I have to sit at a traffic flow system every day, you know the ramp meter system. So today I just noticed that they are easy to hack. If you give a car length away from a car infront of you (keep off the Tar filler for the sensor in the pavment) and the other car in traffic, and then once they get the green light and it turns red again pull foward over the sensor and bam green light. I assume they all work the same or close to it. give it a try and mess up the traffic a little more.