This synthesis will be of interest to traffic control systems managers and designers, maintenance managers and staff, communications managers and staff, and others who are responsible for the effective functioning of traffic signal control systems at the state, district, or local level. It will also be of interest to consultants and suppliers of traffic signal systems. It presents information on the current practices of state and local transportation agencies with regard to the maintenance management practices for traffic signal control systems. A previous NCHRP Synthesis, No. 114 (1984), examined the state of the practice with regard to traffic signal maintenance management. This synthesis reexamines current traffic signal control maintenance practices in light of the extensive use of solid state equipment, PCs, integrated systems and other advanced technologies, such as ITS ( intelligent transportation systems). This report of the Transportation Research Board discusses the current technologies and the maintenance concerns related to both hardware and software systems. It also presents information on traffic signal systems maintenance organizations and staff, maintenance programming and scheduling, ancillary equipment and repair facilities, cost of maintenance and funding sources, and management strategies.

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--

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 307: Systems Engineering Processes for Developing Traffic Signal Systems discusses the systems engineering techniques available to traffic signal systems and identifies the key processes in a number of traffic signal systems engineering areas.