Emergency services say the M5 remains closed southbound between J19 and J20 following an collision this morning between two lorries.
Avon Fire and Rescue says three HGVs were involved in the incident and one of the drivers was rescued by crews using cutting and rescue equipment.
Police are advising motorists to avoid the area and find alternative routes for travelling home from work during the rush hour this afternoon, as the obstruction may not be completely cleared.
The incident happened at around 3am this morning.
Police say one of the lorries involved in the incident is carrying chemicals which must be removed before the obstruction can be cleared.
Officers say it is "difficult to say" when the clearing process will be completed.