A group campaigning for the rights of British drivers has called on Rotherham Council to quash the speeding convictions of a number of motorists who were tricked into driving 40mph on a 30mph stretch of road.
The Alliance of British Drivers (ABD) said it is outrageous to penalise drivers who thought they were obeying the correct speed limit after a prankster put up an authentic-looking 40mph sign on the A630.
It was displayed next to the road for three days before police removed it.
ABD director Brian MacDowell said it is up to highway authorities to ensure that the correct signs are displayed at all times, and police should make sure the right speed limit is displayed before taking enforcement action.
Both "clearly failed to do so" in the Rotherham case, he added.
However, police in Rotherham say they will not quash the convictions as the drivers were speeding. They did not say how many people are affected.
A spokesperson for the council said the sign appeared to be a proper sign but was not put there by the local authority, adding that the 30mph limit is there "for a very good reason, which is road safety".
RAC spokesperson Simon Williams, said: "While we support efforts to ensure motorists obey speed limits, in this instance it appears the police have been rather harsh in their attitude to enforcement.
"It's entirely understandable that motorists using this stretch of the A630 for the first time would think the limit was 40mph if that is what the signs are saying, and even regular travellers may assume there has been a change and as far as they are concerned they are abiding by the law."
Copyright Press Association 2014