The Westpac Rescue Helicopter Service airlifted a woman to hospital with serious injuries after her van left the road and rolled in Morisset on Wednesday morning.
About 6.15am, emergency services were called to the M1 at Morisset following reports a Toyota Hi-Ace van had left the roadway and crashed.
Police were told the Toyota and a Kenworth B-double prime mover were both travelling north when the truck has attempted to change lanes.
It is understood that the Toyota attempted to take evasive action and has lost control causing the vehicle to leave the roadway and roll.
The Toyota driver, a 36-year-old woman, was trapped for a short time before being released by Fire and Rescue NSW.
She was treated at the scene by NSW Ambulance paramedics before being airlifted to John Hunter Hospital by the helicopter service where she underwent surgery for a fractured arm and head injuries.
Police said the truck driver, a 34-year-old man, was uninjured.
Lake Macquarie police attended the scene and commenced inquiries into the cause of the crash.
Police are urging anyone who may have dashcam footage of the incident to contact Crime Stoppers on1800 333 000 or nsw.crimestoppers.com.au.