When we need to make an overnight stop on our way from Point A to Point B, we prefer to stay at WalMarts versus truck stops or rest areas for a couple reasons. First, our experience has been that truck stops can be pretty noisy and we don't sleep particularly well there. Second, we believe that if lots of people spend the entire night in a rest area, there may not be enough room left for those travelers who really need a short rest when driving through the night. Our first preference is a campground but as you mentioned in your post, sometimes the unexpected happens.