As far as I know, Arizona is the only state that allows the registration and use of ATV's, Golf Carts, UTV's, Sand Rails, for on road use... Sand Rails may get a full size plate if they are over 1800 lbs, but everything else gets a Motorcycle plate & is registered as such. I know there are other cities across America that allow ORV's to obtain some sort of registration, and operate on the street, but just no place like AZ. As far as the license... since the US sees everything with more than 3 wheels as an automobile, then that is the only license you need.