[bjcintennessee]

Sounds like it's possible that he and the missus had a dispute and maybe he assumed his daughter would pick him up? Yet when she passed him by (either unaware, or forgetful), he takes it personal, thumbs a ride, and "punishes" them by making them worry?

Pure speculation here, but preferable to the possibility that he met with foul play. At least my theory has the potential of a happy ending -- after he gets lambasted for allowing his family to think the worst.

[Lancey Howard]

I like your theory.
Putting myself in Steve's shoes, If I was stranded on the highway like that, I would be very, very pissed. So much so, that I would probably need to cool my heels somewhere. For a long while.

[oceanperch]

What kind of area is Hwy 71 near Joplin Mo? High crime, vagrants/transeints ect?