TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 409: Traffic Signal Retiming Practices in the United States explores practices that operating agencies currently use to revise traffic signal timing. The report examines the processes used to develop, install, verify, fine-tune, and evaluate the plans--

This report provides an overview of practices related to developing and sustaining a Regional Traffic Signal Operations Program. The purpose for a Regional Traffic Signal Operations Program is to provide regional partners a formal framework to collectively manage the signal system performance for efficiency and consistency. A key benefit of a regional program is the development of projects that are of a magnitude that they can be included in a regional or state transportation improvement program (TIP). There are many benefits to the development of a regional traffic signal management and operations program. Agencies and users benefit from regional traffic signal operations programs as planners, engineers, and operators can provide an effective and efficient traffic signal system to the public and also provide higher levels of customer service without increasing costs. Additionally, by sustaining collaboration, regional operators can demonstrate to the public and elected officials that progress is being made on community goals, which then can be leveraged for future funding. Agencies and jurisdictions within a region that use a common framework for developing and establishing expectations, managing resources, and building relationships will result in more successful systems both individually and region-wide.

In response to the 2005 and 2007 Traffic Signal Report Card, the FHWA initiated Regional Traffic Signal Operations peer reviews to take an in depth look at the practices and processes that guide traffic signal management.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 420: Operational and Institutional Agreements That Facilitate Regional Traffic Signal Operations (RTSOPs) identifies and highlights critical attributes of successful RTSOPs across the United States. Regions can use RTSOPs to help improve traffic flow as it crosses from one jurisdiction to another. A central focus of these programs is the coordination of signal timing on multi-jurisdictional arterials; however, RTSOPs can also facilitate the consideration of other traffic operations measures to improve regional mobility. Many RTSOPs have been established through regional metropolitan planning organizations, and successful RTSOPs also have been established by other organizations, including state and local departments of transportation and government corporations.