Traffic Signal Timing & Operations Strategies
Traffic signal timing dictates how the right-of-way and capacity in the form of green time is distributed to the competing movements of signalized intersections. Signal timing must address the needs of all users including, pedestrians, bicycles, and vehicles, and in some cases must specifically accommodate, freight, transit, railroad and emergency vehicles. An objectives and performance based approach to traffic signal timing begins with an examination of organizational goals, considers context such as user mix, land use, network configuration and traffic demand to identify appropriate operations objectives, strategies and performance measures. The publications and training described below support an objectives and performance based design of traffic signal timing and implementation of operations strategies.
Traffic Signal Timing Publications
- Traffic Signal Timing Manual Second Edition, NCHRP Report 812 - Provides guidance to promote a multimodal, objectives and performance based approach to development of traffic signal timing to address the needs of pedestrian, bicycles, transit and automobiles.
- Traffic Signal Timing On a Shoestring (HTML, PDF 1MB) (Publication Number: FHWA-HOP-07-006) - This effort documents the minimum amount of data collection and optimization that should be performed in a signal retiming to acquire some appreciable benefits. This is aimed at jurisdiction or municipalities that cannot afford to perform more extensive data collection and analysis.
- Traffic Signal Timing Process (HTML, DOC 458KMB) - This report identifies the steps that are required to time traffic signals and activities that result in improved traffic signal timing.
- Signal Timing Under Saturated Conditions (HTML, PDF 1.6MB) (Publication Number: FHWA-HOP-09-008) - This document helps agencies to address the risks associated with ASCT implementation. The process involves exploration of agency operations needs to develop requirements that facilitate the procurement of ASCT.
Traffic Signal Timing and Operational Strategies to Address Pedestrians and Bicycles
- NCHRP Research Report 969: Traffic Signal Control Strategies for Pedestrians and Bicyclists - Provides tools, performance measures, and policy information to help agencies design and operate signalized intersections in a way that improves safety and service for pedestrians and bicyclists while still meeting the needs of motorized road users.
- National Institute for Transportation and Communities, Final Report, Improving Walkability Through Control Strategies at Signalized Intersections - This research report explores pedestrian signal timing control strategies, including a concept of pedestrian priority which may be warranted when pedestrian demand is low and vehicular demand is moderate.
- Guidebook on Signal Control Strategies for Pedestrians - This guidebook describes the available safety and efficiency-based control strategies for pedestrians, along with their potential impacts and any site and operational characteristics that could influence the choice of strategy.
- Accessible Pedestrian Signals | A Guide to Best Practices - This website provides a comprehensive source of information on APS, including how APS are used, what features are recommended or required, and how to design intersection corners to accommodate APS appropriately
- Pedestrian and Bicycle Information Center (Pedbikeinfo.org) - the PBIC develops and shares resources vital to advancing mobility, access, equity, and safety for pedestrians and bicyclists.
Traffic Signal Management, Operations and Adaptive Signal Control
- Measures of Effectiveness and Validation Guidance for Signal Control Technologies (HTML, PDF 10.2MB) (Publication Number: FHWA-HOP-13-031) - This report documents the tools and methodology developed for validation of ASCT systems and summarizes the testing of this approach and measures at a field site. The intent of the field study was not to evaluate the field site specifically but rather to demonstrate the application of the validation measures and methodology to a real world implementation of ASCT.
- Model Systems Engineering Documents for Central Traffic Signal Systems (HTML, PDF 3.3MB) (Publication Number: FHWA-HOP-19-019) This guidance document for procuring Central Traffic Signal Systems (CTSS) is part of a series of Model Systems Engineering Documents. This guidance document incorporates and replaces the Model Systems Engineering Documents for Adaptive Signal Control Technology (ASCT) Systems Formerly FHWA-HOP-11-027 published in 2012. This guidance expands the scope to cover central traffic signal systems and performance management technologies. This framework will support the alignment of an agency's over-arching objectives with their system operations strategies to guide the procurement of a system that best suits their needs within stated constraints. It will reduce the level of unmet expectations by stakeholders, improve the confidence of vendors that they will be able to verify compliance with stated requirements, and reduce the incidence of biased specifications. The document has been released in draft form, and will be used to support technical assistance and technology deployment activities to for a 6-8-month period. Any Feedback gained during this period will be incorporated to enhance the utility of the document prior to final approval.
- Additional Publications
Traffic Signal Training
- 133121 Traffic Signal Design and Operation (2-day, Instructor-Led)
This course addresses the steps required to plan, design and implement a signalized intersection including warrant analysis, basic phasing and calculation of signal timing settings.
- 133122 – Traffic Signal Timing Concepts (2-day, Instructor-Led)
This course is for both seasoned professionals and novice traffic engineers to develop additional technical expertise in traffic signal timing design for isolated and coordinated traffic signal systems with the understanding of how the operation fits into an objective-driven, performance-oriented process.