The British Government has approved a controversial plan to build a four-lane highway tunnel beneath the Stonehenge World Heritage Site. The two-mile-long tunnel and its approaches are part of a $2.2 billion package to upgrade the narrow A303 highway that runs startlingly close to the iconic stone circle and has long been notorious for traffic jams and long delays.
The approval came despite strong objections from an alliance of archaeologists, environmentalists, and modern-day druids, who consider the site sacred. But supporters say the tunnel will restore the landscape to its original setting and improve the experience for visitors, now topping 1.6 million a year.
“Visitors will be able to experience Stonehenge as it ought to be experienced, without seeing an ugly snarl of truck traffic running right next to it,” said Anna Eavis, curatorial director for English Heritage, the charity that looks after more than 400 historical monuments around England, including Stonehenge.
Revelers gather to observe the summer solstice sunrise. Thousands flock annually to the site to welcome the longest day of the year in the Northern Hemisphere.
“People forget or don’t realize that Stonehenge is more than just the stone circle, it’s a landscape,” Eavis said. “This will make it a place for walking again. Visitors will be able to approach the stones from the south, for example, without taking their life in their hands trying to cross the highway.”
Opponents contend that the tunnel project may irreparably damage an ancient landscape that is only beginning to be understood and is still full of surprises. Last June the discovery of 20 deep shafts arranged in an enormous circle nearby the site forced the government to delay the decision on the project for another four months while the find could be assessed.
“Remote sensing has revolutionized archaeology and is transforming our understanding of ancient landscapes—even Stonehenge, a place we thought we knew well,” said Vince Gaffney, a landscape archaeologist at Bradford University and co-leader of the Stonehenge Hidden Landscape Project, which discovered the previously unsuspected shafts. “Nobody had any idea these were there. What else don’t we know?”
Originally an 18th-century carriage road between London and Exeter, the A303 highway has evolved to become one of the main arteries to England’s southwest. In addition to Stonehenge visitors, it carries heavy truck traffic and hordes of holiday travelers heading to seaside destinations in Cornwall and Devon.
One of the most notorious bottlenecks along A303 is the narrow two-lane stretch between Amesbury and Berwick Down in Wiltshire. That’s where the highway passes within 200 yards of the iconic stone circle, one of Britain’s most popular tourist attractions. (Stonehenge-era pig roasts united ancient Britain, scientists say.)
“The road was never designed for anything like these levels of traffic,” said Tom Fort, author of Highway to The Sun, a history of the A303. “They've improved segments of it piecemeal over the years, widening them into four-lane divided highways, but the stretch around Stonehenge was always the tricky part. Nobody has ever been able to agree on what to do about it.”
Over the decades more than 50 different proposals have been put forward to solve the traffic problem. The idea of a tunnel was first proposed in the early 1990s and revisited several times over the years, but it was dismissed each time because of its high cost.
The approved plan will expand the highway to four lanes as it approaches Stonehenge, then dip underground in a two-mile-long tunnel that will pass about an eighth of a mile to the south of the stone circle.
While the tunnel itself will run some 130 feet below the surface—well below any archaeological layers—the approaches and portals will be cut through potentially artifact-rich topsoil within the grounds of the World Heritage Site. That concerns Gaffney, who believes the tunnel “needs to be much longer, under the whole of the site. We shouldn’t be gouging up a World Heritage area like this. We have a duty of care.”
Prior to today’s announcement an alliance of tunnel opponents—including the Campaign to Protect Rural England and the British Archaeological Trust—called on the government to reconsider the plan.
“If A303 widening at Stonehenge is felt to be essential, it should be done by means of a deep-bored tunnel at least 4.5 kilometres [2.8 miles] long,” states their petition, which was signed by 150,000 people. “Anything shorter would cause irreparable damage to this landscape, in breach of the World Heritage Convention.”
Opponents have also voiced concern that preparatory archaeology work done in advance of the tunnel excavation won’t be held to the same high standard as an academic dig.
"As a researcher, if I want to excavate in a World Heritage Site like Stonehenge, I’d have to agree to sieve 100 percent of the topsoil," said Michael Parker Pearson of the University College London's Institute of Archaeology, who has excavated at Stonehenge for many years. "I wouldn't get a permit otherwise. The topsoil is where you get the vast majority of your archaeology." The developers building the tunnel, Pearson said, will be allowed to sieve as little as one percent of the topsoil.
English Heritage’s Eavis, however, said sifting all of the topsoil is not standard practice for a project of this size. “The line of the road has been surveyed and archaeologically evaluated, and appropriate excavation and sieving strategies put in place to make certain nothing important is missed,” she said.
Archaeologist Mike Pitts agrees. “The topsoil in the areas relevant to the tunnel project has been heavily plowed for centuries,” said Pitts, editor of British Archaeology, the publication of the Council for British Archaeology. “All that’s likely to be found is stone tools and debris from their manufacture, removed from any archaeological context.” (This ancient British monument was 10 times bigger than Stonehenge.)
Not all archaeologists are opposed to the project. “I’m a big advocate of the tunnel and getting it done as soon as possible,” said Timothy Darvill of Bournemouth University. “People need to remember that this isn’t about building a road in a World Heritage Site, as some people seem to think. It’s a project to remove an existing road and put it underground.”
Everyone agrees that the present road is a disaster and needs fixing, Darville said. “Just listen to the live video of the summer solstice [celebration] back in June. All night you can hear the road, and that was during lockdown when there was supposed to be very little traffic.”
And, Darville said, there’s another factor in the tunnel’s favor: “We understand from Highways England that if the tunnel doesn’t go ahead, there will most probably be an on-surface solution involving a dual carriageway. Nobody wants that!”