说明：小路有传感器 p1.0，有车时，两路按照时间交换红绿灯，无车时，大路一直绿灯，小路绿灯时，若 无车立即向小路红灯、大路绿灯转换。-Cross-country road road traffic lights program Descr iption: path with sensors p1.0, have the car, according to the time two-way exchange of traffic lights, no car, the road