The plan to build a road tunnel underneath the Stonehenge World Heritage site is being considered once again by the Government.
The original proposal, which was backed by a public inquiry in 2005, involved a 2.1km bored tunnel under the prehistoric monument in Wiltshire. Balfour Beatty was awarded the ECI contract. But the scheme was booted out on cost grounds, after unforeseen geological conditions saw the cost spiral up to £540M.
However, the plan has been dusted off following a review of ways to reduce congestion on the A303, which began in the spring.
English Heritage and the National Trust said they were working with the Department of Transport to identify a solution, potentially involving a 2.9km tunnel. The Highways Agency and local authority representatives are also part of the working group.
Ian Wilson, assistant director of operations at the National Trust, said: “The National Trust has a long standing ambition to remove as much of the A303 road from the Stonehenge landscape as possible.
“Huge volumes of traffic on the road are already having a detrimental impact on the site and forecasts suggest this will only get worse. We need to find a solution to this problem sooner rather than later and that solution needs to remove as much of the highly damaging existing road as possible.
“We believe building a tunnel under the landscape is the best way of improving the quality of this special place whilst at the same time significantly improving a major transport link for the South West.
“We would like to see the longest possible tunnel but we recognise that any plan needs to be both affordable and deliverable if we’re to finally solve this long-running challenge.
“Early results from our work to assess various options for the A303 at Stonehenge suggest that a tunnel of 2.9km may bring significant benefits for this special place, reuniting the archaeologically rich wider Stonehenge landscape.
“We’re continuing to work with the Government and partner organisations to look at how we best deliver a world class solution for one of the most important pre-historic landscapes in Europe.”
However, the Stonehenge Alliance, whose members include the Campaign for Better Transport and the Pagan Federation, remains adamant that a 4.5km tunnel is the only option.
George McDonic, chairman of the group, said: “The current proposals for a 2.9km tunnel below Stonehenge might sound long enough, but they would still result in significant harm being done to the World Heritage Site.
“We are urging the Secretary of State to get this right and to protect Britain’s iconic heritage site.
“A 4.5km tunnel might cost more but what price can you place on a landscape that means so much to so many people?
“Once damaged, it will be spoilt forever.”
A Department for Transport spokesperson said: “We are discussing a range of potential options for improving the A303/A30/A358 corridor with interested parties to understand their views, including consideration of the section of the A303 that passes Stonehenge.
“As part of this process we have worked closely with key organisations, including English Heritage and the National Trust, to assess the impacts of potential options on the Stonehenge World Heritage Site.
“No investment decisions have been made as this is work in progress and, when completed the study outcomes will inform the government’s 2014 Autumn Statement.”.