M4 junction upgrade plans move to the next stage

It is hoped the upgrades will increase capacity at junction 17 of the M4

Plans for an upgrade to a busy motorway junction have been approved and are moving to the next stage.

An outline business case (OBC), setting out the full costs and benefits of improving junction 17 of the M4 near Chippenham as part of the Major Road Network (MRN) project, has been approved by the Department for Transport (DfT).

It means the council can now develop a full business case (FBC), which includes the design of the project.

Councillor Nick Holder, Cabinet Member for Highways, said the scheme will "increase the capacity" for motorists, ensuring "it is fit to serve the county for many years to come".

Vital link

The council said the DfT has indicated that once the FBC is confirmed, it will allocate around £26.087m for the completed scheme, against the total cost of £31.937m.

The shortfall will be provided by the council.

The junction, which is a vital link between the motorway network and the A350, connecting Chippenham, Melksham and Trowbridge, has already seen improvement works in recent times thanks to the Chippenham Gateway project.

The FBC for the MRN scheme is expected to be submitted to the DfT by summer 2026, in hope of starting the work by winter 2026.

If all goes to plan, the work should be completed by the end of 2027.