
Roadworks widening the M6 are "the most expensive roadworks in history" according to a social and environmental campaign group.
The work, which involves adding one lane to a 51-mile stretch of road between Birmingham and Manchester, is set to cost almost £3 billion.
According to the Guardian newspaper, this figure breaks down to every inch of the new road costing £897 before construction inflation is taken into account.
Once this upward pressure has been factored in, the cost per inch is likely to be over £1,000 claims the newspaper.
Rebecca Lush, who campaigns on the environmental and social impact of transport with the group Transport 2000 said: "This must be the most expensive roadworks in history. Britain is spending £13bn on new roads and next to nothing on reducing road traffic or railways."
There are at least two factors pushing the price up.
Engineering consultant Roger Bailey, of Faber Maunsell said: "In a greenfield site you are in control of your construction planning. But on a live road you have to work round more traffic."
The massive construction works created by the Olympics are also pushing up the cost of construction according to the Royal Institution of Chartered Surveyors.
A spokesman told the newspaper: "The price of construction is going up because there is a lot of work around. Road building is an international market. In the last ten years costs have gone up 7-9 per cent a year."