A 47-year-old man is in hospital with serious head injuries after the car he was driving left Falmer Road and overturned in a field in Woodingdean.
Police are seeking witnesses to the single-vehicle crash, which happened at around 9.30pm on Saturday.
The man’s blue Rover 25 left the road and overturned in a field, leaving the driver, from South Chailey, near Lewes, with serious head injuries.
He was taken by ambulance to the Royal Sussex County Hospital, Brighton. The road was closed while the incident was dealt with.
Anyone who saw what happened or noticed the Rover being driven shortly before it crashed is asked to phone Sussex Police on 101 or email collision.appeal@sussex.pnn.police.uk.