Traffic lights are an important part of traffic signals and the basic voice of road traffic. Traffic lights are composed of red lights (indicating no traffic), green lights (indicating traffic allowed), and yellow lights (indicating warning). Divided into: motor vehicle signal light, non-motor vehicle signal light, crosswalk signal light, lane signal light, direction indicator light, light warning signal light, road and railway level crossing signal light.
Road traffic lights are a kind of traffic safety products. It is an important tool to strengthen road traffic management, reduce traffic accidents, improve road efficiency, and improve traffic conditions. It is suitable for intersections, T-junctions and other intersections. It is controlled by the road traffic signal controller to assist vehicles and pedestrians to pass safely and orderly.
The main types of traffic signal lights are: motor vehicle lane lights, crosswalk lights (that is, traffic lights), non-motor vehicle lane lights, direction indicators, mobile traffic lights, solar warning lights, toll station canopy lights.
The color of the signal light.
First, there are only two colors, red and green. Later, after improvement, a yellow light was added. A red light means stopping, a yellow light means preparation, and a green light means traffic. On the one hand, three primary colors are used, and other colors are also improved on this basis. On the other hand, the use of these three colors as traffic lights is also related to people’s visual structure and psychological response.
The human retina contains rod-shaped and three cone-shaped photoreceptor cells, which are particularly sensitive to yellow light, while the three cone-shaped cells are most sensitive to red, green and blue light. Because of this visual structure, it is easiest for people to distinguish between red and green. Although yellow and blue are easy to distinguish, red and green are the best way to distinguish colors because very few photoreceptor cells are sensitive to blue light. It can be seen that the traffic lights are not arbitrarily set.
