The Government has today announced plans to build a second toll motorway linking Birmingham and Manchester. The four-lane route will trace the route of the old M6 for 50 miles up to Manchester.

It would have two northbound lanes and two going south.

Environmental groups have criticised the move but freight associations said it will ease traffic congestion.

Transport Secretary Alistair Darling told the House of Commons that private companies would build and run the road.

Although charges have yet to be decided, the new motorway would be twice as long as the current M6 Toll and could cost drivers more to use.

The Government said that the two stretches would give paying motorists more than 70 miles of congestion-free motoring and that traffic would also be drawn away from the old M6, benefiting those drivers not prepared to pay the tolls.

The CBI welcomed the move. Its director-general Digby Jones says: "Shorter and more predictable journey times are vital not only for businesses in the region but for those that travel through it on this key national trade route.

"It is particularly good news if this approach means the new lanes are provided that much more quickly. But it will be crucial to get the level of the toll right. It must provide value for money for freight vehicles if it is to be a genuine alternative.

"It is also important that this is part of a more strategic approach to the way we pay for road use in the UK. Businesses are very aware that they already pay more through fuel duty and other charges than road users elsewhere in Europe."

Darling also revealed a "carpooling" pilot scheme to reserve lanes for cars carrying two or more people on sections of four motorways, including the M1.