42 U.S.C. § 13238

(a) Nonroad vehicles and engines (1) The Secretary shall conduct a study to determine whether the use of alternative fuels in nonroad vehicles and engines would contribute substantially to reduced reliance on imported energy sources. Such study shall be completed, and the results thereof reported to Congress, within 2 years after October 24, 1992 . (2) The study shall assess the potential of nonroad vehicles and engines to run on alternative fuels. Taking into account the nonroad vehicles and engines for which running on alternative fuels is feasible, the study shall assess the potential reduction in reliance on foreign energy sources that could be achieved if such vehicles were to run on alternative fuels. (3) The report required under paragraph (1) may include the Secretary’s recommendations for encouraging or requiring nonroad vehicles and engines which can feasibly be run on alternative fuels, to utilize such alternative fuels. (b) Definition of nonroad vehicles and engines Nonroad vehicles and engines, for purposes of this section, shall include nonroad vehicles and engines used for surface transportation or principally for industrial or commercial purposes, vehicles used for rail transportation, vehicles used at airports, vehicles or engines used for marine purposes, and other vehicles or engines at the discretion of the Secretary. (c) Designation Upon completion of the study required pursuant to subsection (a) of this section, the Secretary may designate such vehicles and engines as qualifying for loans pursuant to section 13239 of this title .