Originally Posted by Wonka2581

Air Unit - or helicopter. some agency have them and what they do is hover high up and look down to the markers they have already set up most of the time they are white X shapes on the side of the highway as you pass the markers the will start a stop watch and then stop the watch as you pass the next marker about a mile down the road or so. Then they take your time and do a math formula and boom they now have how fast you were going. And then radio your vehicle color and make to the cops that are a couple of miles down the road.