Project Update – March 2026

Introduction

The Friday Street Roundabout and Yoxford Roundabout are now open to traffic.

This is a significant milestone for the Sizewell C infrastructure improvement works, making two notorious junctions on the A12 a lot safer.

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 now provide safer access to the A1094 at Friday Street and the B1122 at Yoxford, reducing queuing and lowering the risk of accidents.

Whilst traffic management in the area will reduce, works around the roundabout will continue as the now redundant parts of the A12 are removed and prepared for landscaping and the construction of the two-village bypass that will eventually connect to the Friday Street Roundabout continues.

You can read more on the Sizewell C website

Off Site Infrastructure

Park and Rides: Both Park and Rides continue to open in phases. At the Northern Park and Ride, there are now 280 spaces and eighty spaces at the Southern Park and Ride.

The roundabout that links the Northern Park and Ride with the A12 and Willow Marsh Lane continues to be constructed and linked to the road network; we expect the works to be completed by early summer. This week the traffic management will move to the northbound arm of the roundabout.

In and round the Southern Park and Ride, the gas works at the A12 / Wickham Market junction will be completed tomorrow, Wednesday 1 April.

The next phase of work that is required is on the slip road from the B1078-B1116 roundabout to join the Northbound A12.

This will require night closures (7pm-5am) from Tuesday 7 April - Thursday 16 April. The diversion route follows the A12 southbound, U-turning at the A12-A1152 roundabout before heading northbound on the A12.

Later in April, the A12 Northbound will be closed along the dual carriageway section (Ufford and Wickham Market bypass) at nights (8pm to 5am) from 17 to 24 April for resurfacing.  The Southbound Lane will also be closed to enable the works to be undertaken safely. The diversion route for the A12 Northbound is A1152, A1094, A12.

These works are being highlighted on the road network via the Variable Message Signs (VMS) electronic, LED-based traffic signs and the online Sizewell C Works Tracker  

Roads: A12 road improvements: We have recently completed the first of three signalised road crossings along the A12 in Yoxford. The next crossing will be constructed in Marlesford due to commence in May. Works will then proceed onto Little Glemham for the third signalised crossing. These works will require traffic management along the A12, we will communicate the detail nearer the time.

In the wider road network, this year will also see works to improve local roads on the B1122, B1125 and B1119. These works will improve safety accessibility and include High friction surfacing, new footways, vegetation management for improved visibility, signage, and village gateways. The first work to commence will be the B1122 Footpath improvements commence mid-April.

This work will involve traffic management during the day and some night time closures to maximize time and lessen disruption on the road network during the working day.

We are also conducting these works in collaboration with other Nationally Significant Infrastructure Projects (NSIPs) in the area, in particular Scottish Power Renewables.

Two village Bypass: Good progress on the Two village Bypass, with most of the works being carried out away from the existing road network. The last remaining area for archaeology has commenced at the central part of the road. Alongside this, the haul road from east to west is also nearing completion, with a bailey bridge being installed at the River Alde to complete haul road connectivity.  Piling platforms at the River Alde are also due to commence in early spring. The new works compound that will be accessed from the A12 will start operating from the week commencing 20 April.

Sizewell Link Road:  Fencing and compounds have been set up at the site and earth works have begun.  One of the first priorities will be to build new bridges over the East Suffolk railway line and at Pretty Road with piling starting in early spring.  Our contactor, Galliford Try, will be opening a new works compound at the western end of the site, traffic access will be from the A12.

Rail

Leiston line: The improvements to the Saxmundham to Leiston rail line continue with construction of the branch line to the Temporary Construction Area (TCA) continuing at pace. Trains are arriving weekly at the Ancillary Construction Area (ACA) site in Leiston delivering ballast. Works on level crossings upgrades, including in Leiston at Station Road and Abbey Road ongoing, with level crossings being built in early summer.

Buckleswood Road will be temporarily closed again after Easter bank holiday. This closure is essential to facilitate works associated with the construction of the Buckleswood Road level crossing for the Green Rail Route to Sizewell C. There will be a diversion in place and access to properties will be maintained during the temporary closure. A diverted pedestrian footpath will also be constructed by Thursday 2 April.  The diversion route is Buckleswood Lane, B1119 Waterloo Avenue, B1122 Station Road.

East Suffolk Branch Line: As the works along the East Suffolk branch continue, this will require rail line closures.  The next closure of the link will be between 23 – 31 May.  This will allow Network Rail to carry out heavy maintenance of junction at Saxmundham, increase resilience of existing junction in advance of full upgrade later in the year, expected in October 2026.  These works also include civil engineering to construct the foundations for signalling equipment and troughing installation, which is cables containment structure with concrete lids put on top for protection.

Temporary Construction Area (TCA)

North Plaza: Work has begun to construct the North Plaza which will be the main point of entrance for the construction of Sizewell C. The plaza roundabout will eventually be linked to the Sizewell Link Road and located to the east of Abbey Road and comprises a network of roads and durable surfaces designed to support TCA access.
We expect the plaza to start operating in early 2027.

Green Rail Route (GRR): Construction of the Green Rail Route down towards Abbey Road (B1122) continues at pace and will meet the line being constructed at Buckleswood Road once the level crossings on Abbey Road are installed later this spring (as referenced above).

Plants: The construction of the desalination plant and concrete batching plant also continue, currently the intake and output tunnels for the desalination plant are being installed.  Welfare offices are almost complete with interior fittings.

Campus: Towards the campus, work on constructing the plaza roundabout and linking to the campus will start later in the year, the concrete foundations have been laid with unit construction starting in the summer

Main Construction Area (MCA) including Sizewell Beach   

Main Development Site and Sizewell beach: The temporary Main Bulk Import Facility (MBIF) will continue to be constructed over the beach, a jack up barge is now positioned offshore as part of the construction. The MBIF will extend approximately 500 metres from the Main Construction Site into the North Sea.

The first of three SSSI bridge that connects the temporary construction area to the main development site is now in place. Temporary flood defences are ongoing as is plastic walling.

Upcoming Community Forums

Thank you for patience during these works.

To find out more about the progress of the works the next round of community forums are as follows:

Main Development Site Forum: Wednesday 15 April 1800, at the Leiston Town Athletic Association (LTAA)

Northern Transport Forum: Wednesday 6 May 1800, at the High Lodge in Darsham.

Southern Transport Forum: Wednesday 3 June 1800, Stratford St Andrew Riverside Centre