Description Of The Traffic Light System ● A traffic light system controls the intersection of two streets, one going north-south (N_S) and the other going east-west (E_W). ● The traffic lights remain green (in their respective directions) for a specified amount of time. The time east-west remains green may not be the same as that of north-south. ● The time the lights remain green can change according to traffic conditions. ● The lights can be disabled. In the event of electrical malfunction, the lights blink yellow in all four directions.