交通灯,东面亮绿灯西面亮红灯，定时30秒，再东西方向同时亮黄灯，定时3秒，然后换东面亮红灯西面亮绿灯，定时30秒，再亮黄灯，定时3秒，以此循环-Traffic light, green light east west red light, time 30 seconds, and then east-west direction at the same time bright yellow light, time 3 seconds, and then for the east west red light green light, timer 30 seconds, then light yellow, Timing 3 seconds, this cycle