The Environmental Protection Agency (EPA) is revisiting the requirements that apply to the introduction of glider vehicles into commerce, consistent with statutory requirements and due consideration of air quality impacts, following its November 2017 proposed rule. In the November 2017 action, EPA proposed to repeal the emission standards and other requirements for heavy-duty glider vehicles, glider engines, and glider kits based on a proposed interpretation of the Clean Air Act (CAA) under which glider vehicles would be found not to constitute new motor vehicles” within the meaning of CAA section 216(3), glider engines would be found not to constitute new motor vehicle engines” within the meaning of CAA section 216(3), and glider kits would not be treated as incomplete” new motor vehicles. In that action, EPA also proposed that the agency lacked authority to regulate glider vehicles, glider engines, and glider kits under CAA section 202(a)(1).