Passengers face acute overcrowding on key railway routes because capacity will be exhausted many years before any new lines could be built, according to Network Rail.

The infrastructure company is to commission a study into the costs and benefits of new lines on five inter-city routes. But it admitted that a high-speed network was unlikely to be built soon because of funding constraints and environmental concerns.

The company is expected to focus on a few short stretches of track operating at conventional speed to relieve the worst pinch points on long-distance routes, including London to Peterborough, Rugby and Swindon.

Iain Coucher, the chief executive of Network Rail, said that the Government’s plan for expanding rail capacity by 22.5 per cent by 2014 would be inadequate on some routes, which are growing by 10 per cent a year.

Times Archive, 1901: High-speed trains

Railroad companies wishing to gain the pecuniary and other advantages of high-speed trains should be compelled to reconstruct their tracks

Related Links

• Network Rail 'faces losing rail monopoly'

• Memo exposes Network Rail cover-up over errors

• Rail chiefs: demand is overwhelming network

He said: “Clearly some routes will grow more than that and there may be a problem. The most congested parts of the network are about 80 miles out of London. People used to be prepared to travel for 45 minutes and now it’s an hour and a quarter.”

The high cost of housing in London and fuel prices were two of the factors contributing to the continuing strong growth in demand for rail travel. In the past decade passenger numbers have grown by 45 per cent and the amount of freight carried by trains has grown by 60 per cent. But constraints on the capacity of the network have meant that the number of trains has risen by only about 20 per cent.

The Government is planning to reduce public funding of the railways by £1.5 billion a year and has said that passengers will have to pay three quarters of the cost of the network by 2014. The cost is currently split evenly between the farepayer and the taxpayer.

Mr Coucher said that existing government measures to meet demand, such as altering fares to encourage people to travel off-peak, would be inadequate in the longer term.

The study will consider new lines to relieve pressure on the East Coast, West Coast, Midlands and Great Western main lines and the Chiltern route between London and Birmingham. It is not due to consider any routes south of the Thames. Mr Coucher admitted that this could be an oversight and that they might have to be brought into the scope of the study. He added that Network Rail “was not wedded to high speed”. Tom Harris, the Rail Minister, played down the prospect of 220mph trains recently, saying that they would consume almost double the energy of 125mph trains, the current top speed of domestic services.

The study, which is due to be published in July next year, will not consider specific routes and is unlikely to set a clear timetable for expansion. It will set out whether there is a business case for new lines and which routes would deliver the greatest benefits. Asked when construction could start, Mr Coucher said: “I have no idea.”

It will be the third publicly funded study into the feasibility of high-speed lines in a decade. Neither of the previous studies resulted in a government commitment to fund a line. The Strategic Rail Authority produced a £33 billion plan for a London to Scotland high-speed line in 2004 and the Eddington Transport Study, which was published in 2006, found that high-speed rail would attract many of the eight million passengers a year who fly between London and Scotland and would reduce carbon emissions by up to 330,000 tonnes a year.

This month the Rail Regulator, who was under pressure from the Government to reduce spending, ordered Network Rail to abandon 20 schemes to ease overcrowding, which would have cost £365 million.

David Frost, the director-general of the British Chambers of Commerce, said: “We now need to ensure that there is a real commitment to add new capacity to the network.”

Norman Baker, the Liberal Democrat transport spokesman, said: “The rail network is in desperate need of expansion if we don’t want to force frustrated passengers back into their cars and on to aeroplanes. Instead, the Government has proposed cutting back public funding for the railways, condemning travellers to delay and overcrowding.”

Times Recommends

• Minister in talks with Saudis to protect creditors
• Premier Inn hits back in £29-a-room row
• Bankers hit back at 'populist' bonus supertax