Mich. Comp. Laws § 257.13f

Sec. 13f. "Electric skateboard" means a wheeled device that has a floorboard designed to be stood upon when riding that is no more than 60 inches long and 18 inches wide, is designed to transport only 1 person at a time, has an electrical propulsion system with power of no more than 2,500 watts, and has a maximum speed on a paved level surface of not more than 25 miles per hour. An electric skateboard may have handlebars and, in addition to having an electrical propulsion system with power of no more than 2,500 watts, may be designed to also be powered by human propulsion.