Diversions, closures and speed restrictions
Check this page regularly for the latest updates on road closures, diversions, and speed restrictions
Current closures
18 to 20 December 2025 - A1 southbound overnight closures
Works
We're repairing damaged gullies and kerbs on the A1 southbound near Black Cat roundabout.
Closure
We'll close the A1 southbound overnight (9pm - 5am) between Wyboston and Tempsford from Thursday 18 to Saturday 20 December 2025.
Diversion
- exit A1 at Wyboston junction
- east on A428 towards St Neots
- take Barford Road rejoin the A1 at Tempsford
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.
Long term changes
Black Cat roundabout layout change - 24 November 2025
From Monday 24 November, we'll open new sections of road at Black Cat roundabout, linking with existing road networks.
A1 southbound
We’re moving the A1 southbound onto a new stretch of road passing under the new east bridge at Black Cat roundabout.
Make sure you’re in the correct lane before you reach the junction:
- left hand lane for A1 south, A421 or M1
- right hand lane for A1 north, A421 or M1
A1 northbound
We’re moving the A1 northbound approach onto the new northbound on-slip at Black Cat roundabout.
Make sure you’re in the correct lane before you reach the junction:
- left hand lane for A421 west and Bedford Road
- right hand lane for A1 north
Let us know what you think
Use our A428 Black Cat to Caxton Gibbet improvements feedback tool to have your say.
This tool features an interactive map, allowing you to click on specific locations to leave targeted comments or provide general feedback.
ECHO is a one-way feedback tool, so if you'd like a response to your feedback you can email the project team at info@a428.co.uk.
Planning diversions, traffic management and speed limits
What you can expect to see
The A1, A421, and A428 will mostly stay open while we carry out our work.
There may be some overnight and full weekend closures from time to time. We'll need these for important tasks like:
- connecting new and existing roads
- building bridges
- delivering large pieces of equipment or materials.
We're committed to being a good neighbour. That’s why we’re carefully planning our work to reduce any disruption to drivers and the local community.
Highest safe speed through roadworks
We’ve determined that a temporary speed limit of 40mph is needed to keep both road users and our workers safe.
This reduced speed limit helps junctions function as usual, which means we won’t need to close roads as often
How we choose diversion routes
We're dedicated to ensuring that any traffic diversions around road closures are safe and appropriate. We'll use diversion routes that can handle the type and amount of traffic being redirected.
The diversion routes will mainly follow major A roads to avoid heavy traffic on local streets. We'll work with local authorities to agree on the best routes.
These diversions are required by law, based on the development consent order (similar to our official approval or planning permission).
To minimise disruption, we will manage traffic carefully, providing clear signs and advance warnings to drivers.
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Keep updated on the A428 Black Cat to Caxton Gibbet improvements
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