THE driver of a car involved in a head-on collision with a grain truck on Great Northern Highway last night remains in a stable condition.
He was airlifted to Royal Perth Hospital after his Nissan coupe and the fully laden truck collided north of Apple Street in Upper Swan about 7pm.
Police said the car was believed to have been travelling on the wrong side of the road.
Department of Fire and Emergency Services personnel had to cut both drivers free.
The truck driver was taken to hospital with non-life threatening injuries.
Traffic Enforcement Group officers from Warwick are investigating the crash.
It caused the closure of the highway from 7pm until 10.08pm.
One lane remained open this morning to north and south-bound traffic.
Witnesses to the crash can call 1800 333 000.