Highway patrol officers say they found a body inside a car, but haven't determined if it was the body of the missing man.
The Marin County Sheriff's Office's Search and Rescue team is searching the area hoping to locate Davis.
A Caltrans crew walking along the road during a routine road check for slides and debris Tuesday morning spotted the 2001 silver Toyota Camry, Barclay said.
They looked inside and found Davis' registration and drove to the CHP office in Corte Madera, Barclay said.
The CHP, Marin County Sheriff's Office and the Marin County Search and Rescue Team then went to the scene when it was determined the car belonged to a missing person, Barclay said.
The California Highway Patrol first described the incident Tuesaday as a non-injury vehicle over an embankment, but then changed it to a fatality. Barclay said there is no specific code for the discovery of an unoccupied vehicle belonging to a missing person.
Barclay said the search near the vehicle was hampered by hail, rain and thunder. The car was around 100 feet down an embankment in a heavily wooded area and was not visible by someone driving on the road, Barclay said.
Davis was last seen around 8 p.m. on Feb. 26 after he left Marin Joe's Restaurant at 1585 Casa Buena Drive in Corte Madera. After his weekly dinner with his daughter he drove toward U.S. Highway 101, San Rafael police said.
Police said Davis suffered from a medical condition and might have become disoriented.
Davis was described as a white man with gray hair and gray eyes, 5 feet 7 inches and 139 pounds. He was wearing a beige jacket, yellow sweater and beige slacks.
ABC7 News contributed to this story.