Police said about 5.30am on Friday, the woman was travelling eastbound on the highway on her motorbike when she collided with a vehicle that was entering the westbound lanes from a nearby rest area.

The crash happened at Helidon, about 20 kilometres from Toowoomba.

The rider was taken to the Toowoomba Base Hospital in a critical condition while the 48-year-old female driver in the car was not injured.

Police are urging any members of the public who witnessed the incident or who have relevant dash-cam footage to contact Policelink on 131 444.