• Swindon & Wiltshire Economy
• Tuesday April 14 2026

Civil engineering firm MJ Church lands multi-million pound M4 contract

Wiltshire-based engineering firm MJ Church has been awarded a multi-million pound contract to improve Junction 17 of the M4 by Wiltshire Council.

If approved by the Department for Transport, the £31 million scheme will see the slip roads at J17 – the Chippenham exit – widened, and the motorway bridge expanded from two to three lanes.

Each approach to the roundabout will be controlled by traffic lights to improve traffic flow, and nearby laybys will be removed or reconfigured.

M4 J17 provides an essential link between the M4 and the A350 corridor, supporting travel to key Wiltshire towns including Chippenham, Melksham, Trowbridge and Westbury.

With the A350 increasingly acting as a strategic north-south route between the Midlands and the south coast, enhancements to the junction are needed to accommodate both planned development within Wiltshire and wider regional traffic demand, says Wiltshire Council.

Eighty-five per cent of the project costs will be funded by the Department for Transport, with 15 per cent coming from Wiltshire Council.

The council is now drawing up a full business case to put to the Department for Transport this autumn.

MJ Church will help to 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.

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.

Cllr Martin Smith, Cabinet Member for Highways, said: “We’re pleased to be working with local company MJ Church on this project, following a robust procurement process.

“The M4 J17 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.”

Image by Andrew Hackney reproduced under Creative Commons licence