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

correctly.

The signal may be prioritizing another movement
Even when a sensor detects your car, the controller must coordinate several traffic movements safely. It may need to complete another phase before giving your direction a green light.

If a traffic signal appears to malfunction repeatedly, report it to the local road or transportation authority rather than trying to adjust or inspect the equipment yourself.

Are These Devices Used at Every Intersection?
No. Traffic detection technology varies widely.

Some intersections have sophisticated systems with radar, video detection, communication equipment, and adaptive signal controls.

Others rely on simpler systems, including fixed-time signals