CONSERVATIONISTS say money is being squandered on road projects - after new figures revealed that costs for scores of schemes have soared.

The planned upgrade of the Great North Road to motorway status, in North Yorkshire, is one of many where the bills have spiralled.

In 2002, the projected cost of the A1 scheme, between Dishforth and Leeming, was £125m, while that for the Leeming to Barton stretch was put at £100m. But figures from the Department of Transport now put the combined cost at £325m - a rise of £100m.

Elsewhere in the region, the Sunderland southern radial route has risen from £17m in 2004 to £28.7m, while the A688 Wheatley Hill-Bowburn link has increased from £6.6m in 2000 to £9.1m now.

And the cost of Darlington's eastern transport corridor scheme has more than doubled - from £5.7m in 2000 to a current figure of £12.1m.

The cost of 96 national and local road schemes has increased since first approved - with the bill for 39 of the road proposals going up by an extra £1.3bn.

The Campaign to Protect Rural England says that the average cost of a mile of motorway is now £23m, while a mile of dual carriageway costs £12m.

The campaign's head of transport policy, Paul Hamblin, said road building did not offer a long-term solution to growing transport problems, yet plans to cover green- fields with tarmac continued.

"These figures show that there is a high price to pay - for the taxpayer as well as everyone who cares for our countryside."

He added: "It appears that once the green light is given for these roads, the costs just escalate. With local authorities bidding for more road schemes this needs to stop.

"By concentrating funds on big and increasingly expensive infrastructure, too many people are losing out on the potential benefit of effective traffic management."

But the Highways Agency issued a statement insisting there were good reasons for the leaps in costs.

"Preparation and preliminary costs are now more clearly identified, rather than contained within construction costs," it said.

"Project costs are subject to fluctuation in land and property values, particularly where there are changes in planning use. And the number and size of compensation claims have increased, generally, as society has changed.

"With statutory undertakers now privately owned, many are nowadays seeking full cost recovery from the agency. We are doing all we can to manage these pressures.