Traffic signals are signals that direct the operation of traffic, generally consisting of red, green and yellow lights. The red light indicates that traffic is prohibited, the green light indicates that passage is permitted, and the yellow light indicates a warning. The following is the Fama traffic for you to organize the traffic signal light science knowledge, take you to understand the traffic signal light settings and rules, welcome to read.

Red, yellow and green traffic signals can be called silent “traffic police”. Traffic light is the international unified traffic signal, red light is a stop signal, green light is a pass signal. Intersection of several directions to the car are gathered here, some to go straight, some to turn, in the end, who let the first to go, which is to listen to the traffic light command. Red light prohibit straight or left turn, in the case of pedestrians and vehicles, allowing vehicles to turn right; green light permits vehicles to go straight or turn; yellow light, stop at the intersection within the stop line or crosswalk line, has continued to pass; yellow light flashing, warning vehicles to pay attention to safety.

First, the light color settings

The earliest time only red, green two colors, and later improved, added a yellow light, red light said stop, yellow light table ready, green light is said to pass. The reason for adopting these three colors and using them as traffic signals is also related to people's visual structure and psychological responses.

The human retina contains rods and three kinds of cone photoreceptor cells, rod cells are particularly sensitive to yellow light, three kinds of cone cells are respectively most sensitive to red light, green light and blue light. Because of this visual structure, it is easiest to distinguish red from green. Although yellow and blue are also easy to distinguish, but because the eye is less sensitive to blue light photoreceptor cells, so distinguish colors, or red, green is better.

It can be seen that the traffic signal is not randomly set.

Second, the traffic signal rules

Article I in order to strengthen urban traffic management, facilitate transportation, maintenance of traffic safety, in order to meet the needs of national economic construction, the formulation of these rules.

Article 2 institutions, the military, organizations, enterprises, school personnel, vehicle drivers, citizens and temporary to and from the city of all people must abide by these rules and follow the instructions of the traffic police.

Article 3 Vehicle managers and passengers of institutions, armies, organizations, enterprises and schools are not allowed to force or connive at drivers to violate these rules.

Article IV encountered in this rule does not provide for the situation, vehicles, pedestrians must not interfere with the principle of traffic safety to pass.

Article 5 Driving vehicles, driving and riding livestock must all travel on the right side of the road.

Article 6 Without the consent of the local Public Security Bureau, it is not permitted to occupy sidewalks or driveways or conduct other activities that obstruct traffic.

Article 7 At intersections where railroad tracks cross streets, guardrails and other safety facilities must be installed.