42 U.S. Code § 7586 - Centrally fueled fleets
(a) Fleet program required for certain nonattainment areas
(1) SIP revision
Each State in which there is located all or part of a covered area (as defined in paragraph (2)) shall submit, within 42 months after November 15, 1990, a State implementation plan revision under section 7410 of this title and part D of subchapter I of this chapter to establish a clean-fuel vehicle program for fleets under this section.
(2) Covered areas
For purposes of this subsection, each of the following shall be a “covered area”:
(A) Ozone nonattainment areas
Any ozone nonattainment area with a 1980 population of 250,000 or more classified under subpart 2 of part D of subchapter I of this chapter as Serious, Severe, or Extreme based on data for the calendar years 1987, 1988, and 1989. In determining the ozone nonattainment areas to be treated as covered areas pursuant to this subparagraph, the Administrator shall use the most recent interpretation methodology issued by the Administrator prior to November 15, 1990.
(B) Carbon monoxide nonattainment areas
Any carbon monoxide nonattainment area with a 1980 population of 250,000 or more and a carbon monoxide design value at or above 16.0 parts per million based on data for calendar years 1988 and 1989 (as calculated according to the most recent interpretation methodology issued prior to November 15, 1990, by the United States Environmental Protection Agency), excluding those carbon monoxide nonattainment areas in which mobile sources do not contribute significantly to carbon monoxide exceedances.
(3) Plan revisions for reclassified areas
In the case of ozone nonattainment areas reclassified as Serious, Severe, or Extreme under part D of subchapter I of this chapter with a 1980 population of 250,000 or more, the State shall submit a plan revision meeting the requirements of this subsection within 1 year after reclassification. Such plan revision shall implement the requirements applicable under this subsection at the time of reclassification and thereafter, except that the Administrator may adjust for a limited period the deadlines for compliance where compliance with such deadlines would be infeasible.
(4) Consultation; consideration of factors
Each State required to submit an implementation plan revision under this subsection shall develop such revision in consultation with fleet operators, vehicle manufacturers, fuel producers and distributors, motor vehicle fuel, and other interested parties, taking into consideration operational range, specialty uses, vehicle and fuel availability, costs, safety, resale values of vehicles and equipment and other relevant factors.
(b) Phase-in of requirements
The plan revision required under this section shall contain provisions requiring that at least a specified percentage of all new covered fleet vehicles in model year 1998 and thereafter purchased by each covered fleet operator in each covered area shall be clean-fuel vehicles and shall use clean alternative fuels when operating in the covered area. For the applicable model years (MY) specified in the following table and thereafter, the specified percentage shall be as provided in the table for the vehicle types set forth in the table:
|Light-duty trucks up to 6,000 lbs. GVWR and light-duty vehicles||30%||50%||70%|
|Heavy-duty trucks above 8,500 lbs. GVWR||50%||50%||50%|
|The term MY refers to model year.|
(c) Accelerated standard for light-duty trucks up to 6,000 lbs. GVWR and light-duty vehicles
Notwithstanding the model years for which clean-fuel vehicle standards are applicable as provided in section 7583 of this title, for purposes of this section, light duty  trucks of up to 6,000 lbs. GVWR and light-duty vehicles manufactured in model years 1998 through model year 2000 shall be treated as clean-fuel vehicles only if such vehicles comply with the standards applicable under section 7583 of this title for vehicles in the same class for the model year 2001. The requirements of subsection (b) of this section shall take effect on the earlier of the following:
(1) The first model year after model year 1997 in which new light-duty trucks up to 6,000 lbs. GVWR and light-duty vehicles which comply with the model year 2001 standards under section 7583 of this title are offered for sale in California.
Whenever the effective date of subsection (b) of this section is delayed pursuant to paragraph (1) of this subsection, the phase-in schedule under subsection (b) of this section shall be modified to commence with the model year referred to in paragraph (1) in lieu of model year 1998.
(d) Choice of vehicles and fuel
The plan revision under this subsection shall provide that the choice of clean-fuel vehicles and clean alternative fuels shall be made by the covered fleet operator subject to the requirements of this subsection.
(e) Availability of clean alternative fuel
The plan revision shall require fuel providers to make clean alternative fuel available to covered fleet operators at locations at which covered fleet vehicles are centrally fueled.
(1) Issuance of credits
The State plan revision required under this section shall provide for the issuance by the State of appropriate credits to a fleet operator for any of the following (or any combination thereof):
(B) The purchase of clean fuel  vehicles which meet more stringent standards established by the Administrator pursuant to paragraph (4).
(2) Use of credits; limitations based on weight classes
(A) Use of credits
Credits under this subsection may be used by the person holding such credits to demonstrate compliance with this section or may be traded or sold for use by any other person to demonstrate compliance with other requirements applicable under this section in the same nonattainment area. Credits obtained at any time may be held or banked for use at any later time, and when so used, such credits shall maintain the same value as if used at an earlier date.
(B) Limitations based on weight classes
Credits issued with respect to the purchase of vehicles of up to 8,500 lbs. GVWR may not be used to demonstrate compliance by any person with the requirements applicable under this subsection to vehicles of more than 8,500 lbs. GVWR. Credits issued with respect to the purchase of vehicles of more than 8,500 lbs. GVWR may not be used to demonstrate compliance by any person with the requirements applicable under this subsection to vehicles weighing up to 8,500 lbs. GVWR.
Credits issued for purchase of a clean fuel  vehicle under this subsection shall be adjusted with appropriate weighting to reflect the level of emission reduction achieved by the vehicle.
(3) Regulations and administration
Within 12 months after November 15, 1990, the Administrator shall promulgate regulations for such credit program. The State shall administer the credit program established under this subsection.
(4) Standards for issuing credits for cleaner vehicles
Solely for purposes of issuing credits under paragraph (1)(B), the Administrator shall establish under this paragraph standards for Ultra-Low Emission Vehicles (“ULEV”s) and Zero Emissions Vehicles (“ZEV”s) which shall be more stringent than those otherwise applicable to clean-fuel vehicles under this part. The Administrator shall certify clean fuel  vehicles as complying with such more stringent standards, and administer and enforce such more stringent standards, in the same manner as in the case of the otherwise applicable clean-fuel vehicle standards established under this section. The standards established by the Administrator under this paragraph for vehicles under 8,500 lbs. GVWR or greater shall conform as closely as possible to standards which are established by the State of California for ULEV and ZEV vehicles in the same class. For vehicles of 8,500 lbs. GVWR or more, the Administrator shall promulgate comparable standards for purposes of this subsection.
(5) Early fleet credits
The State plan revision shall provide credits under this subsection to fleet operators that purchase vehicles certified to meet clean-fuel vehicle standards under this part during any period after approval of the plan revision and prior to the effective date of the fleet program under this section.
(g) Availability to public
At any facility owned or operated by a department, agency, or instrumentality of the United States where vehicles subject to this subsection are supplied with clean alternative fuel, such fuel shall be offered for sale to the public for use in other vehicles during reasonable business times and subject to national security concerns, unless such fuel is commercially available for vehicles in the vicinity of such Federal facilities.
(h) Transportation control measures
The Administrator shall by rule, within 1 year after November 15, 1990, ensure that certain transportation control measures including time-of-day or day-of-week restrictions, and other similar measures that restrict vehicle usage, do not apply to any clean-fuel vehicle that meets the requirements of this section. This subsection shall apply notwithstanding subchapter I of this chapter.
 So in original. Probably should be “light-duty”.
 So in original. Probably should be “clean-fuel”.