What error-proof principle does the traffic light adopt?

Warning principle for traffic lights. The principle of early warning is that some processes are prone to make mistakes, and the possibility of making mistakes can be reduced by early warning before thinking about evasive measures. When an abnormal situation occurs, a signal is sent in the form of a warning. And traffic lights use this principle to warn drivers how to exercise.

Traffic lights generally consist of red light, green light and yellow light. Red light means no traffic, green light means permission, and yellow light means warning. It is divided into: motor vehicle traffic lights, non-motor vehicle traffic lights, crosswalk traffic lights, direction traffic lights (arrow traffic lights), lane traffic lights, flashing warning traffic lights, and road and railway intersection traffic lights.

The scientific principle of traffic lights.

According to the optical principle, red light has a long wavelength and strong ability to penetrate the air, which is more noticeable than other signals. It is used as a signal to prohibit traffic, and green is used as a notification signal because red and green are the most different and easy to distinguish (red and green color blindness is a minority after all). In addition, colors can also express some specific meanings. Indicates heat or intensity, the strongest is red, followed by yellow. Green has a colder and calmer meaning. Therefore, people often use red for danger, yellow for warning and green for safety.