Notorious bottlenecks on the M1 and M6 motorways are to get an extra lane, taking them to four lanes wide.

Transport Secretary Alistair Darling announced the transport package - totalling �5.5bn for England's roads, rail and bus infrastructure - to the Commons on Tuesday.

	:	At a glance
Quick guide to the transport plans

Environmentalists fear the plans will destroy key wildlife sites, with Transport 2000 calling the announcement "a serious return to big road building".

But motoring bodies including the RAC and AA have praised the government initiative.

This is a kick in the teeth for integrated transport Tim, UK Click here to send your comments

Plans include a two kilometre tunnel to carry the A303 past Stonehenge in Wiltshire, to help protect the World Heritage Site from traffic - a move which has been welcomed by the National Trust.

The key points of the announcement were:

• �600m extra to local councils for road maintenance

• Widening the M6 between Manchester and Birmingham to four lanes and the M1 to four lanes through the East Midlands

• Dual the A453 from the M1 to Clifton, Nottinghamshire

• Safety improvements on the A1 north of Newcastle

• Plans to improve the junctions on the M4 and M5 around Bristol

• A303 dualled east of Ilminister

• �183m tunnel to carry the A303 past Stonehenge

• New rail lines on the Greater Manchester Metrolink, a major light rail line in Liverpool and a second phase to Nottingham's express transit system.

In a statement to MPs, Mr Darling said the plan aimed to tackle "decades of under-investment and stop-go funding".

Building and widening roads as a solution to transport problems has failed in the past and there's no reason to think it will work now Friends of the Earth

On rail links, Mr Darling announced that councils would get a further �1.6 billion, which would include funding for new lines on the Greater Manchester Metrolink, a major light rail line in Liverpool and a second phase to Nottingham's express transit system.

There would also be new investment in bus routes.

Professor David Begg, who chairs the government's Commission for Integrated Transport, sounded a note of caution about the plans.

He told BBC News: "On the M25 when it went from three to four lanes, within one year traffic increased by one third, negating the benefits.

"So the key issue for government is how can you make sure that the gains in journey time do not just evaporate in five or six years?"

'Conceded defeat'

Bob Crow, general secretary of the biggest rail union the RMT, said there should have been more emphasis in the plan on public transport.

"It is scandalous that a government that has been lecturing about traffic congestion, emissions and global warming should buckle under pressure from the roads lobby and shift its policy towards the environmentally-unfriendly car," he said.

Friends of the Earth said the government had "conceded defeat on getting people out of their cars and abandoned any attempt at having a sustainable transport policy".

Spokesman Tony Bosworth said: "Building and widening roads as a solution to transport problems has failed in the past and there's no reason to think it will work now."

Integrated transport should include road schemes Edmund King RAC Foundation

But Conservative transport spokesman Tim Collins said it was "a welcome partial U-turn" for a government that had previously claimed the nation could not build its way out of traffic congestion.

Motoring groups have argued that congestion cannot be tackled by increasing public transport alone.

The RAC hailed the motorway and trunk road improvements as "a realisation that an integrated transport policy includes road building".

And Roger King, chief executive of the Road Haulage Association, said: "Clearly, the government shares our view that, in environmental terms, it is more sensible to keep traffic moving rather than do nothing and let gridlock take over."