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

Darsham

The A12 at Darsham will be closed for four nights (8pm-5am) from 13 April to 17 April for works associated with the Northern Park and Ride roundabout. Diversion in place via A14, A140, A143, A146, A12 and vice versa.

Wickham Market

The slip road from the B1078/B1116 roundabout onto the A12 Northbound will be closed at nights (7pm to 5am) from 7 April to 16 April for works associated with the Southern Park and Ride. The diversion route is the A12 Southbound, around the Melton (Woods Lane) roundabout onto A12 Northbound. 

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. Lane 2 Southbound will also be closed to enable the works to be undertaken safely. The diversion route is A1152, A1094, A12.

A shorter section of the A12 Northbound at the Wickham Market junction will then be closed at nights (8pm to 5am) from 24 April to 3 May 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 rejoin the A12 Northbound.

Yoxford

The A12 and B1122 (Middleton Road) will be closed for two full weekends, from 8pm Friday 8 May to 5am Monday 11 May and from 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.

B1122 Closures

Leiston 

The B1122 (Abbey Road) between Rowley Mews and Leiston Abbey access, and the western end of Lovers Lane, will be closed on weeknights (8pm to 5am)  from 7 to 10 April.

The B1122 (Abbey Road) between Rowley Mews and Leiston Abbey access will be closed from 9am to 12 noon on Friday 24 April to facilitate a track laying engineering train at the Green Rail Route level crossing.

The B1122 (Abbey Road) will be closed for the following three weekends:

• 8pm Friday 10 April-5am Monday 13 April – Abbey Road from Eastbridge Road to Rowley Mews, and the western ends of Eastbridge Road and Lover’s Lane
• 8pm Friday 17 April-5am Monday 20 April – Abbey Road from Leiston Abbey access to Rowley Mews, and the western end of Lover’s Lane
• 8pm Friday 24 April-5am Monday 27 April – Abbey Road from Eastbridge Road to Rowley Mews, and the western ends of Eastbridge Road and Lover’s Lane

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 Onners Lane will have an advisory one-way system to aid traffic flow between Eastbridge and Theberton.

Yoxford to Theberton

The B1122 (Middleton Road) will be closed on weeknights from 20 April for B1122 improvements moving from the western end to the east. The diversion route is B1122, B1069, A1094, A12, and vice versa. We will continue to provide updates on the works tracker.

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.

A night-time closure is in place along Lovers Lane and Valley Road from the 22 October 2025 to 6 April 2026 20:00 – 05:00. This is to enable the installation of power cables, with daytime two-way traffic lights in place. The diversion is via the B1122 and King George’s Avenue.

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

Moat Road and George Road will be fully closed in the coming months. Details will be included in the works tracker when they are available. The diversion route is Pretty Road and B1122.

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.

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 on the A12 at Darsham from 16 February to 1 May for works associated with the Northern Park and Ride roundabout.

A1094

Multi-way traffic signals will be in place at the A1094-B1069 (Leiston Road) 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.