Some motorways are plagued by congestion

Transport Secretary Alistair Darling has said he would like the pilot scheme - due to begin on the M42 in the Midlands next year - to cover more roads including some around London

But the idea of extending the test scheme has raised concern among motoring organisations.

They fear opening the hard shoulder to ease congestion could result in more accidents, injuries and deaths.

A Department of Transport spokesman told BBC News Online Mr Darling was keen on schemes already in use in Holland.

Under these schemes, use of the hard shoulder at heavy traffic times is monitored by CCTV cameras, designed to alert emergency vehicles of accident situations.

'Exasperations'

The spokesman said: "Holland has similar problems to us, so it would not be unusual to try to replicate their scheme."

The government would want the existing pilot scheme to be under way before starting any more - but this could happen before the end of the trial, he said.

Congestion charging was introduced to central London in February

"If that (the pilot scheme) went well it would not be in anyone's interest to wait for it to finish," he said.

Mr Darling told Saturday's Financial Times he was keen on widening the M42 pilot scheme as part of efforts to cope with heavy traffic around London and in the North West.

"One of my exasperations is we plan something for two years, we trial it, then we think about it for another year," he is quoted as saying.

"I want to do this in a wider way in the next couple of years or so."

Congestion charging

But motoring organisations the RAC and AA believe a full assessment of the trial should be carried out before any more motorway hard shoulders are opened to traffic.

The RAC said the move backtracked on a commitment given to Parliament that the M42 trial would be judged before wider approval to expand the schemes.

The pilot scheme also includes initiatives to speed up the clearance of accidents and break-downs.

Motorways which could see hard shoulder schemes if the pilot were extended include the M5, M6 and M25.

The development might also mean that extra work was needed to improve the road surface and surrounding infrastructure.

Mr Darling told the FT that there would be no change to the government's 10-year transport plan, but said there would have to be some consideration of widening congestion charging.

"I think that in the next 15-20 years, unless we take measures to manage the use of our roads so that you control the cars on them, then you face gridlock at some point in the future," he said.