Sizewell C has opened two major new roundabouts on the A12, marking a significant milestone in its programme of infrastructure improvements across East Suffolk.

The upgraded junctions at Friday Street and Yoxford will improve safety, ease congestion and support smoother journeys for the local community, businesses, and visitors. They will also play a key role in ensuring the efficient movement of workers and materials to Sizewell C.

Delivered as part of Sizewell C’s commitment to strengthening regional infrastructure, the new roundabouts replace older junctions that had become increasingly congested and challenging to navigate at peak times. The redesigned layouts, which still require further works, now provide safer access to the A1094 at Friday Street and the B1122 at Yoxford, reducing queuing and lowering the risk of accidents.

Damian Leydon, Sizewell C site delivery director, said: “Opening the new roundabouts is a major step forward, not just for the Sizewell C project, but for the whole of East Suffolk. These upgrades will make journeys much safer and more reliable, while giving our project the transport links it needs to progress smoothly.”

The junctions opened ahead of the Easter weekend. Although both roundabouts are now open to traffic, finishing works and landscaping will continue in the coming months.

Leydon added: “We’re committed to leaving a lasting positive legacy on East Suffolk, and improvements like these – as well as the other upgrades we’re making to the local road network – will continue to deliver benefits long after construction of the power station is complete.”

The openings form part of a wider programme of upgrades along the A12 corridor and other key roads. These include the 6.5km Sizewell Link Road – which will divert construction traffic away from Theberton and Middleton Moor – and the 1.8km Two Village Bypass, which will connect to the new Friday Street roundabout and redirect vehicles around the small villages of Stratford St Andrew and Farnham. Together, these improvements will ease congestion and improve safety.

Suffolk-based Breheny Civil Engineering – headquartered in Needham Market – secured the contract to build the roundabouts last year. The company originally worked on Sizewell B in the 1980s and had already completed several projects on Sizewell C before starting work on the two roundabouts.

Mark Burrows, regional commercial director of Breheny Civil Engineering, said: “The opening of these roundabouts to traffic marks a major milestone. They’ll deliver much-improved traffic flow to the A12 and vastly improved access for road users from the A12 onto the A1094.

“Our site teams delivered a great job on both schemes. We faced challenging conditions during construction, working diligently and safely through an exceptionally wet winter to deliver the roundabouts to exceptionally high standards. We’ll continue to work on the roundabouts until the works are fully completed in the next few months.”

As part of wider efforts to reduce traffic on East Suffolk’s roads, Sizewell C has already opened its two park and ride facilities at Darsham and near Wickham Market. Once fully operational later this year, the sites will accommodate up to 2,500 vehicles, significantly cutting the number of daily car journeys into Leiston.

In February, the project also welcomed its first engineering train via the newly upgraded Sizewell Branch Line, delivering aggregate to support ongoing rail infrastructure works. This new line into the project’s Ancillary Construction Area, together with the Green Rail Route – which will link the branch line to the Temporary Construction Area – will remove thousands of truck journeys from local roads.

Construction is also underway on the project’s Marine Bulk Import Facility – a 500‑metre structure extending into the North Sea that will enable construction materials to be delivered by freight vessel. These vital pieces of infrastructure are central to Sizewell C’s commitment to transporting 60% of materials by rail or sea, reducing road traffic, lowering emissions, and minimising disruption for local communities.

At peak construction, almost 8,000 people will work at Sizewell C. Once operational, the power station will generate 3.2GW of low-carbon electricity – enough to power six million homes – and reduce UK carbon emissions by around nine million tonnes each year.

It will also create at least 1,500 apprenticeships, with around a third earmarked for people living in Suffolk.