42 U.S.C. § 6374e

(a) Mandatory reduction in petroleum consumption (1) In general Not later than 18 months after December 19, 2007 , the Secretary shall issue regulations for Federal fleets subject to section 6374 of this title to require that, beginning in fiscal year 2010, each Federal agency shall reduce petroleum consumption and increase alternative fuel consumption each year by an amount necessary to meet the goals described in paragraph (2). (2) Goals The goals of the requirements under paragraph (1) are that not later than October 1, 2015 , and for each year thereafter, each Federal agency shall achieve at least a 20 percent reduction in annual petroleum consumption and a 10 percent increase in annual alternative fuel consumption, as calculated from the baseline established by the Secretary for fiscal year 2005. (3) Milestones The Secretary shall include in the regulations described in paragraph (1)— (A) interim numeric milestones to assess annual agency progress towards accomplishing the goals described in that paragraph; and (B) a requirement that agencies annually report on progress towards meeting each of the milestones and the 2015 goals. (b) Plan (1) Requirement (A) In general The regulations under subsection (a) shall require each Federal agency to develop a plan, and implement the measures specified in the plan by dates specified in the plan, to meet the required petroleum reduction levels and the alternative fuel consumption increases, including the milestones specified by the Secretary. (B) Inclusions The plan shall— (i) identify the specific measures the agency will use to meet the requirements of subsection (a)(2); and (ii) quantify the reductions in petroleum consumption or increases in alternative fuel consumption projected to be achieved by each measure each year. (2) Measures The plan may allow an agency to meet the required petroleum reduction level through— (A) the use of alternative fuels; (B) the acquisition of vehicles with higher fuel economy, including hybrid vehicles, neighborhood electric vehicles, electric vehicles, and plug-in hybrid vehicles if the vehicles are commercially available; (C) the substitution of cars for light trucks; (D) an increase in vehicle load factors; (E) a decrease in vehicle miles traveled; (F) a decrease in fleet size; and (G) other measures.