A woman died after her car collided with four vehicles in the early hours of Saturday as she drove down the wrong side of the M5 motorway.
The victim, aged in her late 20s or early 30s, was driving a small blue Ford Ka hatchback when the accident occurred near Portishead in Somerset.
She hit two cars in separate collisions as she drove north up the southbound carriageway from Weston-super-Mare towards Clevedon at 12.30am, police said.
When the car came to a standstill, it was hit by two further vehicles, police said.
"At around 12.30am a blue Ford Ka started driving in the wrong direction on the southbound carriageway from Weston-super-Mare towards Clevedon," said a spokesman for An Avon and Somerset Police spokesman.
"It was involved in separate collisions with two vehicles and was left stationary when it was hit by two more vehicles.
"Unfortunately the driver of the Ford Ka, a woman in her late twenties or early thirties, died at the scene.
"The road was closed while the emergency services dealt with the incident and to allow us to start our investigation into the circumstances of the collision. It was open again by 7.30am.
"A family liaison officer has been appointed to support the family of the woman who died."
The road, a key tourist route in the West Country, was closed for around seven hours while the emergency services dealt with the incident and police investigated the crash.
The motorway was closed between junction 19 for Portishead and junction 21 at Weston-super-Mare while emergency services were at the scene. It was reopened around 7.30am.
Police are appealing for anyone who witnessed the crash, or anyone who saw the Ford Ka being driven in the area prior to the incident, to call the accident investigation unit on 101.