A1 Black Cat to Biggleswade safety barrier replacement

We’ve completed a number of upgrades to the A1 between the Black Cat roundabout and Biggleswade in Bedfordshire.

Start date 24 October 2022
End date July 2023
Cost £4.6 million

Project information


We will be replacing the safety barrier and drainage, resurfacing and refreshing the road markings on the A1 from the Black Cat roundabout to Biggleswade.

We plan to do this work over 9 months between Monday 24 October 2022 to July 2023. We will work between 8pm and 6am on weeknights, weather conditions permitting.

We’ll replace 3.8 miles of safety barrier on the dual carriageway and improve the road resurface to make journeys smoother. We’ll also replace the drainage system to reduce the risk of flooding.

We’re spending more than £200 million on more than 80 schemes across Norfolk, Suffolk, Essex, Bedfordshire, Cambridgeshire, Hertfordshire and Buckinghamshire.

Here is a full list of planned closures we intend to use for these works:

Closure Date/Time Diversion

A1 Biggleswade North Roundabout to Sandy Roundabout (northbound) 

12 April to 23 June, 8pm to 6am (weeknights only)

Traffic will be diverted via the A507, A6 and the A421 to re-join the A1 at Black Cat Roundabout.  

Remember that dates and time may change due to weather conditions. For the latest information, check our planned closures page.

Southbound diversion

When the A1 is closed between the Black Cat junction and Sandy, drivers heading southbound will take the A421 southwest.

Then they will take the A603 Bedford Road/Sandy Road east through Moggerhanger, re-joining the A1 at Sandy.

Drivers heading northbound will following this route in reverse.

Northbound diversion

When the A1 is closed between the Sandy and Biggleswade northbound, drivers will take the A507 Arlesey road / Ampthill road west at Radwell to Clophill.

Then they will take the A6 north through Haynes West End and Duck End to Elstow,

Then they will take the  A421 east to rejoin the A1 at Black Cat Roundabout.

This scheme is part of a multi-million-pound package of improvements we are bringing to roads, pavements and bridges across the region this year.

We’ll be working on well-known roads like the M11, A14, A1, A47 and A12 as part of this package, including:

  • skid resistance schemes (A428 Wyboston Lakes A1 junction and A421 Barford Rd junction)
  • A421 Marston Shelton to Wootton noise barrier
  • M1 Ridgmont junction 13 bridge repairs
  • A421 Salford Rd junction redesign near M1
  • A428 Black Cat to Caxton Gibbet major improvement


Traffic information

Information about scheduled roadworks and events on our motorways and major roads.

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