Nottinghamshire's red light camera experiment

摘要

Describes a system, tested in Nottinghamshire, UK, for the detection of road vehicles that pass red traffic lights. Loop detectors are placed in the road just beyond the stop line. Cameras are mounted in cabinets on hinged poles. Cables connect the loop detectors, the camera, and either the red light or the junction signal controller. If, more than a certain length of time after the light has turned to red, a vehicle crosses the stop line and activates the loop detectors, then a photograph of it is taken. Another photograph is taken a short while after, to show that the vehicle did not stop just beyond the stop line. Besides considering the technology, the paper also considers its effectiveness as a means of enforcement.