Weekend traffic alert: A1 to close for Black Cat roundabout upgrade works

If you’re planning to drive through Bedfordshire this weekend, be aware of major closures on the A1 northbound and A421 eastbound due to ongoing Black Cat improvement works.

Anglian Water will be connecting a new watermain near Nags Head Lane, close to the A1. So, to keep both workers and drivers safe, sections of the road will be closed.

Here are more details on the closure:

• A1 northbound: Between Tempsford and Wyboston.
• A421 eastbound: Between Cardington Interchange and Black Cat Roundabout.
• When: 9pm Friday 10 October to 5am Monday 13 October 2025.

The Black Cat Roundabout is one of the region’s busiest junctions, linking the A1 and A421 and connecting traffic between Milton Keynes, Bedford, and Cambridge. Because of its importance, any work here can cause significant delays, especially for commuters and freight drivers.

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Here are some recommended detours if you’re driving through the area:

1. Exit the A421 at Cardington Interchange onto the A603 towards Sandy.
2. At Sandy, join the A1 northbound to the Tempsford Interchange.
3. Exit onto St Neots Road, then join the A428 at St Neots.
4. Rejoin the A1 northbound at Wyboston.

These closures are part of the £1bn project to upgrade the A428 between the Black Cat and Caxton Gibbet – and it’s the biggest scheme National Highways has ever done. Once it’s finished, it should make trips between Milton Keynes and Cambridge smoother, cut congestion around the Black Cat Roundabout, and make local journeys easier.

Here are some tips to avoid delays:

• Plan extra travel time and check your route in advance.
• Use local roads where possible and avoid peak hours.
• Consider public transport for part of your journey.
• Keep an eye on live traffic updates via National Highways or GPS apps.

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