Preliminary Scope

State DOTs traditionally manage traffic signals through routine, scheduled processes that lack active performance monitoring, leading to inefficient resource allocation and potential safety and operational issues going unaddressed. Recently, there has been a shift toward Automated Traffic Signal Performance Measures (ATSPM) to actively manage signal operations, including timing optimization. ATSPM offers insights and performance metrics, facilitating dynamic signal timing optimization without extensive manual data collection. By directing resources strategically, ATSPM aims to enhance safety and reliability across all transportation modes. However, DOTs face barriers hindering ATSPM's full potential.

The objective of this synthesis is to document state DOT practices for enhancing traffic signal management, operations, and maintenance along networks and corridors. The synthesis will focus primarily on practices related to the application of ATSPM to streamline these tasks.

Information to be gathered includes (but is not limited to):

• State DOTs use of ATSPM for active traffic signal monitoring, evaluation, and optimization;
• ATSPM’s role in supporting maintenance and ensuring a state of good repair;
• Development of skills within DOTs concerning policy, procedure, and mandatory software for ATSPM implementation, including staff training initiatives;
• Common applications of traffic signal optimization processes, encompassing in-house programs, corridor studies, and post-construction projects;
• Factors influencing traffic signal optimization, including procedural policies, funding and scheduling constraints, extent of data collection, geographic considerations, and safety performance factors;
• Adoption of big data practices and procedures, encompassing data sources, data age, frequency of updates, and data flow techniques in operational models;
• Review practices for traffic signal optimization and safety performance analysis;
• Examination of qualitative and quantitative return on investment metrics; and
• Barriers and constraints hindering the transition from traditional reactive traffic signal timing to active approaches using tools like ATSPMs. 

Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs for the development of case examples. Gaps and suggestions for research to address those gaps will be identified. 

Information Sources (Partial)

• Nevers, B. et al. (2020). NCHRP Research Report 954: Performance-Based Management of Traffic Signals. National Academies of Sciences, Engineering, and Medicine; Washington, DC. 
•  Day, C. M., Bullock, D. M., Li, H., Lavrenz, S., Smith, W. B., and Sturdevant, J. R. (2015). Integrating Traffic Signal Performance Measures into Agency Business Processes. Purdue University, West Lafayette, Indiana. https://doi.org/10.5703/1288284316063

TRB Staff
Arefeh Nasri
Phone: 202-334-2763 
Email: anasri@nas.edu

Meeting Dates
First Panel Meeting: October 1, 2024, in-person meeting in Washington, DC 
Teleconference with Consultant: TBD 
Second Panel Meeting: TBD