Humans should not be timing stoplights. Machine learning should be used to study traffic patterns and then time the lights dynamically. For instance, if you're driving at night and there are no other cars around, then every light should be green for you. Or let's say there are five cars that are waiting to turn left at an intersection. The left turn signal should be green for exactly as long as it takes to let all five cars through, rather than letting four cars through and making the fifth car wait another cycle.