This diagram shows how a traditional traffic light works.
Picture 1: A red light means stop.
Picture 2: A green light means go.
Picture 3: A yellow light means slow down and be ready to stop.

Traffic lights (or traffic signals) are lights used to control the movement of traffic. They are placed at road intersections and crossings. The different colors of lights tell drivers what to do.

In South Africa, they call them robots. view more...