I was stopped earlier this season, and cited for two things. 1, was not having signs on my doors (they were on bed). On open back vehicles, they must be on the doors, include co. name, city, and state, and letter be no less than 3 inches in height. The second thing was I didn't have a medical certificate. In Michigan, all commercial drivers are required to have a D.O.T. physical card obtained from a D.O.T. certified doctor. The way it works is any truck or truck/trailer combination exceeding 8000# GVW combined weight (was 10,000#, but they are changing it this year), is required to have a GVW registration. Also ANY staketrucks, dumps, or trucks of this type with service bodies that pull any trailer are required to have this registration, as well. In other words, (and this is no exageration) if somone takes a pickup truck, dually or not, and builds their own bed for it like a wooden rack, it becomes a stake. This is then required. As far as all the other trailer requirements, they are all required here, too. Brakes on both axles, brakeway, triangles (not flares), ADEQUATE chains, etc.