From the BBC website
http://news.bbc.co.uk/1/hi/england/cambridgeshire/7555906.stmQuote:
Cameras reduce collisions on A14
Serious and fatal collisions on a Cambridgeshire road have fallen by 80% after new speed cameras were installed.
The overall rate of collisions on the A14 between Cambridge and Huntingdon has dropped by 21% in 2007-2008 compared with the previous year.
Insp Clinton Hale said: "We have had feedback from motorists saying the road is calmer and journeys are safer."
The new cameras work by recording a car twice on the same stretch of road and calculating their average speed.
Insp Hale added: "I am delighted the number of prosecutions and, of course fines, has gone down because it means that people are paying heed to the speed limit."
This section of road is about 12 miles long and used to be littered with Gatsos. They have rather neatly proved that the Gatsos caused lots of the crashes. The road is so busy that you can rarely get up to the speed limit let alone exceed it so the SPECS don't really cause any problems. Of course the official line is that the installation of SPECS caused the improvement rather than the removal of the Gatsos. Elephant racing lorries are still a source of frustration but at least the traffic does seem to flow more smoothly now most of the time.