VASCAR (Visual Average Speed Computer And Recorder) is a type of device for calculating the speed of a moving vehicle. The first VASCAR device was created in 1966 by Arthur Marshall. It is used by police officers to enforce speed limits, mainly in jurisdictions in Pennsylvania where radar or lidar is illegal, or to prevent detection by those with radar detectors.
A VASCAR unit couples a stopwatch with a simple computer. An operator records the moment that a vehicle passes two fixed objects (such as a white circle or square painted on the road) that are a known distance apart. The vehicle's average speed is then calculated by dividing the distance by the time. By applying the mean value theorem, the operator can deduce that the vehicle's speed must equal its average speed at some time between the measurements.
VASCAR can be used from a moving or stationary patrol vehicle, and the target vehicle may be travelling in the same direction, in front of or behind the officer. It can be approaching from the front, or even on an intersecting highway. This technique can also be used to determine a vehicle's speed from helicopters and other aerial platforms, making it easier to secure a conviction.
Mi rotas ti mu simbainei
ki eho papsi na gelo
ki ime pandote thlimeni
ki eho mesa mu kaimo
Fisa Ageri mu ke agiazi
na swisti i fotia
pu mu ehi anapsi stin kardia
ftaei to agori pu kitazi
oli ti bradia
ke me kani na pistevo
pos isos m'agapa
Mi rotas ti mu simbainei
ke apopse xenichto
ke adiazo to potiri
ke goulia goulia metho
Fisa Ageri mu ke agiazi
na swisti i fotia
pu mu ehi anapsi stin kardia
ftaei to agori pu kitazi
oli ti bradia
ke me kani na pistevo
pos isos m'agap