With city modernization degree unceasing enhancement, the traffic demand of urban traffic and traffic is in constant increase, this kind of situation of present make traffic congestion is becoming more and more serious. And a good traffic light control system design, can keep the traffic in a steady operation condition, and then prevent or smooth traffic congestion, improve the transportation operation power, therefore, everybody about traffic light control system scheme design appears increasingly pay attention to.

The traffic condition changes from the beginning of condition 1, until condition 4 and then circulates to condition 1, and the cycle repeats, and the four conditions are summarized as follows:

The lights are red and the lights are green in the north and south, counting down to 27 seconds.

In this situation, dongxi was forbidden to pass through, and the south and north were allowed to pass.

Two, the direction red light is bright, north and south direction yellow light shine, countdown 3 seconds.

In this condition, the vehicle will have to wait for the transition in addition to what is already being done.

3, the north and south lights are red, the lights are green and the countdown is 27 seconds.

In this situation, dongxi was allowed to pass, and south and north were forbidden to pass.

The north and south lights are red and the yellow light shines in the direction of three seconds.