Initial designs for a tunnel at Stonehenge have been published, seeking to show how the £1.6bn scheme could restore a sense of beauty and tranquillity to the ancient landscape.

A slightly longer tunnel than previously mooted has been proposed – spanning just under two miles (3km) – to counter concerns that precious barrow burial mounds could be damaged and a view of the setting sun at the winter solstice lost.

A grass-covered canopy at the western end of the tunnel is also featured to try to conceal the road and help the scheme blend into the landscape. Also included is a viaduct to carry the road over the river Till, west of the tunnel.

However, three heritage bodies closely involved with the Unesco site have expressed surprise and concern that under the plan, which is supposed to remove the sound and sight of traffic, a new route for vehicles on the surface and close to the stone circle would be created.

Other groups opposed to the tunnel go further, claiming the project will wreck the site, and want it scrapped completely.

Highways England published the designs at the start of a public consultation phase that runs until April. It said it was seeking feedback to help shape the scheme further before it submitted an application for a development consent order, which it said it hoped to do by the end of the year.

The Stonehenge site. Photograph: Joana Kruse/Getty Images/age fotostock RM

It explained the route had been chosen to avoid monuments and barrow groups and to avoid intrusion on views of the winter solstice. Highways England said that by taking the A303 underground it would reconnect the two halves of the site that has been spilt by the road for decades. Under the plan, work on the tunnel will begin by 2021 and be completed by 2025.

English Heritage, the National Trust and Historic England support the concept and, in a joint statement, welcomed what they see as improvements to the western end.



But the bodies flagged up particular concerns about the linking of two ancient byways, currently separated by the A303. If the byways are joined as is suggested, it could mean vehicles will still pass close to the circle, albeit going slower than on the A303 and in much smaller numbers.

The three organiations said: “We are very concerned about the detrimental impact of traffic on the byways and believe this will be made worse by the proposal to link existing byways after the surface A303 is removed.

“This is a once-in-a-generation opportunity to reunite this ancient landscape, giving people the opportunity to tread pathways used by our ancestors who built the monuments, to visit and appreciate the monuments and see and hear wildlife without the intrusion of the traffic and noise.”

Ian Morrison, the director of planning for Historic England, said: “The primary purpose of the scheme is to remove the A303 from the centre of the landscape.”

The proposal to connect the byways opened up the prospect of 4x4s trundling close to the stones and people setting up camp there, he said, adding: “There is a danger you will continue to have motorised vehicles travelling through the landscape.”

One option might be to try to ban motorised vehicles from the byways, though this will be resisted by people who use the routes to get close to the stones without having to pay the site’s custodians, English Heritage.

The Stonehenge Alliance, which includes archaeologists and environmental campaigners, called the plan an “international scandal”.

It said the new road would be “gouged” through the chalk and argued: “However well-designed, the devastating impact of this road engineering would destroy archaeology and deeply scar this iconic landscape and its setting forever.”

Kate Fielden, the vice-chairman of Rescue – the British Archaeological Trust, said: “Our government proposes to spend £1.6bn trashing a world heritage site.”

Siôn Elis Williams of Friends of the Earth said: “Instead of building another road that increases traffic, money for the road scheme could be invested in a region that is crying out for significant investment in its bus and rail network to increase accessibility, improve air quality and boost sustainable tourism.”

If the tunnel does go ahead, at the eastern end the road would pass beneath a feature called the Avenue, believed to be a ceremonial approach to Stonehenge from the river Avon. This would allow visitors and pilgrims to follow the ancient route safely for the first time in decades.