At first glance, traffic lights are stunningly simple: green means go, red means stop, and yellow means it’s about to turn red. But like cars, phones, and just about everything else on this ...

If you've ever wondered how traffic lights work and how they can detect your car, you've probably also been curious about those small blue lights mounted above the signals themselves.

The blue lights on top of traffic signals, also known as confirmation lights, are designed to assist law enforcement detect drivers who run red lights.