Yes, a good RV GPS (usually costs about $250) will have the RV’s dimensions (height, width, length, and weight) and avoid roads that are not wide enough for your RV.
If you are renting from an RV dealer then rent an RV GPS, if you are renting from a peer to peer site like http://www.RVShare.com or http://www.Outdoorsy.com then negotiate with the RV owner so he/she buys an RV GPS and rents you for the duration of your trip.