High-tech signs are to be installed on a low bridge in Preston which has been hit 47 times by motorists between 1994 and 2004.

The bridge in Lytham Road, between Mill Lane and Blackbull Lane, is only acessible to vehicles less than 6ft 6ins tall.

It ranks fourth in a league table of the most struck bridges in the North West.

But the problem extends further than damage to the bridge and vehicles, as trains have to be brought to a standstill until an engineer can asses whether it is safe for trains to pass over if it is struck.

The £31,000 scheme, the first of its kind in Preston, features warning signs that will flash 'turn back' if an over-height vehicle passes through a detection point before the bridge.

Frank Edmondson, 62, whose daughter Loraine Turner, 34, lives yards from the bridge, said it was easy to see how so many vehicles had hit the bridge.

He said: "On Friday afternoon, a hire van scraped its top on the bridge.

"It's okay for people round here who know how low it is, but if you don't come round here often,you just don't realise how low it is.

"It could also do with a spotlight on it, and traffic lights because there's only one lane and no pavement for pedestrians."

A spokesman for Lancashire County Council said warning signs were already in place, but that, given the high number of times the bridge had been struck, the council and Network Rail had decided to take further action, by installing the new interactive signs.

The scheme is due to be finished by September.

North West Liberal Democrat MEP Chris Davies, is now campaigning for the penalty on motorists who hit the bridge to be increased from three to six points on their driving licence, with further discretionary powers made available to the court.