I like the CoPilot app. $6.99 in the itunes store. You can also subscribe to active traffic. CoPilot does not need cell service to work. It has the following settings: RV (favors main roads and no u-turns, quickest route or shortest route (I chose quickest) height restrictions 12.6 or 13', no toll roads, no propane, no ferries, and international borders open. I have been using it for 6 months and so far so good. I did not check to see if it routes on parkways but it seems it would if any of the above settings would restrict that route. It's also easy to select an alternate route.