FAQs
- a Thames Water main running along the centre of the A423 that needs to be diverted
- other utilities along the route which will also need relocation
- overhead high voltage cables located over the rail bridge which might impact construction.
Why is this work needed?
Firstly, we need to replace the Kennington railway bridge which is in poor condition.
This presents the opportunity to replace the bridge with a wider structure and allocate road space to buses, cyclists and pedestrians between Hinksey Hill and Redbridge Park & Ride.
This programme will also assist the local area with better flooding protection. The new rail bridge will allow increased flood flow through the Hinksey streams, running under the side spans of the current rail bridge. This will enable part of the Environment Agency’s (EA) Oxford Flood Alleviation Scheme (OFAS) to take place. Visit https://consult.environment-agency.gov.uk/thames/oxfordscheme/ for more details.
What is OFAS and how is it linked to the improvements on the A423?
OFAS is a project owned by the EA. It has been designed to create a new stream with a wetland wildlife corridor to the west of Oxford to reduce flood risk from the River Thames in the city and surrounding areas.
Oxfordshire County Council are working in partnership with the EA as part of the OFAS. The work on Kennington Rail bridge is an integral part of the OFAS as the capacity of the streams underneath the new rail bridge will be increased, creating more space for floodwater, away from built-up areas.
How are the works being funded?
The scheme is being financed through multiple sources including the county council, Oxfordshire Local Enterprise Partnership (OxLEP) and OFAS.
When will the planning application be submitted?
The planning application for the A423 Kennington improvements programme was submitted in February 2023 and we expect a decision (known as determination) in the summer.
Where can I see any drawings, maps or plans?
Drawing, maps and plans are available to view at the events we are holding on 13 and 14 September and on this page.
How long will construction take?
We estimate it will take three years, starting in autumn 2023.
Will traffic in the area be impacted for the full duration of construction?
We will maintain two lanes of traffic in each direction of the A423 for as much of the work as possible. Also, some work will be undertaken underneath the rail bridge so traffic flow will be unaffected during that stage.
Temporary widening and contraflow traffic management will also be in place at time. More details will be available closer to construction.
This will minimise disruption to the A34 and Oxford ring road, by maintaining at least two eastbound traffic lanes and at least one westbound traffic lane across the rail bridge for the duration of the works.
In order to maintain road safety, we are likely to need to close the westbound off-slip road from the A423 to Kennington Road. Diversion will be via A4144 Abingdon Road and Old Abingdon Road.
Will the road be completely closed at any point?
Short night closures of the A423 may be required at certain stages of the work, but most of the work will be undertaken by rebuilding half of the rail bridge at a time so that traffic can flow over the remaining half.
Further information relating to traffic management phasing will be available before construction starts.
How is OCC considering the environmental impact of the planned improvements and will any trees be removed?
Oxfordshire County Council is undertaking an Environment Impact Assessment as part of the planning submission. This will assess the likely impact on important environmental features (e.g. ecology, landscape and water) and will suggest measures to be put in place to minimise these impacts during both the construction phase and operational phase.
Some trees will need to be removed to allow for the widening of the highway, to accommodate the new bus lane. Tree loss will be kept to a minimum and compensatory planting will be proposed to replace the loss.
Recycled and low carbon materials will be specified in the design where possible and we will try to leave the natural environment in a better condition than it was beforehand.
How were the designs determined and which design standards have been followed?
The new rail bridge and retaining walls will be designed in accordance with the latest European and UK standards.
The type of structure was determined as the most effective solution for the required span (width). The length of the new rail bridge was fixed to span over the existing railway tracks.
The scheme is based upon the requirements set by Oxfordshire County Council and has been refined into a workable design using key industry standards, government guidance and local authority recommendations.
What is the width of the proposed shared cycle and footpath?
The existing eastbound footway between the Hinskey Hill Interchange and Old Abingdon Road will be upgraded to a three-metre-wide shared footway / cycleway.
The existing westbound shared footway / cycleway between Kennington Road and Kennington roundabout will be three metres wide.
Have the requirements of disabled users been considered in the design proposals?
Where possible the design has taken into consideration requirements for visually impaired and reduced mobility individuals, ensuring movement corridors are safe and welcoming for all.
Will there be changes to speed limits during and after construction?
Permanent speed limit reductions are expected to be applied to the A423 and Old Abingdon Road. These changes will need to be consulted upon under the Traffic Regulation Orders (TRO) process.
The speed limit on the A423 will be reduced to 50mph.
During construction it is expected that the speed limit will be reduced to 30mph to ensure the safety of the workforce and the travelling public. Again, these changes will need to be consulted upon under the Temporary Traffic Regulation Orders process (TTRO).
Are there any constraints which may affect the programme and cause a delay?
The improvement programme is complex, and several utility and communications cables span the rail bridge and the A423. These include:
We are looking to minimise disruption to road and rail users. The railway line underneath the rail bridge must also remain open throughout.
Therefore, we need to work closely with a number of partners to stay aware of these constraints which might impact the programme and cause delay.
How will the feedback I submit today be considered?
The feedback we receive from you will inform how we communicate with you about the improvement programme and help us to consider how we can minimise the impact of construction on residents and businesses.
How can I keep up to date with the programme’s progress?
You can sign up to receive regular news and alerts from Oxfordshire County Council by visiting the A423 Kennington improvements web page - https://www.oxfordshire.gov.uk/kennington
How can I ask a question or make a complaint/comment?
You can email the programme team on a423kenningtonimprovements@oxfordshire.gov.uk