NCHRP Synthesis 659: Automated Traffic Signal Performance Measures: Management, Operation, and Maintenance examines how state departments of transportation are using high-resolution traffic signal controller data to monitor, manage, and improve signal performance. Automated Traffic Signal Performance Measures (ATSPMs) enable continuous, data-driven oversight of traffic operations and maintenance, supporting more proactive and efficient decision-making. While the benefits of ATSPMs are well documented, adoption across state DOTs varies due to challenges such as funding constraints, equipment and technology upgrades, staffing capacity, and organizational readiness. The synthesis highlights current practices, including the use of both controller-based and crowdsourced signal performance measures. It also explores implementation barriers, funding strategies, staffing considerations, and examples of how agencies integrate ATSPMs into day-to-day operational and maintenance workflows.

This conduct of Research Report for NCHRP Project 20-44(40) was submitted July 2025. It accompanies the Transportation Agency Capability Building Web-Based Guide in order to support implementation efforts and build upon the framework established in NCHRP 20-24(95) and facilitate the use of ACB guidance by transportation agencies. Practitioners may also find the Performance Management Reporting Peer Exchange Final Report – NCHRP Project 20-24 Task 124 (2019) of interest as well.

A product of NCHRP Project 20-24(95)A — Ensuring Essential Capability for the Future Transportation Agency. This memo provides instructions and a brief explanation of the Agency Capability Building Portal and digital guidebook for NCHRP 20-24(95).

Accompanying web-only document, Implementing the Agency Capability Building Framework to Activate Organizational Change, was published in November 2025 to support implementation of the ACB Guide and is available now for download. Practitioners may also find the Performance Management Reporting Peer Exchange Final Report – NCHRP Project 20-24 Task 124 (2019) of interest as well.