Diversions, closures and speed restrictions

Check this page regularly for the latest updates on road closures, diversions, and speed restrictions

Diversions, closures and speed restrictions

Current closures

23 to 28 February 2026 - A1 northbound & A421 eastbound overnight closures

Works

We're construction a new bus stop on the A1 northbound.

Closure

We'll close the following roads overnight (9pm to 5am) from Monday 23 to Saturday 28 February 2026:

  • A1 northbound between Tempsford and Wyboston.
  • A421 eastbound between Renhold Interchange and Black Cat junction.

Diversion

A1 northbound

  • exit A1 at Tempsford Interchange onto St Neots Road
  • take A428 towards Wyboston
  • rejoin A1 at Wyboston Interchange

A421 eastbound

  • exit A421 at Cardington Interchange
  • follow A603 towards Sandy
  • join A1 northbound towards Black Cat junction

See A1 northbound & A421 eastbound diversion route map

Works

We’ll be installing key components of the new flyover at Caxton Gibbet, including:

  • lifting and placing 11 bridge beams over the A1198
  • installing glass-reinforced plastic (GRP) panels between the beams to form the base of the new bridge deck
  • fitting temporary safety barriers to keep the bridge deck work area safe and secure during construction

Closure

We'll close the A1198 between Caxton Gibbet roundabout and Caxton Gibbet North roundabout overnight (8pm-6am) from Monday 16 February to Saturday 7 March 2026.

Diversion:

  • A428 traffic to head east joining the A14 at Histon
  • take A14 towards Godmanchester
  • re-join A428 by A1198

See A1198 closure diversion route map

Closed all weekend from 8pm Friday 6 to 6am Monday 9 March for:

  • earthworks
  • drainage
  • work on the new Barford Road layout

We're due to finish the new Barford Road layout in summer 2026.

Diversion –

  • continue north on the A1
  • join the A428 at Wyboston junction

Barford Road weekend closure diversion map.

Closed overnight (8pm to 6am) ending 20 March morning, for kerb fitting and drainage on the A428.

Diversion –

  • head north on the B1040
  • take the A1198 to rejoin the A428

A428 overnight closure diversion route map.

Closed all weekend from 8pm Friday 20 to 6am Monday 23 March, for kerb fitting and drainage on the A428.

Diversion –

  • head north on the B1040
  • take the A1198 to re-join the A428

A428 weekend closures diversion route 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.

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

Map of Black Cat roundabout layout from November 2025.

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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