| 摘要 |
A traffic monitoring system comprising apparatus for establishing a pair of precisely spaced radiation beams in association with a thoroughfare, whereby passage of a vehicle along the thoroughfare interrupts the radiation beams, apparatus for sensing interruption of the radiation beams and providing output indications of vehicle speed and separation between adjacent vehicles (headway) and apparatus for photographing vehicles fulfilling predetermined criteria including photography trigger apparatus which is responsive to the sensed vehicle speed of the vehicle being photographed for providing a consistently positioned photographic record of the vehicle, irrespective of vehicle speed. |
