Central West Police District Chief Inspector Dave Harvey said both vehicles appeared to be travelling east on an overtaking lane near the intersection of Wells Road at Shadforth at 5.45pm.

Chief Inspector Harvey said the woman, who was from Bathurst, was driving a Hyundai in the left lane and a 44-year-old man from Eglinton was driving the prime mover on the inside lane.

"As the vehicles approached the end of lane one, at the end of the overtaking lanes, the Hyundai has indicted to merge into lane two," Chief Inspector Harvey said.

He said the two cars crashed and the Hyundai was slung across the west-bound lane and came to a halt in a ditch on the southern side of the road.

Chief Inspector Harvey said there was major damage to the Hyundai and minor damage to the prime mover.

"The driver of the Hyundai was conveyed to Orange hospital with a back injury," he said.

The woman remained in hospital on Thursday morning where she was reported to be in a stable condition.

Police, ambulance, State Emergency Service Volunteers and fire fighters attended the scene along with Orange City Council employees who closed one of the west-bound lanes of the road.

Police also conducted an investigation and breath tested the truck driver at the scene with nothing detected.

They also spoke to a witness at the scene and dash cam footage was available.

"Police attended Orange Health Service and spoke to the driver of the Hyundai," Chief Inspector Harvey said.

"The incident remains under investigation at this point.

"No one has been given an infringement notice but that should come in the near future."