RCW 46.04.336: Motorized foot scooter.

"Motorized foot scooter" means a device with two or three wheels that has handlebars, a floorboard that can be stood upon while riding, and is powered by an internal combustion engine or electric motor that has a maximum speed of no greater than twenty miles per hour on level ground.

For purposes of this section, a motor-driven cycle, a moped, an electric-assisted bicycle, or a motorcycle is not a motorized foot scooter.