Prosecutors in Warwickshire confirmed the signs posted on the M24 highway west of Coventry did not meet strict government specifications.
Although the Highways Agency insists the printing was easily readable, prosecutors and police decided to stop using them as the basis for speeding citations and dropped its pending cases. The action prompted lawyers to argue that all previous speeding cases should be reversed and the accumulated fines refunded to the drivers, The Daily Telegraph said Saturday.
One traffic analyst said the law regards an incorrect sign as the same as no sign at all.
"If there are no traffic signs, the Act of Parliament prohibits the conviction and these are definitely not traffic signs," consultant Richard Bentley told the BBC.