In general, a "motorized scooter" is a vehicle that is designed to be stood or sat upon by the operator and that has two small-diameter wheels in tandem, upright t-shaped handlebars, and is powered by an internal combustion engine or electric motor that is capable of propelling the device with or without human propulsion. Top speeds are generally 8-20 mph.  These may not be operated on the roadway, sidewalks or bicycle ways.  They can be operated with permission on private property, and on private roads and driveways.

Do not confuse motorized scooters with mopeds. Mopeds, of course, can be operated lawfully on public
roads. A "moped" is usually a Type 1 motorcycle that is incapable of speeds faster than 30 miles per hour,
is equipped with an automatic transmission, an engine certified by the manufacturer at not more than 50
cubic centimeters or an equivalent power unit, and a seat for the operator. Sec. 340.01(29m), Wis. Stats.
This definition includes models such as the Honda Spree, Honda Metropolitan, Yamaha Jog and Yamaha
Vino (shown below).