Transparency data

A428 Black Cat to Caxton Gibbet: accounting officer assessment (October 2023)

Updated 30 July 2024

Background

The assessment was completed to align with the updated full transport business case: assessment and process procedures which was submitted to the Department for Transport (DfTInvestment, portfolio and delivery committee (IPDC) in July 2023.

The accounting officer assessment (AOA) was produced by National Highways in conjunction with DfT.

The senior responsible owner sits within National Highways and the National Highways Chief Executive is the accounting officer for the expenditure which the project reports to. The project also reports to the DfT IPDC committee which is chaired by the DfT permanent secretary as principal accounting officer for the DfT group.

Overview

The A428 provides an important east-west link connecting Oxford, Milton Keynes, Bedford, and Cambridge and allows for onward journeys to the Haven Ports of Felixstowe and Harwich. It sits in the Oxford-Cambridge Arc, a globally significant area which is home to 3.3 million people, supports over 2 million jobs, adds over £110 billion to the UK economy annually, and is earmarked for an ambitious additional 1.1 million jobs by 2050. The sub-region performs well in both economic and social terms relative to the England average, however, the scheme will serve pockets of deprivation in the area.

The A428 upgrade aims to enable growth in jobs and housing by providing a free-flowing and reliable connection between the Black Cat roundabout and Caxton Gibbet. Whilst this is considered as a standalone scheme, once completed it will support journeys along the east-west strategic road network transport corridor. It will also create 18.6 kilometres (km) of high-quality and reliable route between the A1/A421 interchange to the junction of the A1198, which in turn links to A14/M11 and will meet the future forecasted traffic flows.

Transport modelling forecasts show that without the scheme, congestion and delays will worsen over time, and the inability of the route to accommodate trip growth will stifle economic growth.

Regularity

The updated full business case presents an overall cost for the upgrade of the A428 that is affordable as part of the RIS2 portfolio. The project will extend into RIS3 and is deemed affordable within the RIS3 settlement.

Propriety

A428 falls under the department’s definition of a Tier 1 Project and, therefore, adheres to control and governance arrangements within National highways and at departmental and HM Treasury (HMT) levels. Final approval of each stage of the business case is made by DfT and HMT ministers. Investment approval to support contract awards will also be made at this level. Under its procurement delegations, NH would approve all other steps in the process.

National Highways has appointed a senior responsible owner and overall progress is assured by the Infrastructure and Projects Authority (IPA) and reported through the Government Major Project Portfolio (GMPP).

As a Nationally Significant Infrastructure Project, legal powers for construction will be gained through a development consent order (DCO) as defined under the Planning Act 2008. At the time of approving the FBC, a decision on the DCO was expected in August 2022.

Value for money

At the time of the AOA, the value for money (VfM) of the scheme is medium with a current benefit-cost ratio of 1.63.

The scheme has key strategic benefits, including improving resilience and safety on the road network and driving growth in the region.

Feasibility

Overall, the delivery of the project is agreed by all assurers to be feasible and the key milestones (2023 to 2024 Q4 for start of works and January to December 2027 for open for traffic) achievable.

Conclusion

There is a strong strategic case for the A428 and at the time of this assessment, the BCR of 1.63 reflects the benefits for the region that this scheme will deliver. The scheme aims to enable growth in jobs and housing, reduce journey time and increase journey time reliability whilst also tackling safety concerns.

Addressing these issues forms part of National Highways strategic objectives. I am therefore satisfied that the programme presents a satisfactory use of public funds and should deliver wider economic benefits to the region and wider national economy.

Bernadette Kelly

Permanent Secretary, Department for Transport

27 November 2023

Nick Harris

Chief Executive, National Highways

27 November 2023