Police are seeking witnesses to a serious collision in Bexhill.
The incident happened on the A259 King Offa Way carriageway, at approximately 4pm on Saturday (February 1).
A police spokesman said a 24-year-old man was driving east in a black Vauxhall Corsa when the vehicle left the road close to the bridge spanning Holliers Hill, struck a tree and rebounded into the road. No other vehicle was involved, police added.
The driver was taken to the Royal Sussex County Hospital, Brighton, with serious, potentially life-threatening injuries, police said.
The A259 was closed in both directions while the incident was dealt with. It was re-opened to traffic six hours later, at 10pm.
Anyone who saw what happened, or who may have dash-cam footage of the incident or the Vauxhall Corsa being driven shortly beforehand, is asked to contact email@example.com or phone 101, quoting Operation Dalewood.