Ok well if we are talking just one of those stand up scooters then im going to say its not legal for public roads.
BUt here is what the state says about motorized bicycles/scooters
What are the licensing laws for motor scooters (under 50cc)?
Licensing for a scooter or moped depends on whether the vehicle meets the definition of a motorized bicycle. The Missouri statute definition of a motorized bicycle is as follows:
"Any two-wheeled or three-wheeled device having an automatic transmission and a motor with a cylinder capacity of not more than fifty (50) cubic centimeters, which produces less than three (3) gross brake horsepower, and is capable of propelling the device at a maximum speed of not more than thirty (30) miles per hour on level ground."
A motorized bicycle does not have to be registered with the Missouri Department of Revenue. However, you must have a valid driver license (though no motorcycle endorsement is required).
Missouri statute does not require a helmet to be worn when operating a motorized bicycle. Please contact your local law enforcement agencies for any county/municipal codes that deal with helmets and motorized bicycles.
Keep in mind that no motorized bicycle may be operated on any public thoroughfare located within this state that has been designated as part of the federal interstate highway system.
http://www.dor.mo.gov/mvdl/drivers/faq/general.htm#q16
dgridley said:
Gah, forgot to call today.. will post what I find out. Inquiring minds want to know