十字路*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 eac