As far as picking the route, most GPS units have settings to take you the "fastest" route or the "shortest" route. Mine also has settings to avoid interstate highways or toll roads. My Garmin also allows me to set up a "custom" route to take me on roads that I prefer which may not fit in to any of the other categories. In other words, if your GPS tries to guide you to roads you do not want to travel on, check your settings. If properly set up, most GPS units will guide you exactly where you want to go. If not set up properly, you may end up taking a route that is great for an automobile, and not suitable for an RV.