The A428 Black Cat to Caxton Gibbet improvement project is one of the most significant infrastructure upgrades currently underway in the East of England. Part of a £1 billion scheme led by National Highways, this initiative will transform travel between Milton Keynes and Cambridge, tackling congestion and improving journey times for thousands of road users every day.

The A428 between the Black Cat roundabout and Caxton Gibbet junction has long been a bottleneck, with frequent traffic delays during peak commuter hours due to single-lane carriageways and outdated junction designs. These issues have caused frustration for commuters and businesses alike, slowing down commercial traffic and impacting local economies.

Recognising the urgent need for a modern road infrastructure to support regional growth, National Highways secured approval for an extensive upgrade in 2021, with construction starting in 2022. The project’s primary objectives are to reduce congestion, enhance safety, and bolster connectivity between key commercial hubs across the region.

The core of the scheme involves constructing a new 10-mile dual carriageway to replace the existing single carriageway. Key elements include:



• New Three-Tier Junction at Black Cat Roundabout
  Enabling free-flowing traffic between the A1, A421, and the new A428 dual carriageway.
• Upgraded Junctions at Cambridge Road and Caxton Gibbet
  Improving traffic flow and providing better access to local routes.
• Environmental Enhancements
  Introducing wildlife crossings, improved drainage, and replanting initiatives to minimise ecological impact.
• Cycle and Pedestrian Routes
  Ensuring better local connectivity and promoting sustainable transport options.

Construction has advanced significantly since 2022. The initial phase involved intensive earthworks, including large-scale excavation, embankment formation, and drainage system installation. By mid-2023, the project moved on to bridge construction and the formation of the new carriageway, with foundational layers for the road surface now in place.



Recent drone photography and time-lapse footage highlight the progress on key junctions, notably the Black Cat roundabout, where a multi-level interchange is beginning to take shape. These visual updates offer a broader view of the project’s scale and the engineering expertise involved.

2021 – Project approval and completion of planning.

2022 – Groundbreaking and start of construction.

2023 – Major earthworks completed; bridge construction underway.

2024 – Focus on surfacing works and interchange connections.

2025–2026 – Final construction phases and landscaping.

2027 – Expected completion and opening to traffic.

Like any large-scale infrastructure initiative, this project has navigated logistical and environmental hurdles. Adverse weather conditions in the winter of 2022–2023 affected earthworks, and adjustments to construction schedules were necessary to minimise disruptions to local communities and wildlife.

As construction progresses, the focus will shift to laying the final road surface, installing signage, and connecting the new carriageway to existing transport links. Once complete in 2027, the upgraded A428 will significantly boost regional connectivity, streamlining travel between Milton Keynes, Bedford, and Cambridge.

This modern dual carriageway promises to alleviate congestion, enhance road safety, and support the economic vitality of the East of England.