Although GPS is the simplest solution for us for travel, I really scratch my head why simple things like dragging and dropping to modify your route can't be done on a GPS. MapQuest, for example lets me "create" a route. There is no GPS that I know of that enables you to do this. If you don't like the route given you only have 2 options; drive where you want until the re-calculation finally falls in line, or create several small destinations to force the route you want. This can be tricky because one of your points might accidentally fall in a shopping center or side street. Often the route proposed by a GPS is not the best. That said I usually "plan" my route in MapQuest, and replicate it on my Garmin DZL. (which btw is the best GPS I have found for Rv's).