Development of Guidelines for Quantifying Benefits of Traffic Incident Management Strategies​ (2022)

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NCHRP Web-Only Document 301: Development of Guidelines for Quantifying Benefits of Traffic Incident Management Strategies Vaishali Shah Greg Hatcher Elizabeth Greer Janet Fraser Noblis, Inc. Reston, Virginia Mark Franz Kaveh Sadabadi Center for Advanced Transportation Technology at the University of Maryland College Park, Maryland Conduct of Research Report for NCHRP Project 03-108 Submitted January 2017 NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state departments of transportation (DOTs) administrators and engineers. Often, highway problems are of local or regional interest and can best be studied by state DOTs individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation results in increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research. Recognizing this need, the leadership of the American Association of State Highway and Transportation Officials (AASHTO) in 1962 initiated an objective national highway research program using modern scientific techniques—the National Cooperative Highway Research Program (NCHRP). NCHRP is supported on a continuing basis by funds from participating member states of AASHTO and receives the full cooperation and support of the Federal Highway Administration (FHWA), United States Department of Transportation, under Agreement No. 693JJ31950003. COPYRIGHT INFORMATION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FTA, GHSA, NHTSA, or TDC endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-for-profit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. DISCLAIMER The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research. They are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; the FHWA; or the program sponsors. The information contained in this document was taken directly from the submission of the author(s). This material has not been edited by TRB.

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C O O P E R A T I  V E  R E S E A R  C H  P R O G R A M S  CRP STAFF FOR NCHRP WEB-ONLY DOCUMENT 301 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Waseem Dekelbab, Associate Program Manager, National Cooperative Highway Research Program David M. Jared, Senior Program Officer Clara Schmetter, Senior Program Assistant Natalie Barnes, Director of Publications Heather DiAngelis, Associate Director of Publications Scott E. Hitchcock, Senior Editor Kathleen Mion, Senior Editorial Assistant NCHRP PROJECT 03-108 PANEL Field of Traffic—Area of Operations and Control Lisa Vieth, Missouri Department of Transportation, Jefferson City, MO (Chair) Yupo Chan, University of Arkansas, Little Rock, Little Rock, AR Steven Cyra, HNTB Corporation, Milwaukee, WI Sreenath Reddy Gangula, Washington State Department of Transportation, Olympia, WA Ismael Garza, Nevada Department of Transportation, Carson City, NV David Graham, Gannett Fleming, Inc., Raleigh, NC Sean M. Hill, Delaware River Joint Toll Bridge Commission, New Hope, PA Timothy R. Huibregtse, Wisconsin Department of Transportation, Milwaukee, WI Jennifer L. Portanova, North Carolina Department of Transportation, Raleigh, NC Jawad N. Paracha, FHWA Liaison Richard A. Cunard, TRB Liaison Author Acknowledgments The research reported herein was performed under NCHRP Project 03-108 by Noblis, Inc., the Center for Advanced Transportation Technology at the University of Maryland, and HEi, Inc. Vaishali Shah at Noblis served as the Principal Investigator and Greg Hatcher served as Project Manager. The other authors of this report are Elizabeth Greer and Dr. Janet Fraser, Transportation Systems staff at Noblis, and Mark Franz and Kaveh Sadabadi, research assistants at the Center for Advanced Transportation Technology and doctoral candidates at the University of Maryland.

iv CONTENTS Summary ......................................................................................................................................... 1  Introduction and Background ................................................................................ 5  Review of TIM Definitions, Strategies, and Evaluation Methods ........................ 6  Stakeholder Engagement ..................................................................................... 58  Estimating Available Capacity Reduction from Incidents .................................. 81  Evaluation of Methods for Quantifying Benefits of TIM Programs ................... 98  Monetization of Benefits ................................................................................... 129  Common TIM Rules of Thumb Assessment ..................................................... 137  Summary of Findings and Next Steps ............................................................... 141  References ................................................................................................................................... 146  Abbreviations, Acronyms, Initialisms, and Symbols .................................................................. 156  Note: The guidelines document associated with this conduct of research report has been published as NCHRP Research Report 981: Guidelines for Quantifying Benefits of Traffic Incident Management Strategies and can be found on the TRB website (http://www.trb.org/) by searching for “NCHRP Research Report 981.”

v LIST OF FIGURES AND TABLES Table of Figures Figure 1: TIM Framework .............................................................................................................. 7  Figure 2: Timeline of an Incident (TIM Handbook) ..................................................................... 16  Figure 3: Sample Distribution of Sources for Incident Detection (Chang and Raqib, 2013) ....... 23  Figure 4: Site Decision Support Tool Flow Chart (Khattak and Rouphail, 2004) ....................... 33  Figure 5: Impact Boundary for Identification of Secondary Incidents ......................................... 36  Figure 6: Three Stage Time Savings Analysis for TIM (Chou, 2010) ......................................... 37  Figure 7: HELP Methodological Flow Chart (Haghani et. al. 2006)........................................... 39  Figure 8: Queue (Left) and Modified Queue (Right) Diagrams (Moss, 2012) ............................. 42  Figure 9: Incident Progression Curves (Ryan et al., 2009) ........................................................... 45  Figure 10: TRIP Coverage Map 2011 (Source: GDOT's Evaluation of the TRIP, 2011) ............ 66  Figure 11: ITD Safety Service Patrol Coverage ........................................................................... 70  Figure 12: SOC and TOC Locations (Chang and Raqib, 2012) ................................................... 71  Figure 13: Sample Incident Response Performance Measures (Source; WSDOT Gray Note Book December 2013) ............................................................................................................................ 77  Figure 14: Experimental Methodology ......................................................................................... 86  Figure 15: Schematic of Traffic Flow during an Incident (Cambridge Systematics, 1990) ......... 87  Figure 16: Graphical Representation of 109 Incidents’ Available Capacity Ratio by Incident Duration ........................................................................................................................................ 93  Figure 17: Shoulder Incident by Type and Facility Lanes ............................................................ 94  Figure 18: Incidents on Left and Right Shoulder .......................................................................... 95  Figure 19: Summary of Methods Applied for Estimating TIM Outcomes ................................... 99  Figures 20 and 21: Incident Progression Curve for Property Damage Only Crashes v. Injury and Fatal Crashes ............................................................................................................................... 103  Figure 22. Time and Space Boundaries through Corner Point Identification (Chou, 2010) ...... 104  Figure 23. I-405 Seattle Segmentation ........................................................................................ 111  Figure 24. US-75 North Texas Segmentation ............................................................................. 111  Figure 25: I-495 Maryland Segmentation ................................................................................... 112  Figure 26. Search Area Boundaries for Auto Mapping Incidents to Segments in Maryland Corridor ....................................................................................................................................... 114  Figure 27. Structure of the Incident to Historical Volume Matching Tool ................................ 114  Figure 28. Overall TIM Program Benefit Analysis Flowchart ................................................... 127  Table of Tables Table 1: Summary of Available Capacity Ratio Estimates from Incidents in Maryland, Virginia, and Texas ........................................................................................................................................ 3  Table 2: Incident Definitions ........................................................................................................ 17 

vi Table 3: Examples of Incident Type Defined from State TIM Programs ..................................... 19  Table 4: Definition of Secondary Incidents .................................................................................. 21  Table 5: Hoosier Helper Evaluation Methods and Outcomes ...................................................... 29  Table 6: Georgia NaviGAtor System Evaluation Methods and Outcomes .................................. 30  Table 7: Rutgers Incident Management System Methods and Outcomes .................................... 32  Table 8: Incident Management Assistance Patrols Decision-Support Tool for Service Expansion ....................................................................................................................................................... 33  Table 9: Regional Emergency Action Coordination Team (REACT) Evaluation ....................... 34  Table 10: Impact of Incidents and Incident Management Programs on Freeway Mobility and Safety ............................................................................................................................................ 35  Table 11: Methodology for Quantifying the Cost Effectiveness of Freeway Service Patrol Programs: A Case Study ............................................................................................................... 38  Table 12: Assessing Return on Investment of Freeway Safety Service Patrol Programs ............ 40  Table 13: A Benefit Cost Model for Traffic Incident Management, Knoxville, TN .................... 41  Table 14: Benefit Cost Analysis of Accelerated Incident Clearance in South Carolina .............. 43  Table 15: Evaluated Incident Clearance Strategies in Chowdhury et al. (2007) .......................... 44  Table 16: Evaluation of Arterial Service Patrol Programs (I-64 Traffic Response) ..................... 45  Table 17: Evaluation of Freeway Motorist Assist Program in St. Louis, MO .............................. 46  Table 18: Evaluation of Freeway Motorist Assist Program in Florida ......................................... 47  Table 19: FIRST Program Evaluation in Minnesota .................................................................... 48  Table 20: FIRST Benefits and Costs in 2003 Dollars (Mn/DOT, 2004) ...................................... 49  Table 21: Maryland CHART Program Annual Performance Evaluation ..................................... 49  Table 22: Results of Service Patrol Benefit-Cost Studies (Lin, 2012) ......................................... 51  Table 23: Relative Disutility Factors by Injury Severity Level (AIS) and Monetized Value of Injuries .......................................................................................................................................... 53  Table 24: Average Monetary Values for Different Types of Vehicle Crashes ............................. 53  Table 25: Recommended Hourly Values of Travel Time Savings (2009 $ per Person-Hour) ..... 54  Table 26: Recommended Hourly Values of Travel Time Savings (2009 $ per Person-Hour) ..... 54  Table 27: Passenger Value of Time from Previous TIM Studies ................................................. 54  Table 28: Average Vehicle Occupancy by Trip Purpose (Person-Miles per Vehicle-Mile) ........ 55  Table 29: Values for Avoided Air Emissions (Year 2010) ........................................................... 55  Table 30: Proportion of Freeway Segment Capacity Available under Incident Conditions. (Transportation Research Board, 2010) ........................................................................................ 82  Table 31: Typical Capacity Reductions for a Three Lane Freeway (Texas Transportation Institute, 1999) .............................................................................................................................. 83  Table 32: Statistics on Available Capacity for Different Incident Types (Knoop et al., 2009) .... 84  Table 33: Comparison of Incident Capacity at Different Sites (Lu and Elefteriadou, 2013) ....... 84  Table 34: Comparison of Percent Freeway Capacity Available under Incident Conditions from Different Studies ........................................................................................................................... 85  Table 35: Summary of Archival Incident and Traffic Data Accessed and Used in this Study ..... 90 

vii Table 36: Frequency of Incident Types ........................................................................................ 90  Table 37: Number of Analyzed Cases in Various Jurisdictions and Incident-Induced Lane Closure Scenarios.......................................................................................................................... 91  Table 38: Available Capacity Ratio (ACR) Under Incident Conditions across Jurisdictions and HCM ACR .................................................................................................................................... 92  Table 39: Estimated Proportion of Freeway Segment Capacity Available under Incident Conditions ..................................................................................................................................... 94  Table 40: Strengths and Limitations of Methods Applied for Delay Reduction ........................ 100  Table 41: Data Needs and Assumptions for Methods ................................................................ 100  Table 42. Sample from Khattak and Rouphail (2004) Delay Model. ......................................... 101  Table 43: Strengths and Limitations of Secondary Crash Methods ........................................... 102  Table 44: Data Needs for Estimating Secondary Crashes .......................................................... 102  Table 45. Corner Point Regression Model (Chou, 2010) ........................................................... 105  Table 46: Emission Rates (Chang and Igbinosun, 2013) ............................................................ 106  Table 47: Data Availability ......................................................................................................... 107  Table 48: Maryland Lane Closure-Duration Summary ............................................................. 109  Table 49: Delay Reduction Estimates for Seattle Corridor with Varying Levels of Volume Aggregation................................................................................................................................. 113  Table 50: Delay Savings Results ................................................................................................ 116  Table 51: Seattle, WA Lane Closure Profile .............................................................................. 116  Table 52: Seattle, WA Incident Duration Profile ........................................................................ 117  Table 53. North Texas Lane Closure Profile .............................................................................. 117  Table 54. North Texas Incident Duration Profile ....................................................................... 118  Table 55: Maryland Lane Closure Profile .................................................................................. 118  Table 56: Maryland Incident Duration Profile ............................................................................ 119  Table 57: Estimated Secondary Crash Reduction in the Study Datasets .................................... 120  Table 58: Emissions Savings Results for the Study Datasets ..................................................... 121  Table 59: Fuel Consumption Savings for All Datasets (in gallons) ........................................... 121  Table 60. Application of Hybrid Delay Estimation Methods to the Seattle Data ....................... 122  Table 61: Inputs for Monetization of Delay Savings .................................................................. 129  Table 62: Monetization of Delay Savings for I-405 ................................................................... 130  Table 63: Monetization of Delay Savings for U.S. Route 75 ..................................................... 130  Table 64: Monetization of Delay Savings for I-495 ................................................................... 130  Table 65: Composite Value for Crashes ..................................................................................... 131  Table 66: Monetization of Secondary Incident Reduction on I-405........................................... 131  Table 67: Monetization of Secondary Incident Reduction on U.S. Route 75............................. 131  Table 68: Monetization of Secondary Incident Reduction on I-495........................................... 131  Table 69: Emissions Values for Monetization ............................................................................ 132  Table 70: Monetization of Emissions Reduction Savings on I-405 Based on Delay Savings ... 132  Table 71: Emissions Reduction on I-405 Based on Service Patrol Interactions ......................... 132 

viii Table 72: Emissions Reduction on U.S. Route 75 Based on Delay Savings .............................. 132  Table 73: Emissions Reduction on U.S. Route 75 Based on Service Patrol Interactions ........... 133  Table 74: Monetization of Emissions Reduction Savings on I-495 Based on Delay Savings ... 133  Table 75: Monetization of Emissions Reduction Savings on I-495 Based on Service Patrol Interactions .................................................................................................................................. 133  Table 76: Average Fuel Values for Datasets .............................................................................. 133  Table 77: Monetization of Fuel Consumption Savings .............................................................. 134  Table 78: ACR Estimates from Incidents in Maryland, Virginia, and Texas ............................. 142