A road train driver was airlifted to hospital overnight after his vehicle left the road and smashed into a power pole at Muchea.
The man lost control of the vehicle just after 1am on the Brand Highway, about 60km north of Perth.
His road train careered through a ditch and heavy scrub for about 200m before hitting the pole.
The RAC rescue helicopter was called in to fly the seriously injured driver to Royal Perth Hospital.
His passenger was taken to Swan Districts Hospital with minor injuries.
A police spokesman said a large crane would remove the road train today.