Call me crazy...

We always call ahead to Wal-marts since there are a lot of jurisdictions that have made it illegal to stay there (otherwise it is company policy to allow it, going back to Walton's day).  That saves a trip off the highway just to discover you can't stay.  If we tried Cracker Barrel or Camping World I would do the same - any place except a truck stop.

Truck stops by definition are always situated where it is allowed so we don't call, but we do check in with the person at the counter to see where they want us to park (while I'm filling up at the pump so they see we're patronizing them).  Often they point to a corner of the regular parking lot to keep the long truck slots open.

I've read that people do often get away with using rest stops, but since it is illegal just about everywhere I'd rather not get a wake-up at 2 am.  Plus ticket.

The reason we prefer truck stops now is we've had a few experiences at Wal-Marts.  Kids doing burn-outs down the line of campers at 2 am, for one.  The local idiots know there are campers there and they can be messed with - or worse.  That isn't going to happen at a truck stop or they'll have 30 truckers beating their @ss.