A truck driver is in police custody after a crash on the Hume Motorway near Drapers Road just after midday.
Two people in their late 60s were injured when a semi-trailer collided with their southbound hatchback, forcing it into a station wagon.
A 69-year-old female passenger in the hatchback sustained multiple injuries and was airlifted to Liverpool Hospital.
The male driver, 69, was taken by road to Liverpool Hospital to be treated for cuts and for mandatory testing.
The truck driver was taken to Bowral Hospital for mandatory testing before being transferred into custody at Southern Highlands Police Station.
The driver of the station wagon also underwent mandatory testing – neither him nor his passenger were injured.
The Hume Motorway remains closed at time of publication, more than four hours after the southbound crash.
Crash investigators remain onsite, with diversions through Mittagong via the Old Hume Highway.