Tunnel built under major new road between Cambridge and Bedfordshire – but it’s not for drivers

The road is expected to open next year

A tunnel has been built under a new dual carriage way to help guide bats and other wildlife. This forms part of the major £1 billion Black Cat to Caxton project.

The 45-metre long (5-metre-wide and 4.5-metre-high) tunnel runs beneath the new 10-mile dual carriageway. This is located between the Black Cat roundabout in Bedfordshire and Caxton Gibbet in Cambridgeshire.

Ecological surveys carried out in 2021 helped National Highways to understand how wildlife uses the area, including identifying bat flight paths crossing the route of the new dual carriageway.

It said the tunnel will help bats to “safely navigate” the new road. Alongside bats, the tunnel will help to guide other wildlife towards the crossing.

The underpass has been built alongside new hedgerows, trees, shrubs and specifically designed fencing. “It’s one of the ways we’re working to make sure the new road and the surrounding environment can live alongside each other”, a National Highways spokesperson said in a social media update.

The A428 Black Cat to Caxton Gibbet upgrade aims to deliver a new 10-mile dual carriageway. It will replace the final stretch of single carriageway on the road between the M1 at Milton Keynes and the east coast ports of Harwich and Felixstowe.

Most of the scheme is set to open in spring 2027 including the new 10-mile A421 dual carriageway between Black Cat junction and Caxton Gibbet.

Other key junction improvements, include:

• the new A421 flyover at Black Cat junction;
• dual carriageway entry and exit access at the new Cambridge Road junction;
• fully upgraded Caxton Gibbet junction.

The final phase of the scheme is expected to open in mid-summer 2027, when the new A1 underpass at Black Cat junction comes into use.