Sizewell C related Traffic Management & Road Closures

See below for Sizewell C current and up and coming road closures and traffic management:

Road Closures

Willow Marsh Lane, Darsham is closed until June 2026 to enable the construction of the Northern Park & Ride roundabout and site. Diversion in place via Walpole Road, A144, A12.

Abbey Lane, Leiston is closed until January 2027 to enable the construction of the new railway line. Diversions are in place via Harrow Lane, Hawthorn Road and Pretty Road.

The B1122 Middleton Road will also be closed at night time from 8pm-5am from 5 to 9 January 2026. Diversion route B1122, B1069, A1094 and A12.

Old High Road Yoxford will be fully closed between 5 January and 27 February. Diversion route will be A1120 and A12.

A12 Yoxford south of B1122 will be closed at nighttime from 12 to 15 January 2026 as part of the delivery of the Yoxford pedestrian crossing. The diversion route will be B1122, B1069, A1094 and A12.

A12 Darsham will be closed at nighttime from 19 to 23 January 2026 for resurfacing for the park and ride roundabout. The diversion route will be A12, A146, A143, A140 and A14.

The A12 will be closed to the south of the A1094 at Friday Street for a full weekend closure from 9 to 12 January 2026 to facilitate works associated with the new roundabout. The diversion route will be A12, A146, A143, A140 and A14.

The A12 northbound will be closed at nighttime (8pm to 5am) north of the A1094 at Friday Street for 3 weeks, 26 to 30 January, 2 to 6 February and 9 to 13 February for utility diversion works.

Hill Farm Road will be fully closed from 12 January 2026 for works associated with the two village bypass. The diversion route is A12, Tinker brook Lane. Station Road and Langham Road.

Full-weekend closures of the junction at Abbey Road and Lovers Lane will take place from 19-22 December, 16 to 19 January and 23 to 26 January. There will also be nighttime closures from 19 to 23 January. B1122 diversions is via B1069, A1094, A12 and B1122.

A night-time closure is in place along Lovers Lane and Valley Road from the 22 October to 24 February 20:00 – 05:00. This to enable the installation of power cables, with daytime two-way traffic lights in place. Diversion via B1122 and King George’s Avenue.

Kettles Lane, Benhall, is closed until Summer 2026 for the construction of the Friday Street roundabout.

Littlemoor Road, Middleton, closed from 19 November 2025 and is not expected to be reopened.

Buckleswood Road will be closed from 17 November until 31 January 2026. Diversion route Buckleswood Lane, B1119 and B1122.

Further closures related to the schemes are being progressed through discussions with SCC and will be communicated once approved.

Traffic Management

A12, Friday Street, varying traffic management is in place, including lane closures and traffic signals until Summer 2026 as part of construction of the new roundabout.

Traffic lights on the A12 at Darsham from 4 November to 23 January to enable the delivery of the Northern Park and Ride roundabout.

Traffic lights on the B1122 Middleton Road on nights for construction of the new road and kerb alignment for the Yoxford roundabout from 3 to 20 December between the hours of 20:00-05:00. ESW potential signals nighttime 22 December to 3 January for contingency.

Multi way traffic lights at Leiston level crossing, Abbey Road 7 - 22 December to install the UKPN DNO supply for the level crossing and rail route.

Speed restrictions

A12 between Glemham and Benhall, 30 mph speed limit in place whilst works are carried out to construct the new by-pass.

A12 Friday Street 30 mph speed limit in place whilst works are carried out to construct the new roundabout.

A12 between Kelsale and Yoxford, 30 mph speed limit in place whilst works are carried out to construct the Sizewell Link Road and roundabout.

A12 Darsham, 30 mph speed limit in place whilst works are carried out to construct the Northern Park & Ride roundabout.

B1122, Lover’s Lane and Sizewell Gap 30 mph speed limit in place.

B1125, 30mph and 50mph speed limits in place associated with speed cameras.

Buckleswood Road and Westward Ho 30 mph speed limit in place whilst works are carried out to construct the Green Rail Route.

30 mph speed restrictions on Eastbridge Road.