A421 Marsh Leys Roundabout to Black Cat Roundabout road markings - 24 November 2025 to February 2026

We’ll work overnight (8pm-6am) on weeknights only.

We'll work from Monday 24 November 2025 to Saturday 28 February 2026, weather permitting.

Closures

Monday 24 November to Tuesday 2 December 2025 - A421 eastbound Marsh Leys Roundabout to Elstow Interchange

Diversion:

• exit Marsh Leys Roundabout onto the A6 (the Branston Way)
• continue onto the A4280 (Bromham Road)
• follow the A4280 onto Goldington Road
• re-join the A421 at Renhold junction

A421 eastbound Marsh Leys Roundabout to Elstow Interchange diversion map.

Tuesday 2 to Thursday 4 December 2025 - A421 eastbound Harrowden Interchange to Cardington Roundabout

Diversion:

• exit the A421 at Harrowden Interchange onto Wallis Way
• continue onto Cambridge Road
• turn right onto Cardington Road
• re-join the A421 at Cardington Roundabout

421 eastbound Harrowden Interchange to Cardington Roundabout diversion map.

Thursday 4 December to Wednesday 10 December 2025 - A421 eastbound Marsh Leys Roundabout to Cardington Roundabout

Diversion:

• exit Marsh Leys Roundabout onto the A6 (the Branston Way)
• continue onto the A4280 (Bromham Road)
• follow the A4280 onto Goldington Road
• re-join the A421 at Renhold junction

A421 eastbound Marsh Leys Roundabout to Cardington Roundabout diversion map.

Wednesday 10 to Saturday 20 December 2025 - A421 eastbound Cardington Roundabout to Renhold junction

Diversion:

• exit Cardington Roundabout onto the A603 (Cambridge Road)
• continue onto Bedford Road and then Sandy Road
• join the A1 northbound
• re-join at Black Cat Roundabout

A421 eastbound Cardington Roundabout to Renhold junction diversion map.

Please remember that closures can change at short notice. You can check the latest information on our daily closures page or find live travel information on our Traffic England site. Our travel alerts give details of live incidents on our network.