Ed,

This topic is confusing. The answers to your question may lie with your local state police or in the commercial driver book that you can get at the facilities in your state that administer driving test.

Some states require non-commercial class B licenses, and others only require a regular driver license.

As you can see from the attached link, even within your own state there is a degree of confusion since your state's commercial driver manual states one is required, but apparently your class D is all that is required. I would verify it and carry a copy of the law with me in case a cop hasn't done the research.

http://changingears.com/rv-sec-state-rv-license.shtml