Police have launched an investigation after a woman died in a head-on collision at Balladoran, north of Dubbo, yesterday afternoon.

About 4.30pm (Tuesday 2 June 2015), a Holden Commodore and Hino truck collided head-on while travelling along Milpulling Road, about 1.5km west of the Newell Highway intersection.

The vehicle became trapped underneath the truck, which had overturned as a result of the collision.

The Commodore driver and sole occupant, a 28-year-old woman, was trapped in the wreckage before being extricated by SES personnel.

She was airlifted to Westmead Hospital in a critical condition and rushed into emergency surgery. The woman later died in hospital.

The Hino driver and sole occupant, a 54-year-old man, was not injured during the incident.

He was taken to Gilgandra District Hospital for mandatory blood and urine tests.

Officers from Orana Local Area Command established a crime scene, which was examined by specialist crash investigators.

The roadway was blocked for a number of hours while emergency services conducted inquiries.

Investigations to determine the exact circumstances behind the crash are continuing and a report will be prepared for the information of the Coroner.