自动交通管理系统 用红、绿、黄三支共两组发光二极管表示交通信号灯，利用单片机模拟有时间显示的定时交通信号灯控制管理。信号灯的变化规律可如下： 1）放行线：绿灯亮放行25秒，黄灯亮警告5秒，然后红灯亮禁止。 2）禁止线：红灯亮禁止30秒，然后绿灯亮放行。 3）当某一方向的红灯亮时，若该方向有车通过，则用扬声器声报警。（撞红灯信号可用3-5V模拟量表示） 同时用2位数码管进行30秒钟递减时间显示。-automatic traffic management system using red, green, yellow a total of three light-emitting diodes, said two traffic lights, using SCM time simulation shows the regular traffic signal control. Signal changes in the law to be as follows : 1) Release Line : green clearance 25 seconds, bright yellow warning five seconds, and then the red-ban. 2) prohibit the lines : red-Ban 30 seconds, then green clearance. 3) When the red light in one direction- that if the direction of a car passed, the use of loudspeakers sound alarm. (Red light signals can hit 3- 5V analog said), while using two digital tube for 30 seconds decreasing time displayed.