The reason why I am against a lot of laws is that it's like a camel with his nose under the tent type of thing. I feel that DP owners and drivers get training on air brakes absolutely. I am even for a certification of such thing as lone as it stops there and not get more and more restricting. Americans where i live in the rural areas of the mid west like to be left alone and not deal with more laws. I think it would behoove anyone who spends 500K on a DP to protect it from accidents and themselves.. I got a class B with air brake and passenger with school bus endorsements and it took me about 4 hours of testing time. no big deal in the scheme of things but I have the certifications to legally operate anything that is straight. I am getting a semi tractor and my employer who is giving me the truck will help me with getting a class A I am probably going to go for it.