The 58-year-old male truck driver was in the same hospital in a serious but stable condition with severe leg injuries.

The vehicles crashed at Kenny under the Federal Highway Overpass about 11.15am, with scaffolding, from the back of the truck, spilling across the road.

ACT Fire and Rescue commander Leigh Curtis said it was fairly easy to move the car driver, aged in his 20s, from the car, but it was ''extremely difficult'' to rescue the truck driver, as the vehicle had slammed into the wall of the bridge and the cab crushed as some of the scaffolding slipped forward.

The driver was pinned by his legs, and a heavy duty tow truck had to be called in.There were 12 ACT Fire and Rescue crew members involved in rescuing the two men and they worked for more than an hour to free the truck driver using the hydraulic rescue tools.

The truck driver was conscious and able to talk to ambulance officers as they drove him to hospital, Commander Curtis said. ''We don't normally like to move the vehicle while people are still in them, but this time it was imperative,'' he said.

ACT Policing Acting Superintendent Rod Anderson said the truck driver was travelling along Majura Road entering Horse Park Drive when the car allegedly crossed into its path, but he said investigation of the accident was continuing.

It took police more than six hours to clear the road and ensure it was safe.

Westbound traffic was diverted from Majura Road to Federal Highway via the up-ramp.

Superintendent Anderson took the opportunity to remind Canberrans to drive safely this holiday season.

''It certainly is a timely reminder to be very careful and be aware of the road conditions and the traffic control conditions, particularly if you're not familiar with the area,'' he said.

''Those Canberrans travelling out of the capital and interstate, please be careful and take care with your driving.''

Eleven people have died on ACT roads this year.