Al Bathaa line) and the red line (King Abdullah Road). These two major lines connect the city from the north to the south and from the east to the west (see Figure 60). In addition to these two major blue and red lines, other Metro lines are planned to provide an access to important facilities like King Khaled International Airport and to integrate the city peripheries into the Metro major lines via interchanging stations. Metro Riyadh consists of 6 lines, including these two major lines referred, they are: 1. Line 1 (Blue line): the axis of Al Aliaa- Al Bathaa- Al Hayer, 38 Km in length. 2. Line 2 (Red line): King Abdullah Road, 25.3 Km in length. 3. Line 3 (Orange line): the axis of Madinah- Prince Saad Bin Abdul-Rahman the first, 40.7 Km in length. 4. Line 4 (Yellow line): the axis of King Khaled International Airport Road, 29.6 Km. 5. Line 5 (Green line): the axis of King Abdul-Aziz Road, 12.9 Km. 6. Line 6 (Purple Line): the axis of Abdul-Rahman Bin Auf Road- Sheikh Hassan Bin Hussain Bin Ali Road, 30 Km in length. The metro lines are planned to be fully automated and to be driverless operating in order to achieve the most favorable operational and safety conditions. A park and ride system was integrated in the design; therefore the intermodal travel behavior can be promoted.

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Figure 60: Metro Riyadh Route Scheme (source: Arriyadh.com 2014). Subsequent to this brief introduction to Riyadh City, and Metro Riyadh project, the thesis at this point commences to reveal the worksite that is going to be addressed in the case study. The worksite is located on the route of Line 3 (Orange line) of Madinah Rd. Axis, where the underground construction works of the station 3F2 were planned, at the junction between Al Amin Abdullah Al Ali AL Naeem Rd., Salah Ad Din Rd., and Zayd Ibn Al Khatab Rd. Figure 61 shows the worksite location at this junction. The design and implementation of this stage of Riyadh Metro Project (Line 3) was awarded by the HCDA to “ArRiyadh New Mobility Consortium- ANM). Dornier Consulting GmbH was subcontracted to undertake the TTM of this specific worksite at the station 3F2. Hence, the following data concerning to the construction worksite, construction method, socioeconomic structure and the traffic characteristics in the implementation area was provided in the report released by Dornier Consulting GmbH and its appendices80. These data will be henceforth referred to as “(source: Dornier Consulting GmbH Report)”.

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Figure 61: 3F2 Station Worksite (source: Google Earth 2014, 24°39ʹ40.29ʺN 46°44ʹ42.27ʺE, elevation 1964 ft., Google, DigitalGlobe. 7 March 2014). In the following section, this worksite will be analyzed in order to assess the work zone anticipated impacts, consequently perform an appropriate TTM strategic planning in order to manage these impacts.

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3.2

Work Zone Impact Assessment

In light of the key findings concluded in the literature review (section ‎1.3.1) and the lessons learned from the analyzed projects in (CHAPTER 2: CASES ANALYSIS), the WZIA of the case study shall be undertaken in a similar approach. At first, two sets of data have to be compiled and consolidated in order to conduct an analysis of the anticipated impacts. First set of data is the project construction data, this comprises: the planned works description, the construction dimensions, the works duration, the method of construction and the possible phasing of works. The second data set is the implementation area data concerning to its nature (whether it is urban or rural), the socioeconomic structure, concurrent projects (worksites) in the vicinity of the implementation area, the baseline traffic volumes and composition, and the influenced transport modes. Within this sequence, these two sets of data will be described in the following paragraphs, so that the WZIA can be concluded at the end of this section.

3.2.1

Construction Data

The implementation area tackled in the case study is the worksite of the underground station 3F2 on Line 3 (Orange line) (see Figure 62). The station is the first deep underground station in the construction segment between station 3F2 and 3E1; therefore a transitional ramp shall be constructed between the deep underground station 3F2 and the elevated station 3G1. This transitional ramp is planned to be constructed by means of cut-and-cover. Although the Metro tunnel of the deep underground segment (between 3F2 and 3E1) is planned to be excavated by TBM, open pit excavation methodology is planned for the stations. The TBM is planned to be assembled and launched from the station 3F2 worksite, therefore an entry shaft is required for the TBM at this worksite.

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Figure 62: Schematic Plan of Metro Line 3 (Orange line) - Station 3F2 (Source: Dornier Consulting GmbH Report). The main planned works can be briefly described as one open pit excavation for the station worksite and one cut-and-cover line section for the transitional ramp worksite. Other utility relocation works at the station worksite as well as the transitional ramp worksite have to be taken into account. These utility relocation works however are not extensively addressed in the work zone impacts analysis since they have no significant impact on the roadways. Major impacts are corresponding to the station and the ramp worksites. The planned construction works of the station have the following sequence: 1. 2. 3. 4. 5. 6. 7. 8.

Excavation. TBM launch. Foundation. Sub structure. Superstructure. Station Finishing. Station Mechanical, Electrical and Plumbing (MEP) works. Station Testing.

The construction dimension of the worksite shown in Figure 63 depicts the station construction footprint at the busiest construction phase. It illustrates as well the site access/exit points and the interference with the road links (Zayd Ibn Al Khatab Rd. and Salah Ad Din St.). As regards the transitional ramp’s cut-and-cover line section, the

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required width for construction including the utility relocation working space and the safe buffer space is 14.65 m along the median center line of Salah Ad Din St.

Figure 63: Station 3F2 Construction Footprint (source: Dornier Consulting GmbH Report). The previously described works are planned for five construction phases in order to refrain from cumulative impacts triggered by simultaneous worksites, particularly for the station worksite and the works planned along Salah Ad Din St. Therefore, the station planned works including the utility relocation are planned as the second construction phase (II), for approximately two years (June 2014- May 2016). The first construction phase (I) is determined for the utility relocation along the median of Zayd Ibn Al Khatab

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Rd., which has no considerable impact on the roadway. The remaining works of the transitional ramp’s cut-and-cover line section were planned at the preliminary engineering stage to be executed in three construction phases (III, IV, V) due to the extensive length of this line section and the significance of Salah Ad Din St. Figure 64 shows the planned construction phases of the station 3F2 construction zone.

Figure 64: Station 3F2 Construction Zone- Construction Phases (source: Dornier Consulting GmbH Report). A part and parcel of the construction data is the data for construction logistics in general and the construction fleet in particular. Construction logistics data should encompass all the data relevant to the material delivery to the site, spoil removal from the site and in some specific cases the workers transportation to and from the site. For this particular case study, the project daily activities include three shifts. The overall number of workers corresponding to every work shift is 200 workers who are supposed to be transported to and from the worksite by means of small buses (25 seats in capacity); hence the total number of buses for each work shift would be 8 buses. Based on Salah Ad Din St. capacity and the existing traffic volumes, which will be

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shown later, the anticipated impacts from these small buses are minor to be considered as a deterministic parameter for the TTM strategic planning. Before analyzing the remaining construction logistics parameters, it is worth mentioning that the traffic police in Riyadh has adopted a restriction starategy towards the heavy trucks traffic. “Trucks are allowed only between 11 P.M. and 5 A.M. from Saturday until Wednesday. During weekends, the hours are flexible.” (Al Fawzan, R. 2012)81. Therefore, the material delivery and spoil removal trucks have to be managed within these allowed operating hours. Herein, the impacts from the material delivery trucks and the soil removal trucks are going to be addressed. They are combined here, since the trip frequency for both is correlated to the TBM productivity, as will be explained. The TBM is planned to be assembled and launched from the station 3F2 worksite in order to excavate the tunnel segment until the station 3E1 worksite. The total length of this tunnel segment will be approximately 5300 m, and the cross-sectional area is 81.7 m² (see Figure 65). The volume of soil to be excavated estimated for the TBM is 433,000 m³ of in-situ (bank) soil. When considering the spoil removal trucks, this volume has to be applied to an expansion factor due to the destabilization and alteration of the soil particles. Hence, the soil volume for the spoil removal trucks is 606,000 m³.

Figure 65: Structural Precast Concrete Elements of the Tunnel Segment (source: Dornier Consulting GmbH Report). The proposed tunnel-boring machine (TBM) for this worksite is an Earth Pressure Balance (EPB) with an average speed of 8-18 m/day. This speed primarily depends on the soil conditions and the route alignment. On this basis, the daily rate of soil excavation was estimated at 18 longitudinal meters (1,500 m³ per day). This excavation rate highlights two crucial parameters for the TTM, first is the frequency of the material

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(precast concrete elements) delivery, and the second is the spoil removal trucks traffic volume. Due to the worksite limitations, the precast concrete elements are planned to be supplied for immediate installation, therefore a specific number of tunnel rings has to be supplied to the site on daily basis in order not to delay the TBM progress. TBM daily rate of 18 longitudinal meters is corresponding to 9 tunnel rings (2 longitudinal meters per ring). Each ring is composed of 4 quarters (see Figure 65), whilst the capacity of the delivery truck is 2 quarters per truck. The total number of material delivery trucks that have to operate within the allowed trucks working hours can be obtained as per illustrated in Equation 4. The anticipated impacts of the material delivery trucks are expected to be minor as well as the ones from the workers transportation. 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑡𝑟𝑢𝑐𝑘𝑠 = 9 (𝑡𝑢𝑛𝑛𝑒𝑙 𝑟𝑖𝑛𝑔𝑠) ∗ 4 (𝑞𝑢𝑎𝑟𝑡𝑒𝑟𝑠 𝑠𝑒𝑔𝑚𝑒𝑛𝑡𝑠) ∗

1 𝑇𝑟𝑢𝑐𝑘 2 (𝑞𝑢𝑎𝑟𝑡𝑒𝑟𝑠 𝑠𝑒𝑔𝑚𝑒𝑛𝑡𝑠)

Equation 4 =

18 𝑡𝑟𝑢𝑐𝑘𝑠/𝑑𝑎𝑦 As regards the impacts from the spoil removal trucks, the estimated excavation rate of 1,500 m³ of bank soil per day corresponds to 2,100 m³ of disturbed or excavated soil per day, whilst the assumed truck capacity is 15 m³, hence the required number of trucks is approximately 140 trucks/ day. This number of spoil removal trucks has to be running along the planned route to the dumpsite located at the south of the Southern Ring Road (see Figure 66) only during the allowed operating hours for trucks (6 hours). The anticipated truck traffic volume therefore becomes 23 trucks/ hour. Considering the volumes outside the peak hours, within the assigned working hours to trucks, these volumes from the soil removal trucks are manageable.

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Figure 66: Soil Removal Trucks Route from 3F2 Station Worksite to the Dump Site (source: Google Earth 2014, 24°38ʹ02.54ʺN 46°45ʹ58.02ʺE, elevation 1986 ft., Google, DigitalGlobe. 4 July 2014).

3.2.2

Implementation Area Data

The implementation area lies in Al-Malaz neighbourhood, in which a similar demographic structure as the predominant trend in Riyadh-Saudi Arabia is expected. The neighbourhood is primarily characterized by residential usage with some soft commercial (retail) and community service facilities. A landmark of the neighbourhood is the 22,500-capacity Stadium of Prince Faisal Bin Fahd for El- Nasr Football Team. Another landmark is King Abdullah Park adjacent to the stadium and within the same urban block. An existing fuel station in front of station 3F2 worksite on the other side of Salah Ad Din St. may raise some safety and mobility concerns due to flammable material handling and the access/exit points that have to be preserved. There are no existing significant facilities like hospitals or schools within the work zone impact domain. The nearest school is a Preparatory School at Prince Abdul Muhsin Bin Abduaziz Rd., south of the station 3F2 worksite. Noteworthy here is the remarkable existence of electrical and plumbing fixtures outlets. This specific kind of business may necessitate the securing of manoeuvring areas for heavy goods vehicles for deliveries and supplies, but these businesses are only used as showrooms for the products. As regards the traffic characteristics of the implementation area, the worksite of station 3F2 is bounded by two road links; Salah Ad Din Rd. to the north, and Zayd Ibn Al Khatab Rd. to the east. Salah Ad Din Rd. is an arterial road (40 m in width) with three lanes in each direction separated by raised central reserves. Salah Ad Din Rd. is

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branching into 6 lanes in the eastbound direction at the intersection with Zayd Ibn Al Khatab Rd. (see Figure 67). Actually Salah Ad Din Rd. composes the east and the west legs of the 4-legs signalized (4 phases) intersection adjacent to the worksite. The traffic characteristics and the operational conditions of the intersection (coded as 15 in the analysis) are going to be extensively analysed in the baseline condition analysis within the framework of the TTM strategic planning. As concerns Zayd Ibn Al Khatab Rd., which the second road link in direct conflict with the worksite, it is a collector road with two lanes in each direction separated again with a “raised central reserve”. Besides its collecting function, it provides a connection between Salah Ad Din Rd. and Omar Ibn Al Khattab Rd., where the Riyadh Train Station exists.

Figure 67: 4-Legs Signalized Intersection In the Implementation Are (source: Google Earth 2014, 24°39ʹ40.41ʺN 46°44ʹ38.95ʺE, elevation 1956 ft., DigitalGlobe. 7 March 2014). On-street parking stalls are provided in a parallel pattern along Salah Ad Din Rd., and in an inclined pattern along Zayd Ibn Al Khatab Rd. Though, these on-street parking are among the main factors of the deteriorated capacity of Zayd Ibn Al Khatab Rd., “In fact, these parking lots reduce the available space for traffic on Zayd Ibn Al Khatab Road to one lane per direction” (Dornier Consulting GmbH Report, P.22). Besides these on-street parking stalls, there are some more parking facilities are provided along and adjacent to the right-turn lane off-Zayd Ibn Al Khatab Rd. inside the triangular parcel accommodating an existing concrete monument (see Figure 68).

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Figure 68: Parking facilities along right-turn lane off-Zayd Ibn Al Khatab Road (source: Dornier Consulting GmbH Report).

3.2.3

Assessment of the Impacts on the Mobility

In light of the construction and implementation area data compilation and analysis, the work zone impacts on safety and mobility can be methodologically concluded. The impacts assessment will be performed on qualitative basis as per recommended in the literature review. Since the TTM Plan is not yet elaborated, therefore the impacts shall be assessed qualitatively in light of the available data concerning to the construction method and the implementation area characteristics. The impacts on the society here in this section will be addressed within the context of the overall impacts. Later, in the TTM strategic planning, the impacts on the society are considered amongst the deterministic factors, and will be an essential criterion of assessment for the potential TTM alternatives. The impacts on the mobility will be addressed following the sequence of the works phasing plan. Hence, the utility relocation works shall be addressed at first. The utility relocation will be running along the median of Zayd Ibn Al Khatab Rd. to one lane from the southbound carriageway (Zayd Ibn Al Khatab Rd.). This lane is planned to be obtained on the expense of the on-street parking along Zayd Ibn Al Khatab Rd. by restricting the parking for 50 m (see Figure 69). Therefore, significant mobility impacts are not expected for this phase since the utilities are mostly power supply cables that needed to be relocated from the median to the lane occupied by the parking stalls, with minimized direct interference with the roadway. The encountered mobility impacts for

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this phase are limited to the loss of number of parking stalls due to this 50 m on-street parking restriction along Zayd Ibn Al Khatab Rd

Figure 69: Impacts on Mobility along Zayd Ibn Al Khatab Rd. (source: Google Earth 2014, 24°39ʹ37.19ʺN 46°44ʹ42.26ʺE, elevation 1962 ft., DigitalGlobe. 7 March 2014). The adopted construction method (cut and cover) and the construction footprint in the second phase of construction impose the full closure of the right-turn lane off-Zayd Ibn Al Khatab Rd., and the full closure of the northbound carriageway along Zayd Ibn Al Khatab Rd. (see Figure 69). Indeed, this lane and road closure is considered significant due to two considerations, first consideration is the influenced traffic volumes (right-turn volume) and the second is the exposure time (duration of phase 2 is two years). Besides these impacts on the traffic pattern, there will be loss of approximately 72 parking stalls along and adjacent to this right-turn lane. As regards other transport modes and streams, there are no existing considerable public transport lines or SM (pedestrians or cyclists) along the road link, or in the vicinity of the worksite. However, sufficient and safe pedestrian paths have to be secured in order to provide safe and adequate access to the residential buildings and the business activities. For phase 3, 4 and 5, whereas the transitional ramp is planned to be executed by means of cut-and-cover along Salah Ad Din Rd., the anticipated mobility impacts tend to be more determined since the proposed works are planned along the median of the street for a construction footprint of 14.65 m. As per discussed before, Salah Ad Din Rd. is an arterial road, 40 m in width. The roadway encompasses 3 lanes in each direction besides the median and the on-street provided parking stalls. The required

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14.65 m for the transitional ramp worksite is expected to impose limited impact on the lanes’ width, since the lane width will be 3 m instead of 3.3, but not on the number of lanes. However, recalling the construction layout of the station 3F2 in relation to the transitional ramp reveals that the convergence point between the two elements (see Figure 70) would impose mobility impacts on Salah Ad Din Rd., particularly the eastbound direction, and it needs to be addressed adequately in the temporary traffic management plans as well as the construction (work) method statement.

Figure 70: Convergence Point between the Transitional Ramp and the Station Worksite.

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3.3

Temporary Traffic Management Strategic Planning

In light of the concepts and fundamentals perceived from the literature review and the lessons learned from the cases analysis, the TTM strategic planning shall be conducted in a similar approach that endeavors at addressing the anticipated impacts of the work zone in an effective strategic process. The section commences with an analysis of the traffic baseline operational conditions at the implementation area. Thereafter, one newly included aspect arises here in the case study chapter, which will be the detailed worksite traffic layout. This worksite layout would point out the points where the worksite would receive and release the construction traffic from and into the road links adjacent to the worksite. Finally, the proposed TTM strategies and its effectiveness assessment will be exhibited in this section.

3.3.1

Baseline Condition Analysis

As per discussed in the work zone impacts assessment, the baseline traffic operational conditions of the 4-legs intersection adjacent to the worksite should be tackled here in the TTM strategic planning. The operational performance of this 4-legs intersection, analyzed prior to any traffic pattern changes, and later on, assessed for the different alternatives of TTM, would build a robust strategic planning methodology, so that the TTM performance can be comparable to the pre-existed situation. Traffic counts were conducted during April, 2014 for the signalized intersection within the whole traffic zone that accommodates the worksite and expected to be exposed to the potential detours. Table 11 depicts the observed hourly volumes of the different traffic streams at the intersection during the morning and evening peak hours respectively. Table 11: Morning and Evening Peak Hourly Volumes of the Signalized Intersection for the Different Traffic Streams (source: Dornier Consulting GmbH Report). Traffic Stream

Description

Morning Peak Volume (VPH)

Evening Peak Volume (VPH)

EBU

Eastbound Direction- U-turn

28

46

EBL

Eastbound Direction- Left-turn

259

260

EBT

Eastbound Direction- Through

1146

1261

EBR

Eastbound Direction- Right-turn

118

292

WBU

Westbound Direction- U-turn

58

83

WBL

Westbound Direction- Left-turn

433

431

WBT

Westbound Direction- Through

2228

1209

WBR

Westbound Direction- Right-turn

109

229

NBU

Northbound Direction- U-turn

21

63

NBL

Northbound Direction- Left-turn

128

119

NBT

Northbound Direction- Through

574

322

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i

NBR

Northbound Direction- Right-turn

4

22

SBU

Southbound Direction- U-turn

4

26

SBL

Southbound Direction- Left-turn

207

289

SBT

Southbound Direction- Through

172

282

SBR

Southbound Direction- Rightii turn

77

169

The traffic counts of the whole observation area were video-based; therefore, it was feasible to conclude to an early finding of the nature of the trips throughout Zayd Ibn Al Khatab Rd., that they are predominantly serving the local neighborhood. On another hand, the summarized traffic volumes shown in Figure 71 reveal the major role that Salah Ad Din Rd. (Eastbound Through-EBT and Westbound Through-WBT) plays in the implementation area’s mobility, therefore the need to find other TTM solutions, rather than the full or partial closure during the transitional ramp construction.

Traffic Volumes (Vehicles/hour)

2500 2000 1500 1000

Morning Peak

500

Evening Peak

SBR

SBT

SBL

SBU

NBR

NBT

NBL

NBU

WBR

WBT

WBL

WBU

EBR

EBT

EBL

EBU

0

Intersection Traffic Streams

Figure 71: Intersection Summarized Traffic Volumes (source: Traffic Counts- Dornier Consulting GmbH Report). The further step of the baseline condition analysis in this particular section of the thesis is to analyze the capacity of this intersection in light of the available data concerning to the traffic volumes, traffic movements, intersection geometry, lanes geometry, and the existing signal program for the morning and evening peak. The aim of this analysis is to obtain traffic-performance characteristics (volume-capacity ratio, control delay per vehicle, level of service (LOS) and queue lengths) prior to the introducing of the TTM proposed alternatives. The aim behind obtaining these values is to set up a reference

i

This right-turn traffic volume is not the volume that is going to be considered after the right-turn

lane closure, yet these minor volumes (4 and 22 vehicles) were observed from the video-based traffic counts, and they are probably not aware of the right-turn lane. ii

There is exclusively right-turn lane, thus the SBR is not considered for any stage of the

intersection capacity analysis.

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line to assess the traffic performance for the proposed TTM alternatives in a later stage of the TTM strategic planning. The methodology used to conduct this analysis is the methodology described in the (HIGHWAY CAPACITY MANUAL-HCM 2000)82, accordingly with the commonly used standards for traffic engineering practice in the implementation area (Saudi Arabia). Figure 72 depicts the intersection geometry, the allowed traffic movements and the existing signal phase sequence. Some highlights concerning to the traffic movements and the intersection geometry should be borne in mind in conjugation with the demonstrated figure; the right-turn movement at the northbound direction (NBR), indicated in dotted lines in Figure 72 is a minor movement that is taken into account because it exists in the video-based traffic counts. This particular traffic movement is expected to be undertaken by some drivers who are not aware of the intersection geometry and the existence of separate right-turn lane. Another highlight is the removal of the volumes form the right-turn movement at the southbound direction due to the existence of the separate right-turn lane in a self-explanatory geometry, so that the right-turners are most likely to realize it and use it without need to approach the signalized intersection.

Figure 72: Geometry and Signal Phase Sequence of the Intersection in the Implementation Area (source: Dornier Consulting GmbH Report).

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Table 12 and Table 13 show the existing signal program at the intersection for the baseline condition during the morning and the evening peak hours. Cycle time at the morning peak is 130 seconds and for the evening peak is 90 seconds. The total green times shown in the tables below encompass the effective green times in addition to the change interval times. “Change interval: The yellow plus red clearance interval that occurs between phases of a traffic signal to provide for clearance of the intersection before conflicting movements are released” (Koonce, P. et al 2008, P.3)83. For the existing signal program, the change intervals are unified as four (4) seconds for all of the intersection approaches. The “MUTCD” determine the minimum duration of yellow change interval as 3 seconds (MUTCD 2009, P.489), whilst the red clearance interval is determined for a maximum value of 6 seconds (MUTCD 2009, P.489). The De-facto operational condition obtained from Dornier Consulting GmbH identifies this value of four (4) seconds as standard value used for the change intervals in Riyadh signal plans. Table 12: Signal Program- Morning Peak Hour (source: Dornier Consulting GmbH Report). Signal Phase

Total Green Time (seconds)

Change Interval (seconds)

Red Time (seconds)

Phase 1

34

4

96

Phase 2

20

4

110

Phase 3

24

4

106

Phase 4

52

4

78

Table 13: Signal Program- Evening Peak Hour (source: Dornier Consulting GmbH Report). Signal Phase

Total Green Time (seconds)

Change Interval (seconds)

Red Time (seconds)

Phase 1

20

4

70

Phase 2

20

4

70

Phase 3

20

4

70

Phase 4

30

4

60

As per explained, the aim from this baseline condition analysis is to investigate the control delays in seconds per vehicles (s/veh), consequently the level of service. “Level of service (LOS) is a quality measure describing operational conditions within a traffic stream, generally in terms of such service measures as speed and travel time, freedom to maneuver, traffic interruptions, and comfort and convenience” (HCM 2000, P.2-2). Referring to the intersections capacity analysis methodology adopted in the HCM, the “Intersection LOS is directly related to the average control delay per vehicle” (HCM 2000, P.16-23). Table 14 identifies the LOS criteria for signalized intersection as per described in the HCM 2000.

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Table 14: LOS Criteria for Signalized Intersections (source HCM 2000, Ch.16, P.16-2) LOS

Control Delay Per Vehicle (s/veh)

A

≤ 10

B

≤ 10-20

C

≤ 20-35

D

≤ 35-55

E

≤ 55-80

F

> 80

Although the LOS indication is usually used to assess the mobility performance and the traffic efficiency at the signalized intersections, yet the LOS as an abstract value doesn’t justify the existing performance and operational conditions. Therefore, it would be an asset for the baseline condition analysis to introduce another parameter to the analysis; the volume-capacity ratio of the different lane groups composing the intersection approaches, which will be displayed along with the LOS of the intersection lane groups in order to highlight the degree of saturation and the capacity reserves. This brings up the concept of “lane grouping”, since the analysis methodology of the HCM 2000 “consider individual intersection approaches and individual lane groups within approaches” (HCM 2000, P.16-6), where a group of lane(s) in each approach are aggregated based on the geometry of the intersection and the allowed traffic movements. Figure 73 depicts the determined lane groups at the intersection on basis of geometry (exclusive or shared lanes) and the traffic movements. This lane grouping principle should be adopted for the whole baseline analysis as well as for the TTM alternatives assessment. Eight (8) lane groups were the resultant of this grouping.

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Figure 73: Lane Groups of the Intersection in the Implementation Area (source: Dornier Consulting GmbH Report). Herein a demonstration of the capacity analysis methodology set forth in the HCM 2000 utilizing the volume-to-capacity ratio for analyzing the intersection capacity and estimating the vehicles control delays. The methodology assumes the peak-adjusted demand volume over the lane group capacity (v/c ratio) as the deterministic factor for estimating the queue lengths, control delays and consequently the LOS. The lane group capacity (c) is obtained from saturation flow rate of the lane group multiplied by the effective green time ratio. The term “saturation flow rate” refers to the traffic flow rate at which the lane (group) operates at saturation condition, and it can be obtained by adjusting the lane group base capacity for some geometric and operational conditions.

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Example: Saturation Flow Rate (S) calculation for the Lane Groups No.5 and No.6 at the northbound direction. 𝑆 = 𝑆0 × 𝑁 × 𝑓𝑤 × 𝑓𝐻𝑉 × 𝑓𝑔 × 𝑓𝑝 × 𝑓𝑏𝑏 × 𝑓𝑎 × 𝑓𝐿𝑈 × 𝑓𝐿𝑇 × 𝑓𝑅𝑇 × 𝑓𝐿𝑝𝑏 × 𝑓𝑅𝑝𝑏

Equation 5

(Source: HCM 2000, P.16-9) Table 15: Saturation Flow Rate per Lane Group, Calculation Parameters (source: HCM 2000, P.16-11) Parameter

Description

Value for Lane Group 5

Value for Lane Group 6

𝑆0

Base saturation flow rate per lane

1900 VPH/lane

1900 VPH/lane

𝑁

Number of lanes in each lane group

1

2

𝑓𝑤

Adjustment factor for lane width

1.044

1.044

𝑓𝐻𝑉

Adjustment factor for Heavy Vehicles in traffic ii stream

1

1

𝑓𝑔

Adjustment factor for approach grade

1

1

𝑓𝑝

Adjustment factor for existence of parking lane and parking activity adjacent to the lane group

1

0.995

𝑓𝑏𝑏

Adjustment factor for blocking effect of local buses

1

1

𝑓𝑎

Adjustment factor for area type

1

1

𝑓𝐿𝑈

Adjustment factor for lane utilization

1

1

𝑓𝐿𝑇

Adjustment factor for left turns in lane group

0.95

1

𝑓𝑅𝑇

Adjustment factor for right turns in lane group

1

=~ 1

𝑓𝐿𝑝𝑏

Pedestrian adjustment factor for left-turn movements

1

1

𝑓𝑅𝑝𝑏

Pedestrian-bicycles adjustment factor for rightturn movements

1

1

Saturation flow rate for lane group

1884 VPH

3947 VPH

𝑆

i

iii

Subsequent to the determination of the Saturation flow rate of each lane group approaching the intersection using the same methodology, the lane group capacity (c) can be obtained by multiplying the effective green time ratio (g/C) by the saturation flow (S) (see Equation 6). The effective green time ratio is the ratio of the actual green time to the total cycle time. As per referred to, the change intervals are unified as four (4) seconds, hence the effective green time is calculated as the total green time minus

i

Lane width (w) at baseline condition = 4 m.

ii

Heavy Vehicles traffic is banned for peak hours.

iii

Maximum number of possible parking movements is 18 due to the available space adjacent to

the lane group approach.

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these four (4) seconds. Whilst the lane group capacity is the number of vehicles that the lane group can accommodate within the designed green time and dispatch it at acceptable operational conditions. 𝑐𝑖 =

𝑔 𝐶

× 𝑆𝑖

Equation 6

(Source: HCM 2000, 16-14) The v/c ratio is the fraction of the lane group adjusted flow rate (𝑣𝑖 ) over the lane group capacity (𝑐𝑖 ). Besides the summation of the lane traffic volumes for each lane group, other factors have to be taken into account for calculating the lane group adjusted flow rate. For the case of Riyadh, the right-turn movements are allowed during the red times, considerable number of right-turn on red (RTOR) can significantly influences the analysis results when subtracted from the right turn volumes. These RTOR volumes were obtained from the video-based traffic counts conducted by Dornier Consulting GmbH. Another consideration is the shared traffic, where a certain traffic movement is shared among more than one lane groups, thus the appropriate share of the traffic volume should be assigned adequately to each lane group. The methodology adopted for allocating the traffic volumes adequately over the shared lanes is based on an assumption that the headway between the successive turning vehicles is 2 seconds, whilst for the successive straight-forward vehicles is 1.8 seconds. In this way, the volumes can be time evenly distributed over the shared lanes. For example, the left-turn movement traffic shown in Figure 74, which is distributed between lane group number 1 and lane group number 2, hence this left-turn volume should be distributed between the two lane groups in order to calculate the lane group flow rate. By means of the referred headway methodology, and application of trial and error approach, the adequate volume can be readily allocated over shared lanes (Table 16). Lane Group 1: Left-turn and Lane Group 2: Left-turn and U-turn (One Lane) Through (Two Lanes)

Figure 74: Example of Two Lane Groups with Shared Lane Traffic.

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Table 16: Example of Lane Group Allocated Volumes U-Turn Volume

Left-Turn Volume

Through-Volume

4

204

172

Lane Group 1 Allocated Volume

Lane Group 2 Allocated Volume

121

259

These considerations were all tackled concisely in the capacity analysis in order to obtain the exact value of the v/c ration for each lane group. The subsequent step to the v/c ratio calculation described in the HCM 2000 methodology for analyzing the intersections capacity is to determine the anticipated delays. The methodology is extensively described in chapter 16 (SIGNALIZED INTERSECTION), though, the general outlines and the assumptions made specifically for this intersection should be highlighted in this section. Equation 7 demonstrates the HCM approach for determining the vehicles control delays. The uniform control delay is based on an assumption that the vehicles at the lane group arrive at the same time, which is not the actual case. This delay component is therefore adjusted for the progression effect using the progression adjustment factor. The incremental delay component is related to the delays triggered by the oversaturation and the queue spillback. The third delay component is calculated to include the existed queue that might have been formed prior to the very start of the analysis period. However, this third delay component is neglected for the case of the intersection in question, since the analysis is undertaken for specific time period (peak period). Equation 8, Equation 9 and Equation 10 provide the calculation steps of the control delay components according to the HCM 2000. 𝑑 = 𝑑1 (𝑃𝐹) + 𝑑2 + 𝑑3     

Equation 7

“𝑑: control delay per vehicle (s/veh); 𝑑1 : Uniform control delay; 𝑃𝐹: Uniform delay progression adjustment factor; 𝑑2 : Incremental delay; 𝑑3 : Initial queue delay.” (Source: Source: HCM 2000, P.16-19) 𝑃𝐹 =

(1 − 𝑃)𝑓𝑃𝐴 𝑔 1− ( ) 𝐶

Equation 8

 “𝑃: Proportion of vehicles arriving on green;  𝑓𝑃𝐴 : Supplemental adjusting factor for platoon arriving during green.” (Source: HCM 2000, P.16-19) The HCM 2000 recommends for the value of P to be obtained from site measurements. In case of analysis or forecasting scenarios, the HCM identifies 6 arrivals types, from which the analyst may select an appropriate arrival type. For the case of the intersection in question, “arrival type 3” (AT3) (HCM 2000, 16-20) is selected, hence the 𝑃𝐹 = 1.

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CHAPTER 3: CASE STUDY- METRO RIYADH 𝑔 )² 𝐶 𝑑1 = 𝑔 1 − [min(1, 𝑋) × ] 𝐶 0.5 𝐶 (1 −

Equation 9

 “𝐶: Cycle Length (s);  𝑔: effective green time for the lane group (s);  𝑋: Volume-capacity ratio (v/c ratio).” (Source: HCM 2000, P.16-21) 𝑑2 = 900 𝑇 [(𝑋 − 1) + √(𝑋 − 1)2 +

8𝐾𝐼𝑋 ] 𝑐𝑇

Equation 10

 “𝑇: Duration of analysis period (h); (An analysis period (T)i of 15 minutes (0.25 h) is considered for the analysis)  𝐾: Incremental delay factor; (For pre-timed signal programs, 𝐾= 0.5).  𝐼: Upstream filtering/metering adjustment factor.” (Assumption: Isolated intersection; 𝐼= 1). (Source: HCM 2000, P.16-21) The detailed calculation sheet of the intersection capacity analysis for the baseline condition is provided in (Appendix 1) and (Appendix 2) for the morning peak and the evening peak hours respectively. Figure 75 and Figure 76 demonstrate the v/c ratios, control delays and the LOS for the 8 lane groups of the intersection at the morning and evening peaks. The correlation between the v/c ration and the control delays (especially for v/c above 85%); consequently the LOS can be readily interpreted throughout the two figures. In light of these shown figures, the baseline condition analysis can conclude to the fact that the traffic operational conditions during the morning peak tend to be more critical. More particularly, lane groups 3 and 4 are the most critically operating lane groups due to their excessive v/c ratio. Moreover, the northbound approach (lane groups 5 and 6) maintains some capacity reserves that can be exploited efficiently for the TTM strategies.

i

“The length of the analysis period (T) determines how long the demand is assumed to be at the

specified flow rate” (HCM 2000, 16-25).

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Figure 75: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Morning Peak Hour- Baseline Condition.

Figure 76: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Evening Peak Hour- Baseline Condition.

3.3.2

Worksite Traffic Layout

The traffic routes within the worksite, access and exit points to the worksite and the trucks holding area are all TTM-related parameters that have to be addressed in the TTM strategic planning and to be determined prior to the launching of the constructions works. In some particular worksites, the construction fleet size and routes are among the deterministic factors for the TTM plans due to the trucks added traffic volumes. Although this is not the case here in the TTM plans for the worksite of station 3F2 due to the restriction starategy towards the heavy trucks traffic, since they are allowed only between 11:00 PM and 5:00 AM during weekdays. Yet addressing this aspect (worksite traffic routes) is still a part and parcel of a comprehensive temporary traffic mangement plan. Moreover, highlighting the potential access and exit points to and from the worksite at this stage of TTM strategic planning could be an asset for the TTM alternatives assessment in a later stage. Figure 77 depicts the proposed traffic routes layout, providing access/exit points, respectively at Salah Ad Din Rd., and Zayd Ibn Al Khatab Rd. for the soil removal trucks to the dumpsite located in the south of the Southern Ring Road (Figure 66). As

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regards the material delivery trucks and the workers buses, the same route can be used. This traffic pattern is elaborated based on the existing pattern prior to the construction and before any alteration for the layout. Hence, maintaining this traffic pattern for the TTM plan should be taken into consideration for the TTM proposed alternatives.

Figure 77: Soil Removal Trucks Route To/From the Dumpsite Along Dharan St., and Maneuvering Inside the Worksite (source: Google Earth 2014, 24°39ʹ34.65ʺN 46°44ʹ18.26ʺE, elevation 1957 ft., DigitalGlobe. 7 March 2014).

3.3.3

Potential TTM Strategies Elaboration

TTM strategies have to be elaborated and assessed in this section to address two major impacts from the worksite. First impact comes from the closure of the right-turn lane off-Zayd Ibn Al Khatab Rd and the closure of the northbound carriageway along the same link (Zayd Ibn Al Khatab Rd.). The second one is the impact from the transitional ramp worksite on Salah Ad Din Rd., particularly the convergence point between the ramp and the station’s worksite (Figure 70). Therefore, TTM alternative strategies will be proposed and elaborated in this section, prior to assessing their effectiveness in the next section. At first comes the traffic pattern along Zayd Ibn Al Khatab Rd. adjacent to the 3F2 station worksite. It is worth mentioning here that Zayd Ibn Al Khatab Rd. has two (2) lanes per each direction at the baseline condition. However, “Site visits have shown that the existing cross section of the road is reduced due to parking to 1 lane per direction, without significant impact on traffic flow” (Dornier Report 2014, P.24). These “de facto” operational conditions should be taken into account during the TTM strategies elaboration and assessment.

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There are two proposed alternatives of TTM comprising primarily TTC strategies (full Lane closure, lane shift, reduced lane width, possible diversion, and deployment of traffic control devices) aiming at controlling the traffic locally within the road (Zayd Ibn Al Khatab Rd.), adjacent to the work zone, and may require some specific TO strategies (Corridor/ Network Management Strategies/ Signal Coordination and Optimization) in order to mitigate the pressure on the urban corridor (Salah Ad Din Rd.). Of course PI strategies are always recommended for altering the travel behaviour (departure time or route choice), or to enhance the rational driving within the areas adjacent to worksites. The first alternative considers the remaining carriageway (2 lanes) in addition to the attainable right of way width (remaining of the median and shoulder) for its TTM strategy. The resultant of these segments is approximately 10.00 m, which can be readily rearranged into 3 lanes (=~ 3.3 m). Hence, the first alternative of TTM proposal is to assign 2 lanes to the northbound direction (including the shifted volumes from the right movement), and one lane to the southbound direction. Besides this carriageway rearrangement, there is still sufficient area to maintain the geometry at the intersection, yet to add an individual right-turn lane in order to mitigate the interference between the added right movement volumes and the existed volumes (see Figure 78). The second alternative is to assign the 3 lanes exclusively to the northbound direction (see Figure 79). For the second TTM alternative, the area at the intersection still allows for an additional right-turn lane to serve the newly added right-turning volumes. Both alternative are technically feasible and have their pros and cons, as will be assessed in the effectiveness assessment section.

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Figure 78: TTM Alternative No. 1 at Zayd Ibn Al Khatab Rd. (source: Dornier Consulting GmbH Report).

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Figure 79: TTM Alternative No. 2 at Zayd Ibn Al Khatab Rd. (source: Dornier Consulting GmbH Report).

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As concerns Salah Ad Din Rd., the closure solution of the eastbound carriageway in order to allow the construction of the convergence segment between the station worksite and the transitional ramp could be the very direct strategy to adopt. However, the traffic analysis conducted in the WZIA highlighted the crucial role of Salah Ad Din Rd. and revealed the significance of the traffic volumes that would be diverted in case of this closure being adopted. Therefore, investing in innovative construction methods in a similar approach that is used for Stuttgart 21 can be a better TTM solution for this particular worksite. The TTM alternative is to disassemble the construction worksite into two construction elements, as per demonstrated in Figure 80 and Figure 81, so that the number of lane along Salah Ad Din Rd. can be preserved during the construction, unless for the U-turn in the westbound direction during construction element no.2, hence, the traffic flow can be maintained without disruption. The strategy, as per discussed before in Stuttgart 21, is primarily a TTC measure that is recommended to be applied with PI in order to get the drivers acquainted with the work progress and the real time traffic operational conditions.

Figure 80: Transitional Ramp Worksite at Salah Ad Din Rd., Construction Element No.1

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Figure 81: Transitional Ramp Worksite at Salah Ad Din Rd., Construction Element No.2

3.3.4 I.

TTM Strategies Effectiveness Assessment Zayd Ibn Al Khatab TTM Effectiveness Assessment

Assessment Criterion 1: Safety In reference to the literature review highlights, the safety performance of specific TTM measure or strategy is crucially related to the site-based considerations (location and length of works, traffic volumes and method of construction). On another hand, forecasting and quantifying the impact of the work zone on the number of crashes is usually performed by means of statistical processing of the existed crash records prior to the works. Due to the lack of such kind of records for the implementation area, only qualitative assessment of the proposed two TTM alternatives will be conducted in light of the available data. In brief, both alternatives encompass three lanes along Zayd Ibn Al Khatab Rd., however, alternative no.2 saves extra space at the exit of the worksite of station 3F2 (Figure 79). This space at the worksite exit would provide more safe operation area for the construction fleet (soil removal trucks, workers buses….etc.). Although the buffering space (see ‎1.4.1 Work Zone Dissection According to the MUTCD-USA) is taken into the consideration of the construction footprint, yet this extra saved space by alternative no.2 would provide some backup for trucks holding area or other

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emergencies related to the construction logistics (e.g. worksite evacuation). Therefore, in terms of safety, this space at the worksite exit could prioritize alternative no.2. Assessment Criterion 2: Mobility (Traffic Efficiency) In reference to one of the early findings of the literature review, concerning to assessing and quantifying the traffic efficiency of TTM alternatives by means of sketch planning tools that utilizes volume/capacity ratio and spreadsheet-based queue analysis tools, and with the help of the HCM intersections capacity analysis method, the v/c ratio, control delays, and LOS will be obtained for each alternative and compared to the baseline condition performance indicators. Moreover, queue lengths will be calculated and compared with the available storage spaces in order to avoid the occurrence of spillovers. A brief description of the geometry of each alternative and the involved traffic volumes would be therefore necessary to understand the assessment of each alternative. Alternative no. 1 for Zayd Ibn Al Khatab Rd. (shown in Figure 82) assigns two lanes for the northbound direction; however, the construction footprint is limited to an extent that enables the leverage of the intersection geometry as proposed in Figure 82. According to this proposal, extra queuing distances are provided with the shown dimensions (lane width (w) = 3.3 m) in order to improve the operational conditions and enhance the LOS. The volumes shown here are the volumes observed at the morning peak, though both peaks volumes are considered in the analysis. As could be realized, the right-turn volume from the closed right-turn lane is added here. The other movements are maintained as per observed in the baseline condition. For alternative no.1, a new lane group comprising the right-turn movement is considered for the analysis; thus, the number of lane groups, considered in the analysis at the northbound approach becomes three (3) lane groups (see Figure 83 and Figure 84).

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Figure 82: The Intersection Geometry and Traffic Volumes (Morning Peak) for TTM Alternative No.1 (source: Dornier Consulting GmbH Report).

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Figure 83: Intersection Lane groups for TTM Alternative No.1. Lane Group 5: Left-turn and U-turn (One Lane)

Lane Group 6: Through (Two Lanes)

Lane Group 7: RightTurn (One Lane)

Figure 84: Lane Grouping of Northbound Direction for TTM Alternative No.1 at Zayd Ibn Al Khatab Rd. For the capacity analysis of the intersection considering TTM alternative no.1, it is worth mentioning that the alternative has neither significant impact on the other approaches’ allowed movements, nor on the intersection geometryi. The change intervals therefore were maintained at same values (4 seconds). On another hand,

i

The geometry and the traffic movements at the intersection for the TTM alternative no.1 is

similar to the ones at the baseline condition, however, detailed geometry design for the intersection is outside the context.

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adjustment of the right-turn volumes was undertaken in order to time evenly distribute the traffic volume over lane group no.6 and lane group no.7 (see Figure 84) using the same methodology described in the baseline analysis. In light of these boundary conditions, the analysis was conducted on the same basis used for the baseline condition analysis, and the summarized results are shown in Figure 85and Figure 86. Detailed calculations of the intersection capacity analysis are provided in Appendix 3 and Appendix 4 for the morning and the evening peak respectively.

Figure 85: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Morning Peak- TTM Alternative No.1.

Figure 86: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Evening Peak- TTM Alternative No.1. Noteworthy here is that the RTOR volumes that were obtained from Dornier Consulting GmbH traffic counts for the baseline condition are maintained the same for the TTM alternatives analysis. Although the HCM recommends for RTOR to use field observation counts, but the analyzed scenario here is a future proposal. However, the RTOR volume obtained from these traffic counts is still reliable, since the factors influencing the RTOR are more or less similar to the ones in the TTM alternatives analysis. The RTOR influencing factors are “Approach lane allocation”, “Demand for right-turn movements”, and “Sight distance at the intersection approach” in addition to other factors described in the (HCM 2000, P.16-9).

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As regards alternative no.2 for Zayd Ibn Al Khatab Rd. (shown in Figure 87), the three lanes of the remaining carriageway are assigned to the northbound direction exclusively. This alternative is proposed to provide some extra buffering space around the worksite, however, an exclusive right-turn lane (72 m in length) can still be added at the intersection approach as per shown in Figure 87. Noteworthy here is that this solution has undergone some optimization; since it was found from the preliminary checking that the added right-turn lane (72 m in length) wouldn’t be sufficient to accommodate the expected queue lengths. Therefore, one full lane of the road carriageway along with the right-turn lane was treated in the analysis as right-turn lane group. On another hand, the U-turn movements is eliminated here from the traffic volumes, and it hasn’t been aggregated to the left-turn movement since it is more likely to be dissipated in the left local roads off-Zayd Ibn Al Khatab Rd. This U-turn volume elimination enhanced the capacity reserve of the left-turn lane, thus it could be exploited if used as shared lane traffic. Therefore, the through movement and the leftturn movement were grouped in one lane group. The lane groups of the intersection considered for TTM alternative no.2 are shown in Figure 88, and the particular lane groups of the northbound traffic approach are illustrated in Figure 89.

Figure 87: The Intersection Geometry and Traffic Volumes (Morning Peak) for TTM Alternative No.2 (source: Dornier Consulting GmbH Report).

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Figure 88: Intersection Lane groups for TTM Alternative No.2 (source: Lane Group 5: Left-Turn and Lane Group 6: Right-Turn Through (Two Lanes) (Two Lanes)

Figure 89: Lane Grouping of Northbound Direction for TTM Alternative No.2 at Zayd Ibn Al Khatab Rd. (Morning Peak). For this TTM alternative, the geometry of the intersection and the allowed traffic movements have some major changes, some traffic streams are merged (westbound through and westbound left are merged together), other streams were expected to relocate (southbound through is relocated entirely in the southbound right and expected to be exposed to detour), and finally anther trend where the stream is expected to dissipate in the detour before approaching the intersection (eastbound right is expected to start the detour before approaching the intersection). These major changes in the intersection geometry and movements have to be taken concisely into

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account for the capacity analysis. On another hand, the impacts of the geometry changes on the change intervals were found to be minor, and the de-facto standard value (4 seconds) is still used for the analysis. Moreover, the erasing (merging) of some specific traffic streams would necessitate the lane dimension (width) adjustment, which will consequently influence the lane group saturation flow. Again, in light of these boundary conditions, the analysis was performed, and the obtained results are demonstrated in Figure 90 and Figure 91 for the morning and the evening peak respectively. The detailed analysis calculations are provided in Appendix 5 and Appendix 6.

Figure 90: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Morning Peak- TTM Alternative No.2.

Figure 91: Lane Groups’ v/c Ratios, Control Delays and LOS at the Intersection during Evening Peak- TTM Alternative No.2. Noteworthy here is that the control delay per vehicle at the intersection is not the only delay component encountered for TTM alternative no.2, since the restricted traffic movements that have to undergo kind of detour, encounter another delay component (detour delay). In order to estimate this detour delay, at first the potential detours route has to be anticipated. Figure 92 demonstrates the shortest possible detours from the intersection centroid considered for these particular traffic streams that need to undertake detour. These traffic streams are the westbound-left movement, the southbound-through movement and the eastbound-right movement. The three shortest

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possible detours for the respective traffic streams are shown to the nearest point on the road course of Zayd Ibn Al Khatab after the road has started to operate normally in both directions. The lengths of this detours are approximately 0.87 Km for the southbound-through and westbound-left, and 0.39 Km for the eastbound-right, whilst the length of the original route before the introducing of the TTM alternative is 0.24 Km, thus the extra traveled distance is 0.63 Km for the southbound-through and westboundleft, and 0.15 for the eastbound-right. Noteworthy here is that the traffic stream northbound-U-turn is not included in the detour calculations since the TTM alternative no.2 shifts the lane adjacently to the local roads that would have been probably the destination of those U-turners, therefore they would not have to undertake any detours. An average speed of 25 Km/h is assumed for the proposed detour link, taking into account the acceleration from the intersection and the deceleration for the turns, besides the speed restrictions in local roads. Hence, the excess in the delay due to the potential detour induced by TTM alternative no.2 is expected to be approximately 90 seconds per vehicle for the detoured southbound through and the detoured westbound left, and expected to be approximately 22 seconds per vehicle for the detoured eastbound right.

Figure 92: Potential Detour for Zayd Ibn Al Khatab Southbound Direction (source:

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The effectiveness assessment of the proposed TTM alternatives in terms of mobility (traffic efficiency) should compare the total delays (control delays and detour delays) for each alternative with the baseline condition, and to investigate the expected queue lengths in order to make sure that the available storage lanes can accommodate these queues. The total delays are obtained by multiplying the each delay category by its corresponding number of vehicles at each intersection approach. The detailed calculations of the total delays are provided in Appendix 7 and Appendix 8. The summarized total delays for both TTM alternatives in comparison to the baseline condition are shown in Figure 93 and Figure 94 for the morning peak and the evening peak respectively. Alternative no.2 tends to trigger extra total delays in the morning peak, whilst alternative no.1 triggers extra total delays in the evening peak.

Figure 93: Total Delays at the Intersection- Morning Peak.

Figure 94: Total Delays at the Intersection- Evening Peak.

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In reference to the conducted intersection capacity analysis for the proposed TTM alternatives, besides the baseline condition, it can be readily observed that the overall LOS of the intersection is better at operational conditions of TTM alternative no.1 (LOS D), than at the ones of TTM alternative no.2 (LOS E) during the morning peak hour. For the evening peak, both alternatives have the same LOS D. Moreover, the alternative no.1 utilizes the available carriageway and the space at the intersection approach (Zayd IbnAl Khatab Rd.) efficiently. This efficient exploitation is underlying in the fact that carriageway of alternative no.1 comprises two major lanes only, whilst for alternative no.2 comprises three major lanes; however, the average control delay per vehicle of the whole approach (northbound approach) for TTM alternative no.1 is less than the average control delay of the whole approach for TTM alternative no.2, at the morning peak hours (see Table 17and Table 19), which is considered the critical peak hour. Although this is not the case during the evening peak hours (see Table 18 and Table 20), but the detoured traffic streams due to TTM alternative no.2 should be taken into account. The approach LOS for both alternatives remains the same, (E) for the morning peak hours and (D) for the evening peak hours, but for the overall intersection LOS, it is inclined towards TTM alternative no.1, as per highlighted. Table 17: Northbound Approach Control Delays and LOS for TTM Alternative No.1Morning Peak Northbound

Lane Group 5

Lane Group 6

Lane Group 7

Average

No. of Vehicles

162

680

337

Control Delay per Vehicle (sec)

45.34

55.16

81.88

61.45

LOS

D

E

F

E

Table 18: Northbound Approach Control Delays and LOS for TTM Alternative No.1Evening Peak Northbound

Lane Group 5

Lane Group 6

Lane Group 7

No. of Vehicles

198

461

269


43.85

41.15

82.93

53.83

LOS

D

D

F

D

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Table 19: Northbound Approach Control Delays and LOS for TTM Alternative No.2Morning Peak Northbound

Lane Group 5

Lane Group 6

Average

No. of Vehicles

763

393


73.44

47.53

64.63

LOS

E

D

E

Table 20: Northbound Approach Control Delays and LOS for TTM Alternative No.2Evening Peak Northbound

Lane Group 5

Lane Group 6

Average

No. of Vehicles

479

380


46.57

42.59

44.81

LOS

D

D

D

Based on the demonstrated results for the northbound approach, and the number of vehicles engaged in the morning and the evening peak hours, taking into account the impact on the whole intersection approaches (total delays), either due to control delays or detour delays, TTM alternative no.1 is recommended based on the mobility (traffic efficiency) assessment. Meanwhile, the traffic efficiency of the southbound lane in alternative no.1 is questionable, but referring to the fact that for the baseline condition, Zayd Ibn Al Khatab Rd. operates with one lane only due to the on-street parking as per discussed in the implementation area data, and the de-facto traffic operational condition “Site visits have shown that the existing cross section of the road is reduced due to parking to 1 lane per direction, without significant impact on traffic flow” (Dornier Consulting GmbH, P. 24); this can guarantee the functionality of the single operating lane at Zayd Ibn Al Khatab Rd., for the TTM alternative no.1 at the southbound direction. The control delays as a traffic measure could initially help in assessing the two proposed TTM alternatives; consequently prioritize one alternative on the expense of the other. In order to fully assess the two alternatives from technical feasibility perspective, the queue lengths should be estimated for both alternatives and checked in light of the available distances between the intersection in question, and the successive intersections, thus the occurrence of spillovers is minimized. HCM 2000 provides a model to determine the back of queue at signalized intersections in Chapter 16, Appendix G. Hereinafter, a brief description of the model and its application in the case study, is demonstrated throughout Equation 11 to Equation 19. 𝑄 = 𝑄1 + 𝑄2

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Equation 11

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 “𝑄: Maximum distance in vehicles over which queue extends from stop line on average signal cycle (veh);  𝑄1 : first-term queued vehicles(veh);  𝑄2 : second-term queued vehicles (veh).” (Source: HCM 2000, P.16-152) 𝑄1 = 𝑃𝐹2

𝑉𝐿 𝐶 3600 ×

𝑔

(1 − ) 𝐶⁄ 𝑔 1 − [min(1.0, 𝑋𝐿 ) ]

Equation 12

𝐶

    

“𝑃𝐹2 : Adjustment factor for effects of progression; 𝑉𝐿 : Lane group flow rate per lane (veh/h); 𝐶: Cycle time (sec); 𝑔: Effective green time (sec); 𝑋𝐿 : volume-capacity ratio v/c.” (Source: HCM 2000, P.16-152) 𝑃𝐹2 ≅ 1

Equation 13

𝑄2 = 0.25 𝑐𝐿 𝑇 [(𝑋𝐿 − 1) + √(𝑋𝐿 − 1)2 +     

8𝐾𝐵 𝑋𝐿 𝑐𝐿 𝑇

+

16𝐾𝐵 𝑄𝑏𝐿 ] (𝑐𝐿 𝑇)²

Equation 14

“ 𝑐𝐿 : Lane group capacity per lane (veh/h). 𝑇: Length of analysis period (h). 𝑋𝐿 : Volume-capacity ratio v/c. 𝐾𝐵 : Second-term adjustment factor. 𝑄𝑏𝐿 : Initial queue at start of analysis period(≅ 0).” (Source: HCM 2000, P.16-153) 𝐾𝐵 = 0.12 𝐼 (

𝑆𝐿 ×𝑔 0.7 ) 3600

(Pre-timed Signals)

Equation 15

 “𝑆𝐿 : Lane group saturation flow rate per lane (veh/h).  𝑔: Effective green time (sec).  𝐼: Upstream filtering factor for platoon arrivals.” (Source: HCM 2000, P.16-153) Average queue lengths estimated for both alternatives at morning and evening peak hours seem to be technically feasible and fit within the available distances (see Appendix 9, Appendix 10, Appendix 11 and Appendix 12). The HCM recommends calculating the percentile back of queue (Equation 16) for any desired percentile on the analyzed lane. The percentile is a factor of safety that considers the deviation of the operational conditions from the average performance. In other words, the probability for the average back of queue to be exceeded is 50%, whilst for the 95 th percentile back of queue; it is only 5%. The percentile back of queue is obtained by multiplying the average back of queue by the desired percentile back of queue factor; this factor is calculated dependently on three parameters (Equation 17) corresponding to the mode of the signal operation whether it is pre-timed or actuated (HCM 2000, P.16-156). For

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the case study, the signal is pre-timed. The 95th percentile back of queue is considered in the calculations provided in the appendices in order to investigate the queue lengths at the most unfavorable operational conditions. These conditions, however, would not be the predominant ones during the peak hours due to the rarity of occurrence for such event (95th). 𝑄% = 𝑄 𝑓𝐵

Equation 16

 “𝑄% : Percentile back of queue (veh);  𝑄: Average number of vehicles in queue (veh);  𝑓𝐵 : Percentile back-of-queue factor.” (source: HCM 2000, P.16-155) −𝑄

𝑓𝐵 = 𝑃1 + 𝑃2 𝑒 𝑃3

Equation 17

 “𝑃1 : First parameter for percentile back-of-queue factor;  𝑃2 : Second parameter for percentile back-of-queue factor;  𝑃3 : Third parameter for percentile back-of-queue factor.” (source: HCM 2000, P.16155, 156) Subsequent to the back of queue (percentile back of queue) calculations, here comes the final step of this assessment according to the HCM 2000; the queue storage ratio. “The back-of-queue measure is useful for dealing with the blockage of available queue storage distance, determined by the queue storage ratio.” (HCM 2000, P.16-156). In the analysis, both back of queue values are considered, the average back of queue and the percentile back of queue. 𝑅𝑄 =

𝐿ℎ 𝑄 𝐿𝑎

Equation 18

 “𝑅𝑄 : Average queue storage ratio;  𝐿ℎ : Average queue spacing (6.0 m);  𝑄: Average number of vehicles in queue (veh);  𝐿𝑎 : Available queue storage distance (m).” (source: HCM 2000, P.16-156) 𝑅𝑄% =

𝐿ℎ 𝑄% 𝐿𝑎

Equation 19

 “𝑅𝑄% : Percentile queue storage ratio.” (source: HCM 2000, P.16-156) Figure 95 and Figure 96 depict the average and 95th percentile queue storage ratio for the different traffic movements at the intersection approach, estimated for TTM alternative no.1 during the morning and the evening peak hours respectively. Whilst Figure 97 and Figure 98 depict the same parameters estimated for alternative no.2 during the morning and the evening peak hours as well. Noteworthy here is the TTM no.1 potential for blockage at the shared lane for the northbound u- and left-turn movements. This could be explained in terms of the limited available storage distance

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(68 m); therefore, some geometry adjustment is recommended in case the TTM alternative is adopted. Indeed, this is conforming to Wu, N.84 abstract highlights concerning to the average queue length and the 95th percentile queue length, since the first terms (average queue length) assesses the performance at the intersection, whilst the second term (percentile queue) “used for determining the length of the turning lane”, (Wu, N. Bochum, Germany). On the other and, all back of queues for all the approaches fit adequately within the available storage distances for both TTM alternatives.

Figure 95: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.1Morning Peak Hour.

Figure 96: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.1Evening Peak Hour.

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Figure 97: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.2Morning Peak Hour.

Figure 98: Average and 95th Percentile Queue Storage Ratio for TTM Alternative No.2Evening Peak Hour. Assessment Criterion 3: Environment (Pollution Reduction) As per discussed in the literature review, assessing the alternative impacts based on their effectiveness in reducing the traffic-related pollution triggered by work zones, can be efficiently performed by means of emission forecasting models (static or dynamic), which is integrated in most of the microscopic traffic simulation programs. Due to the unavailability of this tool for the implementation area, another approach may be adopted for predicting and comparing the emission rates for the two alternatives. The approach is to synthesize two trends of emission rates predicting; first is to obtain the vehicles emissions as a function of “commonly used traffic measure, control delay” (Rouphail, et. Al, 2000)85. This first trend can be readily applied to the capacity analysis results of the two TTM alternatives, performed in the previous part. The second trend is to obtain the vehicles emissions as a function of the driven Kilometers as per described in different literatures. Abu-Allaban, M., et al, 200786 is selected to be used in the analysis here since it provides emissions rates from Jordan, where exist similar traffic and climatic conditions to the ones in the implementation area (Saudi Arabia). This

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shall be utilized to calculate the emissions of the diverted fleets in TTM alternative no.2 (eastbound-right, westbound-left and southbound-through), and compare them with the emissions from the same un-diverted fleets for TTM alternative no.1. Table 21 summarizes the rates obtained from the two trends of calculation for three kinds of emissions; namely Nitrogen oxides (NOx), Hydrocarbons (HC) and Carbon monoxide (CO). It is worth mentioning here the rates obtained from (Rouphail, et. Al, 2000) were based on the observation of mixed size fleet, hence average value of observations was selected to be utilized in the analysis here. Whilst the values obtained from (Abu-Allaban, M., et al, 2007) are average values for the prevailing operational conditions and traffic composition. Table 21: Emissions Rates for TTM Alternatives Assessment (source: Rouphail, et. Al, 2000, and Abu-Allaban, M., et al, 2007) Nitrogen oxides (NOx)

Hydrocarbons (HC)

Carbon monoxide (CO)

Milligrams/seconds (Rouphail, et. Al, 2000)

1.1

0.45

15

Grams (g)/Kilometer Traveled

0.1

1

33.9

(Abu-Allaban, M., et al, 2007)

Appendix 13 and Appendix 14 demonstarte the calculation steps of the emissions produced by TTM alternatives for the morning peak as well as the evening peak hours. The emissions calculation methodology in brief comprises two steps; first to calculate the emissions from the control delays at the intersection pproaches, second to calculate the emissions from the traveled kilometers by the traffic streams. It is worthy highlighting that in this step of emissions calculation per traveled kilometer, not all traffic streams were considered, yet only the traffic streams that have to undergo detour for TTM alternative no.2 (southbound-through, westbound-left, and eastboundright). Consequently, the traveled kilometers by the same traffic streams in alternative no.1 have to be taken into account in order to maintain the assessment rigorous and robust. The summarized results of the environment (pollution reduction) assessment of the two proposed TTM alternatives are demonstrated in Table 22and Table 23 for the morning and the evening peak hours respectively, and graphical comparisons between the two alternatives are demonstrated in Figure 99 and Figure 100, for the two peak hours as well. Table 22: Emissions Values during Morning Peak Hour for the Two TTM Alternatives Alternative No.1 (grams/Morning Peak)

Alternative No.2 (grams/Morning Peak)

Nitrogen oxides (NOx)

391.7

493.8

Hydrocarbons (HC)

341.2

799


11480.5

26986.3

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Figure 99: Comparison between the Two TTM Alternatives for Emissions Produced at Morning Peak Hour. Table 23: Emissions Values during Evening Peak Hour for the Two TTM Alternatives Alternative No.1 (grams/Morning Peak)

Alternative No.2 (grams/Morning Peak)

Nitrogen oxides (NOx)

350.9

287.3

Hydrocarbons (HC)

395

882.9


13314.7

29883.4

Figure 100: Comparison between the Two TTM Alternatives for Emissions Produced at Evening Peak Hour.

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It could be easily interpreted from the demonstrated results and figures that TTM alternative no.2 tends to produce more emissions. This excess in emissions production is remarkable for the carbon monoxide, either for the morning peak hour or the evening peak hour. The difference in the produced emissions between the morning peak and the evening peak for alternative no.2 can be explained in terms of the excess in the demand on the traffic streams that have to make detours for this alternative. Assessment Criterion 4: Social Inclusion As per recommended in the literature review, the criterion of social inclusion is preferred to be studied individually depending on the socioeconomic context of the implementation area. From the socioeconomic structure described in the implementation area data section, it was concluded that the area is predominantly residential area. Therefore, to address the social inclusion as an assessment criterion for TTM alternatives, two aspects shall be covered; first is the anticipated impacts from the TTM alternatives on the residents (noise, safety or deteriorated accessibility), second is the land used for purpose of TTM. Assessing these two aspects could investigate to a great extent the social acceptance of a specific TTM measure or alternative, and profoundly include the society as an assessment criterion for TTM. First are the anticipated impacts on the society from each TTM alternative. For alternative no.1, apart from the encountered impacts on the road users (delays, queues), the road carriageway is still aligned within its preexisted course along Zayd Ibn Al Khatab Rd., therefore, no significant excess in noise or air pollutants is expected to be encountered by the residents in the implementation area. Safe and adequate pedestrian routes are provided along the east perimeter of the worksite to provide an access to the residential buildings entrances, thus minimized impacts on the pedestrian accessibility are expected for alternative no.1. However, this is not the case for alternative no.2, since the closure of Zayd Ibn Al Khatab southbound direction is expected to expose the residential areas to “rat-runs”, associated with extra noise and air pollutants. Moreover, the roads within these residential areas are designed for local traffic only; the exposure to through traffic may trigger serious safety concerns. As regards the used land for purpose of TTM, two kinds of land use can be introduced here, direct use; where the land is occupied directly by the TTM measure (including carriageways, taper lengths, installed devices…etc.), and indirect use, where extra land may be used by specific diverted fleet, as per described in the previous paragraph in what is so called “rat-runs”. The direct use of land for both alternatives is approximately the same, but for the indirect use, alternative no.2 has an increased land use (consumption). Thus, alternative no.2 tends to occupy more land. Taking into account the two assessed aspects (impacts on residents and land use) for both alternatives, alternative no.1 is expected to gain more societal acceptance and enhances the social inclusion role in the TTM planning.

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II.

Salah Ad Din Rd. TTM Effectiveness Assessment

The proposed TTM strategy for Salah Ad Din Rd. shall be assessed against the nooption alternative described in section ‎1.6.3 (Cost Effectiveness Evaluation). The strategy proposed for Salah Ad Din Rd. is to utilize innovative construction that divides the construction segment in conflict with the roadway into two successive finite construction elements in a sequence that maintains the same number of lanes during the construction of each element, unless for the U-turn in the westbound direction during construction element no.2 (see Figure 80 and Figure 81). This innovative solution was proposed as TTM strategy since the possible alternative is the fully close the eastbound carriageway of Salah Ad Din Rd., where significant volumes of traffic should be diverted, besides the major role of the road not only for the neighborhood, yet for Riyadh mobility. Hence, to decide upon the adoption of this proposed TTM strategy, a cost effectiveness evaluation should be conducted as per recommended in the literature review for these kind of situations, where one specific TTM solution is assessed against the no-option alternative (full closure). In the following paragraphs, the developed methodology of the cost effectiveness analysis will be described, although the application is limited in the thesis case study of Metro Riyadh due to the lack of data needed for the developed methodology (data concerning to the cost and other fiscal parameters). Hence, the methodology will be described in terms of development process only. At first, the impact of the strategy on the construction duration should be studied and described for the two alternatives as following: 𝑇0 is the construction duration for no-option alternative (Full closure), and 𝑇1 is the construction duration, taking into account the proposed TTM strategy. Thereafter, the first cost component, which is the worksite daily operation cost should be investigated and calculated, including the fixed and the variable cost. There might be some differences between the worksite operation cost for the two different construction methods, since the dividing of the construction segment into two elements may require specific high-tech solutions, certain curing material or high-qualified expertise. Besides the TTM strategy non-recurrent cost (𝐶𝑇𝑇𝑀,𝐼 ) that encompasses the strategy cost of implementation (devices, signs, signals …etc.), the worksite daily operation cost should be addressed again for the two alternatives as 𝐶𝑤,0 and 𝐶𝑤,1 for the no-option alternative and the proposed TTM strategy respectively. The second cost component addressing the road user cost (RUC) shall be calculated as per described in the literature review. It comprises four (4) parameters; work zone travel delay cost, work zone vehicles operation cost, work zone crash cost and work zone emissions cost. It should be borne in mind that these costs are the excessive ones incurred by the road users due to specific operational conditions deviated from the baseline conditions. The RUC is not limited to the no-option alternative, since the introducing of the TTM strategy will necessarily trigger some extra RUC due to the changed geometry of the roadway, the minimized lane width and the expected declined

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speed. The potential detours for the no-option alternative shall be determined since it is the main input to calculate the travel delays, vehicles operating costs and to forecast the excess in the crash rates as well as the emissions rates. This task is strongly recommended to be performed by means of traffic macroscopic simulation, since it considers the origin-destination relations and it is equipped with emissions estimating models. RUC parameters should be described for the no-option alternative and the TTM strategy as following:  Work zone travel delay cost: 𝐶𝑡𝑡,0 𝑎𝑛𝑑 𝐶𝑡𝑡,1 ; for the no-option alternative and the TTM strategy respectively. (Currency/day)  Work zone vehicles operating cost: 𝐶𝑣𝑜,0 𝑎𝑛𝑑 𝐶𝑣𝑜,1 ; for the no-option alternative and the TTM strategy respectively. (Currency/day)  Work zone crash cost: 𝐶𝑐,0 𝑎𝑛𝑑 𝐶𝑐,1 ; for the no-option alternative and the TTM strategy respectively. (Currency/day)  Work zone emission cost: 𝐶𝐸,0 𝑎𝑛𝑑 𝐶𝐸,1 ; for the no-option alternative and the TTM strategy respectively. (Currency/day) Hence, the RUC for the no-option alternative can be obtained as illustrated in Equation 20, and the RUC for the TTM alternative as illustrated in Equation 21. 𝑅𝑈𝐶0 = 𝐶𝑡𝑡,0 + 𝐶𝑣𝑜,0 + 𝐶𝑐,0 + 𝐶𝐸,0

Equation 20

𝑅𝑈𝐶1 = 𝐶𝑡𝑡,1 + 𝐶𝑣𝑜,1 + 𝐶𝑐,1 + 𝐶𝐸,1

Equation 21

Finally, the cost effectiveness of the TTM alternative can be assessed by means of the Cost Effectiveness Index (CEI), illustrated in Equation 24. 𝐶𝑜𝑠𝑡 𝐸𝑓𝑓𝑒𝑐𝑡𝑖𝑣𝑒𝑛𝑒𝑠𝑠 𝐼𝑛𝑑𝑒𝑥 (𝐶𝐸𝐼) (𝑅𝑈𝐶0 × 𝑇0 ) − (𝑅𝑈𝐶1 × 𝑇1 ) = 𝐶𝑇𝑇𝑀,𝐼 + (𝐶𝑤,1 × 𝑇1 ) − (𝐶𝑤,0 × 𝑇0 )

Equation 22

The CEI is an efficient planning tool that enables the planner from making decisions supported by rigid figures obtained from a rigorous analytical framework. It is commonly used in the U.S practice as decision making tool in different areas of application, among which is the transport sector and traffic measures strategic planning. Massachusetts Department of Transportation87 identifies the CEI as “An index that is based on cost, average insertion loss, and the number of benefited receptors and, if applicable, average time per visit”. For the proposed TTM strategy (innovative construction method) to conclude to an adopting-supported decision making, CEI (Equation 22) must be higher than 1, so that the strategy can reflect economic feasibility.

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3.4

Recommended Temporary Traffic Management Plan for Zayd Ibn Al Khatab Rd.

The effectiveness assessment of the proposed TTM alternatives, conducted in the previous section, highlighted the performance of each alternative in terms of the four criteria of assessment. Noteworthy here is that for the 3F2 worksite, the assessment is inclined towards specific assessment criteria (mobility, pollution reduction and the social inclusion) on the expense of the remaining assessment criterion (safety). Indded, this is profoundly related to the residential nature of the implementation area neighborhood, hence, enhancing the traffic efficiency which would consequently reduce the traffic-related emissions triggered by the work zone, should be a clear objective of the TTM plan. On another hand, the nature of this residential area boosts the significance of the social acceptance. As regards the safety criterion context here in 3F2 station worksite, it is concerned primarily about the construction site safety, which could be enhanced throughout other feasible measures. Table 24 summarizes the assessed criteria, and the evaluation of each TTM alternative on their scale. The recommended alternative for Zayd Ibn Al Khatab Rd. is the TTM alternative no.1, where the available carriageway is leveraged for three lanes; two lanes for the northbound direction, and one lane for the southbound direction. At point, accordingly with the literature review findings and the lessons learned from the cases analysis, the TTM plan shall comprise certain measures that integrate with each other on exclusive scales (local scale, corridor/network scale and the regional scale), but in a collective way. These measures referred to are the TTM typical components; namely the TTC, TO and the PI. The TTC plan is the one elaborated throughout the previous sections, striving at controlling the traffic flow adjacent to the worksite at Zayd Ibn Al Khatab Rd. The detailed TTC plan is shown in Figure 101, and the dimensions justification is provided hereinafter. As regards the TO and the PI, they will be addressed in the mitigation measures section. Table 24: TTM Alternatives- Summarized Evaluation Criteria Criterion

TTM Alternative No.1

TTM Alternative No.2

Safety

Feasible

Feasible

Mobility (Traffic Efficiency)

Recommended

Feasible

Environment (Pollution Reduction)

Strongly Recommended

Not Recommended

Social Inclusion

Strongly Recommended

Not Recommended

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Figure 101: Recommended TTC Plan for Zayd Ibn Al Khatab Rd. The elaborated TTC plan is similar to typical application (TA-31) of the “MUTCD”; namely “Lane Closure on a Street with Uneven Directional Volume” (MUTCD 2009, P.695), besides another typical application (TA-24) from the “MUTCD”; namely “Half Road Closure on the Far Side of an Intersection” (MUTCD 2009, P.681). Hence, the recommended plan of the TTM proposed for Zayd Ibn Al Khatab Rd. that provides the TTC devices deployment, recommended speed limit, consequently the recommended taper lengths, and the restricted traffic movement is a hybrid plan of these two typical applications. The taper lengths are calculated based on an allowed speed of 40 Km/h

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as per described in the literature review ( ‎1.4.1 Work Zone Dissection According to the MUTCD-USA; Table 2), thus the first taper length for the northbound direction subsequent to the advance warning area is obtained as following (Equation 23), taking into account that it is a shifting taper. 𝑇𝑎𝑝𝑒𝑟 𝐿𝑒𝑛𝑔𝑡ℎ 1 (𝑓𝑡) = (≥ 0.5) ×

𝑊𝑆² 60

Equation 23

 “𝑊: width of offset in ft.”  𝑆: anticipated operating speed in mph” (Source: MUTCD 2009, P.557). 𝑊 = 6.5 m in feet = 21.33 ft., and 𝑆 = 40 Km/h = 24.85 mph. ∴ 𝑇𝑎𝑝𝑒𝑟 𝐿𝑒𝑛𝑔𝑡ℎ 1 ≥ 109.76 ft. = 33.45 m ≅ 35 m. In a similar sequence, but functioning as a merging taper, the second taper length for the southbound direction is calculated as following (Equation 24): 𝑇𝑎𝑝𝑒𝑟 𝐿𝑒𝑛𝑔𝑡ℎ 1 (𝑓𝑡) =

𝑊𝑆² 60

Equation 24

(Source: MUTCD 2009, P.557). 𝑊= 3.5 m = 11.48 ft., and 𝑆= 40 Km/h = 24.85 mph. ∴ 𝑇𝑎𝑝𝑒𝑟 𝐿𝑒𝑛𝑔𝑡ℎ 2 ≥ 118.15 ft. = 36 m ≅ 45 m. As regards the advance warning area, comprising the three warning signs, they are distributed at equal distances of 30.48 m, in accordance to the recommendation of the MUTCD 2009, referred to in Table 1 in the literature review. At this point, the TTC Plan is fully developed, and justified in terms of dimensioning. In the following two sections, this recommended TTM alternative is going to be analyzed in terms of its strengths and weaknesses in order to highlight the necessary mitigation measures to be adopted on urban/network scale (TO) and on the regional/state scale (PI), that would be an asset to use in case of any performance deficiencies that may arise during the post-installation monitoring phase.

3.4.1

Strengths and Weaknesses (SW) Analysis

On one hand, the recommended TTM alternative maintains the same traffic movement at the intersection in the implementation area, which will consequently minimize the disruption induced by the worksite. The alternative is considered for the same signal plan (program) existed prior to the work zone, thus, no re-timing impacts are transferred to the other intersection in the neighborhood, in the vicinity or successive to the intersection in the implementation area. Moreover, the overall intersection LOS for the recommended alternative is preserved as the baseline condition (LOS D). Hence, it

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could be concluded that the work zone will not significantly influence the traffic streamlining, and the traffic flow will be operating in semi-similar pattern to the one existed at the baseline condition. Minor impacts are expected from the lanes geometry alteration, and the reduced speed limit (40 Km/h instead of 50 Km/h), only along the link adjacent the worksite (3F2 station). On the other hand, there two weaknesses observed during the TTM strategic planning. One weakness is the exceeded queue length for northbound left- and U-turn traffic movement, particularly the 95th percentile back of queue, since the average back of queue is within the available storage distance. The 95th percentile queue storage ratio at this traffic movement is 1.06 for the morning peak and 1.32 for the evening peak. This reflects shortage in the available storage distance (turning lane storage length), and would trigger risk of queue spillover to the adjacent lane, although this might not be the prevailing operational condition. The second weakness underlying in the alternative is the single operating lane in the southbound direction of Zayd Ibn Al Khatab, despite of the site visits and observation during the baseline condition revealed no severe impacts from such condition (single operating lane).

3.4.2

Mitigation Measures

A phenomenon was observed during the baseline condition analysis, which is the existence of right-turn volumes at the northbound direction approaching the intersection despite of the existed exclusive right-turn lane off-Zayd Ibn Al Khatab Rd., this reflects the lack of self-explanatory TTC and TO measures in the implementation area, prior to the worksite activities to commence. The lack of user-friendly measures would trigger aggravate impacts after the construction works to be launched in full capacity. For example, if the same non-self-explanatory traffic signage exists at the southbound direction for the exclusive right-turn lane, this would convey undesired right-turn volumes to the signalized intersection, which will consequently deteriorate the capacity drastically. Hence, an efficient exploitation of self-explanatory traffic control measures is strongly recommended in order to mitigate the potential weaknesses in the plan. In regard to the particular weaknesses highlighted in the SW analysis, here are potential TTM measures and solutions are recommended. For the exceeded percentile queue length of the left-turn lane at the northbound direction of Zayd Ibn Al Khatab Rd., the area available for the turning lane has some certain restrictions, thus adjusting the geometry may not be feasible. However, adjusting the lane geometry might not be the optimum solution, taking into account the prevailing operational conditions. Therefore, traffic surveillance via CCTV is recommended for the post-installation monitoring phase for this particular left-turn lane. Based on traffic surveillance, signal plan optimization and coordination with the other signalized intersection could be an effective solution for exceeded queue lengths. Regular team meetings for the TTM concerned bodies are indispensable to regularly assess the TTM performance and step back to optimize the plan.

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The existence of the 22,500-capacity Stadium of Prince Faisal Bin Fahd for El- Nasr Football Team in the vicinity of the worksite (300 m) as a trigger for sport events, involving massive volumes of traffic and pedestrians, is considered among the issues that should be addressed in the TTM plan. Traffic management and enforcement strategies shall apply for such case and the coordinator shall be declared and authorized for undertaking this task. Finally, acquainting the people with the planned construction works, potential local detours, work progress and the de-facto traffic conditions in the implementation arae from one hand and in the other work zones of Metro Riyadh on another hand would facilitate the task of the TTM plan and enhance the rational driving within the work zones. This could be pursued by means of launching project website, press release, leveraging the role of the social media and finally provide visual information. Table 25 summarizes the discussed mitigation measures and strategies accordingly with the provision set forth in “RULE ON WORK ZONE SAFETY AND MOBILITYDeveloping and Implementing Transportation Management Plans for Work Zones”, P.4-2 and P.4-3 and the literature review understanding. Table 25: TTM Integrative Mitigation Measures and Strategies (source: RULE ON WORK ZONE SAFETY AND MOBILITY- Developing and Implementing Transportation Management Plans for Work Zones, P.4-2 and P.4-3) Transportation Operation Strategies (TO)

Public Information Strategies (PI)

Corridor/Network Management Strategies

Work Zone Safety Management Strategy

Traffic/Incident Management and Enforcement Strategies

Public Awareness Strategies

Signal Timing/ coordination improvements

TMP (TTM Plan) Monitor/ inspection team

Surveillance

Project website

Coordination with adjacent construction sites

Team meetings

Local detour routes

Press release and media alert

Incident/ emergency management coordinator

Visual information

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4 Conclusion The thesis endeavored to elaborate a comprehensive temporary traffic management framework for major construction projects, in which, a considerable fraction of the road network is engaged. Within this context, the challenges, limitations and the construction impacts induced by these kinds of projects were aimed to be analyzed and processed, in order to be addressed within this framework of sustainable traffic management that strive at providing safe and efficient traffic flow. Published international standards from USA and UK were investigated in the literature review in order to develop a coherent understanding for the theme of the thesis. In light of this investigation and analysis, it could be possible to conclude to the three main finding of the literature review. The findings are highlighted as follows: 1. Temporary Traffic Management Strategic Planning. 2. Temporary Traffic Management Strategies. 3. Evaluation Scheme of Temporary Traffic Management Strategies. The planning and elaboration of comprehensive temporary traffic management scheme for a major construction project was addressed as “strategic planning”. This terminology refers to the process of developing specific sets of strategies in order to address, mitigate and minimize the impacts triggered by certain condition. The development process were investigated in light of the provisions from USA and UK, and led to the second and the third findings of the literature review. The analytical loop of the strategic planning can be concluded here in the following few key words: Work Zone Impacts Assessment; Impacts on Safety and Mobility Identification; Elaboration of Strategies (Alternatives); Assessing the Effectiveness of the Alternatives; Recommended Alternative; Strengths-Weaknesses Analysis of the Alterative; Recommended Mitigation Measures; Implementation; Post-Installation Monitoring and finally, Modify If needed. This logical workflow is described in the developed scheme of the “comprehensive temporary traffic management plans” at the end of the literature review. As per aforementioned, the strategic planning notion led to reveal the trends of the temporary traffic management strategies. The strategies of temporary traffic management described in the investigated standards fall under three categories, namely; temporary traffic control, transportation operation and public information. Further investigations revealed that each strategy category act independently, but in a collectively exhaustive approach within the temporary traffic management framework. In other words, the level of influence of each strategy is distinct, but they integrate with each other. For the temporary traffic control strategies, the area of influence is the local scale of the work zone, since the strategy strive at providing measures and solutions in order to maintain the traffic flow, within or adjacent to the work zones, at safe and acceptable operational conditions. As regards the transportation operation, the level of influence goes to another tier, which is the corridor or road network level. For this

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Conclusion

strategy, the work zone impacts are tackled on a larger scale, consequently other trend of traffic management solutions and measures are addressed. The last category of the revealed strategies is the public information, it could be readily interpreted that the area of influence is upgraded to the state or the regional level. The three categories of temporary traffic management strategies were found to be profoundly related to the area of application of major construction projects, due to the extensive impacts triggered by the work zones of these projects, and the need to address these impacts on a multi-level scale. The third finding of the literature review is the evaluation scheme used to assess the effectiveness of proposed temporary traffic management alternatives, or to evaluate the performance in the post-installation phase. Two trends of effectiveness assessment were revealed in the literature review. First trend is to assess two or more scenarios of temporary traffic management in terms of safety, mobility (traffic efficiency), pollution reduction and the social inclusion. Second trend is to assess one specific temporary traffic management solution or strategy against the no-option alternative in terms of cost effectiveness. The “no-option alternative” refers to the construction works implementation without adopting any traffic management solutions. This second trend is based on comparing two cost components; the cost of implementation for the temporary traffic management strategy or solution, and the cost incurred by the road users for the no-option alternative. A review of the road user cost monetizing methodology was provided in the literature review. This extensive analysis of the temporary traffic management framework could facilitate to track the real practice in the cases analysis. The aim behind the cases analysis chapter was to impart rigorous analysis in the thesis methodology throughout analyzing three major projects; hence the link between the theory and the real practice could be revealed and highlighted. Moreover, the lessons learned from these cases analysis can be conveyed to be applied in the case study. The projects analyzed in the cases analysis chapter were Dulles Corridor Metrorail, London Crossrail and Stuttgart 21. The three cases analysis enriched the thesis framework, since each project belongs to distinct area of implementation that is characterized by its own attributes and values. The cases analysis started from Dulles Corridor Metrorail, where the tackled implementation area was in direct conflict with two urban highways. Thereafter, London Crossrail comes, where the implementation area was located in the periphery of the central business district of the highly urbanized city of London. Finally, Stuttgart 21 is tackled to address the impacts and analyze the strategy adopted to manage the trafficrelated issues triggered by several worksites in the very middle of the City of Stuttgart. Hereinafter, the main highlights and the lessons learned from the cases analysis are going to be briefly illuminated. In Dulles Corridor Metrorail, the early analysis of the implementation area and the involved urban highways could help to recognize the high reliance on single-occupancy vehicles in commuting along the corridor, and identify the historical congestion factors

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Conclusion

along the corridor. The temporary traffic management plan of Dulles Corridor Metrorail project was primarily elaborated in light of these findings. Hence, there was extensive application of demand management strategies, in addition to other temporary traffic management strategies that would have been able to mitigate the revealed congestion factors. In London Crossrail, the complexity of the implementation area in terms of its socioeconomic structure and traffic patterns, besides the problematic construction method (cut-and0cover) constituted a challenge to the temporary traffic management plans. Enhanced social participation throughout the undertaken neighborhood consultation highlighted the societal reservations and concerns towards the proposed temporary traffic management alternatives. It is worth highlighting here the approach adopted for the effectiveness assessment of the alternatives, since they underwent to two independent assessments, conducted by two different traffic consultants in order to fully assure the quality of the adopted alternative. Another finding here worth to highlight is the comprehensive “live” temporary traffic management approach adopted for the implementation area in London Crossrail. The eminent case of Stuttgart 21 illuminated how to manage the traffic during the implementation of major construction projects, with transferring nearly no impacts to the road network. Innovative construction methods were revealed from the project worksites located in the middle of Stuttgart City. It is worth to mention that the traffic operational condition, prior to the construction works to be launched, were at the stake, especially for the three major roads in conflict with the project worksites. The existed baseline traffic condition would be a real challenge to a major project in the size of Stuttgart 21. However, the revealed innovative construction methods that were provided as temporary traffic management (control) solutions could help in minimizing the impacts and enhancing the safety and traffic efficiency. The key learnings from the cases analysis can be summarized as follows. For temporary traffic management plan of major construction project, it is advised to integrate it within the transportation master plan in the implementation area (case: Dulles Metrorail), to calibrate the traffic management plan with the socioeconomic structure and construction method (case: London Crossrail), and finally to include the traffic management plan to the preliminary engineering stage (case: Stuttgart 21). The coherent understanding of temporary traffic management throughout the literature review and the cases analysis could help to elaborate an appropriate approach for developing the temporary traffic management plan of the case study from Metro Riyadh. An extensive analysis was conducted for the implementation area, in terms of the key issues highlighted in the literature review and cases analysis. These analyzed key issues were the attributes of the worksite, the implementation area socioeconomic structure and the baseline traffic condition. Temporary traffic management strategic planning was conducted for the implementation area, accordingly with the one

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highlighted in the literature review. Two schemes of temporary traffic management were elaborated for two worksites in the implementation area. One scheme could be tracked until the level of full details, and the other scheme was outlined and structured in terms of assessing its cost effectiveness, but was not fully-detailed elaborated due to some limitation will be revealed later. The key highlights that were revealed in the case study chapter were primarily related to the strategic planning section. In particular the effectiveness evaluation scheme leveraged for assessing the proposed alternatives. The assessment criteria were in line with the findings of the literature review; safety, mobility, pollution reduction, social inclusion and from another perspective, cost effectiveness. For assessing the mobility, spreadsheet-based capacity analysis tool was used to estimate the potential impacts from the proposed traffic management alternatives on the mobility in the implementation area. The tool was sufficient for the area tackled in the case study; however, for more complex origin-destination relationships and network structure, macroscopic simulation tools are advised. As regards the pollution reduction, the consolidated approach for estimating the traffic emissions triggered by the proposed alternatives is considered among the thesis key achievements, since it combines two trends of estimating traffic emissions, one is from the control delays and the other is from the traveled kilometers. However, leveraging integrated instantaneousperformance models for more complex implementation areas is advised. The limitations encountered in the case study chapter were particularly in assessing the safety for the proposed traffic management alternatives, and estimating the fiscal cost of implementing particular temporary traffic management solution as well as the cost of road users triggered by the no-option alternative. These limitations were encountered for the second scheme of temporary traffic management outlined in the case study chapter, as per aforementioned. These limitations were encountered due to the lack of data concerning to historical records of crashes in the implementation area, for assessing the safety, and the lack of data concerning to the cost components (implementation cost and road user cost), referred to in the cost effectiveness evaluation. However, the methodology was developed throughout the literature review and illustrated in the case study chapter, and ready for application upon the data is available. The key results of the case study chapter was the recommended temporary traffic management alternative, along with other recommended mitigation measures were revealed based on strengths-weaknesses analysis of the recommended alternative. Full detailed temporary traffic management plan was prepared in light of the technical specification set forth in the provisions covered in the literature review. As a final commentary on the undertaken work, the extensive investigation of the available literature revealed that the eminent USA approach provides more comprehensive and collective framework for the temporary traffic management,

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Conclusion

especially for major construction projects. This approach can be conveyed to other areas of implementation and on different levels (agency level or project level), taking into account the different parameters of the environment, travel behavior, traffic operational conditions and other parameters that may influence the elaboration of temporary traffic management plans. As regards the investigated approach from UK, it was necessary to combine the schemes provided in the literature with the methodology analyzed in London Crossrail project in order to reach to comprehensive understanding of the UK approach. Even though, the US approach remains self-explanatory and more applicable to other areas of implementation. Further research works could be potentially underlying in the area of cost effectiveness assessment of temporary traffic management alternatives, particularly the impact of a specific measure on the construction time, consequently on the overall cost of the site operation and the exposure time for the road users. Moreover, assessing the safety of the work zones, and its temporary traffic management measures based on its geometric attributes could be an interesting research theme that would facilitate tracking the safety of specific temporary traffic management measure and assessing its impacts on the safety without the need for the historical crashes data.

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Appendices:

5 Appendices: 5.1

Appendix 1: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Morning Peak Hour at the Baseline Condition

BASELINE CONDITION- Morning Peak Intersection Approaches Intersection Streams Intersection Lane Groups Volume (VPH) Peak Hour Factor (PHF) Adjusted flow rate, vp = V/PHF (VPH) Lane groups

EB EBU

EBL

WB EBT

259 0.92

1146 0.92

118 0.92

58 0.92

433 0.92

2228 0.92

109 0.92

21 0.92

128 0.92

574 0.92

4 0.92

4 0.92

207 0.92

30

282

1246

128

63

471

2422

118

23

139

624

4

4

225

187

3489

5392

3740

7084

1884

3947

1885

3232

282

1246 15

471

2422 8

139

624

225

187

312

1359

534

2532

162

628

130.00 20.00 0.15 537 0.58 51.11 4.54 55.65 E

130.00 48.00 0.37 1991 0.68 34.58 1.92 36.49 D

130.00 30.00 0.23 435 0.37 42.08 2.44 44.52 D

130.00 30.00 0.23 911 0.69 45.74 4.26 50.01 D

LG2

WBL

WBT

LG3

WBR

NBU

LG4

NBL

NBT

LG5

NBR

SB SBL

28 0.92

Adjusted Lane Group saturation flow, s (VPH)

WBU

NB

SBT LG8 172 0.92

LG1

EBR

SBU

LG6

LG7

Capacity Analysis Adjusted flow rate, v (VPH) Right-Turn On Red Shared Lane Traffic (%) Lane Group Adjusted flow rate [v] (VPH) Cycle Length [C] Sec Effective Green Time [g] Effective Green Time Ratio g/C Lane Group Capacity [c] v/c Ratio [X] Uniform Delay [sec/veh] Incremental Delay [sec/veh] Control delay per vehicle (sec) LOS Total Delays (sec) Total No. of Vehicles Average Delay at the Intersection (sec)

182

30

128

63

118

23

4

4

0.58

130.00 20.00 0.15

130.00 48.00 0.37

130.00 20.00 0.15

130.00 130.00 20.00 48.00 0.15 0.37 575 2616 0.93 0.97 54.28 40.25 23.34 11.57 77.63 51.82 E D 305124.75 5943.30

130.00 48.00 0.37

130.00 30.00 0.23

51.34

135 130.00 30.00 0.23

130.00 16.00 0.12

130.00 130.00 16.00 16.00 0.12 0.12 232 398 0.58 0.71 53.84 54.75 10.22 10.16 64.05 64.92 E E Seconds/Morning Peak Hour Vehicles/Morning Peak Hour LOS: D

 VuV 2014

281

Appendices:

5.2

Appendix 2: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Evening Peak Hour at the Baseline Condition

BASELINE CONDITION- Evening Peak Intersection Approaches Intersection Streams Intersection Lane Groups Volume (VPH) Peak Hour Factor (PHF) Adjusted flow rate, vp = V/PHF (veh/h) Lane groups

EB EBU

EBL

WB EBT

260 0.92

1261 0.92

292 0.92

83 0.92

431 0.92

1209 0.92

229 0.92

63 0.92

119 0.92

322 0.92

22 0.92

26 0.92

289 0.92

50

283

1371

317

90

468

1314

249

68

129

350

24

28

314

307

3489

5392

3740

7084

1884

3947

1885

3232

283

1371

468

1314 45

129

350

314

307

LG2

WBL

WBT

LG3

WBR

NBU

LG4

NBL

NBT

LG5

NBR

SB SBL

46 0.92


WBU

NB

SBT LG8 282 0.92

LG1

EBR

SBU

LG6

LG7


 VuV 2014

50

317

90

249

68

24

28

0.70

90.00 16.00 0.18

333

1688

90.00 16.00 0.18 620 0.54 33.63 3.30 36.93 D

90.00 26.00 0.29 1558 1.08 32.00 49.13 81.13 F

559 90.00 16.00 0.18

90.00 16.00 0.18

1518

90.00 90.00 16.00 26.00 0.18 0.29 665 2046 0.84 0.74 35.76 28.96 12.18 2.47 47.94 31.44 D C 274156.30 5318.04

90.00 16.00 0.18

90.00 16.00 0.18

51.55

198

374

90.00 16.00 0.18 335 0.59 33.99 7.45 41.44 D

90.00 16.00 0.18 702 0.53 33.61 2.89 36.49 D

240 90.00 16.00 0.18

90.00 16.00 0.18

90.00 90.00 16.00 16.00 0.18 0.18 335 575 0.72 0.71 34.87 34.82 12.41 7.30 47.27 42.13 D D Seconds/Morning Peak Hour Vehicles/Morning Peak Hour LOS: D

183

409

Appendices:

5.3

Appendix 3: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Morning Peak Hour for TTM Alternative No.1

TTM Alternative No. 1- Morning Peak Intersection Approaches Intersection Streams Intersection Lane Groups Volume (VPH) Peak Hour Factor (PHF) Adjusted flow rate, vp = V/PHF (veh/h) Lane groups

EB EBU

EBL

WB EBT

28 0.92

259 0.92

1146 0.92

118 0.92

58 0.92

433 0.92

2228 0.92

109 0.92

21 0.92

128 0.92

30

282

1246

128

63

471

2422

118

23

139

624

572

3489

5392

3740

7084

1750

3669

1566

282

1246 15

471

2422

139

624

572 179 0.86


WBU

LG2

WBL

NB NBT LG6 574 0.92

LG1

EBR

WBT

LG3

WBR

NBU

LG4

NBL LG5

NBR LG7 526 0.92

SB SBL

SBU 4 0.92

207 0.92

SBT LG9 172 0.92

4

225

187

1885

3232

225

187

LG8


184

30

130.00 20.00 0.15

312

1359

130.00 20.00 0.15 537 0.58 51.11 4.54 55.65 E

130.00 48.00 0.37 1991 0.68 34.58 1.92 36.49 D

128

63

118

23

8 534 130.00 48.00 0.37

130.00 20.00 0.15

2532

130.00 130.00 20.00 48.00 0.15 0.37 575 2616 0.93 0.97 54.28 40.25 23.34 11.57 77.63 51.82 E D 338918.3777 6331.70

130.00 48.00 0.37

130.00 30.00 0.23

53.53

162

680

337

130.00 30.00 0.23 404 0.40 42.38 2.95 45.34 D

130.00 30.00 0.23 847 0.80 47.21 7.95 55.16 E

130.00 30.00 0.23 361 0.93 49.00 32.88 81.88 F

4

0.58 135 130.00 16.00 0.12

130.00 130.00 16.00 16.00 0.12 0.12 232 398 0.58 0.71 53.84 54.75 10.22 10.16 64.05 64.92 E E Seconds/Morning Peak Hour Vehicles/Morning Peak Hour LOS: D

 VuV 2014

281

Appendices:

5.4

Appendix 4: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Evening Peak Hour for TTM Alternative No.1

TTM Alternative No. 1- Evening Peak Intersection Approaches Intersection Streams Intersection Lane Groups Volume (VPH) Peak Hour Factor (PHF) Adjusted flow rate, vp = V/PHF (veh/h) Lane groups

EB EBU

EBL

WB EBT

46 0.92

260 0.92

1261 0.92

292 0.92

83 0.92

431 0.92

1209 0.92

229 0.92

63 0.92

119 0.92

50

283

1371

317

90

468

1314

249

68

129

350

567

3489

5392

3740

7084

1750

3669

1566

129

350

567 187 0.71


WBU

LG2

WBL

NB NBT LG6 322 0.92

LG1

EBR

WBT

LG3

WBR

NBU

LG4

NBL LG5

NBR LG7 522 0.92

SB SBL

SBU 26 0.92

289 0.92

SBT LG9 282 0.92

28

314

307

1885

3232

314

307

LG8

Capacity Analysis- TTM Alternative No. 1- Evening Peak Adjusted flow rate, v (VPH) Right-Turn On Red Shared Lane Traffic (%) Lane Group Adjusted flow rate [v] (VPH) Cycle Length [C] Sec Effective Green Time [g] Effective Green Time Ratio g/C Lane Group Capacity [c] v/c Ratio [X] Uniform Delay [sec/veh] Incremental Delay [sec/veh] Control delay per vehicle (sec) LOS Total Delays (sec) Total No. of Vehicles Average Delay at the Intersection (sec)

 VuV 2014

50

90.00 16.00 0.18

283

1371 15

333

1673

90.00 16.00 0.18 620.267 0.54 33.63 3.30 36.93 D

90.00 26.00 0.29 1557.69 1.07 32.00 45.58 77.58 E

317

90

468

1314 45

559 90.00 16.00 0.18

90.00 16.00 0.18

249

68

1518

90.00 90.00 16.00 26.00 0.18 0.29 664.889 2046.49 0.84 0.74 35.76 28.96 12.18 2.47 47.94 31.44 D C 295134.03 5659.52

198 90.00 16.00 0.18

90.00 16.00 0.18

52.15

461

90.00 90.00 16.00 16.00 0.18 0.18 311.111 652.267 0.64 0.71 34.30 34.80 9.55 6.35 43.85 41.15 D D

28

0.70

269 90.00 16.00 0.18 278.4 0.97 36.74 46.19 82.93 F

240 90.00 16.00 0.18

90.00 90.00 16.00 16.00 0.18 0.18 335.111 574.578 0.72 0.71 34.87 34.82 12.41 7.30 47.27 42.13 D D Seconds/Morning Peak Hour Vehicles/Morning Peak Hour LOS: D

185

409

Appendices:

5.5

Appendix 5: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Morning Peak Hour for TTM Alternative No.2

TTM Alternative No 2- Morning Peak Intersection Approaches Intersection Streams Intersection Lane Groups Volume (VPH) Peak Hour Factor (PHF) Adjusted flow rate, vp = V/PHF (VPH) Lane groups

EB EBU

EBL

WB EBT

259 0.92

1146 0.92

0 0.92

58 0.92

0 0.92

2661 0.92

109 0.92

0 0.92

128 0.92

574 0.92

526 0.92

4 0.92

207 0.92

30

282

1246

0

63

0

2892

118

0

139

624

572

4

225

0

3489

5529

2045

7600

282

1246 15

0

2892 8

312

1231

63

3003

130.00 20.00 0.15 537 0.58 51.11 4.54 55.65 E

130.00 48.00 0.37 2041 0.60 33.27 1.33 34.59 C

LG2

WBL

WBT

LG3

WBR

NBU

LG4

NBL

NBT

LG5

NBR

SB SBL

28 0.92


WBU

NB

SBT LG8 0 0.92

LG1

EBR

SBU

LG6

3436

LG7

3013

3610


186

30

0

63

118

0

130.00 130.00 20.00 48.00 0.15 0.37 315 2806 0.20 1.07 48.02 41.00 1.43 39.39 49.45 80.39 D F 373699.56 5600.91 66.72

139

624

572 179

4

225

763

393

229

130.00 30.00 0.23 793 0.96 49.44 24.00 73.44 E

130.00 30.00 0.23 695.308 0.56 44.23 3.30 47.53 D

130.00 16.00 0.12 444.308 0.52 53.38 4.24 57.62 E Seconds/Morning Peak Hour Vehicles/Morning Peak Hour LOS: E

 VuV 2014

0

Appendices:

5.6

Appendix 6: Capacity Analysis and Vehicles Control Delays Calculation for the Intersection in the Implementation Area during the Evening Peak Hour for TTM Alternative No.2

TTM Alternative No 2- Evening Peak Intersection Approaches Intersection Streams Intersection Lane Groups Volume (VPH) Peak Hour Factor (PHF) Adjusted flow rate, vp = V/PHF (VPH) Lane groups

EB EBU

EBL

WB EBT

260 0.92

1261 0.92

0 0.92

83 0.92

0 0.92

1640 0.92

229 0.92

0 0.92

119 0.92

322 0.92

522 0.92

20 0.92

289 0.92

50

283

1371

0

90

0

1783

249

0

129

350

567

22

314

0

3489

5529

2045

7440

283

1371

0

1783 45

LG2

WBL

WBT

LG3

WBR

NBU

LG4

NBL

NBT

LG5

NBR

SB SBL

46 0.92


WBU

NB

SBT LG8 0 0.92

LG1

EBR

SBU

LG6

3350

LG7

3013

3610


 VuV 2014

50

0

90

249

0

129

350

567 187

22

314

0

0.58 333

1371

90.00 16.00 0.18 620.27 0.54 33.63 3.30 36.93 D

90.00 26.00 0.29 1597.27 0.86 30.26 6.21 36.47 D

90

1987

90.00 90.00 16.00 26.00 0.18 0.29 363.56 2149.33 0.25 0.92 31.83 31.04 1.63 8.23 33.45 39.28 C D 188674.01 4843.67 38.95

479

380

204

90.00 16.00 0.18 595.56 0.80 35.50 11.07 46.57 D

90.00 16.00 0.18 535.64 0.71 34.82 7.77 42.59 D

90.00 16.00 0.18 641.78 0.32 32.24 1.30 33.54 C Seconds/Morning Peak Hour Vehicles/Morning Peak Hour LOS: D

187

Appendices:

5.7

Appendix 7: Total Delays Calculation for the TTM Alternatives In Comparison To the Baseline Condition at the Morning Peak Hour

BASELINE CONDITION- Morning Peak Intersection Approaches Lane Groups Lane Group Adjusted flow rate [v] (veh/h) Control delay per vehicle (sec) Total Delays/Lane Group Total Delays/Approach

Eastbound

Westbound

Northbound

Southbound

LG1

LG2

LG3

LG4

LG5

LG6

LG7

LG8

312

1359

534

2532

162

628

135

281

55.65

36.49

77.63

51.82

44.52

50.01

64.05

64.92

17361

49591.7 41454.4

131209

7209.59 31416.8

8646.75 18242.5

66952.7

172664

38626.4

26889.3

TTM Alternative No. 1- Morning Peak Intersection Approaches Lane Groups Lane Group Adjusted flow rate [v] (veh/h) Control delay per vehicle (sec) Total Delays/Lane Group Total Delays/Approach

Eastbound

Westbound

Northbound

Southbound

LG1

LG2

LG3

LG4

LG5

LG6

LG7

LG8

LG9

312

1359

534

2532

162

680

337

135

281

55.65

36.49

77.63

51.82

45.34

55.16

81.88

64.05

64.92

17361

49591.7 41454.4

66952.7

131209

7342.46 37502.8 27574.7 8646.75 18242.5

172663.7

72420.0

26889.3

Northbound

Southbound

TTM Alternative No. 2- Morning Peak Intersection Approaches Lane Groups Lane Group Adjusted flow rate [v] (veh/h) Control delay per

Eastbound LG1

LG2

LG3

LG4

LG5

LG6

LG7

312

1231

63

3003

763

393

229

49.45

80.39

73.44

47.53

57.62

55.65 34.59 vehicle (sec) Detoured Vehicles 118 Extra Traveled Km 0.153 Average travel 25.00 Speed (Km/h) Detour Delay per 22.032 Vehicle (sec) Total Delays/Lane 19960.7 42573.5 Group Total Delays/Approach

188

Westbound

62534.3

3117.3

433.00 0.63

172.00 0.63

25.00

25.00

90.29

90.29

280506

283623.2

56039.5

18667.2 28724.5 74706.8

28724.5

 VuV 2014

Appendices:

5.8

Appendix 8: Total Delays Calculation for the TTM Alternatives In Comparison To the Baseline Condition at the Evening Peak Hour

BASELINE CONDITION- Evening Peak Intersection Approaches Lane Groups Lane Group Adjusted flow rate [v] (veh/h) Control delay per vehicle (sec) Total Delays/Lane Group Total Delays/Approach

Eastbound

Westbound

Northbound

Southbound

LG1

LG2

LG3

LG4

LG5

LG6

LG7

LG8

333

1688

559

1518

198

374

240

409

36.93

81.13

47.94

31.44

41.44

36.49

47.27

42.13

47721

8198.73

13645

11360.2 17213.4

21844

28574

Northbound

Southbound

12283.6

136948 26786.2

149232

74507

TTM Alternative No. 1- Evening Peak Intersection Approaches Lane Groups Lane Group Adjusted flow rate [v] (veh/h) Control delay per vehicle (sec) Total Delays/Lane Group Total Delays/Approach

Eastbound

Westbound

LG1

LG2

LG3

LG4

LG5

LG6

LG7

LG8

LG9

333

1673

559

1518

198

461

269

240

409

36.93

77.58

47.94

31.44

43.85

41.15

82.93

47.27

42.13

47721

8674.02

18973

12283.6

129792 26786.2

142075.8751

74507.11885

22330.4 11360.2 17213.4

49977.45636

28573.58008

Northbound

Southbound

TTM Alternative No. 2- Evening Peak Intersection Approaches Lane Groups Lane Group Adjusted flow rate [v] (veh/h) Control delay per vehicle (sec) Detoured Vehicles Extra Traveled Km Average travel Speed (Km/h) Detour Delay per Vehicle (sec) Total Delays/Lane Group Total Delays/Approach

 VuV 2014

Eastbound

Westbound

LG1

LG2

LG3

LG4

LG5

LG6

LG7

333

1371

90

1987

479

380

204

36.93

36.47

33.45

39.28

46.57

42.59

33.54

292 0.153

433.00 0.63

172.00 0.63

25

25.00

25.00

22.032

90.29

90.29

18717

49984.7 3018.01

68701.7

117116 22324.8

120134.3

16200.3 22370.4 38525.2

22370.4

189

Appendices:

5.9

Appendix 9: Queue Lengths Calculation Sheet for TTM Alternative No.1 during Morning Peak Hour

Queue lengths Calculations- TTM Alternative No. 1- Morning Peak Intersection Approaches Eastbound Westbound Northbound Intersection Streams EBL& U EBT& R WBL& U WBT& R NBL& U NBT/R No. of Lanes/ group 2 3 2 4 1 2 (vL) lane group flow rate per lane (VPH) 156 453 267 633 162 340 (sL) lane group saturation flow rate (VPH) 1745 1797 1870 1771 1750 1835 (cL) lane group capacity per lane (VPH) 268 664 288 654 404 423 (PF2) Adjustment Factor for effect of 1.00 1.00 1.00 1.00 1.00 1.00 progression (Q1) first-term queued vehicles (veh) 5.23 13.79 9.51 22.44 4.96 11.59 XL (vL/cL) 0.58 0.68 0.93 0.97 0.40 0.80 I (upstream filtering factor for platoon arrivals) 0.75 0.63 0.18 0.10 0.92 0.50 (kB) second-term adjustment factor related to 0.44 0.70 0.11 0.11 0.72 0.40 early arrivals (Q2) second term of queued vehicles, 0.59 1.43 1.02 1.92 0.48 1.45 estimate for average overflow queue Q- average number of vehicles in queue 5.82 15.22 10.53 24.36 5.43 13.04 (veh) Q (No. of Vehicles) 6.00 16.00 11.00 25.00 6.00 14.00 Percentile back of queue factor fB95% 1.90 1.64 1.71 1.61 1.90 1.66 Percentile back of queue (Q95%) 11.41 26.25 18.82 40.17 11.41 23.25 Q 95% (No. of Vehicles) 12 27 19 41 12 24 Average queue spacing (Lh) 6 6 6 6 6 6 Available Distance (La) 780 780 750 750 68 370 Average queue storage ratio (RQ) 0.05 0.12 0.09 0.20 0.53 0.23 95% Percentile queue storage ratio (RQ%) 0.09 0.21 0.15 0.33 1.06 0.39

190

 VuV 2014

NBR 1 337 1566 361

Southbound SBL& U SBT/R 1 2 135 141 1885 1616 232 199

1.00

1.00

1

11.92 0.93 0.25

4.60 0.58 0.75

4.8815 0.70756 0.65

0.18

0.40

0.31008

1.62

0.53

0.68559

13.54

5.13

5.56709

14.00 1.66 23.25 24 6 370 0.23 0.39

6.00 1.90 11.41 12 6 970 0.04 0.07

6 1.90119 11.4072 12 6 970 0.04 0.07

Appendices:

5.10

Appendix 10: Queue Lengths Calculation Sheet for TTM Alternative No.1 during Evening Peak Hour

Queue lengths Calculations- TTM Alternative No. 1- Evening Peak Intersection Approaches Eastbound Westbound Northbound Intersection Streams EBL& U EBT& R WBL& U WBT& R NBL& U NBT/R No. of Lanes/ group 2 3 2 4 1 2 (vL) lane group flow rate per lane (VPH) 166 558 279 380 198 231 (sL) lane group saturation flow rate (VPH) 1745 1797 1870 1771 1750 1835 (cL) lane group capacity per lane (VPH) 310 519 332 512 311 326 (PF2) Adjustment Factor for effect of 1.00 1.00 1.00 1.00 1.00 progression (Q1) first-term queued vehicles (veh) 5.46 20.14 9.75 12.40 6.62 7.83 XL (vL/cL) 0.54 1.07 0.84 0.74 0.64 0.71 I (upstream filtering factor for platoon arrivals) 0.86 0.09 0.40 0.58 0.71 0.65 (kB) second-term adjustment factor related to 0.43 0.06 0.21 0.41 0.36 0.34 early arrivals (Q2) second term of queued vehicles, 0.49 5.61 0.97 1.11 0.60 0.77 estimate for average overflow queue Q- average number of vehicles in queue 5.94 25.75 10.72 13.51 7.22 8.60 (veh) Q (No. of Vehicles) 6.00 26.00 11.00 14.00 8.00 9.00 Percentile back of queue factor fB95% 1.90 1.61 1.71 1.66 1.80 1.77 Percentile back of queue (Q95%) 11.41 41.74 18.82 23.25 14.42 15.89 Q 95% (No. of Vehicles) 12 42 19 24 15 16 Average queue spacing (Lh) 6 6 6 6 6 6 Available Distance (La) 780 780 750 750 68 370 Average queue storage ratio (RQ) 0.05 0.20 0.09 0.11 0.71 0.15 95% Percentile queue storage ratio (RQ%) 0.09 0.32 0.15 0.19 1.32 0.26

 VuV 2014

191

NBR 1 269 1566 278

Southbound SBL& U SBT/R 1 2 240 204 1885 1616 335 287

1.00

1.00

1.00

9.66 0.97 0.09

8.18 0.72 0.65

6.94 0.71 0.65

0.04

0.35

0.31

0.75

0.82

0.71

10.40

9.00

7.66

11.00 1.71 18.82 19 6 370 0.18 0.31

9.00 1.77 15.89 16 6 970 0.06 0.10

8.00 1.80 14.42 15 6 970 0.05 0.09

Appendices:

5.11

Appendix 11: Queue Lengths Calculation Sheet for TTM Alternative No.2 during Morning Peak Hour

Queue lengths Calculations- TTM Alternative No 2- Morning Peak Intersection Approaches Eastbound Intersection Streams EBL& U EBT No. of Lanes/ group 2 3 (vL) lane group flow rate per lane (VPH) 156 410 (sL) lane group saturation flow rate (VPH) 1745 1843 (cL) lane group capacity per lane (VPH) 268 680 (PF2) Adjustment Factor for effect of 1.00 1.00 progression (Q1) first-term queued vehicles (veh) 5.23 12.02 XL (vL/cL) 0.58 0.60 I (upstream filtering factor for platoon arrivals) 0.75 0.77 (kB) second-term adjustment factor related to 0.44 0.87 early arrivals (Q2) second term of queued vehicles, 0.59 1.27 estimate for average overflow queue Q- average number of vehicles in queue 5.82 13.29 (veh) Q (No. of Vehicles) 6.00 14.00 Percentile back of queue factor fB95% 1.90 1.66 Percentile back of queue (Q95%) 11.41 23.25 Q 95% (No. of Vehicles) 12 24 Average queue spacing (Lh) 6 6 Available Distance (La) 780 780 Average queue storage ratio (RQ) 0.05 0.11 95% Percentile queue storage ratio (RQ%) 0.09 0.18

192

Westbound Northbound WBU WBT& R NBL& T NBR 1 4 2 2 63 751 382 196 2045 1900 1718 1507 315 702 396 348

Southbound SBL& U 2 115 1805 222

1.00

1.00

1.00

1.00

1.00

1.99 0.20 0.92

27.11 1.07 0.09

13.62 0.96 0.19

6.27 0.56 0.80

3.88 0.52 0.86

0.61

0.10

0.15

0.56

0.44

0.15

7.45

1.87

0.71

0.46

2.14

34.56

15.50

6.98

4.33

3.00 2.15 6.45 7 6 750 0.02 0.06

35.00 1.60 56.03 57 6 750 0.28 0.46

16.00 1.64 26.25 27 6 370 0.26 0.44

7.00 1.85 12.93 13 6 370 0.11 0.21

5.00 1.97 9.84 10 6 970 0.03 0.06

 VuV 2014

Appendices:

5.12

Appendix 12: Queue Lengths Calculation Sheet for TTM Alternative No.1 during Evening Peak Hour

Queue lengths Calculations- TTM Alternative No 2- Evening Peak Intersection Approaches Eastbound Intersection Streams EBL& U EBT No. of Lanes/ group 2 3 (vL) lane group flow rate per lane (VPH) 166 457 (sL) lane group saturation flow rate (VPH) 1745 1843 (cL) lane group capacity per lane (VPH) 310 532 (PF2) Adjustment Factor for effect of 1.00 1.00 progression (Q1) first-term queued vehicles (veh) 5.46 15.60 XL (vL/cL) 0.54 0.86 I (upstream filtering factor for platoon arrivals) 0.81 0.40 (kB) second-term adjustment factor related to 0.41 0.29 early arrivals (Q2) second term of queued vehicles, 0.46 1.53 estimate for average overflow queue Q- average number of vehicles in queue 5.92 17.13 (veh) Q (No. of Vehicles) 6.00 18.00 Percentile back of queue factor fB95% 1.90 1.63 Percentile back of queue (Q95%) 11.41 29.29 Q 95% (No. of Vehicles) 12 30 Average queue spacing (Lh) 6 6 Available Distance (La) 780 780 Average queue storage ratio (RQ) 0.05 0.14 95% Percentile queue storage ratio (RQ%) 0.09 0.23

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Westbound Northbound WBU WBT& R NBL& T NBR 1 4 2 2 90 497 240 190 2045 1860 1675 1507 364 537 298 268

Southbound SBL& U 2 102 1805 321

1.00

1.00

1.00

1.00

1.00

2.80 0.25 0.92

17.40 0.92 0.30

8.30 0.80 0.50

6.46 0.71 0.65

3.21 0.32 0.92

0.52

0.22

0.24

0.30

0.48

0.17

1.96

0.90

0.68

0.22

2.97

19.35

9.20

7.14

3.43

3.00 2.15 6.45 7 6 750 0.02 0.06

20.00 1.62 32.37 33 6 750 0.16 0.26

10.00 1.74 17.35 18 6 370 0.16 0.29

8.00 1.80 14.42 15 6 370 0.13 0.24

4.00 2.05 8.20 9 6 970 0.02 0.06

193

Appendices:

5.13

Appendix 13: Emission Calculation Steps for TTM Alternatives during Morning Peak Hour

Step 1: Estimating the Emissions Triggered by Control Delays at the Intersection for all approaches. Intersection Control Delays (sec)/Morning Peak Hour Approach Eastbound Alternative 1 66952.7 Alternative 2 59934.5

Westbound Northbound Southbound 172663.705 72420.0 26889.27 244528.472 74706.8 13194.98

Total 338925.7 392364.7

Emissions from Control Delay NOx m.grams/sec HC m.grams/sec CO m.grams/sec 1.1 0.45 15 NOx grams/Peak Hour HC grams/Peak Hour CO grams/Peak Hour 372.8 152.5 5083.9 431.6 176.6 5885.5

Step 2: Estimating the Emissions Triggered by Extra Traveled Kilometers at the Intersection Only for Traffic Streams Detoured due to TTM Alternative No.2. [Although the detour is triggered by alternative no.2 only, traveled kilometers of the influenced traffic streams are considered during the operational conditions of both TTM alternatives in order to consider only the excess in the emissions triggered by the extra traveled kilometers due to detour]. Detoured Streams Eastbound-Right Westbound-Left Southbound-Through Adjusted flow rate, v (veh/h) 128 471 187 Traveled Km (Alternative No.1)/Vehicle 0.24 0.24 0.24 Traveled Km (Alternative No.2)/Vehicle 0.39 0.87 0.87 Total Traveled Kilometers (Alternative 1) 30.8 113.0 44.9 Total Traveled Kilometers (Alternative 2) 50.0 409.8 162.7

194

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Appendices: Intersection Extra Traveled Kilometers/Morning Peak Hour Approach Eastbound Alternative 1 30.8 Alternative 2 50.0


Total 188.7 622.4

Emissions from Traveled Kilometer NOx grams/Km HC grams/Km CO grams/Km 0.1 1 33.9 NO grams/Peak Hour HC grams/Peak Hour CO grams/Peak Hour 18.9 188.7 6396.7 62.2 622.4 21100.8

Step 3: Aggregating the Emissions from Control Delays and Traveled Kilometers at Each Intersection Approach for Both TTM Alternatives. Total Produced Emissions (grams)/ Morning Peak Hour NOx HC Alternative 1 391.7 341.2 Alternative 2 493.8 799.0

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CO 11480.5 26986.3

195

Appendices:

5.14

Appendix 14: Emission Calculation Steps for TTM Alternatives during Evening Peak Hour

Step 1: Estimating the Emissions Triggered by Control Delays at the Intersection for all approaches. Intersection Control Delays (sec)/Evening Peak Hour Approach Eastbound Alternative 1 142075.9 Alternative 2 62268.3


Total 295134.0 188674.0

Emissions from Control Delay NOx m.grams/sec HC m.grams/sec CO m.grams/sec 1.1 0.45 15 NOx grams/Peak Hour HC grams/Peak Hour CO grams/Peak Hour 324.6 132.8 4427.0 207.5 84.9 2830.1

Step 2: Estimating the Emissions Triggered by Extra Traveled Kilometers at the Intersection Only for Traffic Streams Detoured due to TTM Alternative No.2. Detoured Streams Eastbound-Right Westbound-Left Southbound-Through Adjusted flow rate, v (veh/h) 317 468 307 Traveled Km (Alternative No.1)/Vehicle 0.24 0.24 0.24 Traveled Km (Alternative No.2)/Vehicle 0.39 0.87 0.87 Total Traveled Kilometers (Alternative 1) 76.2 112.4 73.6 Total Traveled Kilometers (Alternative 2) 123.8 407.6 266.7

196

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Appendices: Intersection Extra Traveled Kilometers/Evening Peak Hour Approach Eastbound Alternative 1 76.2 Alternative 2 123.8


Total 262.2 798.0

Emissions from Traveled Kilometer NOx grams/Km HC grams/Km CO grams/Km 0.1 1 33.9 NOx grams/Peak Hour HC grams/Peak Hour CO grams/Peak Hour 26.2 262.2 8887.7 79.8 798.0 27053.3

Step 3: Aggregating the Emissions from Control Delays and Traveled Kilometers at Each Intersection Approach for Both TTM Alternatives.

Alternative 1 Alternative 2

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Total Produced Emissions/ Evening Peak Hour NOx HC 350.9 395.0 287.3 882.9

CO 13314.7 29883.4

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