December 8, 2010 

Margo T. Oge 

Director 

Office of Transportation and Air Quality 

Office of Air and Radiation 

U.S. Environmental Protection Agency 

1200 Pennsylvania Avenue, NW 

MC-6401A 

Washington, DC 20460 

Dear Margo: 

 Thank you for the opportunity to speak last month with you, your staff and your colleagues 

from the National Highway Traffic Safety Administration (NHTSA) regarding the U.S. 

Environmental Protection Agency’s (EPA’s) and NHTSA’s joint effort to develop 2017 and later 

model year (MY) light-duty vehicle greenhouse gas (GHG) emissions standards and Corporate 

Average Fuel Economy (CAFE) standards and, in particular, the agencies’ Notice of Intent 

regarding this initiative, as published in the Federal Register on October 13, 2010 (75 FR 62739). 

In follow up to that telephone discussion, we would like to briefly reiterate our comments regarding 

three overarching issues raised by the group of National Association of Clean Air Agencies 

(NACAA) leaders who participated in the call: 1) the need for stringent GHG emissions standards, 

2) the need for concomitant co-benefit reductions in criteria pollutant and toxic air pollutant 

emissions and 3) how states are preparing for electric vehicles. 

Stringency of GHG Emissions Standards

 As EPA and NHTSA take the next step in regulating GHG emissions from light-duty 

vehicles, this step must help ensure that we are on a pathway for achieving an 80-percent 

reduction in carbon dioxide emissions by 2050 – a goal that has been set by many states through 

legislation or action plans. Meeting this goal will require deep reductions in every sector; in the 

case of light-duty motor vehicles, states and localities are relying on the greatest emissions 

reductions feasible. Given the many technological advances that have been made and the great 

potential for weight reduction reflected in the Lotus study report1

, it appears clear that the stage is 

set for a substantial reduction beginning with MY 2017. Accordingly, we urge EPA to consider the 

highest end of the range of annual reductions contemplated in the EPA-NHTSA-California Air 

Resources Board (CARB) September 2010 Interim Joint Technical Assessment Report, (i.e., 6 

percent), but not be bound by the reduction levels in the report and to consider whatever level of 

stringency can feasibly be achieved. 

 

1

 Lotus Engineering, Inc. (March 2010), An Assessment of Mass Reduction Opportunities for a 2017-2020 Model Year Vehicle 

Program, published by The International Council on Clean Transportation (http://www.theicct.org/2010/03/lightweight-future). 
2

Co-Benefit Reductions in Criteria Pollutant and Toxic Air Pollutant Emissions

 State and local air quality agencies are responsible for ensuring attainment and 

maintenance of new nitrogen dioxide and sulfur dioxide National Ambient Air Quality Standards 

(NAAQS), will imminently face a new ozone NAAQS and are looking toward a new fine particulate 

matter NAAQS. At the same time, we continue to face challenges ameliorating toxic air pollutants. 

For many areas, meeting these NAAQS and controlling air toxics will require significantly more 

stringent motor vehicle emissions standards due to the large contribution of motor vehicles to air 

pollution problems, as evidenced by NATA data as well as local monitoring and related studies. 

Although EPA and NHTSA are focused on reducing motor vehicle GHG emissions and increasing 

fuel efficiency in this current effort, a broader view of the landscape reveals an urgent need for the

two federal agencies to take into account the criteria pollutant and air toxics co-benefits that are 

possible and necessary in the timeframe of this rulemaking (2017 to 2025). We urge EPA and 

NHTSA to broaden their rulemaking effort to take advantage of the co-benefit opportunities. 

States’ Readiness for Electric Vehicles

 EPA and NHTSA should be aware that the 14 states across the nation that have adopted 

CARB’s low-emission vehicle (LEV) standards are working hard to be ready for electric and fuel 

cell vehicles. We anticipate success on this front. Therefore, in addition to desiring that the 

current regulatory effort achieve a GHG emissions reduction of at least 6 percent per year for the 

overall emissions benefit to the nation, these states also seek rigorous standards and requirements 

that will ensure that electric and electric-drive vehicles will be part of the fleet mix. Related to this 

issue, we urge that EPA use a non-zero emission factor to account for the emissions of electric 

vehicles. We would welcome further discussion of this issue so we may assist EPA in determining 

the most appropriate methodology for quantification of the emission factor. 

 Again, we thank you for talking with us and our colleagues. We remain keenly interested in 

this rulemaking and offer our assistance as you move ahead. 

Sincerely, 

 

Nancy L. Seidman Barry R Wallerstein 

Co-Chair Co-Chair 

NACAA Mobile Sources and Fuels Committee NACAA Mobile Sources and Fuels Committee 

cc: Ron Medford (U.S. DOT, NHTSA) 

Tom Cackette (CARB)