A REPORT published into the Stonehenge tunnel plans have recognised the benefits it could bring to the World Heritage Site, if it is designed and delivered well.
The International Council on Monuments and Sites (ICOMOS) and the United Nations Educational, Scientific and Cultural Organisations (UNESCO) report comes after an advisory mission to the heritage site last October.
It said: "The mission considers the project for the relocation of the existing road underground into a 'tunnel of at least 2.9km' could readily adopt appropriate well-established construction methods and spatial planning approaches. Hence, with good design and construction controls, and respecting essential archaeology and heritage management measures the tunnelled length of the road would be expected to have a beneficial impact on the attributes of Outstanding Universal Value (OUV)."
However, it said, the siting and design of the tunnel portals, approach cuttings/embankments, entry/exit ramps, mitigation measures and the temporary construction works have the "potential to adversely impact OUV".
Adding: "These latter aspects of the scheme, in particular, will require rigorous investigation, evaluation, iterative design and assessment if they are to protect the attributes of OUV within the World Heritage site and the surrounding Archaeological Priority Area (APA)."
Historic England, National Trust and English Heritage have welcomed the report, which it says mirrors their views.
The report acknowledges a solution needs to be found for the A303 traffic bottleneck, and commends the UK Government for its proactive and collaborative approach.
It also highlights the scheme's potential to become "a best practice case" for the governance of the project, the design, implementation and management of heavy infrastructure within a World Heritage property.
Helen Ghosh, the director-general for the National Trust said: “We welcome this report which recognises the unmissable opportunity the Government’s road improvement scheme presents finally to address the blight of the existing A303 and the recommendation that heritage is put at the heart of any proposed scheme. At the moment the A303 cuts through the middle of the World Heritage Site, compromising its integrity and harming the setting of many monuments.”
And Duncan Wilson, the chief executive of Historic England, added: “We share the mission's view that the design and location of all aspects of the road improvement need to be very carefully considered. But with sensitive design there is a real opportunity both to deal with the problem of the current A303 and to deliver significant public access and landscape quality benefits to the World Heritage Site. We will work closely with Highways England and other partners to ensure that the mission’s advice is fully taken on board.”
In 2014 Historic England, English Heritage and the National Trust welcomed the Government’s announcement that it would be committing to a new tunnel of at least 2.9km to remove the A303 from the Stonehenge Landscape as part of its Road Investment Strategy.
Currently there are no detailed designs, but all three heritage and conservation organisations are committed to working closely with Highways England to ensure that only schemes which protect and enhance the World Heritage Site are moved forward.
Kate Mavor, the chief executive of English Heritage, said: “We are delighted that the mission recognises the benefits our recent improvements have brought to the World Heritage Site. Provided that it is designed and built in the right way, a tunnel would reunite the wider landscape around the ancient stones, helping people to better understand and enjoy them."