Science could 'switch off' car jams

White lines that can be switched on and off could solve the growing congestion crisis on Britain's motorways, transport experts have claimed.

Developed by Dutch scientists using the latest fibreoptic technology, the lines could transform hard shoulders on the M25 or M4 into an extra lanes during emergencies - or when traffic volumes reach a critical level.

The hi-tech lines replace traditional white paint and are buried in the road surface. A Highways Agency official said the system, reported to have improved traffic flow and cut accidents in Holland, is being considered for use on British roads.