There’s almost some validity to this, because I once saw a guy catch a DUI while riding one of those. They are, technically and according to most state laws, vehicles.

The issue here is the choice of venues. Vehicle or not, they are still likely to prohibited from controlled access freeways. As are bicycles, mopeds that are not capable of going highway speeds, farm tractors, horses, etc. and for the same reason.

On surface streets, however, this guy can probably rock on.