New speed cameras catch thousands (UK)

Just had a thought...Depending on speed differential, traffic density, environmental factors, wouldn't speed cameras possibly cause an accident?

Wouldn't it stand to reason that once the location is known by commuters there will be a bottle neck, then the speed will go up until the next camera.

Arizona has lots of speed cameras, and as far as I know, it does not cause big bottle-necks. Of course they have lots of traffic anyway. I guess, if no one is speeding, it does not matter anyway. California does not have speed cameras-- YET!