Norfol/Suffolk speed camera claims

[simpo one]

BBC local news just had a feature, keypoint of which are:

4 mobile vans on A11 in Norfolk... serious injuries fallen by 64% at camera sites in 1 year.

Haughly bends on A14 Suffolk - accidents halved since cameras introduced 3 years ago.

Then Tame Plod came on and got the 'speeding as socially unacceptable as drink driving' bit in. However, he said 'We often see casualty reductions at camera sites' - meaning that at many sites they don't!