Diversions, closures and speed restrictions
Check this page regularly for the latest updates on road closures, diversions, and speed restrictions
Current closures
17 August to 4 September - B1046 Abbotsley Road closure
We'll close the B1046 Abbotsley Road from Potton Road from Monday 17 August to Friday 4 September for major carriageway works, including the lowering of the road by 4 metres.
Diversion
- from St Neots join the A428 heading towards Cambridge
- exit onto the B1046
4 to 7 September - A1 northbound, A1 southbound, A421 westbound and Bedford Road weekend closure
The following roads will be closed from 9pm Friday 4 to 5am Monday 7 September 2026 for the installation of a new road layout at Black Cat junction.
- A1 northbound between Tempsford and Black Cat
- A1 southbound between Wyboston and Tempsford
- A421 westbound between Black Cat and Renhold Interchange
- Bedford Road between the Roxton Road turn-off and Black Cat.
A signed diversion route will be in place.
11 to 14 September - A1 northbound and A421 eastbound weekend closure
The following roads will be closed from 9pm Friday 11 to 5am Monday 14 September 2026 for drainage works.
- A1 northbound between Tempsford and Wyboston
- A421 eastbound between Renhold and Black Cat junction
A signed diversion route will be in place via the A603, A1 northbound, St Neots Road, and A428.
14 to 18 September - A1 northbound and A421 eastbound overnight closures
The following roads will be closed overnight (9pm to 5am) from Monday 14 to Friday 18 September 2026 for temporary barrier removal and road markings.
- A1 northbound between Tempsford and Wyboston
- A421 eastbound between Renhold and Black Cat junction
A signed diversion route will be in place via the A603, A1 northbound, St Neots Road, and A428.
18 to 21 September - A1 northbound and A421 eastbound weekend closure
The following roads will be closed from 9pm Friday 18 to 5am Monday 21 September 2026 for drainage works.
- A1 northbound between Tempsford and Wyboston
- A421 eastbound between Renhold and Black Cat junction
A signed diversion route will be in place via the A603, A1 northbound, St Neots Road, and A428.
21 to 25 September - A1 northbound and A421 eastbound overnight closures
The following roads will be closed overnight (9pm to 5am) from Monday 21 to Friday 25 September 2026 for temporary barrier removal and road markings.
- A1 northbound between Tempsford and Wyboston
- A421 eastbound between Renhold and Black Cat junction
A signed diversion route will be in place via the A603, A1 northbound, St Neots Road, and A428.
Please remember that closures can change at short notice. You can check the latest information on our daily closures. 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
Caxton Gibbet road layout change - April 2026
From Monday 27 April 2026, we'll move traffic on the A428 onto a new stretch of road, linking with existing road networks.
These changes will help us build the upgraded junction and a new flyover bridge, which will carry the dual carriageway over the junction.
Traffic in both directions on the A428 (east of Caxton Gibbet) will be moved onto a new stretch of road, connecting directly to the northern roundabout.
Services at Caxton Gibbet will remain open and accessible.
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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