Have you tried AAA, Goodsams,TrailerLife,or any of the free mapping software?
You can always check with the DOT for the states you'll be goiing through.Plus where are you comming from?
I really like the AAA online trip tik. I think you have to be a member.
It's nice because you can map multiple locations, and if you need to avoid a certain route, it allows you to do that. There is a list of state regulations about rvs somewhere on the site as well.