M4 diversion route after motorway closed in Wiltshire
The motorway was shut by traffic officers between junction 18 at Bath and junction 17 at Chippenham after the large vehicle caught alight, at around 2.15pm on Saturday, July 20. At the time of writing, the carriageway remains closed westbound heading from Chippenham to Bath with police and fire crews at the scene. The eastbound carriageway was reopened shortly after 3.30pm but there remains long delays.
The AA has reported that smoke has been seen blowing across both carriageways while emergency services work to deal with the situation. In the meantime, National Highways has issued diversion routes for motorists travelling in both directions. There remains severe congestion at both junctions as three lanes of traffic try to exit the motorway at once, and people are warned to reroute or delay their journeys to avoid delays.
“Further information is available from National Highways by visiting our website and travel apps, or via our regional X feed.
“Our 24/7 contact centre team is also available to provide up to the minute information on 0300 123 5000.”
The diversion route for those heading westbound from Chippenham can be found below and drivers should follow the solid diamond diversion symbols.
- Exit the M4 westbound at junction 17 and join the A350 southbound
- Continue until Bumpers Farm Roundabout with the A420
- Turn right and join the A420 Bristol Road westbound
- Continue on the A420 until the roundabout with the A46 near Cold Ashton
- Turn right and join the A46 northbound
- Continue northbound to then re-join the M4 westbound at junction 18
Meanwhile, the diversion for those heading eastbound from junction 18 is as follows, and drivers should follow the solid square diversion symbols.
- Exit the M4 eastbound at junction 18.
- At the roundabout, take the 3rd exit and join the A46 towards Bath.
- At the A46/A420 roundabout, take the 1st exit and join the A420 towards Chippenham.
- At the A420/A350 roundabout, take the 1st exit and join the A350 towards the M4.
- At the A350/M4 roundabout, take the 3rd exit and rejoin the M4 at junction 17.