![[logo] US EPA](https://webarchive.library.unt.edu/eot2008/20081026054744im_/http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}
Tier 2 Study of Vehicle Emissions
This Web page presents information and data related to the Tier 2 Study, which assesses the need for more stringent tailpipe emission standards for light-duty vehicles (passenger cars and light-duty trucks).
For further information or assistance regarding this web page,
contact:
ASD Information Line, phone: (734) 214-4636 or email: asdinfo@epa.gov
NOTE: You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.
What is the Tier 2 Study?
The Tier 2 Study must be performed by EPA according to the requirements of subsection 202(i) of the Clean Air Act Amendments of 1990.
"The Administrator, with the participation of the Office of Technology Assessment, shall study whether or not further reductions in emissions from light-duty vehicles and light-duty trucks should be required pursuant to this title." --From subsection 202(i) of the Clean Air Act, as amended
Subsection 202(i) requires that EPA address specific questions in a report to Congress and in the subsequent required rulemaking. The following issue areas, specified in the Clean Air Act Amendments, define the broad scope of the Tier 2 Study:
- Air Quality Assessment
- Are further emission reductions from cars and light trucks needed to attain and maintain the National Ambient Air Quality Standards (NAAQS)?
- Technology Assessment
- What technology is available and what is the cost to achieve further emissions reductions?
- Cost-Effectiveness Assessment
- Are further emission reductions from light cars and trucks cost-effective in comparison to alternative ways of reducing emissions?
Public Participation
EPA Workshop on Gasoline Sulfur: May 12, 1998, Arlington, VA
- Workshop Agenda (PDF) (1 pg, 4K)
- Attendance List (PDF) (11 pp, 37K)
- EPA Presentation (PDF) (15 pp, 122K)
- STAPPA/ALAPCO Presentation
- Auto Industry Presentations
- Chrysler (PDF) (16 pp, 46K)
- General Motors (PDF) (11 pp, 53K)
- Ford (PDF) (4 pp, 123K)
- Honda (PDF) (4 pp, 16K)
- Toyota (PDF) (16 pp, 218K)
- MECA (PDF) (5 pp, 7K)
- Environmental Community Presentations
- American Lung Association
- Sierra Club [not available]
- Clean Air Network
- Other Presentations
- International Joint Commission/US Section
- Automotive Fuels Consulting, Inc. (PDF) (5 pp, 17K)
Public Workshop: April 23, 1997, Washington DC
An EPA White Paper served as the basis for the public
workshop. Approximately 80 people attended the all-day workshop, representing
the automotive, oil, and related industries, as well as representatives
of state and local air pollution control agencies and environmental
organizations. The workshop began with an introduction and presentation
by EPA staff and comments and information provided by interested parties.
These formal presentations were followed by about an hour of informal
discussions. Some of the presentations and related items are available
below.
- Federal Register Notice of Availability and of Public Workshop (April 15, 1997)
- Presentations given at the workshop
- EPA (PDF) (19 pp, 185K)
- STAPPA/ALAPCO
- AAMA (PDF) (42 pp, 41K)
- NESCAUM [not available]
- MECA (PDF) (17 pp, 236K)
- Ricardo, Inc. (PDF) (1 pp, 7K)
- AIR, Inc. (PDF) (3 pp, 10K)
- Ford Motor Company, Inc. (PDF) (6 pp, 104K) (presentation on AAMA/AIAM sulfur test program)
- General Motors (PDF) (1 pg, 4K) (presentation on CRC/EPA sulfur test program)
Tier 2 Documents
July 31, 1998 Tier 2 Report to Congress
- Report (PDF) (57 pp, 179K, EPA 420-R-98-008, July 1998)
- Appendices (PDF) (90 pp, 326K)
- Fact Sheet (PDF) (3 pp, 12K, EPA 420-F-98-028, July 1998)
May 18, 1998 TIER2.EXE Version of MOBILE5b used in Tier 2 Study
- Readme (important information on use of model)
- Model Documentation
- Download TIER2 model and documentation (ZIP) (320K)
May 1, 1998 EPA Staff Paper on Gasoline Sulfur Issues
- Fact Sheet (PDF) (3 pp, 9K, EPA 420-F-98-022, May 1998)
- Report (PDF) (59 pp, 730K, EPA 420-R-98-005, May 1998)
- Appendices (PDF) (33 pp, 175K)
April 23, 1998 Draft Tier 2 Study
- Fact Sheet (PDF) (3 pp, 12K, EPA 420-R-98-021, April 1998)
- Federal Register Notice of Availability
- Draft Tier 2 Study (PDF) (56 pp, 170K, EPA 420-P-98-009, April 1998)
- Appendices to Draft Tier 2 Study (PDF) (46 pp, 215K)
- Supporting Report: Methodology for Modifying MOBILE5b in the Tier 2 Study (PDF) (43 pp, 500K, EPA 420-R-98-004, April 1998)
November 1997 Benefits and Cost of Potential Tier 2 Emission Reduction Technologies; Energy and Environmental Analysis, Inc.
- Final Report (PDF) (151 pp, 1.7MB)
- EPA White Paper (also available as a PDF file, 14 pp, 97K, EPA 420-S-97-001, April 1997)
- This paper, which served as the basis of the public workshop, outlines the scope and timing of the Tier 2 Study and presents issues identified by EPA as being potentially important to the Tier 2 Study. It also discusses the approach the EPA intends to take in conducting the air quality, technology, and cost-effectiveness assessments required by the Clean Air Act.
Links to Related EPA Sites
- EPA's Updated Air Quality Standards for Smog (Ozone) and Particulate Matter
- EPA "Green Book" listing of NAAQS non-attainment areas
- Real-time Air Pollution Data: Office of Air Quality Planning and Standards, Air Now web site - Several states now have World Wide Web sites containing air pollution data that is "real time" -- up-to-the-minute or frequently updated information from monitors and other sources. The AIRNOW, Real Time Air Pollution Data page gives access to many of these pages.
- Ozone Transport Assessment Group (OTAG) Home Page
- Plain English Guide to the Clean Air Act