For that matter, what if there isn't a manufacturer's shop in my town? I'm going to let my car drive itself to the next state and back, when it's already in need of repair? Um, no. You may have less local auto repair shops, but not none.
Same with rest stops. Over-the-road trucks won't need them, but the majority of highway traffic is cars. The people still need a restroom, even if they don't need a rest stop for fatigue reasons.
