Between 2020 and 2024, Costain, in a joint venture with Jacobs, completed the 9 mile dualling of the A30 between Chiverton and Carland Cross, removing the only remaining stretch of single carriageway on the A30 between Camborne and the M5 at Exeter – a distance of almost 100 miles.
The project
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The scheme aimed to reduce congestion along the route - journeys on this section of road could take up to four times as long compared to other sections of the A30, creating uncertainty for locals, tourists and businesses, holding back the Cornish economy.
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The project was a complex operation, with the team working through a pandemic and an unprecedented 14 Met Office-classified storms over 2023-24, to achieve the opening of the new road in June 2024.
The work
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The team responded to the onset of the pandemic by managing efficient and effective communication remotely with authorities including the Department for Transport to minimise delays.
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Costain pioneered innovative construction practices, including the trialling of the first-ever 3D-printed concrete headwall. Whilst close cooperation with Cornwall Council, created a collaborative process to improve traffic management planning and environmental practices.
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Key milestones included the safe dismantling of the Tolgroggan bridge between Scorrier and Boxheater, the construction of a new traffic-free bridge at Chiverton, and the removal of the old ‘Chivvy’ roundabout, Cornwall’s worst accident hot-spot.
The benefits
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As well as creating a huge improvement in Cornwall’s highways infrastructure, the project has delivered a major economic boost for the county, and at its peak employed over 650 people.
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The team hosted students from the local area and delivered apprenticeships and graduate schemes, improving skills and prospects for those seeking a career in construction.
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The scheme has also met several sustainability objectives – including the use of low carbon materials in construction such as low temperature asphalt.
The numbers
- 8.7 miles of new dual carriageway.
- The project achieved over 4.5 million hours worked without a RIDDOR incident.
- The scheme has achieved a minimum of 20% biodiversity net gain.
“The Costain team has worked incredibly hard to deliver the A30 scheme, overcoming a number of major challenges along the way, most notably the Cornish weather, and the pandemic which had significant impacts on the detailed design and construction phases.
Nick Simmonds-Screech A30 Project Director, National Highways
“Costain’s resilience, focus and teamwork has helped to make this an exemplary scheme for National Highways.”
Contact
Ann-marie Morrison
Sector director