This may seem really mundane, but here goes. Do you live in an area where a regional natural disaster may occur? If so, some thoughts on evacuation and... personal needs. What if you were part of a regional evacuation, a la Sandy or Katrina? Traffic is slow but moving. Or if you find yourself in another situation where stopping just is not an option, are you prepared if nature calls?
For men, gizmos like the 'autojohn' may be useful. If it is even still available, it's basically a funnel and container to allow you to urinate without leaving your seat in the car. For the distaff, it's a little more complicated. What if you also have several children in the car for a day's drive?
Especially from the ladies, what's your plan or solution?