A woman is fighting for her life in hospital after a car fell onto the central reservation of the A1 from a flyover.
A red Vauxhall Astra containing two occupants lost control on the A177 flyover at the Bowburn Interchange.
The vehicle went through a safety barrier and landed on its roof in the central reservation of the A1(M) below.
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A woman in her mid-40s suffered serious injuries, following the incident at around 10.30am on Friday morning.
She was airlifted to hospital where she remains in a critical condition fighting for her life.
A man in his early 30s was arrested at the scene on suspicion of causing serious injury by dangerous driving and remains in custody.
Durham Constabulary said no-one else was injured during the incident.
The force is urging witnesses or anything with information about the collision to contact them on 101, quoting incident number 105 of January 21.
Detective Constable Natalie Horner, of Durham Constabulary’s Collision Investigation Unit, said: "We would like to appeal for anyone who witnessed this incident, particularly anyone who has dashcam footage of the crash or the moments leading up to it, to get in touch with us as soon as possible.
"We would also urge anyone who saw this vehicle being driven between 9am and 10.30am today, especially in the Sherburn Village area, to contact us."
Both the A1(M) and the A177 were closed in both directions while emergency services attended the scene.
They are likely to remain closed until Saturday, while repairs are carried out to the safety barriers and investigations continue.
Drivers are urged to avoid the area and find an alternative route if possible.
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