Scrap metal thieves are putting drivers at risk with the theft of road signs and street lighting cables plunging highways into darkness.
Thieves are turning their attention to roads after a crackdown on rail cable theft by the British Transport Police.
Transport Minister Norman Baker told MPs the thefts were now affecting Britain’s entire transport network.
He said: “This problem transcends the railway. It has affected motorways, the coastguard and the telecoms industry.
“The level of theft tends to follow the price of copper and other metals on world markets.”
Last month a stretch of a dual carriageway more than a mile long in Leeds suffered a blackout after more than £200,000 of street lighting cable was stolen.
Police believe the thieves posed as workmen and engineers as they targeted the section of the A63 link road, leaving the half-mile sections of the highway in complete darkness.
Road safety experts also said vital road signs were vanishing from dangerous bends.
Andrew Howard, head of road safety at the AA, told the Telegraph: “You also have to take into account warning signs being stolen.
“If this happens on a bend, it can be really dangerous. On a remote road in North Yorkshire, for example, you would expect chevron signs and if that is not there it is much more worrying.”