Cobb County Government

How do traffic signals work?

Traffic signals utilize an electronic controller to assign the right-of-way to a particular traffic movement, vehicular and pedestrian, based on a signal timing plan. All traffic signals in Cobb County include vehicle detection typically in the form of an inductance loop in the pavement or a video camera to optimize traffic flow and minimize delays. The traffic signal controller is programmed to reduce time or skip time for a phase of traffic or traffic movement based on input from the vehicle detection equipment. Some signals operate in a system or collection of signals in a coordinated manner to further optimize traffic flow through a corridor or in an area; some operate independently from other traffic signals. Generally coordinated systems favor the predominant direction of traffic flow.