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Guide to Establishing Monitoring Programs for Travel Time Reliability S2-LO2-RR-2 S H R P 2 TR B G uide to E stablishing M onitoring P rogram s for Travel Tim e R eliability

TRANSPORTATION RESEARCH BOARD 2014 EXECUTIVE COMMITTEE* OFFICERS Chair: Kirk T. Steudle, Director, Michigan Department of Transportation, Lansing Vice Chair: Daniel Sperling, Professor of Civil Engineering and Environmental Science and Policy; Director, Institute of Transportation Studies, University of California, Davis Executive Director: Robert E. Skinner, Jr., Transportation Research Board MEMBERS Victoria A. Arroyo, Executive Director, Georgetown Climate Center, and Visiting Professor, Georgetown University Law Center, Washington, D.C. Scott E. Bennett, Director, Arkansas State Highway and Transportation Department, Little Rock Deborah H. Butler, Executive Vice President, Planning, and CIO, Norfolk Southern Corporation, Norfolk, Virginia (Past Chair, 2013) James M. Crites, Executive Vice President of Operations, Dallas–Fort Worth International Airport, Texas Malcolm Dougherty, Director, California Department of Transportation, Sacramento A. Stewart Fotheringham, Professor and Director, Centre for Geoinformatics, School of Geography and Geosciences, University of St. Andrews, Fife, United Kingdom John S. Halikowski, Director, Arizona Department of Transportation, Phoenix Michael W. Hancock, Secretary, Kentucky Transportation Cabinet, Frankfort Susan Hanson, Distinguished University Professor Emerita, School of Geography, Clark University, Worcester, Massachusetts Steve Heminger, Executive Director, Metropolitan Transportation Commission, Oakland, California Chris T. Hendrickson, Duquesne Light Professor of Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania Jeffrey D. Holt, Managing Director, Bank of Montreal Capital Markets, and Chairman, Utah Transportation Commission, Huntsville, Utah Gary P. LaGrange, President and CEO, Port of New Orleans, Louisiana Michael P. Lewis, Director, Rhode Island Department of Transportation, Providence Joan McDonald, Commissioner, New York State Department of Transportation, Albany Abbas Mohaddes, President and CEO, Iteris, Inc., Santa Ana, California Donald A. Osterberg, Senior Vice President, Safety and Security, Schneider National, Inc., Green Bay, Wisconsin Steven W. Palmer, Vice President of Transportation, Lowe’s Companies, Inc., Mooresville, North Carolina Sandra Rosenbloom, Professor, University of Texas, Austin (Past Chair, 2012) Henry G. (Gerry) Schwartz, Jr., Chairman (retired), Jacobs/Sverdrup Civil, Inc., St. Louis, Missouri Kumares C. Sinha, Olson Distinguished Professor of Civil Engineering, Purdue University, West Lafayette, Indiana Gary C. Thomas, President and Executive Director, Dallas Area Rapid Transit, Dallas, Texas Paul Trombino III, Director, Iowa Department of Transportation, Ames Phillip A. Washington, General Manager, Regional Transportation District, Denver, Colorado EX OFFICIO MEMBERS Thomas P. Bostick, (Lt. General, U.S. Army), Chief of Engineers and Commanding General, U.S. Army Corps of Engineers, Washington, D.C. Alison J. Conway, Assistant Professor, Department of Civil Engineering, City College of New York, New York, and Chair, TRB Young Members Council Anne S. Ferro, Administrator, Federal Motor Carrier Safety Administration, U.S. Department of Transportation David J. Friedman, Acting Administrator, National Highway Traffic Safety Administration, U.S. Department of Transportation LeRoy Gishi, Chief, Division of Transportation, Bureau of Indian Affairs, U.S. Department of the Interior, Washington, D.C. John T. Gray II, Senior Vice President, Policy and Economics, Association of American Railroads, Washington, D.C. Michael P. Huerta, Administrator, Federal Aviation Administration, U.S. Department of Transportation Paul N. Jaenichen, Sr., Acting Administrator, Maritime Administration, U.S. Department of Transportation Therese W. McMillan, Acting Administrator, Federal Transit Administration Michael P. Melaniphy, President and CEO, American Public Transportation Association, Washington, D.C. Victor M. Mendez, Administrator, Federal Highway Administration, and Deputy Secretary, U.S. Department of Transportation Cynthia L. Quarterman, Administrator, Pipeline and Hazardous Materials Safety Administration, U.S. Department of Transportation Peter M. Rogoff, Under Secretary for Policy, U.S. Department of Transportation Craig A. Rutland, U.S. Air Force Pavement Engineer, Air Force Civil Engineer Center, Tyndall Air Force Base, Florida Joseph C. Szabo, Administrator, Federal Railroad Administration, U.S. Department of Transportation Barry R. Wallerstein, Executive Officer, South Coast Air Quality Management District, Diamond Bar, California Gregory D. Winfree, Assistant Secretary for Research and Technology, Office of the Secretary, U.S. Department of Transportation Frederick G. (Bud) Wright, Executive Director, American Association of State Highway and Transportation Officials, Washington, D.C. Paul F. Zukunft, (Adm., U.S. Coast Guard), Commandant, U.S. Coast Guard, U.S. Department of Homeland Security * Membership as of July 2014. TRB OVERSIGHT COMMITTEE FOR SHRP 2* Chair: Kirk T. Steudle, Director, Michigan Department of Transportation MEMBERS H. Norman Abramson, Executive Vice President (retired), Southwest Research Institute Alan C. Clark, MPO Director, Houston–Galveston Area Council Frank L. Danchetz, Vice President, ARCADIS-US, Inc. Malcolm Dougherty, Director, California Department of Transportation Stanley Gee, Executive Deputy Commissioner, New York State Department of Transportation Mary L. Klein, President and CEO, NatureServe Michael P. Lewis, Director, Rhode Island Department of Transportation John R. Njord, Executive Director (retired), Utah Department of Transportation Charles F. Potts, Chief Executive Officer, Heritage Construction and Materials Ananth K. Prasad, Secretary, Florida Department of Transportation Gerald M. Ross, Chief Engineer (retired), Georgia Department of Transportation George E. Schoener, Executive Director, I-95 Corridor Coalition Kumares C. Sinha, Olson Distinguished Professor of Civil Engineering, Purdue University Paul Trombino III, Director, Iowa Department of Transportation EX OFFICIO MEMBERS Victor M. Mendez, Administrator, Federal Highway Administration David L. Strickland, Administrator, National Highway Transportation Safety Administration Frederick “Bud” Wright, Executive Director, American Association of State Highway and Transportation Officials LIAISONS Ken Jacoby, Communications and Outreach Team Director, Office of Corporate Research, Technology, and Innovation Management, Federal Highway Administration Tony Kane, Director, Engineering and Technical Services, American Association of State Highway and Transportation Officials Jeffrey F. Paniati, Executive Director, Federal Highway Administration John Pearson, Program Director, Council of Deputy Ministers Responsible for Transportation and Highway Safety, Canada Michael F. Trentacoste, Associate Administrator, Research, Development, and Technology, Federal Highway Administration * Membership as of March 2014. RELIABILITY TECHNICAL COORDINATING COMMITTEE* Chair: Carlos Braceras, Deputy Director and Chief Engineer, Utah Department of Transportation Vice Chair: John Corbin, Director, Bureau of Traffic Operations, Wisconsin Department of Transportation Vice Chair: Mark F. Muriello, Assistant Director, Tunnels, Bridges, and Terminals, The Port Authority of New York and New Jersey MEMBERS Malcolm E. Baird, Consultant Mike Bousliman, Chief Information Officer, Information Services Division, Montana Department of Transportation Kevin W. Burch, President, Jet Express, Inc. Leslie S. Fowler, ITS Program Manager, Intelligent Transportation Systems, Bureau of Transportation Safety and Technology, Kansas Department of Transportation Steven Gayle, Consultant, Gayle Consult, LLC Bruce R. Hellinga, Professor, Department of Civil and Environmental Engineering, University of Waterloo, Ontario, Canada Sarath C. Joshua, ITS and Safety Program Manager, Maricopa Association of Governments Sandra Q. Larson, Systems Operations Bureau Director, Iowa Department of Transportation Dennis Motiani, Executive Director, Transportation Systems Management, New Jersey Department of Transportation Richard J. Nelson, Nevada Department of Transportation Richard Phillips, Director (retired), Administrative Services, Washington State Department of Transportation Mark Plass, District Traffic Operations Engineer, Florida Department of Transportation Constance S. Sorrell, Chief of Systems Operations, Virginia Department of Transportation William Steffens, Vice President and Regional Manager, McMahon Associates Jan van der Waard, Program Manager, Mobility and Accessibility, Netherlands Institute for Transport Policy Analysis John P. Wolf, Assistant Division Chief, Traffic Operations, California Department of Transportation (Caltrans) FHWA LIAISONS Robert Arnold, Director, Transportation Management, Office of Operations, Federal Highway Administration Joe Conway, SHRP 2 Implementation Director, National Highway Institute Jeffrey A. Lindley, Associate Administrator for Operations, Federal Highway Administration U.S. DEPARTMENT OF TRANSPORTATION LIAISON Patricia S. Hu, Director, Bureau of Transportation Statistics, U.S. Department of Transportation AASHTO LIAISON Gummada Murthy, Associate Program Director, Operations CANADA LIAISON Andrew Beal, Manager, Traffic Office, Highway Standards Branch, Ontario Ministry of Transportation * Membership as of July 2014.

THE SECOND STRATEGIC HIGHWAY RESEARCH PROGRAM George F. List, Billy Williams, and Nagui Rouphail, Institute for Transportation Research and Education, North Carolina State University in association with Rob Hranac, Tiffany Barkley, Eric Mai, and Armand Ciccarelli, Iteris/Berkeley Transportation Systems, Inc. Lee Rodegerdts, Katie Pincus, and Brandon Nevers, Kittelson & Associates, Inc. Alan F. Karr, National Institute of Statistical Sciences Xuesong Zhou, University of Utah Jeffrey Wojtowicz, Rensselaer Polytechnic Institute Joseph Schofer, Northwestern University Asad Khattak, Planitek TRANSPORTATION RESEARCH BOARD Washington, D.C. 2014 www.TRB.org Guide to Establishing Monitoring Programs for Travel Time Reliability SHRP 2 Report S2-L02-RR-2

SUBSCRIBER CATEGORIES Highways Data and Information Technology Operations and Traffic Management Planning and Forecasting

THE SECOND STRATEGIC HIGHWAY RESEARCH PROGRAM America’s highway system is critical to meeting the mobility and economic needs of local communities, regions, and the nation. Developments in research and technology—such as advanced materials, communications technology, new data collection technologies, and human factors science—offer a new opportunity to improve the safety and reliability of this important national resource. Breakthrough resolution of significant transportation problems, however, requires concentrated resources over a short time frame. Reflecting this need, the second Strategic Highway Research Program (SHRP 2) has an intense, large-scale focus, integrates mul- tiple fields of research and technology, and is fundamentally different from the broad, mission-oriented, discipline-based research programs that have been the mainstay of the high- way research industry for half a century. The need for SHRP 2 was identified in TRB Special Report 260: Strategic Highway Research: Saving Lives, Reducing Congestion, Improving Quality of Life, pub- lished in 2001 and based on a study sponsored by Congress through the Transportation Equity Act for the 21st Century (TEA-21). SHRP 2, modeled after the first Strategic High- way Research Program, is a focused, time-constrained, management-driven program designed to complement existing highway research programs. SHRP 2 focuses on applied research in four areas: Safety, to prevent or reduce the severity of highway crashes by understanding driver behavior; Renewal, to address the aging infrastructure through rapid design and construction methods that cause minimal disruptions and produce lasting facilities; Reli- ability, to reduce congestion through incident reduction, management, response, and mitigation; and Capacity, to integrate mobility, economic, environmental, and commu- nity needs in the planning and designing of new transporta- tion capacity. SHRP 2 was authorized in August 2005 as part of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). The pro- gram is managed by the Transportation Research Board (TRB) on behalf of the National Research Council (NRC). SHRP 2 is conducted under a memorandum of understand- ing among the American Association of State Highway and Transportation Officials (AASHTO), the Federal Highway Administration (FHWA), and the National Academy of Sci- ences, parent organization of TRB and NRC. The program provides for competitive, merit-based selection of research contractors; independent research project oversight; and dissemination of research results. SHRP 2 Report S2-L02-RR-2 ISBN: 978-0-309-12973-2 Library of Congress Control Number: 2014946503 © 2014 National Academy of Sciences. All rights reserved. COPYRIGHT INFORMATION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from pub- lishers or persons who own the copyright to any previously published or copyrighted material used herein. The second Strategic Highway Research Program 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, or FHWA endorsement of a particular product, method, or practice. It is expected that those reproducing material in this document for educa- tional and not-for-profit purposes will give appropriate ac- knowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from SHRP 2. Note: SHRP 2 report numbers convey the program, focus area, project number, and publication format. Report num- bers ending in “w” are published as web documents only. NOTICE The project that is the subject of this report was a part of the second Strategic Highway Research Program, conducted by the Transportation Research Board with the approval of the Governing Board of the National Research Council. The members of the technical committee selected to moni- tor this project and to review this report were chosen for their special competencies and with regard for appropriate balance. The report was reviewed by the technical commit- tee and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the Governing Board of the Na- tional Research Council. The opinions and conclusions expressed or implied in this report are those of the researchers who performed the re- search and are not necessarily those of the Transportation Research Board, the National Research Council, or the pro- gram sponsors. The Transportation Research Board of the National Acad- emies, the National Research Council, and the sponsors of the second Strategic Highway Research Program do not en- dorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they are considered es- sential to the object of the report. SHRP 2 REPORTS Available by subscription and through the TRB online bookstore: www.TRB.org/bookstore Contact the TRB Business Office: 202.334.3213 More information about SHRP 2: www.TRB.org/SHRP2

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished schol- ars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. On the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and techni- cal matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advis- ing the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achieve- ments of engineers. Dr. C. D. Mote, Jr., is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the ser- vices of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sci- ences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Victor J. Dzau is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sci- ences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. C. D. Mote, Jr., are chair and vice chair, respectively, of the National Research Council. The Transportation Research Board is one of six major divisions of the National Research Council. The mission of the Transportation Research Board is to provide leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdis- ciplinary, and multimodal. The Board’s varied activities annually engage about 7,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state transpor- tation departments, federal agencies, including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation. www.TRB.org www.national-academies.org

SHRP 2 STAFF Ann M. Brach, Director Stephen J. Andrle, Deputy Director Neil J. Pedersen, Deputy Director, Implementation and Communications Cynthia Allen, Editor Kenneth Campbell, Chief Program Officer, Safety JoAnn Coleman, Senior Program Assistant, Capacity and Reliability Eduardo Cusicanqui, Financial Officer Richard Deering, Special Consultant, Safety Data Phase 1 Planning Shantia Douglas, Senior Financial Assistant Charles Fay, Senior Program Officer, Safety Carol Ford, Senior Program Assistant, Renewal and Safety James Hedlund, Special Consultant, Safety Coordination Alyssa Hernandez, Reports Coordinator Ralph Hessian, Special Consultant, Capacity and Reliability Andy Horosko, Special Consultant, Safety Field Data Collection William Hyman, Senior Program Officer, Reliability Linda Mason, Communications Officer Matthew Miller, Program Officer, Capacity and Reliability David Plazak, Senior Program Officer, Capacity and Reliability Rachel Taylor, Senior Editorial Assistant Dean Trackman, Managing Editor Connie Woldu, Administrative Coordinator

vii This work was sponsored by the Federal Highway Administration in cooperation with the American Association of State Highway and Transportation Offi cials. It was con- ducted in the second Strategic Highway Research Program, which is administered by the Transportation Research Board of the National Academies. The project was man- aged by Abdelmename Hedhli, Visiting Professional for SHRP 2 Reliability. ACKNOWLEDGMENTS

ix FOREWORD Travel time reliability can be defi ned as consistency of travel time over time. The pri- mary goal of SHRP 2 Reliability research is to improve the reliability of highway travel times by mitigating the effects of events that cause travel times to fl uctuate unpredict- ably. Through this research, seven sources of unreliable travel times have been identi- fi ed: traffi c incidents, work zones, demand fl uctuations, special events, traffi c control devices, weather, and inadequate base capacity. This guide documents the research of the L02 Project, Establishing Monitoring Programs for Travel Time Reliability. It also provides further discussion of how to develop and use a travel time reliability monitoring system (TTRMS). The Guide will be useful for system operators in determining what actions they need to take to reduce the variability of travel time and enhance reliability. Accompanying the Guide is a brief, stand-alone document that provides suggestions for communicating information about time travel reliability using maps, fi gures, and tables. The document, Handbook for Communicating Travel Time Reliability Through Graphics and Tables, and the Guide are available at http://www.trb.org/Main/Blurbs/168764.aspx. A TTRMS can help operating agencies monitor system performance, understand the impacts of the various factors that infl uence travel time, and provide credible infor- mation to system users about what travel time reliability to expect. With this infor- mation, operating agencies can make better decisions about what actions to take to help improve reliability. At the time this research was performed, most transportation agencies did not have these capabilities. The Guide has two parts. Chapters 1 through 5 describe the process of measuring, characterizing, identifying, and understanding the effects of recurrent congestion and nonrecurrent events that affect travel time reliability. The appendices provide more detailed information about the functional specifi cation of a monitoring system, meth- ods, a series of case studies, and a set of use cases that describe how different users of the TTRMS interact with the system. Abdelmename Hedhli SHRP 2 Visiting Professional, Reliability

xi CONTENTS 1 EXECUTIVE SUMMARY 1 Structure of the Guide 2 Why Is a Travel Time Reliability Monitoring System Needed? 3 What Should a Travel Time Reliability Monitoring System Do? 5 How Should a Travel Time Reliability Monitoring System Be Structured? 6 An Illustration 9 Implementation 9 Conclusion 11 CHAPTER 1 Introduction 15 Context Within Strategic Highway Research Program 2 15 Structure of the Guide 17 How to Use the Guide 17 What Is Travel Time Reliability? 20 Supply-Side and Demand-Side Perspectives 21 Trip-Making Concepts 22 Probability Density Functions 25 References 27 CHAPTER 2 Data Collection and Management 28 Infrastructure-Based Sources 31 Automated Vehicle Identifi cation Sources 34 Automated Vehicle Location Sources 36 Private Sector–Based Sources 37 Data Management for Recurring Conditions

xii 39 Data Management for Nonrecurring Events 42 Summary 42 References 45 CHAPTER 3 Computational Methods 47 Network Concepts 48 Trip-Making Concepts 51 Operating Conditions and Regimes 53 Imputation 59 Segment Travel Time Calculations 74 Route Travel Time Calculations 82 Influencing Factor Analysis 86 Summary 86 References 89 CHAPTER 4 Applications 89 Case Studies 91 San Diego, California 95 Northern Virginia 99 Sacramento–Lake Tahoe, California 102 Atlanta, Georgia 105 New York/New Jersey 108 Berkeley Highway Laboratory 110 Use Cases 113 See What Factors Affect Reliability (AE1) 118 Assess the Contributions of the Factors (AE2) 123 View the Travel Time Reliability Performance of a Subarea (AE3) 125 Assist Planning and Programming Decisions (AE4) 129 Determine When a Route Is Unreliable (AP5) 130 Be Alerted When the System Is Struggling with Reliability (MM2) 134 Summary 135 CHAPTER 5 Summary 136 Step 1. Collect and Manage Traffic Data 138 Step 2. Measure Travel Times 141 Step 3. Characterize Observed Travel Times 142 Step 4. Collect, Manage, and Impute Nonrecurring Event Data 144 Step 5. Identify Sources of Congestion and Unreliability 145 Step 6. Understand the Impact of the Sources of Unreliability 146 Step 7. Make Decisions 147 Conclusion

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TRB’s second Strategic Highway Research Program (SHRP 2) Report S2-L02-RR-2: Guide to Establishing Monitoring Programs for Travel Time Reliability describes how to develop and use a Travel Time Reliability Monitoring System (TTRMS).

The guide also explains why such a system is useful, how it helps agencies do a better job of managing network performance, and what a traffic management center (TMC) team needs to do to put a TTRMS in place.

SHRP 2 Reliability Project L02 has also released Establishing Monitoring Programs for Travel Time Reliability, that describes what reliability is and how it can be measured and analyzed, and Handbook for Communicating Travel Time Reliability Through Graphics and Tables, offers ideas on how to communicate reliability information in graphical and tabular form.

A related paper in TRB’s Transportation Research Record, “Synthesizing Route Travel Time Distributions from Segment Travel Time Distributions,” examines a way to synthesize route travel time probability density functions (PDFs) on the basis of segment-level PDFs in Sacramento, California.

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