There are two kinds of traffic lights, for motor vehicles to see called motor vehicle lamps, usually refers to the red, yellow, green (green for blue green) three kinds of color lamps composed of lights used to direct traffic. When the green light is on, the vehicle is allowed to pass, and when the yellow light flashes, the vehicle that has crossed the stop line can continue to pass; failure to pass should slow down to stop and wait in front of the parking line, and the traffic is closed when the red light is on. For pedestrians to see is called pedestrian crossing lights, usually referred to by red, green (green for blue green) two kinds of color lamps to direct traffic signal lights, red light stop, green light line.