I have been thinking about the new trend of putting speed cameras on motorways..as recently on the M4.
What has struck me, apart from the fact that they haven't been sighted according to the guidelines is that they may not even be legal.
On 30mph roads where speed cameras are located the speed limit applies to all vehicles.
However on motorways for example different vehicles are restricted to different speeds..
For example HGVs over 7.5 tonnes or vehicles pulling trailers are restricted to 60mph on motorways.
Therefore assuming a camera triggering speed of 75mph...
An HGV weighing over 7.5 tonnes or a mini pulling a huge caravan can exceed its own 60mph motorway speed limit by 14mph without triggering a speed camera whereas a car or coach or hgv weighing less than 7.5 tonnes will be prosecuted for only travelling 5mph over its designated limit.
Does this discrimination..ironically against the vehicles which can stop easier make the siting of cameras on motorways illegal or can a motorist argue he shouldn't be prosecuted on the grounds of discrimination or victimisation?
On single carriageway roads and dual carriageways also there variable limits for differing vehicles...
Legal boffins please illucidate.
see here for speed limits....
http://www.highwaycode.gov.uk/09.htm