You may have noticed some traffic lights with a white light that works independently of the others. They're not for normal ...

You’ve trusted the same three traffic light colors your entire driving life. Red, yellow, green: it’s simple enough… until it isn’t. Behind every signal on U.S. roads sits a thick federal rulebook ...

Traffic lights might seem like they let cars stop or go randomly, but that's not always the case. Many of them use special sensors that detect vehicles.