It's a legal classification. Most US states designate a "Moped" as a 2-wheeled vehicle under 50cc and electronically limited to a top speed of 30mph. In NH Reg

It's a legal classification. Most US states designate a "Moped" as a 2-wheeled vehicle under 50cc and electronically limited to a top speed of 30mph. In NH Registering such a vehicle costs about $5 and gives you a license plate that says "MOPED" and can be driven by people with special moped licenses if they do not yet have their drivers license. Anything over 50cc/30mph and you need a "MOTORCYCLE" registration and license plate and must take the motorcycle test to get a motorcycle license. Most motorcycle registrations are much more than $5. ($50-200) In CT it used to be the case that you didn't even need to register it if it was under 50cc, but that might have changed.