交通灯控制系统

某路口有一条主干道和一条支干路交叉而成。根据统

计，主干道的交通流量为支路的两倍。要求：

1)、正常情况下，两路轮流放行，且主干道的放流时间

是支路的两倍。信号转换时，按照以下规律显示：

从通行变为停止时，按绿→黄→红次序变化；

从停止变为通行时，按红→闪动→绿次序变化；

主干道与支路的显示必须保证它们是交叉进行的。

2)、当路上出现特种车辆(如警车、消防车等)时，该路

口应将它立即放行，并使另一方向停止。如果两个方向

同时出现特种车，应时主干道的车辆先放行。-Traffic light control system

A main road and a junction with a cross made ​ ​ of branches trunks. According to Commission

Meter, main road traffic to slip twice. Requirements:

1), under normal circumstances, release of two turns, and the main road of releasing time

Is the branch twice. Signal conversion, the following rule shows:

From the passage into a stop, press the green → yellow → red sequence changes

Into a passage from the stop, press the flashing red → green → order changes

Trunk and branch display must ensure that they are interleaved.

2), when on the road there special vehicles (such as police cars, fire engines, etc.), the Road

Mouth it should be released immediately, and to stop the other direction. If the two directions

At the same time there special vehicles, seasonal vehicles first release trunk