Police are appealing for witnesses after a silver Citroen Saxo collided with a tree on Amesbury Road Weyhill near to the junction of Wire Mead Lane between 3.45am and 4.40am on Saturday, April 2.
The female driver of the Saxo, a 17-year-old girl from Oxfordshire, is currently being treated in hospital suffering from life-threatening injuries.
Acting Police Sergeant Steve Antrobus from the Western Roads Policing Unit said: “I am appealing for any witnesses who may have seen this collision.
"We believe there are no other vehicles involved however we would like to hear from anybody that may have seen a Saxo driving in or around that area at that time. You may be able to assist us with our investigation. Please call 101 and quote 44160125806.”