A speed trap system used to measure the speed of a vehicle, used mostly before radar guns were implemented. It is an acronym for Visual Average Speed Computer and Recorder. Two points are chosen on a road, and the distance between them is measured. A vehicle is measured on the amount of time they take to go between the two points, and finally their speed is calculated from the time and distance measured.

Sometimes I see perpendicular lines drawn on the interstate, and I wonder if that's what these are. Strangely enough, if listening to an AM radio broadcast while travelling on the Florida Turnpike, I can hear a blip of static in the radio at the exact instant I cross over some of these strange perpendicular white lines.