Skip to content U.S. Department of Transportation/Federal Highway AdministrationU.S. Department of Transportation/Federal Highway Administration
Office of Planning, Environment, & Realty (HEP)

Questions Regarding Greenhouse Gas Endangerment Analysis

From: Marchese, April <FHWA>
Sent: Thursday, March 26, 2009 10:53 AM
To: FHWA-#ALLDA-OfficialMailbox
Cc: FHWA-#ALLDFS-PersonalMailbox; HEPRCTeams; FHWA-#ALLFLH-OfficialMailbox; Lucero, Amy [FHWA]; Hecox, Doug <FHWA>; HEPODs; HEPTEAMS; Bini, Robert <FHWA>; Kafalenos, Robert <FHWA>; Turchetta, Diane <FHWA>; Lupes, Rebecca <FHWA>; Shepherd, Gloria <FHWA>; Carlson, David <FHWA>; Hill, Connie <FHWA>; Earsom, Steve; Daniel, Kathy <FHWA>; Culp, Michael <FHWA>; Davies, John <FHWA>; Frost, Mack <FHWA>; Savonis, Michael <FHWA>
Subject: INFORMATION: Questions Regarding Greenhouse Gas Endangerment Analysis


The purpose of the email is to address questions regarding the development of an "endangerment" analysis by EPA regarding greenhouse gas emissions. In response to a 2007 Supreme Court decision on motor vehicle emissions standards (Massachusetts v. EPA), EPA was required to undertake an analysis and prepare a finding of whether greenhouse gases may reasonably be anticipated to endanger public health and welfare. The finding would be made under Section 202(a) of the Clean Air Act, which relates to emission standards for motor vehicles. News media have recently reported that EPA has completed its analysis, but EPA has not made any announcements or released any final decisions yet. Based on the news reports, we have received several questions regarding the potential impact of such a finding on our programs.

If EPA does issue a finding that greenhouse gases endanger public health and welfare, it may become the basis for setting standards for greenhouse gas emissions from new motor vehicles and their engines. However, since the finding would be made under the sections of the Clean Air Act regarding motor vehicle emission standards, it would not directly affect the Federal-aid highway program. Nonetheless, it could raise the question whether a similar determination should be made for other parts of the Clean Air Act, such as the provisions to establish National Ambient Air Quality Standards (NAAQS) that apply to transportation conformity. So far EPA has maintained that NAAQS would not be an appropriate or effective way to regulate greenhouse gases. Establishing NAAQS is a lengthy process, so even if this were to happen, any impact on the Federal-aid highway program would not occur for years.

We will provide more information as it becomes available. If you have any questions, please contact or Cecilia Ho at or (202) 366-9862 or Diane Turchetta at or (202) 493-0158

Updated: 12/3/2012
HEP Home Planning Environment Real Estate
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000