WA grandpa run over in library car park

A man aged in his 90's is in a Perth hospital after being accidentally run over by his granddaughter in a university library car park.

It is understood the man was guiding the P-plate driver into a car bay at Murdoch University's Rockingham campus, in Perth's south, on Wednesday morning when she hit the accelerator instead of the brake and ran over him.

The man was trapped under the car for about half an hour before he was freed by emergency crews and flown to Royal Perth Hospital.

Police said the man sustained a severe injury to his arm.