Signal Timing Manual - Second Edition (2015)

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N A T I O N A L C O O P E R A T I V E H I G H W A Y R E S E A R C H P R O G R A M NCHRP REPORT 812 Signal Timing Manual Second Edition Tom Urbanik Alison Tanaka Bailey Lozner Eric Lindstrom Kevin Lee Shaun Quayle Scott Beaird Shing Tsoi Paul Ryus Kittelson & AssociAtes, inc. Portland, OR Doug Gettman Kimley-Horn And AssociAtes, inc. Phoenix, AZ Srinivasa Sunkari Kevin Balke texAs A&m trAnsportAtion institute College Station, TX Darcy Bullock purdue university West Lafayette, IN Subscriber Categories Operations and Traffic Management TRANSPORTAT ION RESEARCH BOARD WASHINGTON, D.C. 2015 www.TRB.org Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM Systematic, well-designed research is the most effective way to solve many problems facing highway administrators and engineers. Often, highway problems are of local interest and can best be studied by highway departments individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation results in increasingly complex problems of wide inter- est 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 ini- tiated 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, United States Department of Transportation. The Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine was requested by AASHTO to administer the research program because of TRB’s recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive com- mittee structure from which authorities on any highway transportation subject may be drawn; TRB possesses avenues of communications and cooperation with federal, state, and local governmental agencies, univer- sities, and industry; TRB’s relationship to the Academies is an insurance of objectivity; and TRB maintains a full-time staff of specialists in high- way transportation matters to bring the findings of research directly to those in a position to use them. The program is developed on the basis of research needs identified by chief administrators and other staff of the highway and transporta- tion departments and by committees of AASHTO. Topics of the highest merit are selected by the AASHTO Standing Committee on Research (SCOR), and each year SCOR’s recommendations are proposed to the AASHTO Board of Directors and the Academies. Research projects to address these topics are defined by NCHRP, and qualified research agencies are selected from submitted proposals. Administration and surveillance of research contracts are the responsibilities of the Acad- emies and TRB. The needs for highway research are many, and NCHRP can make significant contributions to solving highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement, rather than to substitute for or duplicate, other highway research programs. Published reports of the NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM are available from Transportation Research Board Business Office 500 Fifth Street, NW Washington, DC 20001 and can be ordered through the Internet by going to http://www.national-academies.org and then searching for TRB Printed in the United States of America NCHRP REPORT 812 Project 03-103 ISSN 0077-5614 ISBN 978-0-309-30888-5 Library of Congress Control Number 2015946872 © 2015 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 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, FMCSA, FRA, FTA, Office of the Assistant Secretary for Research and Technology, PHMSA, 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. NOTICE The report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the National Academies of Sciences, Engineering, and Medicine. The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; or the program sponsors. The Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; and the sponsors of the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they are considered essential to the object of the report.

The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, non- governmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Ralph J. Cicerone is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. C. D. Mote, Jr., is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.national-academies.org. The Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to increase the benefits that transportation contributes to society by providing leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdisciplinary, 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 transportation 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. Learn more about the Transportation Research Board at www.TRB.org.

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 REPORT 812 Christopher W. Jenks, Director, Cooperative Research Programs Christopher Hedges, Manager, National Cooperative Highway Research Program B. Ray Derr, Senior Program Officer Charlotte Thomas, Senior Program Assistant Eileen P. Delaney, Director of Publications Ellen M. Chafee, Editor NCHRP PROJECT 03-103 PANEL Field of Traffic—Area of Operations and Control Peter Koonce, City of Portland, Portland, OR (Chair) Mark Luszcz, Delaware DOT, Smyrna, DE Woody L. Hood, Sabra, Wang & Associates, Inc., Columbia, MD Susan Langdon, Savant Group, Dallas, TX Bill J. Shao, City of Los Angeles DOT, Los Angeles, CA Aleksandar Stevanovic, Florida Atlantic University, Boca Raton, FL James R. Sturdevant, Indiana DOT, Indianapolis, IN Eddie Curtis, FHWA Liaison Douglas Noble, Institute of Transportation Engineers Liaison Richard A. Cunard, TRB Liaison

F O R E W O R D In addition to covering basic and advanced signal timing concepts, this second edition of the Signal Timing Manual addresses establishment of a signal timing program including setting multimodal operational performance measures and outcomes, determining staff- ing needs, and monitoring and maintaining the system. Some of the advanced concepts addressed include the systems engineering process; adaptive signal control; preferential treat- ment (e.g., rail, transit, and emergency vehicles); and timing strategies for oversaturated con- ditions, special events, and inclement weather. The manual will be useful to traffic engineers and signal technicians at any agency operating traffic signals. In 2008, the FHWA published the Traffic Signal Timing Manual, providing a basic syn- thesis of signal timing practices in the United States. The manual covered fundamental signal timing related to intersection design, vehicle detection, and coordination of signal- ized intersections; but there were many concepts that, due to resource constraints, were not addressed in great detail. Under NCHRP Project 03-103, Kittelson & Associates, Inc., expanded and upgraded this manual, addressing many of the shortcomings. Several goals guided the development of the manual: (1) provide material useful to agen- cies in documenting their own signal timing policies and practices, (2) facilitate the train- ing of new staff, (3) facilitate implementation of more advanced signal timing concepts where appropriate, (4) include examples that illustrate application of the manual material to real-world intersections and systems, and (5) include references that promote a fuller understanding of topics. During the course of the project, the research team reviewed the pertinent literature (including agency signal timing manuals) and conducted four multi-agency focus groups and a workshop to get feedback on the utility of the 2008 Traffic Signal Timing Manual to typical users. From these efforts, the team identified topics that should be expanded or deep- ened. The user feedback also greatly influenced the organization of the second edition of the manual to increase its usefulness to practitioners. A PowerPoint presentation providing an overview of this second edition of the Signal Timing Manual can be found on the TRB website by searching on NCHRP Report 812. By B. Ray Derr Staff Officer Transportation Research Board

AUTHOR ACKNOWLEDGMENTS There were numerous contributions, large and small, but all very important to this second edition of the Signal Timing Manual. A great TRB project begins with a great panel, and the panel members on this proj- ect were both engaged and patient. The project also included focus groups that critiqued the first edition. While the focus groups were complimentary of the contributions made by the first edition, they challenged the project team to tighten up the document (i.e., no repetitive or “nice to know” material), expand the material on advanced concepts (which were only mentioned in the first edition), and update the graphics. The project team produced an expanded outline, which was used to develop the initial draft chapters. These chapters were reviewed individually by the panel as they were produced. Based on their comments and additional review by the writing team, a second complete draft was provided to the panel and some select outside reviewers. Again, many insightful suggestions were provided and some errors caught. The final product is immensely better due to the thoughtful review by the many contributors below. FOCUS GROUP PARTICIPANTS Nader Ayoub, Iteris, Austin, Texas Don Cashdollar, Florida Department of Transportation Larry Colclasure, Texas Department of Transportation John Deskins, City of Kennewick, Washington Hazem El-Assar, Orange County, Florida Chen Hsu, Virginia Department of Transportation Ken Jacobs, Pinellas County, Florida Sage Kamiya, Sarasota/Manatee County, Florida Mike Kinney, Montgomery County, Maryland Rob Klug, Clark County, Washington Aii Mozdbar, City of Austin, Texas Eric Nelson, Advanced Traffic Solutions, Houston, Texas Keith Orr, City of Portland, Oregon Keith Riniker, Sabra Wang, Baltimore, Maryland Tiffany Slaughter, Oregon Department of Transportation Mark Titus, City of Richardson, Texas Nhan Vu, Virginia Department of Transportation Charlie Wetzel, Seminole County, Florida Paul Zebell, City of Portland, Oregon OUTSIDE REVIEWERS John Black, City of Richardson, Texas Denny Eyler, SRF Consulting, Plymouth, Minnesota Airton Kohls, University of Tennessee Michael Kyte, University of Idaho Paul Olson, FHWA (retired) Wasim Raja, District of Columbia Department of Transportation Robert Saylor, City of Richardson, Texas

C O N T E N T S 1-1 Chapter 1 Introduction 1-1 1.1 Focus for the Second Edition 1-3 1.2 STM2 Organization 1-4 1.3 References 2-1 Chapter 2 Signal Timing Program 2-1 2.1 Elements of Successful Signal Timing Programs 2-3 2.2 Benefits of Regional Signal Timing Programs 2-3 2.3 References 3-1 Chapter 3 Signal Timing Concepts 3-2 3.1 Traffic Signal Basics 3-5 3.2 Initial Signal Timing Considerations 3-10 3.3 Data Collection 3-19 3.4 Operational Objectives and Performance Measures 3-29 3.5 References 4-1 Chapter 4 Signal Design 4-2 4.1 Detection 4-9 4.2 Signal Cabinet Equipment 4-14 4.3 Displays 4-23 4.4 Signalized System Design 4-25 4.5 Comprehensive Design Considerations 4-26 4.6 References 5-1 Chapter 5 Introduction to Timing Plans 5-1 5.1 Basic Signal Timing Concepts 5-19 5.2 Critical Movement Analysis 5-26 5.3 Role of Software in Signal Timing 5-31 5.4 References 6-1 Chapter 6 Intersection/Uncoordinated Timing 6-1 6.1 Basic Signal Timing Parameters 6-23 6.2 Detector Configurations 6-27 6.3 Time-of-Day Plans 6-28 6.4 References 7-1 Chapter 7 System/Coordinated Timing 7-1 7.1 Application of a Coordinated System 7-2 7.2 Coordination Planning Using a Time-Space Diagram 7-11 7.3 Introduction to Coordination Parameters 7-17 7.4 Coordination Parameter Guidance 7-28 7.5 Other Considerations for Coordination 7-35 7.6 Complexities 7-38 7.7 References

8-1 Chapter 8 Implementation and Maintenance 8-2 8.1 Transfer Plans from Office to Field 8-5 8.2 Field Observations and Adjustments 8-7 8.3 After Implementation 8-20 8.4 Staffing Needs 8-22 8.5 References 9-1 Chapter 9 Advanced Signal Systems 9-1 9.1 Systems Engineering 9-3 9.2 Advanced Coordination Features 9-4 9.3 Traffic Responsive Plan Selection Systems 9-11 9.4 Adaptive Signal Control Technology Systems 9-18 9.5 References 10-1 Chapter 10 Preferential Treatment 10-1 10.1 Types of Preferential Treatment 10-2 10.2 Introduction to Preferential Treatment 10-10 10.3 Preferential Treatment Advancements 10-12 10.4 Preemption and Priority 10-14 10.5 Preemption Considerations for Rail 10-23 10.6 Preferential Treatment Considerations for Emergency Vehicles 10-23 10.7 Preferential Treatment Considerations for Transit 10-25 10.8 Preferential Treatment Considerations for Trucks 10-27 10.9 References 11-1 Chapter 11 Special Conditions 11-2 11.1 Weather Events 11-6 11.2 Traffic Incidents 11-9 11.3 Planned Special Events 11-12 11.4 References 12-1 Chapter 12 Oversaturated Conditions 12-2 12.1 Symptoms of Oversaturation 12-5 12.2 Operational Objectives for Oversaturated Conditions 12-5 12.3 Mitigation Strategies for Oversaturated Conditions 12-21 12.4 References A-1 Appendix A Glossary