Check out the wiki https://wiki.openstreetmap.org/wiki/Tag:amenity%3Dparking_space for mapping individual parking spaces. You would still need a highway=service for vehicle routing. (Telsa auto drive feature apparently you can summons your car to pick you up. But it needs well mapped parking lots including curbs and such.

It looked like the access key was added by the park. It is easy to overlook. 

I try to map the footway=access_aisle to connect the sidewalk system to the marked area next to the handicap parking.

