The movie you're thinking of stars:
* Peter Coyote as George
* Mare Winningham as Mary
* David Strathairn as Tom
* David Andrews as Sam
* James Whitmore as Mr. McArthur
* Gena Rowlands as Mrs. McArthur
It is a powerful story about a young couple who take a road trip to escape their troubled lives, and how they learn to face their fears and find their way home.