Boys on the Side/Set It Off
I have two favorite road movies (so far), they are; Boys on the Side, and Set It Off.
Boys on the Side is a great women's road movie that displays women from very different walks of life"coming together to form a bond much stronger than a mere friendship - but a sisterhood.
In addition, I enjoyed the movie Set It Off because it is a different style movie, the four women are not portrayed in the "typical female role" that has been previously set. These women take on the action of robbing a bank which is typically seen as a male role.
The movies themselves are very different, for they depect females in very different aspects, but overall have the same concept of women on the road becoming closer/working together/sisterhood.