Evaluation of the Traffic Signal Timing Manual, Third Edition

The Federal Highway Administration (FHWA) Traffic Signal Timing Manual (STM) has been the most widely accepted reference across the traffic signal timing field. Since the release of the second edition in 2015 (STMv2), there have been significant advances in signal timing research and practices, and several NCHRP and FHWA initiatives have been implemented. New technological trends are emerging, such as applying new computational approaches to the signal timing process, developing signal timing plans using novel datasets, and implementing new signal timing paradigms for connected and autonomous vehicles (CAV) and connected intersections. The traffic signal timing community has highlighted important topics to be addressed in a new version of the STM, including the signal timing of unconventional intersection geometries; advanced bicycle, pedestrian, and transit signal timing; cybersecurity risks tied to the signal timing procedures; and innovative signal timing design using standards-based controller features. The STM has served as a primary reference for the FHWA Traffic Signal Timing Concepts course. The course presents a signal timing workflow that starts with goals, explores context with a focus on vehicle flow, and then selects strategies and tactics that support attainment of objectives. It is envisioned that an update to the STM's structure could better support this workflow, inclusive of performance measurement to validate objectives and demonstrate progress towards goals and enhance the coverage of pedestrians, bicycles, transit, Complete Streets, safety, and equity. The update should consider how signal timing fits in with the overall traffic signal program, as other elements within the program (e.g., maintenance, equipment health) may directly impact the success of signal timing activities. The objective of this research is to provide guidance on utilizing up-to-date effective practices and research outcomes that have been successfully implemented after STMv2. At the minimum, the research shall: (1) Support an objectives-oriented, actively managed traffic signal timing process that starts with goals, considers context, supports the implementation of strategies and tactics, and addresses evaluation of signal timing design outcomes, (2) Address signal timing strategies for various intersection and roadway network users, including nonmotorized users and transit vehicles, (3) Incorporate existing research and effective practices to expand the coverage of over-saturated/congested conditions, and (4) Describe use cases for advanced/innovative controller features, such as peer-to-peer communication, custom logic, etc.


  • English


  • Status: Proposed
  • Funding: $750000
  • Contract Numbers:

    Project 03-149

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Deng, Zuxuan

  • Start Date: 20230515
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01847361
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 03-149
  • Files: TRB, RIP
  • Created Date: May 26 2022 4:54PM