A428 Black Cat upgrade: what the current construction phase means for buyers in Huntingdonshire's A1 south villages.

What the A428 Black Cat to Caxton Gibbet scheme is.

The A428 Black Cat to Caxton Gibbet improvement is a National Highways project to build 16 kilometres of new dual carriageway connecting the A1 at the Black Cat roundabout in Bedfordshire to the A428 Caxton Gibbet roundabout in South Cambridgeshire. From Caxton Gibbet, the existing A428 continues east through Cambourne to Cambridge.

Skanska is the design-and-build contractor. The project costs around £1 billion. Construction began in late 2023 and the scheme passed its halfway construction milestone in autumn 2025. Spring 2027 is the confirmed opening window. You can follow the scheme's progress directly on the National Highways A428 project page.

Where the construction stands in May 2026.

The project has moved into its most visible phase. By early 2026, the primary steelwork for the River Great Ouse viaduct was complete: 20 main girders and 485 crossbeams, totalling 2,067 tonnes of UK-manufactured steel, lifted into permanent bearings in overnight deliveries to reduce disruption to local residents.

The current focus is the Black Cat junction flyover. On 27 April 2026, traffic was switched to a new section of carriageway so crews could begin building the flyover that will carry the dual carriageway over the junction. A 300-tonne crawler crane is now installing 340 concrete deck panels, each weighing around 20 tonnes. The panel installation is expected to complete by the end of spring 2026, after which work moves on to surfacing and the finishing runs.

A series of road closures affecting the junction and approach roads ran from 10 April to 16 May 2026. With those closures now finished, the main lane on the upgraded carriageway between Eltisley North roundabout and Caxton Gibbet North roundabout is open to traffic.

Which Huntingdonshire villages benefit most directly.

The A428 scheme improves journeys between the A1 north-south corridor and the A428's east-west route toward Cambourne and Cambridge. Within the Huntingdonshire patch, the villages with the most direct stake are those in the A1 south corridor who turn east on the A428 to reach Cambourne, Papworth, south Cambridge and Addenbrooke's hospital: Perry, Grafham and Ellington.

Buckden, which sits just south of Perry near the existing A1, also benefits from the improved junction. Residents across the Huntingdon and Brampton area who occasionally travel the A1 south and then east will see improvements, though their main Cambridge route remains the A14 east.

The commute improvement in numbers.

National Highways estimates that drivers on the improved route will save up to 90 minutes per week compared with current conditions. That figure reflects the removal of the existing Black Cat junction bottleneck and the upgrade from mixed single-to-dual carriageway through to Caxton Gibbet.

For a commuter making five return trips per week, 90 minutes saved works out at around nine minutes per single journey, consistently. The more meaningful shift is the reliability improvement: the Black Cat junction in its current form can add significantly longer delays in peak hours and on bank holidays. The upgraded junction removes the main source of unpredictability on that corridor.

What this means for property in the A1 south corridor.

The standard pitch for Huntingdonshire property is access to Cambridge employment at prices below Cambridge and its immediate suburbs. For the A1 south corridor, that argument has always been qualified by the junction: the route exists, but it is slower and less reliable than the A14 corridor to the north.

When the A428 opens in spring 2027, that qualification falls away. Perry, Grafham and Ellington will have a materially better link to Cambourne (already one of the fastest-growing employment locations in the region) and to the south Cambridge cluster including Addenbrooke's, the biomedical campus and the science parks. At current prices, A1-south-corridor properties already represent good value relative to their A14 counterparts. Improved access adds another reason for buyers to look at them seriously.

Sellers in the patch who are marketing now, or who intend to market before the 2027 opening, can honestly describe the upgrade as an imminent improvement to the road network. For a free property valuation that takes the full local picture into account, including what infrastructure changes mean for pricing, our team is available at villagerhomes.co.uk/valuation.