Article from: www.thenewspaper.com/news/11/1184.asp
The UK will expand its use of average speed cameras beyond high-speed major roads and begin using them in low-speed neighborhoods. A series of test cameras in Camden, North London, and Belfast monitor traffic as each vehicle enters a particular section of town. Each camera in the system operates independently. The first device records the plate number and time of entry for each vehicle that drives into the ticketing area. When the same vehicle exits, a second camera records the vehicle plate number along with the time of exit. These records are later gathered and processed so that the average speed of all cars can be computed.