County council working to secure funding for Kennington rail bridge replacement

Oxfordshire County Council is working to secure central government funding to help replace the ageing Kennington rail bridge.

Around 50,000 vehicles a day use the bridge, which is a vital part of the southern bypass and connects key sites across the city.

Alongside the rail bridge replacement, the Kennington improvements project will also provide a shared path for walking and cycling, a new eastbound bus and park and ride lane and improved flood protection for homes, businesses and crucial transport links.

The county council has written to the Chancellor and the Secretary of State for Transport to highlight the importance of the bridge improvements and indicate the need for financial support from the Department for Transport’s new structures fund to close a £71 million funding gap. The remaining cost of the project is being met by the county council and Environment Agency.

The estimated full cost of the project, currently £180 million, has increased since work on detailed design began. Engineering challenges identified during this work, as well as inflation in the cost of construction materials, have contributed to the rise in projected cost.

Councillor Judy Roberts, Cabinet Member for Place, Environment and Climate Action, said: “This project is essential for the future of our local road network, and it also works with the Environment Agency’s Oxford flood alleviation scheme, providing more capacity for flood water and protecting homes, businesses and crucial transport links.

“We have maintained the rail bridge since it was passed to us from central government, but the structure now needs to be replaced. We cannot meet the full cost on our own and we have therefore started work to secure national support to make sure this vital part of the Oxfordshire road network is replaced.”

In October 2024, the county council received planning permission for the improvements. Detailed design work, construction methodologies and all necessary surveys are now nearly complete.

The project involves replacing the bridge one side at a time, to retain access, under traffic management, throughout the construction period.

A water main and fibre optic connections need to be diverted away from the rail bridge and overhead electricity cables need to be considered during work. The site also includes a busy passenger and freight railway line which means that access needs to be planned carefully in advance.

The increase in cost is due to several factors with the main areas being:

• Inflation driving up the cost of materials, labour and specialist construction services.
• The need for complex temporary work to ensure the existing structure remains stable during reconstruction and the road remains open to traffic.
• Utility diversions including a complex two-stage Thames Water pipe diversion.

The county council is now preparing its case for funding ready for when more detail on the Department for Transport’s Structures Fund is provided. The fund was announced by the Chancellor in June to support the renewal of transport infrastructure across the UK.

ENDS

Notes to editors:

Oxford Flood Alleviation Scheme

The A423 Kennington improvements are closely linked to the Oxford Flood Alleviation Scheme (OFAS), a major flood defence project led by the Environment Agency which will create a new stream with a wetland wildlife corridor to reduce flood risk in the city and surrounding areas.

The scheme will pass beneath the new Kennington rail bridge, and the new bridge design allows flood water to flow back into the Thames. The scheme will also significantly reduce the flood risk on the Botley and Abingdon Roads as well as the main railway line that will keep Oxford open for business.

Oxfordshire County Council is a key delivery partner, and the scheme is funding the flood alleviation elements of the Kennington project. 

Kennington improvements

Kennington rail bridge is part of the A423 Southern Bypass. The bridge was built in 1965 and needs to be replaced due to age-related deterioration and the need for an eastbound bus lane.

• The structure was passed to Oxfordshire County Council as part of a de-trunking order made by the Secretary of State in 2003. Subsequent inspections carried out by the county council identified corrosion and over-rotation of the bearings. Replacing the corroded bearings is not possible due to the construction form of the bridge.
• The bridge lies above the same rail section affected by the 2023 Nuneham viaduct closure, which disrupted national freight and passenger services.
• The bridge has been propped at its piers since 2016 to increase its weight bearing capacity and is regularly surveyed and monitored, with the last inspection taking place in August 2025.
• The A423 Kennington improvement programme includes:

o   the replacement of Kennington rail bridge

o   improved facilities for cycling and walking

o   a new eastbound bus lane – also for use by vehicles travelling to Redbridge park and ride

o   increased capacity of the Hinksey streams for flood alleviation

o   maintenance work on the Kennington road bridge.

• Funding for the A423 Kennington improvements comes from multiple sources, including Oxfordshire County Council, the Oxfordshire Local Enterprise Partnership, the Department for Transport, and the Environment Agency (through OFAS).
• The £1 billion Department for Transport Structures Fund was announced on Monday 16 June 2025 is part of a national initiative to repair transport infrastructure and road network in the UK.

For more information about this release, please contact Oxfordshire County Council’s press team at press.office@oxfordshire.gov.uk

Sign up to hear from us and receive the latest news and updates in our fortnightly newsletter, Your Oxfordshire.