Traffic officers are appealing for witnesses and anyone with information to come forward after a red Mercedes estate car mounted the verge on Bournemouth’s Wessex Way and collided with a tree.
The incident happened at around 3pm on Tuesday 15 October 2013.
The car, driven by a man from the Wareham area, apparently left the carriageway close to the Frizzell roundabout.
Police Sergeant Jon Wren, of Dorset Police’s Traffic Unit, said: “The man was treated for his injuries at the scene and was taken to hospital, where his condition is described as serious.
“We are investigating the circumstances of the collision and would like to hear from anyone that witnessed the incident or the vehicle immediately prior to it.
“Anyone with information should contact Dorset Police as soon as possible.”
Witnesses and anyone with information should call Dorset Police in confidence on 101, quoting crime numbers 15:277. Alternatively, call the free and anonymous Crimestoppers line on 0800 555 111 where mobile phone tariffs may apply.