Well, this wasn't exactly a road trip as I didn't have a destination but I rode the east coast of mainland Australia, caught a ferry to Tasmania and generally bummed around on my m/cycle for 3 months. Just bike and tent. Wouldn't have a clue to the amount of miles/kilometres. Many thousands.
Met a guy who was riding around Australia 'cause he lost a bet playing poker!!( He didn't ride his Harley though, bought a junked Honda) For anyone who doesn't know, Australia is the same size as the U.S (except for Alaska).
Ah, the seventies.....