road trip romances

I don't think I'm the only one whose thoughts have turned to spring breaks and vacations.  Since I won't be taking one next month, I thought I'd escape on a fictional vacation and celebrate the road trip romance.  Remember the movies It Happened One Night or Romancing the Stone?  Think of those in book form:  a (usually harrowing) physical journey is accompanied by an emotional journey, played for either laughs or adventure.  I particularly enjoy the historical versions, because you're travelling though another time, as well as another place.