TRAFFIC LIGHT

Traffic lights, commonly known as "red and green lights", are usually set up at intersections or other locations where traffic control is required, using red, yellow and green lights or supplemented by audio signals to indicate vehicles and pedestrians to stop, pay attention and move. Before traffic signals were invented, traffic operations were controlled by traffic policemen, who directed traffic manually. The first traffic light in Hong Kong was opened in 1922. Although the early traffic lights were very simple, with only a spherical red light, the road system has been adjusted and upgraded over the decades, and now the traffic lights in Hong Kong can be controlled in sections so that traffic flows more quickly and smoothly.