Believe it or not, California , as do many other states, already have licensing requirements for certain trailers in place. None of which apply to a pop up camper, or any other trailer under 10,000 lbs GVWR. In 21 years of law enforcement, I have yet to have contact with someone (except commercial license holders) who are properly licensed for the combination of vehicles they are operating other than those who posses a normal driver's license and incidentally pulling a light trailer. Any pull trailer or RV travel trailer over 10,000 lbs GVWR or any fifth wheel RV over 15,000 lbs GVWR: non commercial class A license required. Written test, skills and road test. Modified medical certificate required. Any fifth wheel RV 10,000-15,000 lbs GVWR: Restricted class C license required (this amounts to a written test and a self certification medical). Any stock trailer 10,000-15,000 lbs GVWR operated by a rancher or farmer within 100 miles of farm or ranch: Class C license required. No tests. Any vehicle towing more than one trailer: Commercial Class A with doubles endorsement. Note: No vehicle other than a truck over 4,000 lbs may draw more than one trailer. The caveat to the farm exemption is that it must be loaded with stock animals and within 100 miles of the ranch. Put an ATV or pleasure riding horse in that trailer and you loose the exemption. Have a horse trailer with RV quarters in it. No exemption. You need a class A. pulling a triple axle toy hauler, your gonna need a class A. Anyone who thinks a goose neck and fifth wheel are the same connection, nope. No exemption, need a class A if over 10,000 lbs GVWR. A goose neck is mechanically a ball hitch so it is at the same level as a pull trailer on the back end. So, I don't find anyone complying or even knowing about these existing requirements. implementing a requirement for lesser equipment would be moot, However based upon my experiences, it is needed and would advocate some sort of program like the motorcycle training requirement to fulfill it. Happy Campin'