On the night of April 18, 1984, plaintiff Ralph Ostler was accompanying his father Stephen home to Utah from a business trip to California. At approximately 3:00 a.m., the Ostlers compact pickup was northbound on Interstate 15, a few miles south of Payson, Utah. Stephen Ostler was driving. For unknown reasons, the pickup left the lane of traffic and struck the rear of a truck and semitrailer unit parked on the paved shoulder of the roadway. Stephen Ostler was killed instantly. Plaintiff, who had been sleeping on the bed of the pickup, was thrown onto the roadway and critically injured.
