Car-sharers are to be given dedicated motorway lanes stretching hundreds of miles, ministers will announce this week.
The new lanes will be out of bounds to lone drivers during rush hours, and those flouting the rules will face £100 fines.
Alistair Darling, the Secretary of State for Transport, will tell MPs that he has earmarked around half a dozen sites for trials. The new dedicated car-sharing lanes, to be known officially as "high-occupancy vehicle lanes", will dramatically reduce congestion, he believes.
But motoring organisations, say that they will discriminate against those such as nurses whose shifts make car-sharing impossible. The Government has previously backed down over plans to introduce car-sharing lanes because of fears of a drivers' backlash.
Now, however, Mr Darling has decided the time is right to introduce the radical measure. As a compromise he will limit the first phase of the scheme to those parts of the motorway system being widened to include extra lanes. It means that the likely candidates for the first pilot schemes include sections of the M1, M6 and M25.
The new marked lanes will also only operate in the mornings between the hours of 6.30am and 9am, in recognition of the fact that workers are less likely to be able to co-ordinate their return home.
In a further concession to public opinion, ministers have backed away from proposals to use cameras to enforce the new lanes.
Research commissioned by the Department for Transport has concluded that cameras could not reliably count a vehicle's occupants. Instead it will fall to police patrols to enforce the new lanes.
Mr Darling took the decision to introduce dedicated car-sharing lanes after a visit to the United States earlier this year.
Introduced in the 1970s, there are now around 125 different schemes in 30 states in the US.
Car-sharing lanes into Los Angeles are used by around a million commuters a day, saving workers an estimated 30,000 hours in reduced journey times.
Ministers have also been encouraged to act after local authority schemes on roads in Leeds and south Gloucestershire successfully reduced journey times.
Mark Macarthy-Christie, of the Association of British Drivers, warned the Government it faced serious opposition to its proposals.
"We are concerned that it is not the most efficient use of the roads and that it discriminates against those, like nurses, whose shift patterns make it impossible to share a car into work."
Sue Nicholson of the RAC Foundation, however, said it might welcome the lanes if they are limited only to those areas where extra capacity is being provided.
Mr Darling's announcement to the Commons, probably on Tuesday, is one of a series of set-piece transport policies to be unveiled in the coming weeks.
The most controversial is likely to be measures to introduce road-charging on motorways during peak hours.