Signal Timing Subcommittee

The Signal Timing Subcommittee promotes research and understanding of concepts related to traffic signal timing through identifying research needs and facilitating development and dissemination of related research. A primary focus is the NCHRP/FHWA Signal Timing Manual (STM, click on images below) based on the latest research and advancements in the field. The key activities of the subcommittee include:

  •  Monitor, document, and facilitate developments in the field of traffic signal timing application and research, including future impacts of emerging technologies.

  •   Identify gaps in the field of traffic signal timing and steps to address (e.g., best practices, needed research, etc.).

  • Coordinate with the Research Subcommittee to develop new Research Problem Statements to address unfilled research needs.

  • Track use and log comments on the latest edition of the Signal Timing Manual (STM) and related courses (e.g., NHI).

  • Coordinate with the Education Subcommittee to incorporate the Signal Timing Manual (STM) into educational material.

  • Monitor and encourage liaisons with related TRB Committees and support opportunities for collaboration.

  • Coordinate with the webmaster to update/provide input to TSS Committee web page.


Signal Timing Manual – 1st Edition – 2008   Signal Timing Manual – 2nd Edition – 2015

The Subcommittee values comments and suggestions for the STM, as well as regarding the entire topic of signal timing. Please contact Nithin Agarwal ( or Alison Tanaka ( by email with any input you would like to provide.


Any opinions, findings, or conclusions expressed on this website are those of the authors and do not necessarily reflect the views of the Transportation Research Board or The National Academies