South West traffic officer in charge Gerard Murphy said it appeared the woman in a Holden Commodore failed to give way to a stop sign and went through the intersection before being hit by a Nissan Patrol.

Sgt Murphy said there were witnesses who saw the Holden Commodore speeding and overtaking other vehicles on Hynes Road before the crash.

Sgt Murphy said the male driver of the Nissan was attended to by ambulance officers and was shaken.

Traffic heading towards Bunbury along the bypass was reduced to one lane then diverted.

Both vehicles were towed from the site.

Sgt Murphy said the wet weather had not played a role in the crash.

But he said he was surprised people were not driving to the wet conditions and taking their time on the road.

Sam Martin said he heard the accident three kilometres away from his home in Eaton.

Mr Martin said he heard squealing brakes and impact noise before going to find where the accident was and was shocked by what he saw.