In a landmark infrastructure win that underscores the rapid pace of the UK’s electric vehicle supply chain build-out, Costain has secured a £123 million contract to design and deliver a new junction on the M5 motorway in Somerset, providing critical access to the forthcoming Agratas gigafactory — the UK’s largest planned electric vehicle battery manufacturing facility.
The project — known as Junction 22A — will be constructed over the next five years and is designed to alleviate pressure on the existing motorway network while unlocking direct access for commercial traffic to the Gravity Smart Campus, where the gigafactory is being developed between Puriton and Woolavington, near Bridgwater in the South West of England.
Engineering a Gateway to Electric Mobility
For Costain — a leading UK infrastructure delivery specialist — the contract represents a strategic extension of its long-established partnership with National Highways, the government body responsible for England’s motorway and major A-road network. Under the Regional Delivery Partnership (RDP) framework, Costain will serve as the project’s delivery integration partner and main works contractor, overseeing design, engineering, programme delivery and supply chain coordination.
According to the plans, Junction 22A will feature dedicated slip roads that improve northbound and southbound connections while addressing local topographical constraints, including proximity to the Huntspill River and an adjacent nature reserve.
“This award is built on our long-established highways delivery expertise and trusted partner relationship with National Highways,” said Alex Vaughan, Chief Executive Officer of Costain. “We will work closely with our supply chain partners to design and deliver this new junction that will provide access to the new gigafactory and help to drive economic growth in this region of the UK.”
A Strategic Link in the UK’s Net-Zero Transition
The infrastructure development comes as part of the wider Gravity Smart Campus initiative — a major investment in the West of England with the potential to transform Somerset into a hub for advanced manufacturing and green technology. The gigafactory itself, backed by Tata Group’s global industrial investment and estimated at £4bn, is expected to deliver significant employment and economic benefits once fully operational. Early estimates suggest thousands of new direct jobs and wider supply-chain growth across the region.
By providing dedicated motorway access, Junction 22A is poised to reduce heavy traffic pressure on local roads while improving connectivity for logistics and goods movement, reinforcing the strategic importance of transport links in supporting Britain’s automotive electrification plans.
Collaboration and Future Readiness
Costain will work alongside design partner WSP throughout the development, with an expectation that the junction will be delivered efficiently within the projected timeline and budgetary control parameters. Upon completion, the new junction will be handed over to National Highways for operation and ongoing maintenance.
“This investment, supporting the UK’s growth ambitions, is another example of Costain’s commitment to deliver critical national infrastructure programmes that improve people’s lives,” Vaughan added.
For Somerset and the wider South West economy, the work represents a tangible step toward embedding advanced manufacturing capacity within the UK — aligning infrastructure delivery with net-zero industrial strategy and long-term regional prosperity.