VASCAR (Visual Average Speed Computer And Recorder) is a vehicle speed measuring system that computes speed from two variables, distance target vehicle travels and the time it takes to travel that distance. Distance can be measured using the patrol vehicle odometer (the VASCAR computer is connected directly to the odometer), or entered from a keyboard inside the patrol vehicle.
Unlike many Police Radar Guns, the basic operation of VASCAR has the officer visually select any two landmarks (utility pole, crosswalk, sign, etc.), determine distance between landmarks (already known or measured with patrol vehicle odometer), and measure the time it take a target vehicle to travel between landmarks (push a button when target passes each landmark). VASCAR radar can be used by a stationary or moving patrol vehicle. In moving mode distance between landmarks is determined on the fly by the officer pushing a button when passing each landmark.
VASCAR radar has an advantage over microwave radar (most Police Radar Gun) and laser radar in the fact that a radar has to be close to the road, while VASCAR can be close to or far from the road. The operator only has to see vehicles pass between landmarks, making VASCAR more flexible (easier to hide patrol vehicle) Police Radar Guns. Also VASCAR does not transmit (microwaves or laser infrared signals) and does not alert a driver equipped with a radar detector.