Costain is delivering nine miles of dual carriageway to unlock congestion on the last remaining single carriageway section of the A30 between the Chiverton and Carland Cross roundabouts near Truro in Cornwall.

As part of the road upgrade Costain, on behalf of National Highways, is using traditional, sustainable methods to create Cornish hedges alongside the new route, as well as the restoration of existing hedges.

Protecting and restoring the environment are key to Costain’s Climate Change Action Plan launched in 2020, featuring an industry leading target to become net zero by 2035. Costain is committed to helping nature flourish, contributing to a nature-based recovery for the planet, and is working to achieve biodiversity net gain on all our projects like the A30 Chiverton to Carland Cross.

Particular to Cornwall and dating from the Neolithic period – tracing back to 1,500 BC – Cornish hedges are traditionally five-foot high, stone-faced earth hedge banks with bushes or trees growing along the top. The slate hedges will be topped off with turf, supplemented with additional planting, and this will help to create habitats for numerous species, and increase biodiversity alongside the new route.

The hedges are constructed with locally quarried slate, supplied by Cornish Stone Products from the Tynes Quarry near St Teath – just 21 miles away – and the project team are closing in on their first milestone, the construction of the first mile of hedging.

John Lee, Costain’s A30 Chiverton to Carland Cross project director, said “We are committed to creating connected, sustainable infrastructure to help people and the planet thrive. Costain delivers sustainable solutions by adopting circular economy principles, and our innovative work collaborating with local supply chain on the Cornish hedges at the A30 project is a fitting example of how our 150-year heritage of pioneering problem solving, together with constant innovation, enables us to deliver sustainable, efficient, and practical solutions for our clients.”

Nick Simmonds-Screech, National Highways’ project director for the A30 Chiverton to Carland Cross scheme, said: “We’re proud of the work we’re undertaking to enhance the landscape, and protect the ecology and environment in the area, and the hedging work is a glowing example of this.

“The design of the road has been carried out in the most sympathetic way for both local people, the travelling public, wildlife, and the environment, and we’re currently forecasting a net gain of over 10% in biodiversity as part of the work we’re doing on the scheme.

“A rich flora develops over the lifespan of a Cornish hedge; they play an important part in biodiversity and we’re proud to be adding to the already 30,000 miles of hedging across the county.”

In addition, 33 multi-species crossing points, including a ‘green bridge’ at Marazanvose, are being constructed to assist the habitats and journeys of animals such as otters, badgers, bats, and reptiles.

The scheme will also see over 28 miles of new drainage to protect the local area and water courses, new filtration ponds, native tree planting, the construction of earth barriers and sound-absorbing fencing.

The £330 million upgrade is scheduled to be open to traffic in winter 2023. The cost of developing the scheme is partly funded by an £8 million contribution from the European Regional Development Fund, with an additional £12 million for the construction phase. The remainder of the cost of developing and delivering the scheme is being funded by central Government.

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