Despite efforts to keep road-building costs in check, the Government committee charged with overseeing the costs of such projects has criticised the Highways Agency for allowing schemes to run over budget and over schedule.

“More than a quarter of the agency schemes due to start construction by the end of 2005-06 had not done so,” pointed out the Select Committee on Public Accounts.

It then went on to highlight a typical example: “The A46 Newark to Widmerpool improvement scheme has been delayed until 2012-13.”

Such delays and cost overruns – 36 completed road schemes reviewed by the committee ran 40% over budget – are unacceptable it said.

It recommended the Department for Transport should “hold the agency to account for delivery to time, cost and quality through rigorous assessment of progress against milestones and forecasts; and investigate the differences between actual costs and original estimates.

“It should use this information to challenge future forecasts made by local authorities.”

The committee also pointed out that the current system of prioritising regional road building projects was flawed.

It suggested large schemes of major strategic importance, which would otherwise absorb the majority of a regional budget, should come under the national, rather than the regional, roads programme.