POLICE are investigating whether the driver of a vehicle that crashed into a tree before catching fire this morning may have suffered a medical episode in the lead-up to the tragedy.

The Ipswich forensic crash unit is investigating the cause of the fatal single-vehicle crash at Glamorgan Vale just after 10am Tuesday.

Acting Inspector Donna Stewart said a 57-year-old woman died at the scene, despite attempts from witnesses to help her.

The woman's vehicle caught fire after hitting a tree off Glamorgan Vale Rd, but what caused the vehicle to veer off the road remains a mystery.

A police spokesman said a witness in a following car stopped and freed the woman from the vehicle. "Police are speaking to several witnesses and the forensic crash unit is in the early stages of their investigation," Insp Stewart said.

Firefighters were also called to the scene, with crews extinguishing the blaze and searching the wreckage to confirm there were no other people involved.

Police created diversions around the crash scene as investigations continued.

The crash occurred on Glamorgan Vale Road in Glamorgan Vale about 10.15am.

Queensland Fire and Emergency Services said the car was "well involved" when they arrived.

The driver of the car had been pulled from the burning wreckage by passers-by, but died at the scene.

The fire was extinguished about 11am.

Police are advising motorists avoid the area.