Well, in ILLINOIS you have:
up to 26001 LBS
above 26001 LBS
and CDL (comercial)
What is the problem, our Prevosts are above 26001 LBS and we need this kind of driver license. You don't want attorneys or insurance companys to explain to us again in case of an accident when they do not pay the claim, because you were driving with out a proper license. Case closed !