Their are many things to consider, are you towing a car or truck and what is the overall length, weight.
Road use laws apply to all vehicles not just commercial carriers. Every state and the Federal Government are looking for revenue and the current trend is to look at road use and fees for over size, weight vehicles.
It already is in effect in several states and falls to the discretion of the road officer (except CA where the rules are very specific).
I do not mean to be discouraging, I own a large MH and tow a truck, but from my desk I see the rules changing with out much public knowledge.
We will be offering a course on this topic at our June 'RV Lifestyle, Education & Safety Conference', please visit www.rvsafety.com for more info.
Walter Cannon (Executive Director) RV Safety & Education Foundation