The only app I have found so far for good RV routing is Co-Pilot as mentioned already. There is an RV profile that lets you set height and if you are carrying propane. It pretty much routes where the trucks are routed and so far has done a good job of that. As to knowing a parkway or not - it is going to know height restrictions which is how all of these are programmed. Some do a better job of it than others and no matter what the app or GPS says watch the entrance signs before getting on any limited access road. And to the OP- if a trucker app routed you onto a limited access parkway that app is no good because it should not have sent a truck on that route either. There are a few limited access parkways that allow commercial vehicles or trucks but many don't. Where I am, there are several parkways and RVs are not allowed on any of them.