In New Jersey, as far as I can tell, the Motorcycle helmet statute (39:3-76.7. Protective helmet specifications) reads, in part: "... For the purposes of this section, motorcycle shall not include any three-wheeled motor vehicle equipped with a single cab with glazing enclosing the occupant, seats similar to those of a passenger vehicle or truck, seat belts and automotive steering."
Other than the questionable "glazing enclosing the occupant" part, the rest of it certainly seems to be OK for a M3W.
The same exclusion also exists for protective googles, FWIW.
Last edited by truckin-on; 10/01/17 10:24 PM.