Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportations Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
not been enacted (NHTSA, 2009a). Recently, there has been new activity in establishing
fuel economy or emission standards. The 2007 Energy Independence and Security Act
(EISA) required a 40 percent increase in fuel economy, to 35 miles per gallon (mpg) by
2020 for all light-duty vehicles; required the establishment of new fuel economy standards
for both medium- and heavy-duty commercial vehicles; and made other changes to allow
NHTSA to establish light-duty vehicle standards to minimize adverse safety impacts. In
early 2009, NHTSA set new fuel economy standards for the 2011 model year that will
achieve an industry-wide combined fleet average fuel economy of 27.3 miles per gallon
(NHTSA, 2009b). That rule, for the first time, incorporated an analysis of GHG impacts
associated with the new standards.
In 2009, NHTSA and the United States Environmental Protection Agency (EPA) worked in
concert to develop a consistent, harmonized National Program to deliver substantial
further improvements in fuel economy and reductions in GHG emissions for new cars and
light-duty trucks. On May 22, 2009, these agencies issued a notice of intent to conduct a
joint rulemaking to establish aggressive new CAFE standards and vehicle GHG emissions
standards for passenger cars, light-duty trucks, and medium-duty passenger vehicles built
in model years 2012 through 2016. In addition, on September 28, 2009, NHTSA and EPA
announced in the Federal Register the Proposed Rulemaking To Establish Light-Duty
Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy
Standards (See 74 FR 49454). NHTSA also prepared an environmental impact statement to
analyze and disclose the potential environmental impacts of the proposed model years
2012 through 2016 Corporate Average Fuel Economy standards (See 74 FR 48894). The
proposed standards would increase light-duty vehicle fuel efficiency by an average of
5 percent each year between 2012 and 2016 and require new vehicles to meet an average of
35.5 mpg by 2016 (White House, 2009), effectively equivalent to the requirement of 250
grams of CO 2 per mile that the State of California had proposed in this same timeframe.
The Agencies’ announced intention is to achieve these results through the use of
technology that will be commercially available and can be incorporated at a reasonable
cost. In addition to the NHTSA’s proposed fuel economy standards, EPA expects to
propose the first ever Federal emissions standards for greenhouse gases using its
authority under the Clean Air Act (CAA). The intent of the National Program is to allow
auto manufacturers to build a single light-duty national fleet which satisfies requirements
under both programs. Moreover, the National Academy of Sciences is currently
conducting a study on fuel economy standards for work truck, medium and heavy duty
vehicles that NHTSA will rely upon to set future standards for these types of vehicles.
In addition to raising standards for fuel economy, future mileage testing procedures for
fuel economy standards could be modified to account for aspects of vehicle operation that
currently are not included in testing, such as power steering and air conditioner operation.
This would give manufacturers an incentive to increase efficiency of these components as
well. Standards also could address HFC emissions used in air conditioners and
refrigeration equipment, through best management practices or other regulations to
reduce leaks and require proper recycling and disposal of HFCs during maintenance.
Beyond fuel economy or emission standards, a variety of other policy options can be
considered to encourage consumers to purchase more fuel-efficient vehicles. Fuel
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