UK approves tunnel bypass at Stonehenge 14 Sep 2017

TunnelTalk reporting

The UK Government this week accounted commitment to construction of a 2.9km twin-tube tunnel as part of a 13km upgrade of the A303 road from two lanes of bi-directional traffic to a four lane dual carriageway to eliminate a major traffic bottleneck on the four-lane east-west route in southern England and protect the World Heritage site of the ancient Stonehenge monument.

Fig 1. Preferred route of the proposed 2.9km twin-tube tunnel
Fig 1. Preferred route of the proposed 2.9km twin-tube tunnel

In announcing a new preferred route for the estimated £1.6 billion upgrading bypass, Secretary of State for Transport Chris Grayling brought to a close a period of public consultation that the government was forced to conduct to re-examine a previous route that drew fierce opposition from the general public, commentators and UNESCO which lists sites of World Heritage.

The most significant improvements, according to a statement by Highways England, the project owner, include a change to the route through the western half of the World Heritage site and to the location of the western tunnel portal with both now closer to the line of the existing A303 than they were before the consultation.

The preferred route, it states, avoids many important archaeological sites, including newly-discovered barrows just to the east of another regional road, the A360 and avoids the road intruding on the view of the setting sun from Stonehenge during the winter solstice.

Current view of the current two-lane road
Current view of the current two-lane road
Same view after construction of the new tunnel
Same view after construction of the new tunnel

Upgrading the A303 between Amesbury and Berwick Down and through the new tunnel will improve journeys on a proposed Expressway to the South West of the UK, ease serious congestion in the area and through the village of Winterbourne Stoke and enhance the setting of Stonehenge by reconnecting it with its surrounding landscape and removing the sight and sound of traffic.

Table 1. Stonehenge tunnel timeline (1995-2021)
1995 First concrete proposal to tunnel A303 at Stonehenge is advanced by a Planning Conference, which recommends a 4km bored tunnel alignment.
1996 4km tunnel dropped on cost grounds
1999 UK Government publishes plans for a 2.1km cut-and-cover tunnel, but National Trust objects
2002 New plans for a 2.1km TBM-bored tunnel announced by UK Government
2002 Balfour Beatty win £125 million ECI contract to develop a 12.5km upgrade to A303 including a 2.1km bored tunnel, beating off bids by Amec/Alfred McAlpine; Mowlem/Morgan Est; Robert McAlpine/Buoygues; and Skanska. Design team of Halcrow/Gifford appointed
2004 Public Inquiry passes 2.1km bored tunnel scheme. Cost now estimated at £192 million (2003 prices)
July 2005 Spiralling costs force the Government to announce a review of the project and look at alternatives
Oct 2005 Cross-government steering group formed to review the costs of the 2.1km tunnel scheme passed at public inquiry, cost out alternatives, and launch a public consultation on 5 options, including a cut-and-cover tunnel
Jan 2006 Public consultation begins on 5 options, based on the A303 Stonehenge Improvement Scheme Review (Stage 1), which now costs the tunnel scheme at £510 million
July 2006 A303 Stonehenge Improvement Scheme Review (Stage 2) published by Highways Agency/ Balfour Beatty/ Costain/ Halcrow/ Gifford
Dec 2007 On 6 December 2007, on cost grounds, the UK Department of Transport withdraws all orders and cancels the scheme and the interdepartmental review of alternative options.
2013 A303 feasibility study announced as part of the Autumn Statement
2014 Scheme included in the Roads Investment Strategy
2015-2016 Route identification
12 January to 5 March 2017 Non-statutory consultation on route options
September 2017 Announcement of preferred route
Early 2018 Statutory consultation on proposed scheme
Late 2018 Submit planning application
2021 (TBC) Start on site

Following the announcement by the Department of Transport, Highways England is developing a more detailed proposal of the preferred route for another round of public comment, as required by the Planning Act 2008, before the final scheme is submitted to Government for development consent. If all goes according to its plan, Highways England aims to carry out the next round of consultation in early 2018 and start construction on the new road and its tunnel in 2021.

Upgrade of the A303 has been particularly sensitive and under planning since 1989 (Table 1). Between Amesbury and Berwick Down, the road passes 165m from Stonehenge with some 24,000 vehicles using the stretch of road daily, twice as much as the single carriageway was designed for. The road and traffic can be seen and heard from the Stonehenge monument, is a high accident rate blackspot and creates high levels of air pollution.

Previous efforts to advance the project have been defeated by public opposition and costs. Given the different routes explored in the past, the Government now believes it has adopted an acceptable alignment and has made money available to move forward. The project however remains controversial with leading personalities in the UK calling the current improved route and upgrade plan "the most brutal intrusion into the Stone Age landscape ever" and saying that the project needed a "complete re-think, not a minor tweak".


Add your comment

Thank you for taking the time to share your thoughts and comments. You share in the wider tunnelling community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language professional.
In case of an error submitting Feedback, copy and send the text to
Name :

Date :

Email :

Phone No :

   Security Image Refresh
Enter the security code :
No spaces, case-sensitive