I remember a policeman looking at my bike and calling it a "moped" and when I corrected him with the differences between a moped and a "power assisted bike" he shrugged his shoulders and said "well it's the same thing". When it is for their convenience they go by the "letter of the law". The DOT changed the wording from "capable of" from "primarily" which gave rise to "power on demand", as well as "power assist". The word "bicycle" contains the root word "bi" referring to how many tires the vehicle has. Trike comes from the word "tri" referring to the three wheels that vehicle possesses. To keep the peace I don't refer to it as a bicycle, although it falls under the category of "power assisted bicycles" I refer to mine as a "power assisted bike" which seems to bother cyclists less...LOL (you gotta walk on eggshells with those people)