Dutch,
It was easy for me to tell that Bronson was riding on Pacific Coast Highway, then, I immediately recognized the bridge he crosses at the end of the clip as Bixby Bridge, just south of Big Sur. About 1970, me and my friends climbed down to the beach below there and had a fine afternoon. The symbols in the sand long since washed away along with any other evidence.
Richard L.
EDIT: Just saw that the Bixby Creek Bridge info for Bronson is easily found. I didn't need it.