A 17-year-old girl who died after fleeing a police vehicle and being struck by a car on a motorway was under arrest at the time, an inquest heard.
Tamzin Hall, was being taken to a custody suite in Bridgwater by two officers in an Avon and Somerset Police car from an address in Taunton, Somerset.
The vehicle stopped on the northbound carriageway between junctions 25 at Taunton and 24 at Bridgwater shortly after 23:00 GMT on 11 November.
Samantha Marsh, senior coroner for Somerset, said background information considered as part of the inquiry would include “Tamzin’s presentation, with regard to any potential mental health history”.
An inquest opening at Wells Town Hall heard Tamzin, who was a student, got out of the car and crossed the road before climbing the crash barrier.
She was hit by a vehicle driven by a member of the public travelling on the southbound carriageway and sustained fatal head, neck and chest injuries.
Coroner’s officer Ben Batley told the hearing: “Tamzin was a passenger under arrest in a police vehicle travelling on the northbound carriageway on the M5 when it stopped for reasons yet to be established.”
Mr Batley described how Tamzin then got out of the car before going across the northbound lane, climbing the barrier and making her way on to the southbound lane where she was struck.
“Her injuries were not survivable and Tamzin was declared deceased where she was found on the motorway,” he said.
“Police and the Independent Office for Police Conduct (IOPC) inquiries are ongoing as to the circumstances of the collision and how Tamzin came to be where she was found.”
The inquest heard Tamzin, who lived in Henlade, Somerset, was pronounced dead at 23:10 GMT and identified by fingerprint comparison.
Mr Batley said a post-mortem examination gave a provisional cause of death as head, neck and chest injuries pending further investigations.
Mrs Marsh said: “On the basis of the information provided to me, I believe I should open an inquest into the death of Tamzin Ellen Hall.”
She adjourned the case until a pre-inquest review hearing on 5 November next year, which Mrs Marsh said was the earliest available date due to the complexity of the case.
Tamzin’s family, Avon and Somerset Police, the IOPC and the driver of the vehicle which collided with Tamzin were recognised as interested people in the inquest.
The circumstances of Tamzin’s arrest and her transportation, as well as how she left the police car and what happened afterwards will also be examined.