Texas Transportation Code Sec. § 551.201 Definition In this subchapter, “electric personal assistive mobility device” means a two non-tandem wheeled device designed for transporting one person that is: (1) self-balancing; and (2) propelled by an electric propulsion system with an average power of 750 watts or one horsepower. Added by Acts 2003, 78th Leg., ch. 1318, Sec. 5, eff. Sept. 1, 2003.