Since opening 15 years ago, the Hindhead Tunnel, which rerouted the A3 beneath the Devil's Punch Bowl, has led to the return of rare species, restored a ‘nationally important landscape', and is generally regarded as one of the most successful infrastructure projects of its generation.

National Highways hailed the successful tunnel scheme, which is used by 48,000 vehicles a day as they take the route between London and the South Coast, not just because of the infrastructure success but because the route has been ‘returned to nature'.

Thanks to the efforts of the National Trust and Natural England, Hindhead Common has been turned into a heathland that has seen the return of woodlarks, nightjars, the heath tiger beetle and the silver-studded blue butterfly.

Matt Cusack, lead ranger for the National Trust, said: ‘The removal of the A3 in July 2011 was a major milestone, enabling us to thin trees and transform the site into a swathe of heathland.

'The site has been under a Higher Level Stewardship agreement since 2008 and we are currently midway through an ambitious programme of heathland regeneration funded by Biffa Award. Scrub management, heather and bracken cutting, the expansion of woodlark nesting areas and grazing by ponies and cattle, conducted under these schemes, has transformed it - and we want to thank our countryside volunteers, partner organisations and funders for their support.'

Hindhead Commons and the Devil's Punch Bowl now welcome over 970,000 visitors each year. The introduction of new walking routes and accessible paths has allowed people to experience the restored landscape while helping to protect ‘sensitive wildlife habitats'.

The site also forms part of the Wealden Heaths National Nature Reserve, a partnership dedicated to conserving one of the South East's most important heathland landscapes.

A unique place to work

As well as a hospitable environment for rare wildlife, the tunnel has also provided a ‘unique place to work' for a ‘dedicated team' of National Highways control room operators beside the southbound A3 carriageway, according to National Highways control operator Dominic Holyoak.

‘On one side we're helping keep one of the region's busiest roads moving, and on the other you've got the peace and quiet of beautiful countryside and all the wildlife that's returned since the old A3 was removed. Most people drive through the tunnel every day without realising there's a team here making sure everything keeps running safely.

‘The tunnel has made a real difference over the last 15 years. Journeys are more reliable for drivers, while above ground the landscape has been transformed into a place where nature has been able to thrive again. It's something we're all proud to play a part in.'

National Highways noted that the tunnel has benefited local residents by ‘reducing delays on surrounding roads and improving air quality'.

Stephen Rudd, principal manager, Thames Solent Area, Natural England, added: ‘Fifteen years on, the Hindhead Tunnel stands as a fantastic example of how reconnecting landscapes can benefit both nature and people. The recovery of this nationally important heathland is a testament to the long-term commitment of the National Trust, Natural England and its partners, and to the opportunities created when space is given back to nature. We look forward to building on these successes at Hindhead as part of the wider Wealden Heaths National Nature Reserve.'