A small blue light shines on the backside of a traffic signal at the intersection of Broadway and Everett Avenue on Sunday, Dec. 11, 2022, in downtown Everett, Washington.

The blue light above a traffic signal, also known as a confirmation light, actually isn't there for drivers at all. Instead, it's for law enforcement. When the traffic light turns red, ...

Japanese traffic lights are blue instead of the green Americans know, but the reasoning involves some complex linguistic background and history.