Police are investigating whether a man who rolled his 4WD along Kwinana freeway on June 12 was under the influence of alcohol.
The 60-year-old sustained minor injuries in the incident that left his car on its roof along the median string of the freeway about 9.30pm.
The crash occurred roughly half way between the Paganoni Road and Mandjoogoordap Drive exits.
The man allegedly blew three times the legal alcohol limit at the scene.
The driver was the only occupant in the car and was heading northbound, towards Perth when he lost control of the vehicle.
Police and ambulance were at the scene, slightly affecting traffic on the southbound lane of the freeway.
A spokeswoman from Police Media said inquiries were continuing into the mans state and whether charges would be laid.