十字路*通灯的变化规律要求：

（1）上面路口的绿灯，下面路口的红灯同时亮30秒左右。（2）上面路口的黄灯闪烁若干次，同时下面路口红灯继续亮。（3）上面路口的红灯，下面路口的绿灯同时亮30秒左右。（4）上面路口的红灯继续亮，同时下面路口的黄灯闪烁若干次。（5）转（1）重复。

-Traffic lights at the crossroads of the changes of requirements: (1) above the junction of the green light, following the red light intersection at the same time light about 30 seconds. (2) above the junction of the yellow light flashes several times, at the same time continue to light following a red light intersection. (3) above the junction of the red light, green light junction at the same time the following light about 30 seconds. (4) above the junction of the red light continues to shine, while below the yellow light flashes a number of junctions. (5) to (1) repeat.