One person was killed and another ten injured in a horror crash on the M5.
The smash came as tens of thousands of cars hit the roads ahead of February half-term.
"Several vehicles" were involved in the pile-up near Taunton shortly before 6.20am on Friday, Avon and Somerset police said.
Authorities closed the the motorway between junctions 25 and 26 following the crash.
Both carriageways expected to be blocked for a "significant amount of time," police said.
One person died and ten more were injured, according to the South Western Ambulance Service which dispatched 15 paramedic crews.
Two air ambulances and several rapid response vehicles rushed to the scene.
SERIOUS RTC M5: We are currently at the scene of a serious RTC on the M5 near Wellington. We have attended with 15 resources including ambulances, rapid response vehicles, and two air ambulances. Road is likely to be closed for some time, please avoid the area. pic.twitter.com/mnMODclDXi— swasFT (@swasFT) February 9, 2018
A force spokesman said: "We expect the motorway to be closed for a significant amount of time so would urge motorists to avoid the area and make sure they follow diversions put in place by Highways England.
"If your journey isn't necessary, please consider delaying it until later in the day."
Miles of tailbacks were reported by stranded drivers.
One man wrote on Twitter: "M5 isn't moving this morning. Been stuck in traffic for well over an hour and no end in sight.
"Despite that, thoughts are with the person who passed away in the crash."
M5 isn't moving this morning. Been stuck in traffic for well over an hour and no end in sight. Despite that, thoughts are with the person who passed away in the crash. #somerset pic.twitter.com/yK93iMcvAc— Jim Devlin (@devlinjim) February 9, 2018
Buses to Bristol were hit by long delays as Megabus apologised to customers.
The coach firm tweeted to a customer travelling to Bristol: "Unfortunately, due to a fatal crash the M5 has been closed. This has forced the driver to detour which has caused further delays due to the volume of traffic following the same diversion.
"I do not have an ETA at the moment."
Hi, I'm very sorry for the delay. Unfortunately, due to a fatal crash the M5 has been closed. This has forced the driver to detour which has caused further delays due to the volume of traffic following the same diversion. I do not have an ETA at the moment. ^Nicola— megabusUK (@megabusuk) February 9, 2018
The news came as tens of thousands were set to take to the roads for half-term breaks as schools across the country closed for a week.
Motorists were warned of delays on the A26 at Lewes in East Sussex as well as closures on the A6 in Loughborough.
Lane two was closed on Friday morning on the A27 between Tangmere and Fontwell eastbound carriageway in Sussex as warned drivers to "expect delays".