十字路口交通管理器设计，甲、乙道路交替通行，每次通行时间30s

交替通行时刻，要求有5s的准备时间，即每次绿灯变红灯时，黄灯应先亮5s。而红灯变绿灯则不需要亮黄灯

-Intersection traffic management design, A and B alternate access road, each turn of access time access time of 30s, 5s required preparation time, which changes each time when the red light green light, yellow light should be 5s. The red light is not bright yellow