The M5 was closed for for 10 hours and counting after a vehicle flipped over in a police chase.
The road ground to a halt after the smash shortly after 10pm between J21 (Weston-super-Mare) and J19 (Portishead).
Traffic was halted after emergency services closed all four lanes, Bristol Live reported.
The crash happened after police attempted to stop a car linked to a man wanted by a different force.
A police officer was injured in the crash and has been sent to hospital with injuries not thought to be life-threatening.
The motorway was re-opened at about 8am.
The main carriageway had been closed on the northbound side, along with sliproads leading on and off the busy route.
In a bid to clear the thousands of vehicles stuck on the road, a diversion route was put in place which directed traffic along A roads.
Avon and Somerset Police said: "Officers have arrested a driver on suspicion of dangerous driving after a collision on the M5 northbound near junction 21.
"It happened just before 9.40pm on Monday 5 August as officers in marked police vehicles attempted to stop a car linked to a man wanted by another police force.
"Fire and ambulance crews attended. A police officer went to hospital with injuries not believed to be life-threatening."
A 27-year-old man also received injuries not believed life-threatening and was arrested.
The crash involved two cars.
Anyone who witnessed the collision, or who has any information about the manner of driving of a black Ford Focus in the moments beforehand can get in touch through www.avonandsomerset.police.uk/contact using reference number 5219179902.
