A 72-year-old woman has died after her van and a truck collided south of Gunning on Thursday morning.
NSW Police said a white Hiace van was travelling south on the Hume Highway when it and a heavy vehicle travelling in the same direction collided about 9am.
Fairfax Media understands the woman was driving behind the truck when her van clipped the truck, and rolled.
"The female driver of the van died. No further details are known at this time," police said in a statement.
She was the only person in the car.
As of 12.20pm, there was still a lane closed in each direction on the highway.
There have now been 21 people killed on NSW roads since the start of Operation Safe Arrival on December 16.
This includes three people who were killed during a two-vehicle crash on the Princes Highway south of Sussex Inlet on Tuesday. Another three died on Boxing Day; a 25-year-old woman was killed when her car hit a tree near Taree, a 43-year-old man died when his Ford Falcon ran into a parked semi-trailer at Emu Plains and a 23-year-old Dubbo woman suffered horrific head injuries when she fell from a moving four-wheel drive at Peak Hill.
The deaths, almost triple the number for the same period last Christmas, have senior police flabbergasted.
"This Christmas-New Year period is meant to be a time of happiness, to spend time with family. And sadly, for many, this has resulted in tragedy," Chief Inspector Phil Brooks, of the NSW Police traffic and highway patrol command said earlier this week.
Police are urging anyone with information to call Crime Stoppers on 1800 333 000 or use the Crime Stoppers reporting page at https://nsw.crimestoppers.com.au/