From Leslie Harpold's The Morning News article on How to Road Trip:
Your hair looks fine
On the road even the most meticulous must let go of the expectations they have of their hair. Strange water, sample-size shampoos, the wind, and tiny mirrors all conspire to make your hair so willful it may seem like an additional passenger at times. Let it go. This isn't about looking good, it's about feeling something new; all new feelings worth their salt eventually mess up your hair.
Not just good road trip advice, that's good life advice.