M4 diversion route as motorway closure causes traffic

The M4 was shut in both directions between junction 18 near Bath and junction 19 at Bristol shortly before 2pm on Tuesday, March 26. While the motorway was reopened heading eastbound at around 4pm, the westbound carriageway remains closed while police work at the scene. This has caused significant traffic issues for road users in Wiltshire, with queues backed up towards Leigh Delamere as motorists are diverted away from the crash.

There has also been slow traffic at junction 17 as drivers attempt to turn off the carriageway at Chippenham. National Highways has warned that delays are likely and urged drivers to follow the signed diversion route which has been set up. This can be found in full below.

  • Exit the M4 at junction 18 onto the A46 headed southbound and continue for approximately 3.5 miles.
  • At the A420/A46 junction, take the A420 headed westbound and continue for approximately 5 miles.
  • At the A4174/A420 junction, take the A4174 headed northbound and continue for approximately 5.5 miles to the M32 junction 1 roundabout.
  • Take the M32 northbound and re-join the M4 at junction 19.

    The northbound diversion is in reverse.