The national Christmas/New Year road toll has risen to 22, with the deaths of another three people.

In Mudgee, in central western NSW, a man died after he was hit by a station wagon while he was standing next to his car.

The 50-year-old man suffered extensive injuries and died at the scene. His death took the NSW toll to seven.

The female driver of the Ford, aged in her 30s, was taken to hospital for mandatory blood tests.

The latest fatality follows five deaths in four separate accidents on NSW roads on Boxing Day.

In Adelaide, one person was killed in a two-car crash about 1.20pm (CDT) on Thursday at an intersection at Penfield Gardens.

A second person has been airlifted to the Royal Adelaide Hospital.

The death takes SA's road toll for the holiday period to three.

And in western Victoria, a driver was killed when his car veered into the path of an oncoming truck and burst into flames on a straight stretch of the Princes Highway at Warncoort, near Colac, just before 7am (AEDT).

The driver of the car died at the scene, while the truck driver received minor injuries.

* The national road toll period runs from 0001 December 23, 2012, until 2359 January 3, 2013, local times, in line with the Australia New Zealand Policing Advisory Board.