A traffic signal is a device used to control the flow of vehicles and pedestrians at intersections. It typically consists of three colored lights: red, yellow, and green. The red light indicates that vehicles must stop, the green light means they can go, and the yellow light warns that the signal is about to change. Traffic signals are essential for maintaining safety on the roads. They help prevent accidents by regulating when cars and pedestrians can move. In addition to standard signals, some intersections may also have pedestrian signals that show when it is safe to cross the street.