M4: Update on planned £31m motorway junction improvements

Wiltshire Council has confirmed the awarding of the contract to begin work on the proposed M4 junction 17 improvement scheme to MJ Church following a procurement process. If approved, the scheme will add traffic signals to all approaches to the roundabout, widening the carriageway on the M4 slip roads, expanding the motorway bridge from two to three lanes and removing or reconfiguring nearby laybys. Construction is expected to start in spring next year and take around a year to finish.

It is estimated to cost approximately GBP31 million, with 85 per cent funded by the Department for Transport and 15 per cent funded by Wiltshire Council. The council said that with the A350 increasingly acting as a strategic north-south route between the Midlands and the south coast, improvements to the junction are needed to accommodate planned development within Wiltshire and wider regional traffic demand. It secured Outline Business Case approval for the project from the Department for Transport in spring 2024.

It has since been developing a Full Business Case, and this is scheduled for submission in the autumn. MJ Church has been appointed at the early contractor involvement stage of the scheme. It will help ensure the project is deliverable, cost-effective and ready for consideration by DfT.

MJ Church will also advise on the construction programme and how to maximise potential cost efficiencies before preparing accurate construction cost estimates. This work will provide greater certainty about how the project will be delivered. The information will be used to complete the Full Business Case for DfT, which will then decide whether to fully fund the scheme.

If the Full Business Case is approved by DfT, and subject to a construction cost being agreed, the council will look to enter the construction phase of the contract with MJ Church. MJ Church works across the contracting and waste sectors in England. It is headquartered near Marshfield in South Gloucestershire.

In March, Wiltshire Council said its cabinet had approved the appointment of a specialist contractor to begin the ECI stage of the M4 junction 17 improvement scheme. Martin Smith, cabinet member for highways at Wiltshire Council, said: "We're pleased to be working with local company MJ Church on this project following a robust procurement process. "The M4 junction 17 is a critical gateway into our county, and these improvements will help ensure it can support the growth and economic activity we expect across Wiltshire.

"Appointing a contractor at this stage gives us the expert advice we need to strengthen our business case ahead of moving into construction if funding is confirmed by DfT."

Claire Coetzee, civil engineering director at MJ Church, said: "We are delighted to have the opportunity with Wiltshire Council to build upon the success and lessons learnt from the A350 scheme."