Police are investigating a serious crash near Moss Vale.
About 2.50pm today, a Holden Barina collided with a truck on the Illawarra Highway, Moss Vale.
The female driver and sole occupant of the Barina, a woman aged in her 20s, has been airlifted to Liverpool Hospital in a serious condition.
The male driver of the truck has been taken to Bowral Hospital for a mandatory blood and urine test. He is uninjured.
The Illawarra Highway remains closed in both directions, NSW Police say.
Police from the Lake Illawarra Crash Investigation Unit will conduct inquiries into the incident.
Police are urging anyone with information in relation to this incident to call Crime Stopers.