29SEP to 04OCT25 A421 closure

National Highways has confirmed that new safety barriers and lighting are being installed on the A421 eastbound carriageway near the Black Cat roundabout.

During the scheduled weekend closure, Anglian Water will also be connecting a new water main on Nags Head Lane close to the A1 carriageway.

Closure and Diversion

The following overnight closures will be in place:

• A421 eastbound between Renhold Interchange and Black Cat roundabout

• A1 northbound between Tempsford and Wyboston

Dates:

• Monday 29 September to Thursday 4 October 2025 (9pm – 5am)

• Monday 6 to Friday 10 October 2025 (9pm – 5am)

• Weekend closure: Friday 10 to Monday 13 October 2025 (9pm – 5am)

Diversion route:

• Traffic will leave the A421 at Cardington Interchange onto the A603 towards Sandy.

• At Sandy, vehicles will join the A1 northbound to the Tempsford Interchange.

• From there, drivers will exit onto St Neots Road and join the A428 at St Neots.

• Traffic will then re-join the A1 northbound at the Wyboston junction.