Motoring organisations predicted last night that travelling on Britain's roads could degenerate into a daily drudgery of stress, delay and aggravation after the government's admission that its strategy of tackling traffic congestion had failed.

The transport secretary, Alistair Darling, went further than even the gloomiest commentators had expected by warning that traffic congestion was likely to rise by between 11% and 20% by 2010.

Edmund King, executive director of the RAC Foundation, described the forecast as "incredibly worrying", predicting "severe delays throughout the day, on a daily basis" around every major city. He said: "This scenario really isn't too good, particularly when the prospects for intercity railways aren't good either."

Mr Darling's decision to abandon targets for reducing congestion was one of several serious setbacks revealed in an update of the government's 10-year plan.

The 180-page progress report, nearly twice as long as the original plan, also disclosed that passenger growth on the railways was running well below forecasts, leading to suggestions that a target of 50% growth in rail travel could also be shelved.

Mr Darling faced ridicule in the House of Commons for claiming that "a useful start has been made" to improving Britain's transport network. The shadow transport secretary, Tim Collins, said: "If this is the secretary of state's interpretation of a good start, I shudder to think what a bad start would be.

"The 10-year plan is so much of a corpse that Amanda Burton has been spotted preparing a postmortem."

Drawn up by the deputy prime minister, John Prescott, and the former transport minister, Lord MacDonald, the plan is the centrepiece of the government's well-known but poorly understood "integrated transport policy".

Its central aim was to dampen Britain's love affair with the car by encouraging travellers to use public transport, in the interests of safety and the environment.

In his update yesterday, Mr Darling highlighted the success of a handful of set-piece projects. He pointed out that the first phase of the Channel tunnel rail link was 90% complete, describing it as "the first major new rail line for 100 years".

He said light rail use had grown by a third over the past two years, albeit from a very low base, after the completion of new lines in Sunderland and Nottingham. Mr Darling also pointed out that bus use had risen by 7%, although critics said this was largely due to extra services laid on in the capital by the government's arch enemy, Ken Livingstone.

But experts pointed out that rail travel had barely budged since 2000 and road traffic had continued to rise, in direct opposition to the government's aims.

Tony Grayling, associate director of the Institute for Public Policy Research, said problems had arisen almost as soon as the plan was published: "They were knocked off course even before the ink dried on the paper by the fuel crisis and the Hatfield crash."

He said the chaos caused by lorry drivers' blockades in the summer of 2000 forced the government to offer concessions on petrol prices, which reduced the cost of motoring in comparison to public transport.

The Hatfield tragedy exposed the desperate state of maintenance on the rail network, forcing the government to channel its budget towards repairing existing track, rather than building new lines. Business leaders expressed concern yesterday that many projects, such as a proposed Crossrail east-west railway line in London, and the Thameslink 2000 track upgrade, have fallen well behind schedule. New lines are crucial to any aim of increasing rail travel - Mr Darling admitted that the network was operating near capacity: "Current timetables may be placing unrealistic demands on service providers".

In response to criticisms from MPs on the transport select committee, Mr Darling published a series of "halfway" targets which he hopes to reach by 2005.

But in a sign the government is tiring of setting solid benchmarks of success or failure, most of the targets are relatively vague. They include "significant improvements" in rail reliability, "further steady growth" in bus and light rail use and roads maintained in "optimum condition".

Environmentalists expressed dismay at the government's failure to cut car use, saying that ministers had caved in to motorists by announcing £5.5bn of motorway widening schemes last week.

Progress so far

· Road congestion is proving far worse than anticipated and will rise by between 11% and 20% by 2010

· Train punctuality has fallen from 87% before the Hatfield crash to 79%

· Rail travel has surged by a quarter over five years but growth since 2000 is well below target

· Bus use has risen by 8%, against a forecast of 10% by 2010

· Light rail use has risen by a third

· Reliability on the London underground is up by 7%

· Deaths and serious injuries on the roads have dropped by 15%

Targets for 2005

· Birmingham's northern relief road and 25 other major motorway improvements will be finished

· Work will begin on a further 30 big roadbuilding projects

· All trains will have train protection and warning systems

· The first section of the Channel tunnel high-speed rail link will open

· Some 2,800 new trains will be in service

· Around 1,400 bus priority measures will be in place

· Up to 200 new park and ride schemes will be under way

· An extra 3,000 miles of new and improved cycle routes will be open

· Smartcards will be in use in London