Emergency services were called at around 10.35am yesterday, Friday, January 21, at J61 Bowburn Interchange following a crash involving a red Vauxhall Astra.
The vehicle, which contained two occupants, had been driving on the A177 flyover but lost control, went through a safety barrier and landed on its roof in the central reservation of the A1(M) below.
A man was arrested at the scene on suspicion of causing serious injury by dangerous driving and remains in custody.
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”.
Anyone with information is asked to ring Durham Constabulary on 101, quoting incident number 105 of January 21.
Both the A1(M) and the A177 were closed in both directions for several hours while repairs were carried out to the safety barriers and investigations continued.
National Highways North East Tweeted shortly before 3am that the motorway had reopened.