What are the Little black boxs on top of traffic lights are they sensors or cameras?
ok mate i can put your mind at rest i work on the roads fixing camreas and traffic lights so when they go down we are the guys who fix them right lets get to the point they are sensors send out a beam which goes out over 5mtres and when the last car gets to or over the 5metres mark the lights will trip to green but the hick up is that when you flash your lights at them they dont trip , there is a other sensor built in which detects blue lights so when a emergancey services are goen through with blue lights on they trip to green agian. when there is a speed camrea on them they are usually on there own and you can see them painted in yellow and there must be a sign sayen so.