Sizewell C related Traffic Management, Road Closures & Rail Movements

See below for current and up and coming road closures and traffic management in relation to the Sizewell C project:

Engineering Train Movements

As part of the track renewals and the installation of the Green Rail Route there an engineering train known as the Tamper Train running along the line from Saxmundham Road level crossing into the TCA carrying out tamping work of the track ballast over the next few weeks.

A12 Closures

Friday Street

The A12 / A1094 will be closed from 8pm to 5am on the nights of 13 to 17 July for resurfacing works. The diversion routes will be:

A12 Diversion Route: A1152, B1069, A1094, B1069, B1122 and vice versa

A1094 Diversion Route (South): A1094, B1069, A1152, A12

A1094 Diversion Route (North): A1094, B1069, B1122, A12

Marlesford

The A12 at Marlesford will be closed at nights (9pm-6am) from 9pm Monday 27 July to 6am Saturday 1 August to enable road improvements. The diversion route is A1152, B1069, A1094 and vice versa.

A further A12 closure at Marlesford is likely in Q3/Q4 2026 subject to relevant permissions to being granted.

Darsham

The A12 at Darsham will be closed at nights (9pm to 5am) for two nights, 20 to 21 July ending at 5am 22 July, for surfacing.

The A12 at Darsham will be closed at weeknights (9pm-6am) from 10 to 21 August for works associated with a new pedestrian crossing. The northbound diversion route is A1120, B1116, B1117, A144. The southbound diversion route is B1387, B1125, B1122.

Further closures are expected in Q3 and Q4.

B1122 Closures

Leiston

Abbey Road (B1122) will be closed between Rowley Mews and Abbey Lane for two nights for works associated with the Green Rail Route: 8pm 18 July to 4am 19 July and 8pm 19 July to 6am 20 July.

The diversion route will be B1122, B1069, A1094, A12, B1122 and vice versa.

From 27 July to 30 August, Abbey Road (B1122) will be closed 24/7 at the Leiston level crossing. The eastern end of Westward Ho will also be closed for approximately 80 metres from the junction with Abbey Road.  Pedestrian access will be maintained.

Yoxford to Theberton

There are likely to be several weeks of weeknight closures of the B1122 following the summer holiday period.

Other Road Closures

Darsham

Willow Marsh Lane, Darsham, is closed until Summer 2026 to enable the construction of the Northern Park & Ride roundabout and site.

The diversion route in place is via Walpole Road, A144, A12.

Leiston and Theberton

Buckleswood Road will be closed from 8pm 14 July to 4am 15 July and from 8pm 16 July to 6am 17 July, for works associated with the Green Rail Route.

The diversion route will be Buckleswood Road, Abbey Lane, B1122, Westward Ho and vice versa.

The level crossing between Saxmundham Road and Buckleswood Lane will be closed from 6am Monday 8 June to 6pm Monday 20 July.

The diversion route will be B1119, B1122, Westward Ho, Buckleswood Road, Buckleswood Lane and vice versa.

Moat Road and George Road are closed from 26 May to mid-September 2026 for works associated with the Sizewell Link Road. From mid-September the road will continue to be closed through to the B1122, but a connection from George Road to Moat Road will be open. The diversion route will be Harrow Lane, Abbey Lane and B1122.

Pretty Road will be closed until Q3 2027 for the construction of an overbridge as part of the Sizewell Link Road. The diversion route will be Harrow Lane, Abbey Lane and B1122.

Hawthorn Road will be closed from 10 August 2026 to 30 April 2027 for the construction of the Sizewell Link Road. The diversion route will be Harrow Lane, Abbey Lane and B1122.

The Common (off Lover’s Lane, north of entrance to Sandy Lane) will be closed from 26 June to 25 July. Access to properties will be maintained.

Middleton-cum-Fordley

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

Knodishall 

The level crossing on The Green, Knodishall will be closed from 19 August to 19 September 2026.

Friday Street, Benhall

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

Farnham 

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.

Chapel Road will be closed overnight (8pm to 6am) as part of Essex and Suffolk Water mains diversion works from 3 July to 21 July. The diversion route is Hall Road, Mill Lane, Great Glemham Road, Main Road and vice versa.

Marlesford – local roads

Marlesford Road (north of the A12) will be fully closed for approx. 130 metres from the A12 junction from 1 June to 1 August. Diversion route will be Marlesford Road, B1116 The Street and vice versa.

Bell Lane will be closed from 25 June to 1 August (8pm-5am) and 5 August-20 August (9pm-6am). Diversion route will be via New Road, Keeper’s Lane, A12 and vice versa.

Ashe Road (south of the A12, aka Marlesford Road) will be fully closed for approx. 130 metres from the A12 junction from 27 July to 7 September. Diversion route will be Hacheston Road, B1078 and vice versa.

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

Traffic Management

Leiston

Ongoing traffic signals on Lover’s Lane and B1122 Abbey Road.

Ongoing traffic lights on Buckleswood Road associated with the rail crossing.

The A12

On the A12, at 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 are in place nightly (7pm to 5am) on the A12 at Marlesford from 25 June to 20 August.

Traffic lights are in place nightly (8pm to 5am) and the A12 at Stratford St Andrew from 7 to 21 July.On the A12 at Darsham 3-way traffic lights are in place from 9:30am-5pm from 6 to 17 July and from 5am-8pm 20 and 21 July.

Speed restrictions

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

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

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

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

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

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

B1125: 30mph and 50mph speed limits are in place associated with the speed cameras.

Eastbridge Road: 30mph speed restrictions are in place whilst works are carried out to construct the Sizewell Link Road.

Sizewell Gap: 30mph speed limit on Sizewell Gap up to Sizewell Haul Road.