Traffic officers have closed the M5 in Somerset between J22 in Edithmead and J23 in Dunball, as well as in Devon, between J28 (Cullompton) and J29 (Exeter), after two accidents.
In Devon, the road was closed initially at around 7am today in order for the emergency services to assist and clear the accident.
Traffic was released briefly but was stopped again after 7.30am.
Then, in Somerset, traffic was stopped at around 7.20am for only a few minutes, although resulting in three miles of congestion.
More chaos was erupted just before 8am, when two of the four lanes were closed on the M5 northbound in Somerset between J20 (Clevedon) and J19 (Portishead).
The closure was due to a broken-down vehicle.
National Highways said that recovery is ongoing at the scene.
The service said that there is a 45 minute delay on approach with 6 miles of congestion, and urged motorists to allow extra journey time.
The accident was cleared a few minutes after 8am.
However, delays of over an hour continue as congestion reached 7 miles.
In an update, National Highways said: “This broken down vehicle has now been recovered, and all lanes have re-opened on the #M5 northbound in #Somerset between J20 (#Clevedon) and J19 (#Portishead).
“Delays of over an hour remain in the area, with 7 miles of congestion.
“Allow plenty of extra journey time this morning.”