Three M5 northbound lanes between junction 14 and junction 16 have now been re-opened.
Highway authorities are now appealing for drivers who left their vehicles to return to them in order to get the traffic flowing again.
The lanes were closed following an earlier accident involving a pedestrian getting hit by several vehicles on the M5.
Police believe the pedestrian was hit by a lorry and other vehicles at around 4.40am, after leaving his car parked on a hard shoulder.
Major delays have been reported on the M5 in south Gloucestershire, following the closure of two northbound lanes.
A pedestrian has died after being hit by a car on the M5 northbound. Closures said to remain in place for several hours.