Sizewell C related Traffic Management & Road Closures

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

Road Closures

The A12 - Friday Street, Benhall

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 is A12, A146, A143, A140 and A14. To confirm; this is a hard closure of both lanes on the A12 at Friday street.  Friday Street remains open, drivers can turn right and head north onto the A12 (towards Saxmundham) but will be unable to turn left, and head south. Traffic from the A12 (coming south from Saxmundham) can turn left into Friday street. Traffic from Ipswich will be directed to the official diversion route, outlined here: Causeway one.network The official diversion route (which requires an A road closure to be matched with an A road diversion) is via the A12 is A14, A140, A143 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.

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

Darsham

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.

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.

Full-weekend closures of the junction at Abbey Road and Lovers Lane will take place from 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, with full weekend closures on Lover’s Lane on 13 to 15 and 20 to 22 February. This 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 17 November until 31 January 2026. Diversion route Buckleswood Lane, B1119 and B1122.

Middleton-cum-Fordley

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

Yoxford

The A12 Yoxford, south of the 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 is B1122, B1069, A1094 and A12.

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

The B1122 Middleton Road is closed at nighttime from 8pm-5am from 5 to 9 January 2026. The diversion route is B1122, B1069, A1094 and A12.

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

Temporary traffic lights will be in place on the B1122 Abbey Road junction with Lovers Lane until Friday 23 January.

Traffic lights will be in place on the B1122 at Station Road, Leiston on 13 January.

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 4 November to 23 January to enable the delivery of the Northern Park and Ride roundabout.

Speed restrictions

A12 between 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.