sneaky speed scamra's.

[Deefer666]

Cambs police used to have one that looked almost exactly like an RAC van until you got really close.

[crickleymal]

I thought the leeway was always 10% + 2mph? Avoids any doubt or speedo error.  So you should only get done for a true 36+mph in a 30 limit.

But the ACPO guidelines are just that - Guidelines. They don't have any real legal status, so theoretically you could be done for 31mph. A good lawyer could possibly argue that something breached guidlines and maybe get you off. Probably a better line of arguement if you were close to the limit is to ask what the accuracy of the camera is.

[BBROWN1664]

Speedo's are not allowed to under read- They cannot tell you that you are going slower than you really are but are allowed to make you think you are going faster.
Speeding is an Absolute offence. In other words, 30.1mph in a 30mph limit can get you done but the police don't want the paperwork involved which is why ACPO went with the +10%+2mph guidance.