Police are investigating a serious crash just outside of Dalby this morning.
Around 10.15am, a car crossed onto the wrong side of the Warrego Highway about ten kilometres west of the town.
The car collided head on with a prime mover, and a vehicle that was following the prime mover then also collided with the car.
The driver of the car, a woman in her 50s, suffered critical injuries and was airlifted to hospital.
The driver of the truck suffered minor injuries.
The driver and passenger of the third vehicle were trapped for a short time, but after being freed were transported to Dalby Hospital.
Traffic has been diverted along the Old Warrego Highway as the Forensic Crash Unit investigates.