M4 major traffic delays caused by M5 crash closure
The incident took place on the M5 just after 3pm, between junction 15 which links to the M4 and junction 14 at Thornbury, and involved a lorry which collided with two other vehicles.
It is believed the lorry was travelling southbound and crossed over the central reservation before crashing into two vehicles on the northbound carriageway.
Traffic was initially blocked in both directions and the northbound carriageway is expected to be closed for some time during a police investigation.
Vehicle recovery and barrier repairs will also be carried out if necessary.
The closure is causing serious delays on the M4, as well as the M5, with traffic queued back from Bristol towards junction 18 at Bath.
Anyone travelling westbound on the M4 from Wiltshire should expect long delays of up to 30 minutes if they are heading past Bath.
Drivers heading northbound on the M5 from the M4 are being diverted to junction 14.
National Highways has urged drivers using the motorways in the area to plan ahead and allow extra time for their journey.
Alternative routes should be considered where possible.