Go sit on the side of Highway 60 in the East Valley of Phoenix and see all the rigs from all over the country towing, boats, jeeps four down, Quads on trailers behind 5th wheels. We even had a guy show up a couple years ago with a 40' MH, SUV in tow, with a small box trailer behind the SUV. If you talk to some of these guys they will tell you they tow all over the country and never have a problem. There is an AZ DOT enforcement officer that hands out in Gold Canyon and pulls over commercial trucks for inspection. I have never seen him with a RVer pulled over.
One the more interesting things I saw towed South was a guy that show up with a long cargo trailer. Inside was his Germary Airplane that is made to come apart to be transported. He said it took several people to slide the two piece high wing pieces in phace.
Chris