A journey intended to be enjoyed, especially if accompanied, is called a *[road trip][1]*.

While not a single word, the driver could say she was looking for a **road buddy** or a **trip buddy**. *[Buddy][2]* can mean

>a person who does some activity with you

It has lost its exclusively male connotation and is often used, regardless of the gender of the fellow-traveler.


  [1]: http://en.wikipedia.org/wiki/Road_trip
  [2]: http://www.merriam-webster.com/dictionary/buddy