How Photo Radar Works
Photo radar combines a camera, radar, and a computer that records the date, time, speed and location of the violation. The system is mounted in an unmarked van that may move to any school zone or neighborhood having trouble with speeding.
Although photo radar uses the same Doppler principle as traditional radar, its unique feature is that it transmits a very narrow beam across the road, thereby eliminating the risk of tracking two vehicles at once. Also with photo radar, the offending vehicle is tracked much closer to the photo radar unit.
In Boulder, the photo radar vans are positioned at the side of the road. A radar beam is transmitted from the unit in the van across the roadway immediately preceding the photo radar van. When a vehicle enters the radar beam at a speed higher than the threshold speed established for the program (currently 10 mph or more over the posted speed limit), the camera is activated and takes a photograph of the vehicle, which includes an image of the driver. A second camera takes a picture of the license plate of the vehicle. The computer system captures the speed of the vehicle and then transmits information regarding the speed, date, time and location of the violation to a data box. This data box is then superimposed on the photograph of the vehicle.
Last Updated on Thursday, 07 June 2012 09:15