TRANSPORTATION RESEARCH BOARD 2025 EXECUTIVE COMMITTEE^*

OFFICERS

Chair:Leslie S. Richards,Professor of Practice, University of Pennsylvania, Philadelphia

Vice Chair:Joel M. Jundt,Secretary of Transportation, South Dakota Department of Transportation, Pierre

Executive Director:Victoria Sheehan,Transportation Research Board, Washington, DC

MEMBERS

James F. Albaugh,President and CEO, The Boeing Company (retired), Scottsdale, AZ

Carlos M. Braceras,Executive Director, Utah Department of Transportation, Salt Lake City

Douglas C. Ceva,Vice President, Customer Lead Solutions, Prologis, Inc., Jupiter, FL

Nancy Daubenberger,Commissioner of Transportation, Minnesota Department of Transportation, St. Paul

Marie Therese Dominguez,Commissioner, New York State Department of Transportation, Albany

Garrett Eucalitto,Commissioner, Connecticut Department of Transportation, Newington

Andrew Fremier,Executive Director, Metropolitan Transportation Commission, San Francisco, CA

Martha Grabowski,Professor Emerita, Information Systems, Le Moyne College, Madden College of Business and Economics, Cazenovia, NY

Randell Iwasaki,President and CEO, Iwasaki Consulting Services, Walnut Creek, CA

Carol A. Lewis,Professor, Transportation Studies, Texas Southern University, Houston

Scott C. Marler,Director, Iowa Department of Transportation, Ames

Ricardo Martinez,Adjunct Professor of Emergency Medicine, Emory University School of Medicine, Decatur, GA

Russell McMurry,Commissioner, Georgia Department of Transportation, Atlanta

Craig E. Philip,Research Professor and Director, VECTOR, Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN

Steward T.A. Pickett,Distinguished Senior Scientist, Cary Institute of Ecosystem Studies, Millbrook, NY

Susan A. Shaheen,Professor and Co-Director, Transportation Sustainability Research Center, University of California, Berkeley

Marc Williams,Executive Director, Texas Department of Transportation, Austin

EX OFFICIO MEMBERS

Derek Barrs,Administrator, Federal Motor Carrier Safety Administration, Washington, DC

Bryan Bedford,Administrator, Federal Aviation Administration, Washington, DC

Michael R. Berube,Deputy Assistant Secretary for Sustainable Transportation, U.S. Department of Energy, Washington, DC

Steven G. Bradbury,Deputy Secretary, U.S. Department of Transportation, Washington, DC

Steven Cliff,Executive Officer, California Air Resources Board, Sacramento

Drew Feeley,Acting Administrator, Federal Railroad Administration, Washington, DC

David Fink,Administrator, Federal Railroad Administration, Washington, DC

LeRoy Gishi,Chief, Division of Transportation, Bureau of Indian Affairs, U.S. Department of the Interior, Germantown, MD

Firas Ibrahim,Director, Office of Research, Development, and Technology, Office of the Assistant Secretary for Research and Technology (OST-R), Washington, DC

Jason Kelly,Deputy Commanding General for Civil Works and Emergency Operations, U.S. Army Corps of Engineers, Washington, DC

Sandra Knight,President, WaterWonks, LLC, Washington, DC

Sean McMaster,Administrator, Federal Highway Administration, Washington, DC

Marcus J. Molinaro,Administrator, Federal Transit Administration, Washington, DC

Jonathan Morrison,Administrator, National Highway Traffic Safety Administration, Washington, DC

Niloo Parvinashtiani,Engineer, Mobility Consultant Solutions, Iteris Inc., Fairfax, VA, and Chair, TRB Young Participants Council

Paul Roberti,Administrator, Pipeline and Hazardous Materials Safety Administration, Washington, DC

Karl Simon,Director, Transportation and Climate Division, U.S. Environmental Protection Agency, Washington, DC

Paul P. Skoutelas,President and CEO, American Public Transportation Association, Washington, DC

Jim Tymon,Executive Director, American Association of State Highway and Transportation Officials, Washington, DC

Sang Yi,Acting Administrator, U.S. Maritime Administration, Washington, DC

________________________

^* Membership as of August 2025.

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

NCHRP SYNTHESIS 659

Automated Traffic Signal Performance Measures

MANAGEMENT, OPERATION, AND MAINTENANCE

A Synthesis of Highway Practice

Burak Cesme

Nemanja Dobrota

Kittelson & Associates, Inc.

Washington, DC

Chris Day

Iowa State University

Ames, IA

Subscriber Categories

Operations and Traffic Management

Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration

2026

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state department of transportation (DOT) 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.

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 TRBʼs recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive committee 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, universities, and industry; TRBʼs relationship to the National Academies is an insurance of objectivity; and TRB maintains a full-time staff of specialists in highway 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 transportation departments, by committees of AASHTO, and by the FHWA. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&Iʼs recommendations are proposed to the AASHTO Board of Directors, the FHWA, and the National Academies. Research projects to address these topics are defined by NCHRP, and qualified research agencies are selected from submitted proposals. Administration and oversight of research contracts are the responsibilities of NCHRP.

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.

NCHRP SYNTHESIS 659

Project 20-05, Topic 56-12
ISSN 0547-5570
ISBN 978-0-309-60208-2
Library of Congress Control Number 2026930195

© 2026 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trademarks of the National Academy of Sciences. All rights reserved.

COPYRIGHT INFORMATION

Authors herein are responsible for the originality and accuracy 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.

The National Academy of Sciences (NAS) grants permission to reproduce written material in this publication for classroom and non-commercial purposes subject to the rights of any third parties and appropriate attribution. Permission is given with the understanding that none of the material will be used to imply NAS, TRB, AASHTO, APTA, FAA, FHWA, FTA, GHSA, or NHTSA endorsement of a particular product, method, or practice. For other uses of the written material, users must request permission from the National Academies Press.

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.

This material is based upon work supported by the FHWA under Agreement No. 693JJ32350025. Any opinions, findings, and conclusions or recommendations expressed or implied in this document 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; the FHWA; or the program sponsors.

The Transportation Research Board does not develop, issue, or publish standards or specifications. The Transportation Research Board manages applied research projects which provide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications.

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 manufacturersʼ names or logos appear herein solely because they are considered essential to the object of the report.

Published reports of the

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

are available from

National Academies Press
500 Fifth Street, NW
Washington, DC 20001

(800) 624-6242

and can be ordered through the internet by going to

nationalacademies.org/publications

Printed in the United States of America

The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt 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. Tsu-Jae Liu 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 National 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.nationalacademies.org.

The Transportation Research Board is one of four centers of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to mobilize expertise, experience, and knowledge to anticipate and solve complex transportation-related challenges. The Boardʼs varied activities annually engage more than 5,500 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 departments of transportation, federal agencies including 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.

COOPERATIVE RESEARCH PROGRAMS

CRP STAFF FOR NCHRP SYNTHESIS 659

Monique R. Evans,Director, Cooperative Research Programs

Waseem Dekelbab,Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program

Arefeh Nasri,Senior Program Officer

Stephanie L. Campbell-Chamberlain,Senior Program Assistant

Natalie Barnes,Director of Publications

Brian Haefs,Associate Director of Publications

Doug English,Senior Editor

NCHRP PROJECT 20-05 PANEL

Joyce N. Taylor,Maine Department of Transportation, Augusta, ME (Chair)

Meredith Emily Hill,Maryland Department of Transportation, Hanover, MD

Jessie X. Jones,Arkansas Department of Transportation, Little Rock, AR

Raymond J. Khoury,Virginia Department of Transportation, Richmond, VA

James Murphy,Nevada Department of Transportation, Carson City, NV

Debra A. Nelson,New York State Department of Transportation, Albany, NY

James S. Nelson,Iowa Department of Transportation, Ames, IA

Jesus Alberto Sandoval-Gil,Arizona Department of Transportation, Phoenix, AZ

Cynthia J. Smith,Mississippi Department of Transportation, Jackson, MS

Jean M. Wallace,Minnesota Department of Transportation, St. Paul, MN

Mary Huie,FHWA Liaison

TOPIC 56-12 PANEL

Samuel Ahiamadi,Nevada Department of Transportation, Carson City, NV

Brooke Glidden,Maine Department of Transportation, Augusta, ME

Jeff Jenq,AECOM, Mesa, AZ

Derek Lehrke,Minnesota Department of Transportation, Roseville, MN

Sarah Searcy,North Carolina Department of Transportation, Raleigh, NC

Richard W. Denney, Jr.,FHWA Liaison

ABOUT THE NCHRP SYNTHESIS PROGRAM

Highway administrators, engineers, and researchers often face problems for which information already exists, either in documented form or as undocumented experience and practice. This information may be fragmented, scattered, and unevaluated. As a consequence, full knowledge of what has been learned about a problem may not be brought to bear on its solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem.

There is information on nearly every subject of concern to highway administrators and engineers. Much of it derives from research or from the work of practitioners faced with problems in their day-to-day work. To provide a systematic means for assembling and evaluating such useful information and to make it available to the entire highway community, the American Association of State Highway and Transportation Officials—through the mechanism of the National Cooperative Highway Research Program—authorized the Transportation Research Board to undertake a continuing study. This study, NCHRP Project 20-05, “Synthesis of Information Related to Highway Practices,” searches out and synthesizes useful knowledge from all available sources and prepares concise, documented reports on specific topics. Reports from this endeavor constitute an NCHRP report series, Synthesis of Highway Practice.

This synthesis series reports on current knowledge and practice, in a compact format, without the detailed directions usually found in handbooks or design manuals. Each report in the series provides a compendium of the best knowledge available on those measures found to be the most successful in resolving specific problems.

FOREWORD

By Arefeh Nasri
Staff Officer
Transportation Research Board

NCHRP Synthesis 659: Automated Traffic Signal Performance Measures: Management, Operation, and Maintenance presents the state of practice of state departments of transportation (DOTs) on how they manage, operate, and maintain systems that use high-resolution traffic signal controller data to monitor and improve signal performance. The synthesis provides information on current automated traffic signal performance measures (ATSPMs) and crowdsourced signal performance measures. It describes common challenges and barriers to implementation, funding strategies, staffing and organizational factors, and examples of how agencies integrate these systems into daily operations and maintenance practices.

Under NCHRP Synthesis Project 20-05/Topic 56-12, “Practices on Management, Operation, and Maintenance of Automated Traffic Signal Performances Measures,” Kittelson & Associates, Inc., was asked to (1) synthesize the information on current state DOT practices for enhancing traffic signal management, operations, and maintenance through the deployment and use of ATSPM systems; (2) identify factors leading to ATSPM implementation; and (3) highlight challenges, experience gained, and knowledge gaps. Information used in this study was obtained through a literature review, a survey of state DOTs, and interviews to develop in-depth case examples. The report provides five case examples that highlight how the interviewed DOTs deploy and operate ATSPM solutions, the organizational and funding approaches they use, the challenges they encountered, and the benefits and experience gained through implementation.

This synthesis is an immediately useful document that records the practices that were acceptable within the limitations of the knowledge available at the time of its preparation. As progress in research and practice continues, new knowledge will be added to that now at hand. The audience for this synthesis includes state DOT traffic operations and maintenance engineers, signal system managers, and policymakers who plan, fund, and oversee traffic signal programs. It is also valuable for traffic operations center staff, intelligent transportation system (ITS) engineers, and others involved in managing and optimizing signal timing and performance tools.

CONTENTS

Summary

Chapter 1 Introduction

Background

Definitions

Overview of ATSPM Components

Synthesis Objective and Scope

Report Organization

Study Methodology

Chapter 2 Literature Review

ATSPM Development

Development of Performance Measures for Traditional ATSPMs

Benefits and Costs

Integration into Agency Business

Crowdsourced ATSPMs

Key Findings of the Literature Review

Chapter 3 Survey Results

Survey Design

State DOT Structure and Deployment Overview

Funding and Return on Investment

Staff Capabilities, Resource Allocation, and Institutional Support

Signal Monitoring, Optimization, Maintenance, and Performance Measurement

Systems and Technology

Closing Takeaways from the Survey

Key Survey Findings

Chapter 4 Case Examples

Overview of Case Example DOTs

North Carolina Department of Transportation

Maryland Department of Transportation

Minnesota Department of Transportation

Georgia Department of Transportation

Utah Department of Transportation

Key Findings from the Case Examples

Chapter 5 Summary of Findings

Synthesis Findings

Suggestions for Future Research

References

Appendix A Survey Questionnaire 

Appendix B Survey Responses

Appendix C Case Example Interview Questionnaire

Appendix D Additional Resources