What’s the Purpose of That Little White Device on the Traffic Light Pole?

recognize that you’re waiting and help the controller provide a green signal when the traffic sequence allows it.

Without vehicle detection, some intersections rely more heavily on preset timing schedules.

2. Radar Traffic Sensors

Some small white devices are radar-based traffic sensors.

These use radio waves to detect vehicles and monitor movement. Depending on the equipment, they may estimate vehicle speed, count passing vehicles, determine whether a lane is occupied, or detect traffic queues.

Radar sensors are useful because they can often monitor multiple lanes or a larger area without requiring a separate sensor embedded in the pavement for every lane.