As you'd know if you'd had to do the Speed Awareness Course, like err ... me
=0(
... then you'd know that there are no "speed" cameras ... only "safety" cameras.
(ahem ... bo!!ocks)
But, the point is, as has been said ... they are not there to catch speeders.
(bo!!ocks, again!)
They are there to "calm" the traffic.
So a Sat Nav or Road Angel tells you where you should be calming you car ...
... and thus ASSISTS the speed (sorry, "safety") cameras.