Sizewell C related Traffic Management & Road Closures

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

A12 Closures

Wickham Market

From 25 April to 3 May, the A12 Northbound at the Wickham Market junction will be closed at nights (8pm to 5am) for resurfacing. Lane 2 Southbound will also be closed to enable the works to be undertaken safely. The diversion route is up the slip-road, across the B1078 / B1116 roundabout and down the slip-road to re-join the A12 Northbound.

Yoxford

The A12 and B1122 (Middleton Road) will be closed for two full weekends for works related to the new roundabout:

8pm Friday 8 May to 5am Monday 11 May

8pm Friday 15 May to 5am Monday 18 May

The A12 diversion route is A14, A140, A143, A146, A12 and vice versa. The B1122 diversion route is B1122, B1069, A1094, A12 and vice versa.

Friday Street

The A12 northbound will be closed from 8pm to 5am on the night of 20 May north of the A1094 to facilitate a switch in the lane guard.  The diversion route will be A1094, B1069, B1122, A12.

The A12 / A1094 will be closed from 8pm to 5am on the nights of the 10 and 11 June 2026 for resurfacing works.

The diversion route 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

There are likely to be further night time closures of the A12 and A1094 in July to facilitate resurfacing works. Dates will be communicated when confirmed.

Marlesford

There are likely to be night time closures of the A12 at Marlesford in May to facilitate starting the Marlesford improvement scheme. with the current planned dates as the 1 to 4 June (8pm to 5am). This is subject to relevant permissions to being granted.

Darsham

There are likely to be night time closures of the A12 at Darsham in Q3 and Q4 2026 associated with the pedestrian crossing works. Dates will be communicated when confirmed.

B1122 Closures

Leiston

From 8pm Friday 29 May to 5am 1 June the B1122 (Abbey Road) will be closed from Leiston Abbey to just south of Rowley Mews, and Lover’s Lane will be closed from Abbey Road to the Leiston waste recycling centre.

From 8pm 5 June 5am 8 June and 9pm 12 June to 5am 15 June the B1122 (Abbey Road) will be closed from Potter’s Street to Eastbridge Road, and the western end of Eastbridge Road will also be closed..

Abbey Road (B1122) Diversion: B1122, A12, A1094, and B1069

Lover’s Lane Diversion: King George’s Avenue and B1122 Abbey Road
Eastbridge Road Diversion: Church Lane and Onner’s Lane will have an advisory one-way system to aid traffic flow between Eastbridge and Theberton.

Yoxford to Theberton

The B1122 will be closed for weeknights from 11 May to mid-July for improvements, with the closure moving from the western end of the B1122 to the east. The diversion route is B1122, B1069, A1094, A12, and vice versa. We will continue to provide updates on the works tracker including more specific details when they are available.

Other Road Closures

Darsham

Willow Marsh Lane, Darsham, is closed until June 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

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.

Lover’s Lane will be closed on 11 May from 8pm to midnight. The diversion route is King George’s Avenue and B1122.

Buckleswood Road will be closed from 30 March to 22 May. This is to enable the construction of associated railways works. The diversion route is Buckleswood Lane, B1119 Waterloo Avenue, B1122 Station Road.

Buckleswood Lane (just northeast of Saxmundham Road level crossing) will be closed by Essex and Suffolk Water to facilitate works associated with the construction of the Buckleswood Lane level crossing for the Green Rail Route.

Between 26 May and 6 June, works will take place in the following order:

3-day full closure 26 May to 28 May

2-day full closure 2 June to 3 June

Closure for 2 nights (8pm-5am) 3 June to 5 June

Moat Road will be closed from 26 May to 7 August 2026 for works associated with the Sizewell Link Road. Diversion route will be B1122 and Pretty Road.

Middleton-cum-Fordley

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

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.

B1078

The B1078 will be closed on 8 May for one night, 7pm-5am. The road will be closed in two locations on the same night, with Phase 2 commencing once Phase 1 is completed:

Phase 1: B1078 (Charsfield Road) closed at Clopton Corner. Diversion route B1079, A12, B1438, B1078 and vice versa.

Phase 2: B1078 (Lower Road, Ashbocking Road) closed east of Coddenham and north of Hemingstone. Diversion route B1078, B1077, A1120, A140 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.

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 will be in place overnight (7pm to 5am) in the Yoxford area from 11 to 21 May (A12 south of roundabout), from 26 to 28 May (A12 north of roundabout) and from 1 to 12 June (B1122), for works associated with the Yoxford roundabout.

Traffic lights will be in place on the A12 at Darsham from 16 February to 1 May for works associated with the Northern Park and Ride roundabout.

From 30 April to 6 May traffic lights will be in place on the A12, Kelsale, north of Town Farm Lane on weekdays between 9:30am and 3:30pm.From 5 May to 15 May traffic lights will be in place on the A12 at Marlesford and Little Glemham on weekdays between 9:00am and 3:00pm.

From 14 to 15 May traffic lights will be in place on B1438 Wickham Market on weekdays between 9:00am and 3:00pm.

From 15 to 18 May traffic lights will be in place in Leiston at Sylvester Road between 9:00am and 3:00pm.

From 18 to 25 May traffic lights will be in place in Leiston at Seaward Avenue between 9:00am and 3:00pm.

From 20 to 21 May traffic lights will be in place in Leiston at  Pacton Chadwick Close between 9:00am and 3:00pm.

A1094

Multi-way traffic signals will be in place at the A1094-B1069 junction from 27 April to 12 June for road improvements.

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.