Samenvatting
The variety of techniques used throughout the United States to maintain traffic signal equipment and systems engenders a variety of both technical and management problems. Although the technical problems obviously are important, the scope of this synthesis is limited to the equally important management problems. maintenance of traffic signal equipment and systems falls into several categories. first is the routine maintenance to ensure that the signals continue to operate. This includes lubrication, adjustment, cleaning, and painting. Next is preventive maintenance- the inspection and replacement of parts at regular intervals. Then there are the emergency repairs that are necessary to restore signal operation after a service failure.