A428 Upgrade Reaches Halfway Milestone

National Highways’ £1 billion A428 Black Cat to Caxton Gibbet Improvements have reached a major milestone — the halfway point in construction.

New drone footage released today shows how the 10-mile dual carriageway between Bedfordshire and Cambridgeshire is rapidly taking shape, transforming one of the region’s busiest and most important routes.

Significant progress can already be seen at key locations including Black Cat roundabout, Cambridge Road (St Neots), Eltisley, and Caxton Gibbet, as the project moves towards its planned completion in spring 2027.

Lee Galloway, National Highways Project Director, said:

“Reaching the halfway point is a fantastic achievement and a visible sign of the hard work and dedication of everyone involved. Regular users of the route can already see major changes taking place. We remain on track for completion in spring 2027, and once open, the new road will deliver smoother, safer, and more reliable journeys. Our thanks go to local residents and road users for their ongoing patience and support.”

The scheme — the largest infrastructure project currently under construction by National Highways — will deliver a new 10-mile dual carriageway linking the A1 and A421 at Black Cat roundabout with the A428 at Caxton Gibbet, removing the last single-carriageway section between the M1 near Milton Keynes and the east coast ports of Felixstowe and Harwich.

Both the Black Cat and Caxton Gibbet junctions will become free-flowing roundabouts, cutting congestion and improving journey times, while a new junction at Cambridge Road will enhance access to St Neots and its train station. Once complete, drivers are expected to save up to 90 minutes a week on their journeys.

Dan Trathen, Skanska’s Project Director for the A428 scheme, added:

“This halfway mark isn’t just a point on a timeline — it’s a testament to the teamwork, precision, and determination behind this project. We’re not just building a road; we’re creating safer, faster, and better-connected communities. The second half begins with even greater momentum.”

Progress so far at a glance

• 7.1 million tonnes of earth moved to form the new carriageway and link roads — the equivalent of 7 billion bags of flour.

• 60,000 tonnes of asphalt laid across key junctions and stretches of the new route.

• 27 miles of utilities — including broadband, gas, water, and power — successfully diverted.

• 84 bridge beams lifted into place, with 18 new bridges due to be completed overall.

• 11 miles of drainage installed across the scheme.

What’s next

In the months ahead, drivers will notice major activity continuing around Black Cat roundabout, where engineers are lowering the A1 to pass beneath the new junction and progressing with the A421 flyover bridge.

Elsewhere along the route, work is advancing on the 200-metre River Great Ouse viaduct, where huge beams will soon be lifted into place, while at Caxton Gibbet, the new flyover bridge is beginning to take shape — another clear sign that the project’s completion is firmly on the horizon.