ACT Policing is calling for witnesses and dash-cam footage after a fatal crash on Uriarra Road in the Molonglo Valley on Tuesday morning.
A 40-year-old man died when his white ute left the road and hit a tree shortly before 7.40am.
Ambulance crews attempted to resuscitate the man but he died at the scene.
The silver twin cab Holden Rodeo was travelling towards Canberra at the time of the crash.
Uriarra Road was closed between Uriarra Village and Denman Prospect for several hours, and re-opened about noon.
Police urge anyone who drove between Uriarra Crossing and Denman Prospect from 7.15am to 8am on Tuesday to come forward if they have information or footage that could aid the investigation.
Anyone with information should contact Crime Stoppers on 1800 333 000, or via the website and quote reference 6636573.