Traffic Signal Operations

Traffic signals are tools used to manage traffic movements at intersections. There are two modes of operation - either pretimed/fixed time or actuated. Pretimed/fixed time signals operate the same timing sequence each cycle. An actuated traffic signal uses detection to count traffic volumes per movement and adjust movement times to service each movement. Traffic signals along corridors are interconnected to function as a system. An optimized traffic signal system will have reduced delay and improved safety. Traffic signals can be equipped with ancillary devices such as Emergency Vehicle Pre-emption (EVP) System to expedite the movement of emergency vehicles such as fire trucks and ambulances. To facilitate pedestrian and bicycle movements intersections are equipped with pedestrian signals, Walk/Don’t Walk. The Don’t Walk can be equipped with a countdown display to inform the pedestrian the amount of time available to complete their crossing.

Video stream of traffic at Bismarck intersections.