A teenager has been rushed to hospital after she was hit by a four-wheel-drive in Baldivis.
The 14-year-old had been crossing Safety Bay Road when she was struck near the Baldivis Road roundabout around 3pm.
The teen suffered serious head and facial injuries and was taken to Rockingham General Hospital.
As paramedics worked to stabilise the 14-year-old, traffic coming off the Kwinana Freeway was unable to turn onto Safety Bay Road, causing motorists to bank back southbound.
Traffic is currently at a standstill for more than 6km from the Safety Bay Road exit to Mortimer Road for those trying to head south.
Emergency crews have also attended a serious crash north of Myalup on Friday afternoon.
According to police, a car crashed into a power pole on Lake Preston Road shortly before 4pm.