One person was left dead and another was treated by paramedics after a truck and car collided on the Monaro Highway.
The driver and sole occupant of the car died, and the driver of a semi-trailer was treated at the scene after the crash, which happened about 9.30am near the Royalla solar farm.
Police, who described the scene as "quite complex", closed the highway in both directions between Johnson Drive and Old Cooma Road because of the incident until Tuesday afternoon.
ACT Policing detective acting station sergeant Marcus Boorman said officers who attended the crash had faced a "confronting scene".
"As you can imagine, it is fairly traumatic for everyone involved. Any collision where a very large vehicle is involved is very confronting," he said.
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Detective sergeant Boorman said the crash investigation team was "processing the scene", but early investigations indicated the truck and car had been travelling in opposite directions when they collided.
"The scene is quite complex and the investigation will take some time," he said.
"Police have spoken to the driver of the truck and we are looking after that person's welfare."
Large skid marks from the truck could be seen across a long section of the highway.
Detective sergeant Boorman pleaded with drivers to pay attention, slow down and be careful on the road.
"This is the fourth tragedy on our roads this year. We plead to people to be careful out there and drive in accordance with the road laws," he said.
"Any serious collision where there is trauma and where there involves fatalities is very confronting. We ensure we look after our members' welfare and the appropriate support networks are put around them. There are things you don't really want to see, but unfortunately it's a job we have to do."
