More than one in six drivers caught speeding in England had their fines cancelled last year, as figures show thousands of fines are dodged in the North East.
Analysis of Government data by the RAC Foundation revealed that 404,335 (17%) of 2.4 million speeding cases in the 12 months to the end of March last year were dismissed.
A rise in law-breaking drivers using cloned number plates to fool police may be part of the reason for the rise, the foundation said.
