Unmarked cameras seem to be against their own rules...
Guidance on the use of speed cameras
Department for Transport guidance on the use of speed cameras require that:
- speed camera housings be coloured yellow;
- camera housings should not be obscured, eg, by trees, bushes or signs;
- cameras be visible from 60m away in 40mph or less zones and 100m for all other speed limit zones;
- signs should only be placed in areas where camera housings are sited or where mobile cameras operating;
- mobile speed camera operators wear fluorescent clothing, and their vehicles should be marked with reflective strips;
- camera sites be reviewed at least every six months to ensure cameras are properly visible and signposted.
All authorities operating the speed camera system are expected to abide by these rules, but it is not a defence against a speeding charge if you’re caught by a speed camera which falls short of the rules.
The DoT recommends that speed cameras be located in areas where many speeding accidents have occurred. Before cameras are installed, other measures to improve safety (eg, improving road layout, anti-skid surfacing, enhanced visibility) should first be considered.