Darling outlined his vision of satellite navigation systems collecting tolls from drivers as part of the nationwide project to cut congestion in a speech to the Institute of Public Policy Research.
He said: ‘We need to move away from the idea that Government is going to define and specify all this modern technology. It will not work that way. Instead, we need to start thinking of road-pricing piggy-backing on systems already being offered by the market.
‘Drivers who pay a company for real-time navigational information could use that provider to calculate their road price.’
Darling said pay-as-you-go insurance technology could also collect relevant travel information.
He said: ‘People already choose to pass their locations on to an insurance or navigational company, in return for a service they value.
‘They trust the companies with that information in a way that they don’t trust governments.’
But Darling came under fire from the Association of British Drivers, which accused him of introducing road charging through the ‘back door’ using private companies as a front.
ABD spokesman Mark McArthur-Christie said: ‘It seems that Mr Darling is determined to press ahead with his Big Brother mobility tax no matter what.
‘He realises what a potential vote-loser this is and is now using private firms to front, develop and manage the scheme for him.
‘We are extremely concerned about any tax that involves satellite and computer technology spying on citizens. When unelected and unaccountable private companies are involved, our concern grows still further.
‘We urge Mr Darling to reconsider.’