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EO12866_GHG+Fuel Eff Stds for Med-Heavy-Duty Engines+Vehicles 2060-AP61 FRM 

Preamble_20110725.docx

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 85, 86, 600, 1033, 1036, 1037, 1039, 1065, 1066, and 1068

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration 

49 CFR Parts 523, 534, and 535

[EPA–HQ–OAR–2010–0162; NHTSA-2010-0079; FRL-xxxx-x]

RIN 2060-AP61; RIN 2127-AK74

Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and 

Heavy-Duty Engines and Vehicles

AGENCIES: Environmental Protection Agency (EPA) and National Highway Traffic 

Safety Administration (NHTSA)

ACTION: Final Rules

__________________________________________________________________

SUMMARY:

EPA and NHTSA, on behalf of the Department of Transportation, are each finalizing 

rules to establish a comprehensive Heavy-Duty National Program that will reduce 

greenhouse gas emissions and fuel consumption for on-road heavy-duty vehicles, 

responding to the President’s directive on May 21, 2010, to take coordinated steps to 

produce a new generation of clean vehicles. NHTSA’s final fuel consumption standards 

and EPA’s final carbon dioxide (CO2) emissions standards are tailored to each of three 

regulatory categories of heavy-duty vehicles: (1) Combination Tractors; (2) Heavy-duty

Pickup Trucks and Vans; and (3) Vocational Vehicles. The rules include separate 

standards for the engines that power combination tractors and vocational vehicles. 

Certain rules are exclusive to the EPA program. These include EPA’s final

hydrofluorocarbon emissions standards to control leakage from air conditioning systems 

in combination tractors, and pickup trucks and vans. These also include EPA’s final 

nitrous oxide (N2O) and methane (CH4) emissions standards that will apply to all heavyduty engines, pickup trucks and vans. EPA is also finalizing provisions allowing lightduty vehicle manufacturers to use CO2 credits to meet the light-duty vehicle N2O and 

CH4 standards, technical amendments to the fuel economy provisions for light-duty 

vehicles in 40 CFR part 600, and a technical amendment to the criteria pollutant

emissions requirements for certain switch locomotives in 40 CFR part 1039.

EPA’s final greenhouse gas emission standards under the Clean Air Act will begin with 

model year 2014. NHTSA’s final fuel consumption standards under the Energy
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Independence and Security Act of 2007 will be voluntary in model years 2014 and 2015, 

becoming mandatory with model year 2016 for most regulatory categories. Commercial 

trailers are not regulated in this phase of the Heavy-Duty National Program.

The agencies estimate that the combined standards will reduce CO2 emissions by

approximately 270 million metric tons and save over 500 million barrels of oil over the 

life of vehicles sold during the 2014 through 2018 model years, providing over $7 billion

in net societal benefits, and $49 billion in net societal benefits when private fuel savings 

are considered.

DATES: These final rules are effective on [Insert date 60 days after publication in the 

Federal Register], sixty days after date of publication in the Federal Register. The 

incorporation by reference of certain publications listed in this regulation is approved by 

the Director of the Federal Register as of [Insert date 60 days after publication in the 

Federal Register].

ADDRESSES: EPA and NHTSA have established dockets for this action under Docket 

ID No. EPA–HQ–OAR–2010–0162 and NHTSA-2010-0079, respectively. All 

documents in the docket are listed on the www.regulations.gov web site. Although listed 

in the index, some information is not publicly available, e.g., confidential business 

information or other information whose disclosure is restricted by statute. Certain other 

material, such as copyrighted material, is not placed on the Internet and will be publicly

available only in hard copy form. Publicly available docket materials are available either 

electronically through www.regulations.gov or in hard copy at the following locations: 

EPA: EPA Docket Center, EPA/DC, EPA West Building, 1301 Constitution Ave., N.W., 

Room 3334, Washington DC. The Public Reading Room is open from 8:30 a.m. to 4:30 

p.m., Monday through Friday, excluding legal holidays. The telephone number for the 

Public Reading Room is (202) 566–1744, and the telephone number for the Air Docket is 

(202) 566-1742. NHTSA: Docket Management Facility, M-30, U.S. Department of 

Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New Jersey Avenue, 

SE, Washington, DC 20590. The Docket Management Facility is open between 9 a.m. 

and 5 p.m. Eastern Time, Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: NHTSA: Lily Smith, Office of 

Chief Counsel, National Highway Traffic Safety Administration, 1200 New Jersey

Avenue, SE, Washington, DC 20590. Telephone: (202) 366-2992. EPA: Lauren Steele, 

Office of Transportation and Air Quality, Assessment and Standards Division (ASD), 

Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; 

telephone number: (734) 214-4788; fax number: (734) 214-4816; email address:

steele.lauren@epa.gov, or contact the Assessment and Standards Division, email 

OTAQPUBLICWEB@epa.gov. 

SUPPLEMENTARY INFORMATION: 
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A. Does this Action Apply to Me

This action affects companies that manufacture, sell, or import into the United States new 

heavy-duty engines and new Class 2b through 8 trucks, including combination tractors, 

school and transit buses, vocational vehicles such as utility service trucks, as well as 3⁄4-

ton and 1-ton pickup trucks and vans. The heavy-duty category incorporates all motor 

vehicles with a gross vehicle weight rating of 8,500 pounds or greater, and the engines 

that power them, except for medium-duty passenger vehicles already covered by the 

greenhouse gas emissions standards and corporate average fuel economy standards issued 

for light-duty model year 2012-2016 vehicles. Regulated categories and entities include 

the following: 

Category NAICS CodeaExamples of Potentially Affected Entities

Industry 336111 Motor Vehicle Manufacturers, Engine and 

336112 Truck Manufacturers

336120

Industry 541514 Commercial Importers of Vehicles and 

811112 Vehicle Components

811198

Industry 336111 Alternative Fuel Vehicle Converters

336112

422720

454312

541514

541690

811198

Industry 333618 Manufacturers, remanufacturers and importers of 

336510 locomotives and locomotive engines

Note:

a

 North American Industry Classification System (NAICS)

This table is not intended to be exhaustive, but rather provides a guide for readers 

regarding entities likely covered by these rules. This table lists the types of entities that 

the agencies are aware may be regulated by this action. Other types of entities not listed 

in the table could also be regulated. To determine whether your activities are regulated 

by this action, you should carefully examine the applicability criteria in the referenced

regulations. You may direct questions regarding the applicability of this action to the 

persons listed in the preceding FOR FURTHER INFORMATION CONTACT section.

Table of Contents
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I. Overview

A. Introduction

B. Building Blocks of the Heavy-duty National Program

C. Summary of the Final EPA and NHTSA HD National Program

D. Summary of Costs and Benefits of the HD National Program

E. Program Flexibilities

F. EPA and NHTSA Statutory Authorities

G. Future HD GHG and Fuel Consumption Rulemakings

II. Final GHG and Fuel Consumption Standards for Heavy-duty Engines and Vehicles

A. What Vehicles Will Be Affected?

B. Class 7 and 8 Combination Tractors

C. Heavy-Duty Pickup Trucks and Vans

D. Class 2b-8 Vocational Vehicles

E. Other Standards Provisions

III. Feasibility Assessments and Conclusions

A. Class 7-8 Combination Tractor

B. Heavy-Duty Pickup Trucks and Vans

C. Class 2b-8 Vocational Vehicles

IV. Final Regulatory Flexibility Provisions

A. Averaging, Banking, and Trading Program

B. Additional Flexibility Provisions

V. NHTSA and EPA Compliance, Certification, and Enforcement Provisions

A. Overview

B. Heavy-duty Pickup Trucks and Vans

C. Heavy-Duty Engines

D. Class 7 and 8 Combination Tractors

E. Class 2b-8 Vocational Vehicles

F. General Regulatory Provisions

G. Penalties

VI. How Will This Program Impact Fuel Consumption, GHG Emissions, and Climate 

Change?
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A. What Methodologies Did the Agencies Use to Project GHG Emissions and Fuel 

Consumption Impacts?

B. MOVES Analysis

C. What Are the Projected Reductions in Fuel Consumption and GHG Emissions?

D. Overview of Climate Change Impacts from GHG Emissions

E. Changes in Atmospheric CO2 Concentrations, Global Mean Temperature, Sea Level 

Rise, and Ocean pH Associated with the Program’s GHG Emissions Reductions

VII. How Will This Final Action Impact Non-GHG Emissions and Their Associated 

Effects?

A. Emissions Inventory Impacts

B. Health Effects of Non-GHG Pollutants

C. Environmental Effects of Non-GHG Pollutants

D. Air Quality Impacts of Non-GHG Pollutants

VIII. What are the Agencies’ Estimated Cost, Economic, and Other Impacts of the Final 

Program?

A. Conceptual Framework for Evaluating Impacts

B. Costs Associated With the Final Program

C. Indirect Cost Multipliers

D. Cost per Ton of Emissions Reductions

E. Impacts of Reduction in Fuel Consumption

F. Class Shifting and Fleet Turnover Impacts

G. Benefits of Reducing CO2 Emissions

H. Non-GHG Health and Environmental Impacts

I. Energy Security Impacts

J. Other Impacts

K. The Effect of Safety Standards and Voluntary Safety Improvements on Vehicle 

Weight

L. Summary of Costs and Benefits from the Greenhouse Gas Emissions Perspective

M. Summary of Costs and Benefits from the Fuel Efficiency Perspective

N. Employment Impacts

IX. Analysis of the Alternatives

A. What Are the Alternatives that the Agencies Considered?
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B. How Do These Alternatives Compare in Overall GHG Emissions Reductions and Fuel 

Efficiency and Cost?

C. What Is the Agencies’ Decision Regarding Trailer Standards?

X. Public Participation

XI. NHTSA’s Record of Decision

A. The Agency’s Decision

B. Alternatives Considered by NHTSA in Reaching its Decision, Including the 

Environmentally Preferable Alternative

C. Factors Balanced by NHTSA in Making its Decision

D. How the Factors and Considerations Balanced by NHTSA Entered into its Decision

E. The Agency’s Preferences among Alternatives Based on Relevant Factors, Including 

Economic and Technical Considerations and Agency Statutory Missions

F. Mitigation

XII. Statutory and Executive Order Reviews

XIII. Statutory Provisions and Legal Authority

A. EPA

B. NHTSA

I. Overview

A. Introduction

EPA and NHTSA (“the agencies”) are announcing a first-ever program to reduce 

greenhouse gas (GHG) emissions and fuel consumption in the heavy-duty highway 

vehicle sector. This broad sector – ranging from large pickups to sleeper-cab tractors –

together represent the second largest contributor to oil consumption and GHG emissions

from the mobile source sector, after light-duty passenger cars and trucks. These are the 

second joint rules issued by the agencies, following on the April 1, 2010 standards to 

sharply reduce GHG emissions and fuel consumption from MY 2012-2016 passenger 

cars and light trucks (published on May 7, 2010 at 75 FR 25324). 

In a May 21, 2010 memorandum to the Administrators of EPA and NHTSA (and 

the Secretaries of Transportation and Energy), the President stated that “America has the 

opportunity to lead the world in the development of a new generation of clean cars and 

trucks through innovative technologies and manufacturing that will spur economic 

growth and create high-quality domestic jobs, enhance our energy security, and improve 
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our environment.” 2,3 In the May 2010 memorandum, the President specifically requested

the Administrators of EPA and NHTSA to “immediately begin work on a joint 

rulemaking under the Clean Air Act (CAA) and the Energy Independence and Security

Act of 2007 (EISA) to establish fuel efficiency and greenhouse gas emissions standards 

for commercial medium-and heavy-duty on-highway vehicles and work trucks beginning 

with the 2014 model year (MY).” In this final rulemaking each agency is addressing this 

Memorandum by adopting rules under its respective authority that together comprise a 

coordinated and comprehensive HD National Program designed to address the urgent and 

closely intertwined challenges of reduction of dependence on oil, achievement of energy

security, and amelioration of global climate change. 

At the same time, the final program will enhance American competitiveness and 

job creation, benefit consumers and businesses by reducing costs for transporting goods, 

and spur growth in the clean energy sector. 

The HD National Program the agencies are finalizing today reflects a 

collaborative effort between the agencies, a range of public interest nongovernmental 

organizations (NGOs), the state of California and the regulated industry. At the time of 

the President’s announcement, a number of major HD truck and engine manufacturers 

representing the vast majority of this industry, and the California Air Resources Board

(California ARB), sent letters to EPA and NHTSA supporting the creation of a HD 

National Program based on a common set of principles. In the letters, the stakeholders 

committed to working with the agencies and with other stakeholders toward a program 

consistent with common principles, including:

 Increased use of existing technologies to achieve significant GHG emissions and fuel 

consumption reductions;

 A program that starts in 2014 and is fully phased in by 2018;

 A program that works towards harmonization of methods for determining a vehicle’s 

GHG and fuel efficiency, recognizing the global nature of the issues and the industry;

 Standards that recognize the commercial needs of the trucking industry; and

 Incentives leading to the early introduction of advanced technologies.

The final rules adopted today reflect these principles.

 

2

Improving Energy Security, American Competitiveness and Job Creation, and Environmental Protection 

Through a Transformation of Our Nation’s Fleet of Cars And Trucks,” Issued May 21, 2010, published at 

75 FR 29399, May 26, 2010.

3 The May 2010 Presidential Memorandum also directed EPA and NHTSA, in close coordination with the 

California Air Resources Board, to build on the National Program for 2012-2016 MY light-duty vehicles 

by developing and proposing coordinated light-duty vehicle standards for MY 2017-2025. The agencies 

have taken an initial step in this process, releasing a Joint Notice of Intent and Initial Joint Technical 

Assessment Report in September 2010 (75 FR 62739), and a Supplemental Notice of Intent (75 FR 76337). 

The agencies plan to issue a full light-duty vehicle proposal to extend the National Program to MY 2017-

2025 in September 2011.
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The final HD National Program builds on many years of heavy-duty engine and 

vehicle technology development to achieve what the agencies believe is the greatest 

degree of fuel consumption and GHG emission reduction appropriate, technologically 

and economically feasible, and cost-effective for model years 2014-2018. In addition to

taking aggressive steps that are reasonably possible now, based on the technological 

opportunities and pathways that present themselves during these model years, the 

agencies and industry will also continue learning about emerging opportunities for this 

complex sector to further reduce fuel consumption and GHG emission through future 

regulatory steps. 

Similarly, the agencies will participate in efforts to improve our ability to 

accurately characterize the actual in-use fuel consumption and emissions of this complex 

sector. As technologies progress in the coming years and as the agencies improve the 

regulatory tools to evaluate real world vehicle performance, we expect that we will 

develop a second phase of regulations to reinforce these initial rules and achieve further

reductions in GHG emissions and fuel consumption reduction for the mid- and longerterm time frame (beyond 2018). The agencies are committed to working with all 

interested stakeholders in this effort and to the extent possible working towards alignment 

with similar programs being developed in Canada, Mexico, Europe, China, and Japan. In 

doing so, we will continue to evaluate many of the structural and technical decisions we 

are making in today’s final action in the context of new technologies and the new 

regulatory tools that we expect to realize in the future.

The regulatory program we are finalizing today is largely unchanged from the 

proposal the agencies made on November 30, 2010 (see 75 FR 741512). The structure of 

the program and the stringency of the standards are essentially the same as proposed. We 

have made a number of changes to the testing requirements and reporting requirements to 

provide greater regulatory certainty and better align the NHTSA and EPA portions of the 

program. In response to comments, we have also made some changes to the averaging, 

banking and trading (ABT) provisions of the program that will make implementation of 

this final program more flexible for manufacturers. We have added provisions to further 

encourage the development of advanced technologies and to provide a more 

straightforward mechanism to certify engines and vehicles using innovative technologies. 

Finally in response to comments, we have made some technical changes to our emissions 

compliance model that results in different numeric standards for both combination 

tractors and vocational vehicles to more accurately characterize emissions while 

maintaining the same overall stringency and therefore expected costs and benefits of the 

program.

Heavy-duty vehicles move much of the nation’s freight and carry out numerous 

other tasks, including utility work, concrete delivery, fire response, refuse collection, and 

many more. Heavy-duty vehicles are primarily powered by diesel engines, although 

about 37 percent of these vehicles are powered by gasoline engines.4 Heavy-duty trucks5

 

4 References in this preamble to “gasoline” engines (and the vehicles powered by them) generally include 

other Otto-cycle engines as well, such as those fueled by ethanol and natural gas, except in contexts that are 

clearly gasoline-specific.
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have long been an important part of the goods movement infrastructure in this country

and have experienced significant growth over the last decade related to increased imports 

and exports of finished goods and increased shipping of finished goods to homes through 

internet purchases.

The heavy-duty sector is extremely diverse in several respects, including types of 

manufacturing companies involved, the range of sizes of trucks and engines they

produce, the types of work the trucks are designed to perform, and the regulatory history 

of different subcategories of vehicles and engines. The current heavy-duty fleet 

encompasses vehicles from the “18-wheeler” combination tractors one sees on the 

highway to school and transit buses, to vocational vehicles such as utility service trucks, 

as well as the largest pickup trucks and vans.

For purposes of this preamble, the term “heavy-duty” or “HD” is used to apply to 

all highway vehicles and engines that are not within the range of light-duty vehicles, 

light-duty trucks, and medium-duty passenger vehicles (MDPV) covered by the GHG and 

Corporate Average Fuel Economy (CAFE) standards issued for MY 2012-2016.7 It also 

does not include motorcycles. Thus, in this rulemaking, unless specified otherwise, the 

heavy-duty category incorporates all vehicles with a gross vehicle weight rating above 

8,500 pounds, and the engines that power them, except for MDPVs.8 

The agencies proposed to cover all segments of the heavy-duty category above,

except with respect to recreational vehicles (RV’s or motor homes). We note that the 

Energy Independence and Security Act of 2007 requires NHTSA to set standards for 

“commercial medium- and heavy-duty on-highway vehicles and work trucks.”

9

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standards that EPA is finalizing today cover recreational on-highway vehicles, 

while NHTSA proposed not to include recreational vehicles based on an interpretation of 

the term “commercial medium- and heavy-duty on-highway commercial” vehicles. 

NHTSA stated in the NPRM that recreational vehicles are non-commercial, and therefore 

outside of the term and the scope of its rule. 

Oshkosh Corporation commented that this interpretation did not match the 

statutory definition of the term in EISA, which defines “commercial medium- and heavy-

 

5

In this rulemaking, EPA and NHTSA use the term “truck” in a general way, referring to all categories of 

regulated heavy-duty highway vehicles (including buses). As such, the term is generally interchangeable 

with “heavy-duty vehicle.”

7

 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy 

Standards; Final Rule 75 FR 25323, May 7, 2010.

8

 The CAA defines heavy-duty as a truck, bus or other motor vehicles with a gross vehicle weight rating 

exceeding 6,000 pounds (CAA section 202(b)(3)). The term HD as used in this action refers to a subset of 

these vehicles and engines.

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49 U.S.C. 32902(k)(2). “Commercial medium- and heavy-duty on-highway vehicles” are defined as onhighway vehicles with a gross vehicle weight rating of 10,000 pounds or more, while “work trucks” are 

defined as vehicles rated between 8,500 and 10,000 pounds gross vehicle weight that are not MDPVs. See

49 U.S.C. §§ 32901(a)(7) and (a)(19).
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duty on-highway vehicle” by weight only,

10 and that therefore the agency’s interpretation 

of the term should be explicitly broadened to include all vehicles, and more than only

vehicles that are not engaged in interstate commerce as defined by the Federal Motor 

Carrier Safety Administration in 49 CFR § 202. Alternatively, Oshkosh suggested that if 

NHTSA followed the definition provided in EISA, which makes no direct reference to 

the concept of “commercial,” there would be no logical reason to exclude RVs based on 

that definition. 

NHTSA has considered Oshkosh’s comment and reconsidered its interpretation 

that effectively read words into the statutory definition. Given the very wide variety of 

vehicles contained in the HD fleet, reading those words into the definition and thereby 

excluding certain types of vehicles could create illogical results, i.e., treating similar 

vehicles differently. Therefore, NHTSA will adhere to the statutory definition contained 

in EISA for this rulemaking. However, as RVs were not included by NHTSA in the 

proposed regulation in the NPRM, they are not within the scope and must be excluded in 

NHTSA’s portion of the final program. Accordingly, NHTSA will address this issue in 

the next rulemaking. However, as noted, RVs are subject to the CO2 standards for 

vocational vehicles. 

Setting fuel consumption standards for the heavy-duty sector, pursuant to 

NHTSA’s EISA authority, will also improve our energy and national security by

reducing our dependence on foreign oil, which has been a national objective since the 

first oil price shocks in the 1970s. Net petroleum imports now account for approximately

49-51 percent of U.S. petroleum consumption. World crude oil production is highly

concentrated, exacerbating the risks of supply disruptions and price shocks as the recent 

unrest in North Africa and the Persian Gulf highlights. Recently, oil prices have been

over $100 per barrel, gasoline and diesel fuel prices in excess of $4 per gallon, causing 

financial hardship for many families and businesses. The export of U.S. assets in 

exchange for oil imports continues to be an important component of the historically

unprecedented U.S. trade deficits. Transportation accounts for about 72 percent of U.S. 

petroleum consumption. Heavy-duty vehicles account for about 17 percent of 

transportation oil use, which means that they alone account for about 12 percent of all 

U.S. oil consumption.

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Setting GHG emissions standards for the heavy-duty sector will help to 

ameliorate climate change. The EPA Administrator found after a thorough examination 

of the scientific evidence on the causes and impact of current and future climate change, 

and careful review of public comments, that the science compellingly supports a positive 

finding that atmospheric concentrations of six greenhouse gases taken in combination 

result in air pollution which may reasonably be anticipated to endanger both public health 

 
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and welfare and that the combined emissions of these greenhouse gases from new motor 

vehicles and engies contributes to the greenhouse gas air pollution that endangers public 

health and welfare. In her finding, the Administrator carefully studied and relied heavily 

upon the major findings and conclusions from the recent assessments of the U.S. Climate

Change Science Program and the U.N. Intergovernmental Panel on Climate Change. 74 

FR 66496, December 15, 2009. As summarized in the Technical Support Document for 

EPA’s Endangerment and Cause or Contribute Findings under Section 202(a) of the 

Clean Air Act, anthropogenic emissions of GHGs are very likely (a 90 to 99 percent 

probability) the cause of most of the observed global warming over the last 50 years.12 

Primary GHGs of concern are carbon dioxide (CO2), methane (CH4), nitrous oxide

(N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride

(SF6). Mobile sources emitted 31 percent of all U.S. GHGs in 2007 (transportation 

sources, which do not include certain off-highway sources, account for 28 percent) and 

have been the fastest-growing source of U.S. GHGs since 1990.13 Mobile sources 

addressed in EPA’s endangerment and contribution findings under CAA section 202(a) --

light-duty vehicles, heavy-duty trucks, buses, and motorcycles -- accounted for 23 

percent of all U.S. GHG emissions in 2007.14 Heavy-duty vehicles emit CO2, CH4, N2O, 

and HFCs and are responsible for nearly 19 percent of all mobile source GHGs (nearly

6% of all U.S. GHGs) and about 25 percent of section 202(a) mobile source GHGs. For 

heavy-duty vehicles in 2007, CO2 emissions represented more than 99 percent of all 

GHG emissions (including HFCs).

15

In developing this HD National program, the agencies have worked with a large 

and diverse group of stakeholders representing truck and engine manufacturers, trucking 

fleets, environmental organizations, and states including the State of California.17 

Further, it is our expectation based on our ongoing work with the State of California that 

the California ARB will be able to adopt regulations equivalent in practice to those of this 

HD National Program, just as it has done for past EPA regulation of heavy-duty trucks 

and engines. NHTSA and EPA have been working with California ARB to enable that 

outcome.

In light of the industry’s diversity, and consistent with the recommendations of 

the National Academy of Sciences (NAS) as discussed further below, the agencies are 

adopting a HD National Program that recognizes the different sizes and work 

 

12 U.S. EPA. (2009). “Technical Support Document for Endangerment and Cause or Contribute Findings 

for Greenhouse Gases Under Section 202(a) of the Clean Air Act” Washington, D.C., available at Docket: 

EPA-HQ-OAR-2009-0171-11645, and at http://epa.gov/climatechange/endangerment.html.

13 U.S. Environmental Protection Agency. 2009. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 

1990-2007. EPA 430-R-09-004. Available at 

http://epa.gov/climatechange/emissions/downloads09/GHG2007entire_report-508.pdf 

14 See Endangerment TSD, Note 12, above, at pp. 180-194.

15 U.S. Environmental Protection Agency. 2009. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 

See Note 13, above. 

17 Pursuant to DOT Order 2100.2, NHTSA has docketed a memorandum recording those meetings that it 

attended and documents submitted by stakeholders which formed a basis for this action and which can be 

made publicly available in its docket for this rulemaking. DOT Order 2100.2 is available at 

http://www.reg-group.com/library/DOT2100-2.PDF.
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requirements of this wide range of heavy-duty vehicles and their engines. NHTSA’s final 

fuel consumption standards and EPA’s final GHG standards apply to manufacturers of 

the following types of heavy-duty vehicles and their engines; the final provisions for each 

of these are described in more detail below in this section:

 Heavy-duty Pickup Trucks and Vans

 Combination Tractors

 Vocational Vehicles

As in the light-duty 2012-2016 MY vehicle rule, EPA’s and NHTSA’s final

standards for the heavy-duty sector are largely harmonized with one another due to the 

close and direct relationship between improving the fuel efficiency of these vehicles and 

reducing their CO2 tailpipe emissions. For all vehicles that consume carbon-based fuels, 

the amount of CO2 exhaust emissions is essentially constant per gallon for a given type of 

fuel that is consumed. The more efficient a heavy-duty truck is in completing its work, 

the lower its environmental impact will be, because the less fuel consumed to move cargo 

a given distance, the less CO2 that truck emits directly into the air. The technologies 

available for improving fuel efficiency, and therefore for reducing both CO2 emissions 

and fuel consumption, are one and the same.18 Because of this close technical 

relationship, NHTSA and EPA have been able to rely on jointly-developed assumptions, 

analyses, and analytical conclusions to support the standards and other provisions that 

NHTSA and EPA are adopting under our separate legal authorities.

This program is based on standards for direct exhaust emissions from engines and 

vehicles. In characterizing the overall emissions impacts, benefits and costs of the 

program, analyses of air pollutant emissions from upstream sources have been conducted. 

In this action, the agencies use the term upstream to include emissions from the 

production and distribution of fuel. A summary of the analysis of upstream emissions can 

be found in Section VI.C of this preamble, and further details are available in Chapter 5 

of the RIA.

The timelines for the implementation of the final NHTSA and EPA standards are 

also closely coordinated. EPA’s final GHG emission standards will begin in model year 

2014. In order to provide for the four full model years of regulatory lead time required 

by EISA, as discussed in Section I. B. (5) below, NHTSA’s final fuel consumption 

standards will be voluntary in model years 2014 and 2015, becoming mandatory in model 

year 2016, except for diesel engine standards which will be voluntary in model years 

2014, 2015 and 2016, becoming mandatory in model year 2017. Both agencies are also 

allowing for early compliance in model year 2013. A detailed discussion of how the final 

standards are consistent with each agency’s respective statutory requirements and 

authorities is found later in this preamble. 

 

18 However, as discussed below, in addition to addressing CO2, the EPA’s final standards also include 

provisions to address other GHGs (nitrous oxide, methane, and air conditioning refrigerant emissions). See

Section II.
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Allison Transmission stated that sufficient time must be taken before issuing the 

final rules in order to ensure that the standards are supportable. As explained in Sections 

II and III below, as well as in the RIA, the agencies believe there is sufficient lead time to 

meet all of the standards adopted in today’s rules. For those areas for which the agencies 

have determined that insufficient time is available to develop appropriate standards, such 

as for trailers, the agencies are not including regulations as part of this initial program.

NHTSA received several comments related to the timing of the implementation of 

its fuel consumption standards. The Engine Manufacturers Association (EMA), the 

National Automobile Dealers Association (NADA), The Volvo Group (Volvo), and 

Navistar argued that the timing of NHTSA’s standards violated the lead time requirement 

of 49 U.S.C. 32902(k)(3)(A), which states that standards under the new medium- and 

heavy-duty program shall have “not less than 4 full model years of regulatory lead-time.” 

The commenters seemed to interpret the voluntary program as the imposition of 

regulation upon industry. NADA described NHTSA’s standards during the voluntary

period as “mandates.” 

NHTSA has reviewed this issue and believes that the regulatory schedule is 

consistent with the lead time requirement of 32902(k)(3). To clarify, NHTSA will not be 

imposing a mandatory regulatory program until 2016, and none of the voluntary

standards will be “mandates.” As described in later sections, the voluntary standards 

would only apply to a manufacturer if it makes the voluntary and affirmative choice to 

opt-in to the program. 19 Mandatory NHTSA standards will first come into effect in 

2016, giving industry four full years of lead time with the NHTSA fuel consumption 

standards. 

EMA, NADA, and Navistar also argued that the proposed standards would violate 

the stability requirement of 49 U.S.C. 32902(k)(3)(B), which states that they shall have 

“not less than 3 full model years of regulatory stability.” EMA stated that since there are 

HD emission standards taking effect in 2013, the 2014 implementation date for this rule 

would violate the stability requirements. NADA argued that the MY 2014-2017/2018 

phase-in period was inadequate to fulfill the stability requirement. 

Congress has not spoken directly to the meaning of the words “regulatory

stability.” NHTSA believes that the “regulatory stability” requirement exists to ensure

that manufacturers will not be subject to new standards in repeated rulemakings too 

rapidly, given that Congress did not include a minimum duration period for the MD/HD 

standards.20 NHTSA further believes that standards, which as set provide for increasing 

stringency during the period that the standards are applicable under this rule to be the 

maximum feasible during the regulatory period, are within the meaning of the statute. In 

this statutory context, NHTSA interprets the phrase “regulatory stability” in § 

32902(k)(3)(B) as requiring that the standards remain in effect for three years before they

 

19 Prior to or at the same time that a manufacturer submits its first application for a certificate of 

conformity; see Section V below. 

20 In contrast, light-duty standards must remain in place for “at least 1, but not more than 5, model years.” 

23902(b)(3)(B).
14 of 

may be increased by amendment. It does not prohibit standards which contain predetermined stringency increases. 

As laid out in Section II below, NHTSA’s final standards follow different phasein schedules based on differences between the regulatory categories. Consistent with 

NHTSA’s statutory obligation to implement a program designed to achieve the maximum 

feasible fuel efficiency improvement, the standards increase in stringency based upon 

increasing fleet penetration rates for the available technologies. The NPRM proposed 

phase-in schedules aligned with EPA’s, some of which followed pre-determined 

stringency increases. The NPRM also noted that NHTSA was considering alternate 

standards that would not change in stringency during the time frame when the regulations 

are effective for those standards that increased throughout the mandatory program. As 

described in Section II below, the final rule includes the proposed alternate standards for 

those standards that follow such a stringency phase-in path. Therefore , NHTSA believes 

that the final rule provides ample stability for each standard.

Each standard, associated phase-in schedule, and alternative standard 

implemented by this final rule was noticed in the NPRM. Those fuel consumption 

standards that become mandatory in 2017 will remain in effect through at least 2019. 

This further ensures that the fuel consumption standards in this rule will remain in effect 

for at least three years, providing the statutorily-mandated three full years of regulatory 

stability, and ensuring that manufacturers will not be subject to new or amended 

standards too rapidly. (The greenhouse gas emission standards remain in effect unless 

and until amended in all later model years in any case.) Therefore, NHTSA believes the 

commenters’ concern about regulatory stability is addressed in the structure of the rule.

Neither EPA nor NHTSA is adopting standards at this time for GHG emissions or 

fuel consumption, respectively, for heavy-duty commercial trailers or for vehicles or 

engines manufactured by small businesses. The agencies recognize that aerodynamic and 

tire rolling resistance improvements to trailers represent a significant opportunity to 

reduce fuel consumption and GHGs as evidenced, among other things, by the work of the 

EPA SmartWay program. While we are deferring action today on setting trailer 

standards, the agencies are committed to moving forward to create a regulatory program 

for trailers that would complement the current vehicle program. See Section IX for more 

details on the agencies’ decisions regarding trailers, and Sections II and XII for more 

details on the agencies’ decisions regarding small businesses. 

B. Building Blocks of the Heavy-duty National Program

The standards that are being adopted in this notice represent the first time that 

NHTSA and EPA are regulating the heavy-duty sector for fuel consumption and GHG 

emissions, respectively. The HD National Program is rooted in EPA’s prior regulatory 

history, the SmartWay Transport Partnership program, and extensive technical and 

engineering analyses done at the federal level. This section summarizes some of the most 

important of these precursors and foundations for this HD National Program. 
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15 of

(1) EPA’s Traditional Heavy-duty Regulatory Program

Since the 1980s, EPA has acted several times to address tailpipe emissions of 

criteria pollutants and air toxics from heavy-duty vehicles and engines. During the last 

18 years, these programs have primarily addressed emissions of particulate matter (PM) 

and the primary ozone precursors, hydrocarbons (HC) and oxides of nitrogen (NOX). 

These programs have successfully achieved significant and cost-effective reductions in 

emissions and associated health and welfare benefits to the nation. They have been 

structured in ways that account for the varying circumstances of the engine and truck 

industries. As required by the CAA, the emission standards implemented by these 

programs include standards that apply at the time that the vehicle or engine is sold as well 

as standards that apply in actual use. As a result of these programs, new vehicles meeting 

current emission standards will emit 98% less NOX and 99% less PM than new trucks 20 

years ago. The resulting emission reductions provide significant public health and 

welfare benefits. The most recent EPA regulations which were fully phased-in in 2010, 

the monetized health and welfare benefits alone are projected to be greater than $70 

billion in 2030 – benefits far exceeding compliance costs and not including the 

unmonetized benefits resulting from reductions in air toxics and ozone precursors (66 FR 

5002, January 18, 2001). 

EPA’s overall program goal has always been to achieve emissions reductions 

from the complete vehicles that operate on our roads. The agency has often accomplished 

this goal for many heavy-duty truck categories through the regulation of heavy-duty

engine emissions. A key part of this success has been the development over many years 

of a well-established, representative, and robust set of engine test procedures that industry

and EPA now routinely use to measure emissions and determine compliance with 

emission standards. These test procedures in turn serve the overall compliance program 

that EPA implements to help ensure that emissions reductions are being achieved. By

isolating the engine from the many variables involved when the engine is installed and 

operated in a HD vehicle, EPA has been able to accurately address the contribution of the 

engine alone to overall emissions. The agencies discuss below how the final program 

incorporates the existing engine-based approach used for criteria pollutant regulations, as 

well as new vehicle-based approaches. 

(2) NHTSA’s Responsibilities to Regulate Heavy-Duty Fuel Efficiency under 

EISA

With the passage of the EISA in December 2007, Congress laid out a framework 

developing the first fuel efficiency regulations for HD vehicles. As codified at 49 U.S.C. 

32902(k), EISA requires NHTSA to develop a regulatory system for the fuel efficiency of 

commercial medium-duty and heavy-duty on-highway vehicles and work trucks in three 

steps: a study by NAS, a study by NHTSA, and a rulemaking to develop the regulations 

themselves.22

 

22 The NAS study is described below, and the NHTSA study accompanies this FRM.
16 of 

Specifically, section 102 of EISA, codified at 49 U.S.C. 32902(k)(2), states that 

not later than two years after completion of the NHTSA study, DOT (by delegation, 

NHTSA), in consultation with the Department of Energy (DOE) and EPA, shall develop 

a regulation to implement a “commercial medium-duty and heavy-duty on-highway

vehicle and work truck fuel efficiency improvement program designed to achieve the 

maximum feasible improvement.” NHTSA interprets the timing requirements as 

permitting a regulation to be developed earlier, rather than as requiring the agency to wait 

a specified period of time.

Congress specified that as part of the “HD fuel efficiency improvement program 

designed to achieve the maximum feasible improvement,” NHTSA must adopt and 

implement:

 Appropriate test methods;

 Measurement metrics;

 Fuel economy standards;23 and

 Compliance and enforcement protocols.

Congress emphasized that the test methods, measurement metrics, standards, and 

compliance and enforcement protocols must all be appropriate, cost-effective, and 

technologically feasible for commercial medium-duty and heavy-duty on-highway

vehicles and work trucks. NHTSA notes that these criteria are different from the “four 

factors” of 49 U.S.C. 32902(f)24 that have long governed NHTSA’s setting of fuel 

economy standards for passenger cars and light trucks, although many of the same issues 

are considered under each of these provisions.

Congress also stated that NHTSA may set separate standards for different classes 

of HD vehicles, which the agency interprets broadly to allow regulation of HD engines in 

addition to HD vehicles, and provided requirements new to 49 U.S.C. 32902 in terms of 

timing of regulations, stating that the standards adopted as a result of the agency’s 

rulemaking shall provide not less than four full model years of regulatory lead time, and 

three full model years of regulatory stability.

(3) National Academy of Sciences Report on Heavy-Duty Technology 

In April 2010 as mandated by Congress in EISA, the National Research Council 

(NRC) under NAS issued a report to NHTSA and to Congress evaluating medium-duty

 

23 In the context of 49 U.S.C. 32902(k), NHTSA interprets “fuel economy standards” as referring not 

specifically to miles per gallon, as in the light-duty vehicle context, but instead more broadly to account as 

accurately as possible for MD/HD fuel efficiency. While it is a metric that NHTSA considered for setting 

MD/HD fuel efficiency standards, the agency recognizes that miles per gallon may not be an appropriate 

metric given the work that MD/HD vehicles are manufactured to do. NHTSA is thus finalizing alternative 

metrics as discussed further below.

24 49 U.S.C. 32902(f) states that “When deciding maximum feasible average fuel economy under this 

section, [NHTSA] shall consider technological feasibility, economic practicability, the effect of other motor 

vehicle standards of the Government on fuel economy, and the need of the United States to conserve 

energy.”
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17 of

and heavy-duty truck fuel efficiency improvement opportunities, titled “Technologies and 

Approaches to Reducing the Fuel Consumption of Medium- and Heavy-duty Vehicles.”

25 This study covers the same universe of heavy-duty vehicles that is the focus of this 

final rulemaking – all highway vehicles that are not light-duty, MDPVs, or motorcycles. 

The agencies have carefully evaluated the research supporting this report and its

recommendations and have incorporated them to the extent practicable in the 

development of this rulemaking.

The NAS report is far reaching in its review of the technologies that are available 

and which may become available in the future to reduce fuel consumption from medium 

and heavy-duty vehicles. In presenting the full range of technical opportunities the report 

includes technologies which may not be available until 2020 or even further into the 

future. As such, the report provides not only a valuable list of off the shelf technologies 

from which the agencies have drawn in developing this near-term 2014-2018 program 

consistent with statutory authorities and with the set of principles set forth by the 

President, but the report also provides a road map the agencies can use as we look to 

develop future regulations for this sector. A review of the technologies in the NAS report 

makes clear that there are not only many technologies readily available today to achieve 

important reductions in fuel consumption, like the ones we used in developing the 2014-

2018 program, but there are also great opportunities for even larger reductions in the 

future through the development of advanced hybrid drive systems and sophisticated 

engine technologies such as Rankine waste heat recovery. The agencies will again make 

extensive use of this report when we move forward to develop the next phase of 

regulations for medium and heavy-duty vehicles.

Allison Transmission commented that NHTSA (implicitly, both agencies) had 

improperly relied on the NAS report and failed to do sufficient independent analysis, 

which Allison claimed did not meet the statutory obligation to provide an adequate basis 

for the rule. First, an agency does not improperly delegate its authority or judgment 

merely by using work performed by outside parties as the factual basis for its decision 

making. See U.S. Telecom Ass’n v. FCC, 359 F.3d 554, 568 (D.C. Cir. 2004); United 

Steelworkers of Am. v. Marshall, 647 F.2d 1189, 1216-17 (D.C. Cir. 1980). Here, 

although EPA and NHTSA carefully considered the NAS report, the agencies’ 

consideration and use of the report was not uncritical and the agencies exercised 

reasonable independent judgment in developing the proposed and final rules. Consistent 

with EISA’s direction, NAS submitted a report evaluating MD/HD fuel economy

standards to NHTSA in March of 2010. Indeed, many commenters argued that the 

agencies should have adopted more of the NAS report recommendations. The agencies 

reviewed the findings and recommendations of the NAS report when developing the 

proposed rules, as was clearly intended by Congress, but also conducted an independent 

study, as described throughout the record to the proposal and summarized in Section X of 

 

25 Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles; National 

Research Council; Transportation Research Board (2010). “Technologies and Approaches to Reducing the 

Fuel Consumption of Medium- and Heavy-Duty Vehicles,” (hereafter, “NAS Report”). Washington, D.C., 

The National Academies Press. Available electronically from the National Academies Press Website at 

http://www.nap.edu/catalog.php?record_id=12845 (last accessed September 10, 2010).
18 of 

the NPRM, 75 FR at 74351-56. In conducting its analysis of the NAS report, the 

agencies found that several key recommendations, such as the use of fuel efficiency

metrics, were the best approach to implementing the new program. However, the 

agencies rejected other recommendations of the NAS report, for example, by proposing 

separate regulation of engines and vehicles and the regulation of large manufacturers. 

(4) The NHTSA and EPA Light-duty National GHG and Fuel Economy 

Program

On May 7, 2010, EPA and NHTSA finalized the first-ever National Program for 

light-duty cars and trucks, which set GHG emissions and fuel economy standards for 

model years 2012-2016 (see 75 FR 25324). The agencies have used the light-duty

National Program as a model for this final HD National Program in many respects. This 

is most apparent in the case of heavy-duty pickups and vans, which are very similar to the 

light-duty trucks addressed in the light-duty National Program both technologically as 

well as in terms of how they are manufactured (i.e., the same company often makes both 

the vehicle and the engine). For these vehicles, there are close parallels to the light-duty 

program in how the agencies have developed our respective final standards and 

compliance structures, although, as discussed below, the technologies applied to lightduty trucks are not invariably applicable to heavy-duty pickups and vans at the same 

penetration rates in the lead time afforded in this heavy-duty action. Another difference 

is that each agency adopts standards based on attributes other than vehicle footprint, as 

discussed below.

Due to the diversity of the remaining HD vehicles, there are fewer parallels with 

the structure of the light-duty program. However, the agencies have maintained the same 

collaboration and coordination that characterized the development of the light-duty 

program. Most notably, as with the light-duty program, manufacturers will be able to 

design and build vehicles to meet a closely coordinated, harmonized national program, 

and avoid unnecessarily duplicative testing and compliance burdens. 

(5) EPA’s SmartWay Program

EPA’s voluntary SmartWay Transport Partnership program encourages shipping 

and trucking companies to take actions that reduce fuel consumption and CO2 by working 

with the shipping community and the freight sector to identify low carbon strategies and 

technologies, and by providing technical information, financial incentives, and partner 

recognition to accelerate the adoption of these strategies. Through the SmartWay 

program, EPA has worked closely with truck manufacturers and truck fleets to develop 

test procedures to evaluate vehicle and component performance in reducing fuel 

consumption and has conducted testing and has established test programs to verify

technologies that can achieve these reductions. Over the last six years, EPA has 

developed hands-on experience testing the largest heavy-duty trucks and evaluating 

improvements in tire and vehicle aerodynamic performance. In 2010, according to 

vehicle manufacturers, approximately five percent of new combination heavy-duty trucks 

will meet the SmartWay performance criteria demonstrating that they represent the 

pinnacle of current heavy-duty truck reductions in fuel consumption. 
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19 of

In developing this HD National Program, the agencies have drawn from the 

SmartWay experience, as discussed in detail both in Sections II and III below (e.g., 

developing test procedures to evaluate trucks and truck components) but also in the RIA 

(estimating performance levels from the application of the best available technologies 

identified in the SmartWay program). These technologies provide part of the basis for 

the GHG emission and fuel consumption standards in this rulemaking for certain types of 

new heavy-duty Class 7 and 8 combination tractors. 

In addition to identifying technologies, the SmartWay program includes 

operational approaches that truck fleet owners as well as individual drivers and their 

freight customers can incorporate, that the NHTSA and EPA believe will complement the 

final standards. These include such approaches as improved logistics and driver training, 

as discussed in the RIA. This approach is consistent with the one of the three alternative 

approaches that the NAS recommended be considered. The three approaches were 

raising fuel taxes, relaxing truck size and weight restrictions, and encouraging incentives 

to disseminate information to inform truck drivers about the relationship between driving 

behavior and fuel savings. Taxes and truck size and weight limits are mandated by public 

law; as such, these options are outside EPA’s and NHTSA’s authority to implement. 

However, complementary operational measures like driver training, which SmartWay

does promote, can complement the final standards and also provide benefits for the 

existing truck fleet, furthering the public policy objectives of addressing energy security

and climate change.

(6) Environment Canada

The Government of Canada’s Department of the Environment (Environment 

Canada) assisted EPA's development of this rulemaking by conducting emissions testing 

of heavy-duty vehicles at their test facilities to gather data on a range of possible test 

cycles, and to evaluate the impact of certain emissions reduction technologies.

Environment Canada also facilitated the evaluation of heavy-duty vehicle aerodynamic 

properties at Canada’s National Research Council wind tunnel, and during coastdown 

testing.

We expect the technical collaboration with Environment Canada to continue as 

we implement testing and compliance verification procedures for this rulemaking. We 

may also begin to develop a knowledge base enabling improvement upon this regulatory

framework for model years beyond 2018 (for example, improvements to the means of 

demonstrating compliance). We also expect to continue our collaboration with 

Environment Canada on compliance issues. 

Collaboration with Environment Canada is taking place under the Canada-U.S. 

Air Quality Committee.
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C. Summary of the Final EPA and NHTSA HD National Program

When EPA first addressed emissions from heavy-duty trucks in the 1980s, it 

established standards for engines, based on the amount of work performed (grams of 

pollutant per unit of work, expressed as grams per brake horsepower-hour or g/bhp-hr).26 

This approach recognized the fact that engine characteristics are the dominant 

determinant of the types of emissions generated, and engine-based technologies 

(including exhaust aftertreatment systems) need to be the focus for addressing those 

emissions. Vehicle-based technologies, in contrast, have less influence on overall truck 

emissions of the pollutants that EPA has regulated in the past. The engine testing 

approach also recognized the relatively small number of distinct heavy-duty engine 

designs, as compared to the extremely wide range of truck designs. EPA concluded at 

that time that any incremental gain in conventional emission control that could be 

achieved through regulation of the complete vehicle would be small in comparison to the 

cost of addressing the many variants of complete trucks that make up the heavy-duty 

sector – smaller and larger vocational vehicles for dozens of purposes, various designs of 

combination tractors, and many others.

Addressing GHG emissions and fuel consumption from heavy-duty trucks, 

however, requires a different approach. Reducing GHG emissions and fuel consumption 

requires increasing the inherent efficiency of the engine as well as making changes to the 

vehicles to reduce the amount of work demanded from the engine in order to move the 

truck down the road. A focus on the entire vehicle is thus required. For example, in 

addition to the basic emissions and fuel consumption levels of the engine, the 

aerodynamics of the vehicle can have a major impact on the amount of work that must be 

performed to transport freight at common highway speeds. For this first rulemaking, the 

agencies proposed a complementary engine and vehicle approach in order to achieve the 

maximum feasible near-term reductions.

NHTSA received comments on the proposal to create complementary engine and 

vehicle standards. Volvo and Daimler argued that EISA limited NHTSA’s authority to 

the regulation of completed vehicles and did not give NHTSA authority to regulate 

engines. 49 U.S.C. 32902(k)(2) grants NHTSA broad authority to regulate this sector, 

stating simply that the Secretary “shall determine in a rulemaking proceeding how to 

implement a commercial medium- and heavy-duty on-highway vehicle and work truck 

fuel efficiency improvement program designed to achieve the maximum feasible 

improvement,” considering appropriateness, cost-effectiveness, and technological 

feasibility. NHTSA does not believe that this language precludes the regulation of 

engines, but rather explicitly leaves the regulatory approach to the agency’s expertise and 

discretion. See 75 FR at 74173 n. 36. Considering the factors described in the NPRM 

and in Sections III and IV below, NHTSA continues to believe that the separate 

 

26 The term “brake power” refers to engine torque and power as measured at the interface between the 

engine’s output shaft and the dynamometer. This contrasts with “indicated power”, which is a calculated 

value based on the pressure dynamics in the combustion chamber, not including internal losses that occur 

due to friction and pumping work. Since the measurement procedure inherently measures brake torque and 

power, the final regulations refer simply to g/hp-hr. This is consistent with EPA’s other emission control 

programs, which generally include standards in g/kW-hr.
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21 of

regulation of engines and vehicles is both consistent with the agency’s statutory mandate 

to determine how to implement a regulatory program designed to achieve the maximum 

feasible improvement and facilitates coordination with EPA’s efforts to reduce 

greenhouse gas emissions. The Clean Air act, of course, mandates standards for both 

“new motor vehicles” and “new motor vehicle engines”, so there is no issue of authority 

for separate engine standards under the EPA GHG program. CAA section 202 (a)(1).

As described elsewhere in this preamble, the final standards under the HD 

National Program address the complete vehicle, to the extent practicable and appropriate 

under the agencies’ respective statutory authorities, through complementary engine and 

vehicle standards. The agencies continue to believe that this complementary engine and 

vehicle approach is the best way to achieve near term reductions from the heavy-duty 

sector. However, we also recognize as did the NAS committee and a wide range of 

industry and environmental commenters, that in order to fully capture the multi-faceted 

synergistic aspects of engine and vehicle design a more comprehensive complete vehicle 

standard may be appropriate in the future. The agencies are committed to fully exploring 

such a possibility and to developing the testing and modeling tools necessary to enable 

such a regulatory approach. We intend to work with all interested stakeholders as we 

move forward. 

(1) Brief Overview of the Heavy-duty Truck Industry

The heavy-duty truck sector spans a wide range of vehicles with often unique 

form and function. A primary indicator of the extreme diversity among heavy-duty 

trucks is the range of load-carrying capability across the industry. The heavy-duty truck 

sector is often subdivided by vehicle weight classifications, as defined by the vehicle’s 

gross vehicle weight rating (GVWR), which is a measure of the combined curb (empty) 

weight and cargo carrying capacity of the truck.

27

 Table I-1 below outlines the vehicle 

weight classifications commonly used for many years for a variety of purposes by 

businesses and by several federal agencies, including the Department of Transportation, 

the Environmental Protection Agency, the Department of Commerce, and the Internal 

Revenue Service.

Table I-1: Vehicle Weight Classification

Class 2b 3 4 5 6 7 8

GVWR 

(lb)

8,501 -

10,000

10,001-

14,000

14,001-

16,000

16,001-

19,500

19,501 

-26,000

26,001-

33,000

> 33,001

In the framework of these vehicle weight classifications, the heavy-duty truck 

sector refers to Class 2b through Class 8 vehicles and the engines that power those 

 

27 GVWR describes the maximum load that can be carried by a vehicle, including the weight of the vehicle 

itself. Heavy-duty vehicles also have a gross combined weight rating (GCWR), which describes the 

maximum load that the vehicle can haul, including the weight of a loaded trailer and the vehicle itself. 
22 of 

vehicles.28 Unlike light-duty vehicles, which are primarily used for transporting 

passengers for personal travel, heavy-duty vehicles fill much more diverse operator

needs. Heavy-duty pickup trucks and vans (Classes 2b and 3) are used chiefly as work 

truck and vans, and as shuttle vans, as well as for personal transportation, with an average 

annual mileage in the range of 15,000 miles. The rest of the heavy-duty sector is used for 

carrying cargo and/or performing specialized tasks. “Vocational” vehicles, which may

span Classes 2b through 8, vary widely in size, including smaller and larger van trucks, 

utility “bucket” trucks, tank trucks, refuse trucks, urban and over-the-road buses, fire 

trucks, flat-bed trucks, and dump trucks, among others. The annual mileage of these 

trucks is as varied as their uses, but for the most part tends to fall in between heavy-duty 

pickups/vans and the large combination tractors, typically from 15,000 to 150,000 miles 

per year, although some travel more and some less. Class 7 and 8 combination tractortrailers – some equipped with sleeper cabs and some not -- are primarily used for freight 

transportation. They are sold as tractors and sometimes run without a trailer in between 

loads, but most of the time they run with one or more trailers that can carry up to 50,000 

pounds or more of payload, consuming significant quantities of fuel and producing 

significant amounts of GHG emissions. The combination tractor-trailers used in 

combination applications can travel more than 150,000 miles per year.

EPA and NHTSA have designed our respective standards in careful consideration 

of the diversity and complexity of the heavy-duty truck industry, as discussed next. 

(2) Summary of Final EPA GHG Emission Standards and NHTSA Fuel 

Consumption Standards

As described above, NHTSA and EPA recognize the importance of addressing the 

entire vehicle in reducing fuel consumption and GHG emissions. At the same time, the 

agencies understand that the complexity of the industry means that we will need to use 

different approaches to achieve this goal, depending on the characteristics of each general 

type of truck. We are therefore dividing the industry into three discrete regulatory

categories for purposes of setting our respective standards – combination tractors, heavyduty pickups and vans, and vocational vehicles -- based on the relative degree of 

homogeneity among trucks within each category. For each regulatory category, the 

agencies are adopting related but distinct program approaches reflecting the specific 

challenges that we see in these segments. In the following paragraphs, we discuss EPA’s 

final GHG emission standards and NHTSA’s final fuel consumption standards for the 

three regulatory categories of heavy-duty vehicles and their engines. 

The agencies are adopting test metrics that express fuel consumption and GHG 

emissions relative to the most important measures of heavy-duty truck utility for each 

segment, consistent with the recommendation of the 2010 NAS Report that metrics 

should reflect and account for the work performed by various types of HD vehicles. This 

approach differs from NHTSA’s light-duty program that uses fuel economy as the basis. 

The NAS committee discussed the difference between fuel economy (a measure of how 

 

28 Class 2b vehicles designed as passenger vehicles (Medium Duty Passenger Vehicles, MDPVs) are 

covered by the light-duty GHG and fuel economy standards and not addressed in this rulemaking.
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23 of

far a vehicle will go on a gallon of fuel) and fuel consumption (the inverse measure, of 

how much fuel is consumed in driving a given distance) as potential metrics for MD/HD

regulations. The committee concluded that fuel economy would not be a good metric for 

judging the fuel efficiency of a heavy-duty vehicle, and stated that NHTSA should 

instead consider fuel consumption as the metric for its standards. As a result, for heavyduty pickup trucks and vans, EPA and NHTSA are finalizing standards on a per-mile 

basis (g/mile for the EPA standards, gallons/100 miles for the NHTSA standards), as 

explained in Section I. C. (2) (b) below. For heavy-duty trucks, both combination and 

vocational, the agencies are adopting standards expressed in terms of the key measure of 

freight movement, tons of payload miles or, more simply, ton-miles. Hence, for EPA the 

final standards are in the form of the mass of emissions from carrying a ton of cargo over 

a distance of one mile (g/ton-mi). Similarly, the final NHTSA standards are in terms of 

gallons of fuel consumed over a set distance (one thousand miles), or gal/1,000 ton-mile. 

Finally, for engines, EPA is adopting standards in the form of grams of emissions per unit 

of work (g/bhp-hr), the same metric used for the heavy-duty highway engine standards 

for criteria pollutants today. Similarly, NHTSA is finalizing standards for heavy-duty 

engines in the form of gallons of fuel consumption per 100 units of work (gal/100 bhphr).

Section II below discusses the final EPA and NHTSA standards in greater detail.

(a) Class 7 and 8 Combination Tractors

Class 7 and 8 combination tractors and their engines contribute the largest portion

of the total GHG emissions and fuel consumption of the heavy-duty sector, 

approximately 65 percent, due to their large payloads, their high annual miles traveled, 

and their major role in national freight transport.29 These vehicles consist of a cab and 

engine (tractor or combination tractor) and a detachable trailer. In general, reducing 

GHG emissions and fuel consumption for these vehicles will involve improvements in 

aerodynamics and tires and reduction in idle operation, as well as engine-based efficiency

improvements. 

In general, the heavy-duty combination tractor industry consists of tractor 

manufacturers (which manufacture the tractor and purchase and install the engine) and 

trailer manufacturers. These manufacturers are usually not the same entity. We are not 

aware of any manufacturer that typically assembles both the finished truck and the trailer 

and introduces the combination into commerce for sale to a buyer. The owners of trucks 

and trailers are often distinct as well. A typical truck buyer will purchase only the tractor. 

The trailers are usually purchased and owned by fleets and shippers. This occurs in part 

because trucking fleets on average maintain 3 trailers per tractor and in some cases as 

many as 6 or more trailers per tractor. There are also large differences in the kinds of 

manufacturers involved with producing tractors and trailers. For HD highway tractors 

 

29 The on-highway Class 7 and 8 combination tractors constitute the vast majority of this regulatory 

category, and form the backbone of this HD National Program. A small fraction of combination tractors 

are used in off-road applications and are regulated differently, as described in Section II. 
and their engines, a relatively limited n

of these products. The trailer manufacturing industry is quite different, and includes a 

large number of companies, many of which are relatively small in size and production 

volume. Setting standards for t

recognition of the large differences between these manufacturing industries, which can 

then warrant consideration of different regulatory approaches. 

Based on these industry characteristics

straightforward regulatory approach for combination tractors and trailers is to establish 

standards for tractors separately from trailers

agencies are adopting standards for the tractor

did not propose and are not 

As with the other regulatory categories of heavy

have concluded that achieving reductions in GHG emissions and fuel cons

combination tractors requires addressing both the cab and the engine, and EPA and 

NHTSA each are adopting standards that reflect this conclusion. The importance of the 

cab is that its design determines the amount of power that the engine must

moving the truck down the road. As illustrated in

additional power from the engine include air resistance (aerodynamics), tire rolling 

resistance, and parasitic losses (including accessory loads and friction in the dr

The importance of the engine design is that it determines the basic GHG emissions and 

fuel consumption performance of the engine for the variety of demands placed on the 

engine, regardless of the characteristics of the cab in which it is instal

intend for the final standards to result in the application of improved technologies for 

lower GHG emissions and fuel consumption for both the cab and the engine

Figure 

 

30 Adapted from Figure 4.1. Class 8 Truck Energy Audit,

Program: A Government-Industry Research Partnership, 21CT

24 of 

and their engines, a relatively limited number of manufacturers produce the vast majority

of these products. The trailer manufacturing industry is quite different, and includes a 

large number of companies, many of which are relatively small in size and production 

volume. Setting standards for the products involved -- tractors and trailers 

recognition of the large differences between these manufacturing industries, which can 

then warrant consideration of different regulatory approaches. 

Based on these industry characteristics, EPA and NHTSA believe that the most 

straightforward regulatory approach for combination tractors and trailers is to establish 

tractors separately from trailers. As discussed below in Section 

adopting standards for the tractors and their engines in this rulemaking, 

are not adopting standards for trailers. 

As with the other regulatory categories of heavy-duty vehicles, EPA and NHTSA 

have concluded that achieving reductions in GHG emissions and fuel cons

combination tractors requires addressing both the cab and the engine, and EPA and 

NHTSA each are adopting standards that reflect this conclusion. The importance of the 

cab is that its design determines the amount of power that the engine must

moving the truck down the road. As illustrated in Figure I-1, the loads that require 

additional power from the engine include air resistance (aerodynamics), tire rolling 

resistance, and parasitic losses (including accessory loads and friction in the dr

The importance of the engine design is that it determines the basic GHG emissions and 

fuel consumption performance of the engine for the variety of demands placed on the 

engine, regardless of the characteristics of the cab in which it is installed. The agencies 

intend for the final standards to result in the application of improved technologies for 

lower GHG emissions and fuel consumption for both the cab and the engine

Figure I-1: Combination Tractor and Trailer Loads30

 

Class 8 Truck Energy Audit, Technology Roadmap for the 21st Century Truck 

Industry Research Partnership, 21CT-001, December 2000.

umber of manufacturers produce the vast majority

of these products. The trailer manufacturing industry is quite different, and includes a 

large number of companies, many of which are relatively small in size and production 

tractors and trailers -- requires 

recognition of the large differences between these manufacturing industries, which can 

nd NHTSA believe that the most 

straightforward regulatory approach for combination tractors and trailers is to establish 

As discussed below in Section IX, the 

s and their engines in this rulemaking, but 

duty vehicles, EPA and NHTSA 

have concluded that achieving reductions in GHG emissions and fuel consumption from 

combination tractors requires addressing both the cab and the engine, and EPA and 

NHTSA each are adopting standards that reflect this conclusion. The importance of the 

cab is that its design determines the amount of power that the engine must produce in 

, the loads that require 

additional power from the engine include air resistance (aerodynamics), tire rolling 

resistance, and parasitic losses (including accessory loads and friction in the drivetrain). 

The importance of the engine design is that it determines the basic GHG emissions and 

fuel consumption performance of the engine for the variety of demands placed on the 

led. The agencies 

intend for the final standards to result in the application of improved technologies for 

lower GHG emissions and fuel consumption for both the cab and the engine.

Technology Roadmap for the 21st Century Truck 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

25 of

Accordingly, for Class 7 and 8 combination tractors, the agencies are each 

finalizing two sets of standards. For vehicle-related emissions and fuel consumption, 

tractor manufacturers are required to meet vehicle-based standards. Compliance with the 

vehicle standard will typically be determined based on a customized vehicle simulation 

model, called the Greenhouse gas Emissions Model (GEM), which is consistent with the 

NAS Report recommendations to require compliance testing for combination tractors 

using vehicle simulation rather than chassis dynamometer testing. This compliance 

model was developed by EPA specifically for this final action. It is an accurate and costeffective alternative to measuring emissions and fuel consumption while operating the 

vehicle on a chassis dynamometer. Instead of using a chassis dynamometer as an indirect 

way to evaluate real-world operation and performance, various characteristics of the 

vehicle are measured and these measurements are used as inputs to the model. These 

characteristics relate to key technologies appropriate for this subcategory of truck –

including aerodynamic features, weight reductions, tire rolling resistance, the presence of 

idle-reducing technology, and vehicle speed limiters. The model also assumes the use of 

a representative typical engine, rather than a vehicle-specific engine, because engines are 

regulated separately. Using these inputs, the model will be used to quantify the overall 

performance of the vehicle in terms of CO2 emissions and fuel consumption. The 

model’s development and design, as well as the sources for inputs, are discussed in detail 

in Section II below and in Chapter 4 of the RIA. 

(i) Final Standards for Class 7 and 8 Combination Tractors and Their Engines

The vehicle standards that EPA and NHTSA are adopting for Class 7 and 8 

combination tractor manufacturers are based on several key attributes related to GHG 

emissions and fuel consumption that we believe reasonably represent the many

differences in utility and performance among these vehicles. The final standards differ 

depending on GVWR (i.e., whether the truck is Class 7 or Class 8), the height of the roof 

of the cab, and whether it is a “day cab” or a “sleeper cab.” These later two attributes are 

important because the height of the roof, designed to correspond to the height of the 

trailer, significantly affects air resistance, and a sleeper cab generally corresponds to the 

opportunity for extended duration idle emission and fuel consumption improvements. 

We received a number of comments supporting this approach and no comments that 

provided a compelling reason to change our approach in this final action.

Thus, the agencies have created nine subcategories within the Class 7 and 8 

combination tractor category based on the differences in expected emissions and fuel 

consumption associated with the key attributes of GVWR, cab type, and roof height. The 

agencies are setting standards beginning in 2014 model year with more stringent 

standards following in 2017 model year. Table I-2 presents the agencies’ respective 

standards for combination tractor manufacturers for the 2017 model year. The standards 

represent an overall fuel consumption and CO2 emissions reduction up to 23 percent from 

the tractors and the engines installed in them when compared to a baseline 2010 model 

year tractor and engine without idle shutdown technology. The standard values shown 

below differ somewhat from the proposal, reflecting refinements made to the GEM in 

response to comments. These changes did not impact our estimates of the relative 
26 of 

effectiveness of the various control technologies modeled in this final action nor the 

overall cost or benefits or cost effectiveness estimated for these final vehicle standards. 

As proposed, the agencies are exempting certain types of tractors which operate 

off-road to be exempt from the combination tractor vehicle standards (although standards 

would still apply to the engines installed in these vehicles). The criteria for tractors to be 

considered off-road have been amended slightly from those proposed, in response to 

public comment. The agencies have also recognized, again in response to public coment, 

that some combination tractors operate in a manner essentially the same as vocational 

vehicles and have created a subcategory of “vocational tractors” as a result. Vocational 

tractors will be subject to the standards for vocational vehicles rather than the 

combination tractor standards. See Section II.B of this preamble.

Table I-2: Heavy-duty Combination Tractor EPA Emissions Standards (g CO2/ton-mile) and 

NHTSA Fuel Consumption Standards (gal/1,000 ton-mile)

2017 Model Year CO2 Grams per Ton-Mile

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 104 80 66

Mid Roof 115 86 73

High Roof 120 89 72

2017 Model Year Gallons of Fuel per 1,000 Ton-Mile

Day Cab Sleeper Cab

Class 7 Class 8 Class 8

Low Roof 10.2 7.8 6.5

Mid Roof 11.3 8.4 7.2

High Roof 11.8 8.7 7.1

In addition, the agencies are finalizing separate performance standards for the 

engines manufactured for use in these trucks. EPA’s engine-based CO2 standards and 

NHTSA’s engine-based fuel consumption standards are implemented using EPA’s 

existing test procedures and regulatory structure for criteria pollutant emissions from 

medium- and heavy-duty engines. As at proposal, the final engine standards vary

depending on engine size linked to intended vehicle service class. Consistent with our 

proposal, the agencies are finalizing an interim alternative compression ignition engine 

standard for model years 2014-2016. This alternative standard is designed to provide a 

glide path for legacy diesel engine products that may not be able to comply with the final 

engine standards for model years 2014-16 given the short (approximately 2-year) lead 

time of this program. We believe this alternative standard is appropriate for a first-ever 

program when the overall baseline performance of the industry is quite varied and where 

the short lead time means that not every product can be brought into compliance by 2014. 

The alternative standard only applies through and including model year 2016.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

27 of

Separately, EPA is adopting standards for combination tractors that apply in use. 

EPA is also finalizing engine-based N2O and CH4 standards for manufacturers of the 

engines used in these combination tractors. EPA is finalizing separate engine-based 

standards for N2O and CH4 because the agency believes that emissions of these GHGs are 

technologically related solely to the engine, fuel, and emissions aftertreatment systems, 

and the agency is not aware of any influence of vehicle-based technologies on these 

emissions. NHTSA is not incorporating standards for N2O and CH4 because these 

emissions do not impact fuel consumption in a significant way. The standards that EPA 

is finalizing for N2O and CH4 are less stringent than those we proposed, reflecting new 

data provided to EPA in comments on the proposal showing that the current baseline 

level of N2O and CH4 emissions varies more than EPA had expected. EPA expects that 

manufacturers of current engine technologies will be able to comply with the final N2O 

and CH4 “cap” standards with little or no technological improvements; the value of the 

standards will be to prevent significant increases in these emissions as alternative 

technologies are developed and introduced in the future. Compliance with the final EPA 

engine-based CO2 standards and the final NHTSA engine-based fuel consumption 

standards, as well as the final EPA N2O and CH4 standards, will be determined using the 

appropriate EPA engine test procedure, as discussed in Sections II.B, II.D, and II.E

below. 

As with the other categories of heavy-duty vehicles, EPA and NHTSA are 

finalizing respective standards that will apply to Class 7 and 8 tractors at the time of 

production (as in Table I-2, above). In addition, EPA is finalizing separate standards that 

will apply for a specified period of time in use. All of the standards for these vehicles, as 

well as details about the provisions for certification and implementation of these 

standards, are discussed in more detail in Sections II, III, IV, and V below and in the 

RIA.

(ii) EPA’s Final Air Conditioning Leakage Standard for Class 7 and 8 Combination 

Tractors

In addition to the final EPA tractor- and engine-based standards for CO2 and 

engine-based standards for N2O, and CH4 emissions, EPA is finalizing a separate 

standard to reduce leakage of HFC refrigerant from cabin air conditioning (A/C) systems 

from combination tractors, to apply to the tractor manufacturer. This standard is 

independent of the CO2 tractor standard, as discussed below in Section II.E.5. Because 

the current refrigerant used widely in all these systems has a very high global warming 

potential, EPA is concerned about leakage of refrigerant.32 

Because the interior volume to be cooled for most tractor cabins is similar to that 

of light-duty vehicles, the size and design of current tractor A/C systems is also very

similar. The compliance approach for Class 7 and 8 tractors is therefore similar to that in 

the light-duty rule in that these standards are design-based. Manufacturers will choose 

 

32 The global warming potential for HFC-134a refrigerant of 1430 used in this program is consistent with 

the Intergovernmental Panel on Climate Change Fourth Assessment Report.
28 of 

technologies from a menu of leak-reducing technologies sufficient to comply with the 

standard, as opposed to using a test to measure performance. 

However, the final heavy-duty A/C provisions differ in two important ways from 

those established in the light-duty rule. First, the light-duty provisions were established 

as voluntary ways to generate credits towards the CO2 g/mi standard, and EPA took into 

account the expected use of such credits in determining the stringency of the CO2

emissions standards. In the HD National Program, EPA is requiring that manufacturers 

actually meet a standard – as opposed to having the opportunity to earn a credit -- for A/C 

refrigerant leakage. Thus, refrigerant leakage control is not separately accounted for in 

the final heavy-duty CO2 standards. We are taking this approach here recognizing that 

while the benefits of leakage control are almost identical between light-duty and heavyduty vehicles on a per vehicle basis, these benefits on a per mile basis expressed as a 

percentage of overall GHG emissions are much smaller for heavy-duty vehicles due to 

their much higher CO2 emissions rates and higher annual mileage when compared to 

light-duty vehicles. Hence a credit-based approach as done for light-duty vehicles would 

provide less motivation for manufacturers to install low leakage systems even though 

such systems represent a highly cost effective means to control GHG emissions. The 

second difference relates to the expression of the leakage rate. The light-duty A/C 

leakage standard is expressed in terms of grams per year. For EPA’s heavy-duty

program, however, because of the wide variety of system designs and arrangements, a 

one-size-fits-all gram per year standard would not be appropriate, so EPA is adopting a 

standard in terms of annual mass leakage rate for A/C systems with refrigerant capacities 

less than or equal to 733 grams and percent of total refrigerant leakage per year for A/C 

systems with refrigerant capacities greater than 733 grams. The percent of total 

refrigerant leakage per year requires the total refrigerant capacity of the A/C system to be 

taken into account in determining compliance. EPA believes that this approach -- a 

standard instead of a credit, and basing the standard on percent or mass of leakage over 

time – is more appropriate for heavy-duty tractors than the light-duty vehicle approach 

and that it will achieve the desired reductions in refrigerant leakage. Compliance with 

the standard will be determined through a showing by the tractor manufacturer that its

A/C system incorporates a combination of low-leak technologies sufficient to meet the 

leakage rate of the applicable standard. The “menu” of technologies is very similar to 

that established in the light-duty 2012-2016 MY vehicle rule.33 

Finally, the agencies did not propose and are not adopting an A/C system 

efficiency standard in this heavy-duty rulemaking, although an efficiency credit was a 

part of the light-duty rule. The much larger emissions of CO2 from a heavy-duty tractor 

as compared to those from a light-duty vehicle mean that the relative amount of CO2 that 

could be reduced through A/C efficiency improvements is very small. 

 

33 EPA has approved an alternative refrigerant, HFO-1234yf, which has a very low GWP, for use in lightduty vehicle mobile A/C systems. The final heavy-duty vehicle A/C leakage standard is designed to 

account for use of an alternative, low-GWP refrigerant. If in the future this refrigerant is approved for 

heavy-duty applications and if it becomes widespread as a substitute for HFC-134a in heavy-duty vehicle 

mobile A/C systems, EPA may propose to revise or eliminate the leakage standard. 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

29 of

A more detailed discussion of A/C related issues is found in Section II.E.5 of this 

preamble. 

(b) Heavy-Duty Pickup Trucks and Vans (Class 2b and 3)

Heavy-duty vehicles with GVWR between 8,501 and 10,000 lb are classified in 

the industry as Class 2b motor vehicles per the Federal Motor Carrier Safety

Administration definition. As discussed above, Class 2b includes MDPVs that are 

regulated by the agencies under the light-duty vehicle rule, and the agencies are not 

adopting additional requirements for MDPVs in this rulemaking. Heavy-duty vehicles 

with GVWR between 10,001 and 14,000 lb are classified as Class 3 motor vehicles. 

Class 2b and Class 3 heavy-duty vehicles (referred to in these rules as “HD pickups and 

vans”) together emit about 15 percent of today’s GHG emissions from the heavy-duty 

vehicle sector. 

About 90 percent of HD pickups and vans are 3⁄4-ton and 1-ton pickup trucks, 12-

and 15-passenger vans, and large work vans that are sold by vehicle manufacturers as 

complete vehicles, with no secondary manufacturer making substantial modifications 

prior to registration and use. These vehicle manufacturers are companies with major 

light-duty markets in the United States, primarily Ford, General Motors, and Chrysler. 

Furthermore, the technologies available to reduce fuel consumption and GHG emissions 

from this segment are similar to the technologies used on light-duty pickup trucks, 

including both engine efficiency improvements (for gasoline and diesel engines) and 

vehicle efficiency improvements. 

For these reasons, EPA believes it is appropriate to adopt GHG standards for HD 

pickups and vans based on the whole vehicle (including the engine), expressed as grams 

per mile, consistent with the way these vehicles are regulated by EPA today for criteria 

pollutants. NHTSA believes it is appropriate to adopt corresponding gallons per 100 mile 

fuel consumption standards that are likewise based on the whole vehicle. This complete 

vehicle approach being adopted by both agencies for HD pickups and vans is consistent 

with the recommendations of the NAS Committee in their 2010 Report. EPA and 

NHTSA also believe that the structure and many of the detailed provisions of the recently 

finalized light-duty GHG and fuel economy program, which also involves vehicle-based 

standards, are appropriate for the HD pickup and van GHG and fuel consumption 

standards as well, and this is reflected in the standards each agency is finalizing, as 

detailed in Section II.C. These commonalities include a new vehicle fleet average 

standard for each manufacturer in each model year and the determination of these fleet 

average standards based on production volume-weighted targets for each model, with the 

targets varying based on a defined vehicle attribute. Vehicle testing will be conducted on 

chassis dynamometers using the drive cycles from the EPA Federal Test Procedure 
30 of 

(Light-duty FTP or “city” test) and Highway Fuel Economy Test (HFET or “highway”

test).34

For the light-duty GHG and fuel economy standards, the agencies factored in 

vehicle size by basing the emissions and fuel economy targets on vehicle footprint (the 

wheelbase times the average track width).35 For those standards, passenger cars and light 

trucks with larger footprints are assigned higher GHG and lower fuel economy target 

levels in acknowledgement of their inherent tendency to consume more fuel and emit 

more GHGs per mile. For HD pickups and vans, the agencies believe that setting 

standards based on vehicle attributes is appropriate, but feel that a work-based metric 

serves as a better attribute than the footprint attribute utilized in the light-duty vehicle 

rulemaking. Work-based measures such as payload and towing capability are key among 

the parameters that characterize differences in the design of these vehicles, as well as 

differences in how the vehicles will be utilized. Buyers consider these utility-based 

attributes when purchasing a heavy-duty pickup or van. EPA and NHTSA are therefore 

finalizing standards for HD pickups and vans based on a “work factor” attribute that 

combines their payload and towing capabilities, with an added adjustment for 4-wheel 

drive vehicles. The agencies received a number of comments supporting this approach 

arguing, as the agencies had, that this approach was an effective way to encourage

technology development and to appropriately reflect the utility of work vehicles while 

setting a consistent metric measure of vehicle performance..

As proposed, the agencies are adopting provisions such that each manufacturer’s 

fleet average standard will be based on production volume-weighting of target standards 

for all vehicles that in turn are based on each vehicle’s work factor. These target 

standards are taken from a set of curves (mathematical functions), presented in Section 

II.C below and in §1037.104. EPA is also phasing in the CO2 standards gradually

starting in the 2014 model year, at 15-20-40-60-100 percent of the model year 2018 

standards stringency level in model years 2014-2015-2016-2017-2018, respectively. The 

phase-in takes the form of a set of target standard curves, with increasing stringency in 

each model year, as detailed in Section II.C. The final EPA standards for 2018 (including 

a separate standard to control air conditioning system leakage) represent an average pervehicle reduction in GHGs of 17 percent for diesel vehicles and 12 percent for gasoline 

vehicles, compared to a common baseline, as described in Sections II.C and III.B of this 

preamble. The rule contains separate standards for diesel and gasoline heavy duty 

pickups and vans for reasons described in Section II.C below. EPA is also finalizing a 

compliance alternative whereby manufacturers can phase in different percentages: 15-20-

67-67-67-100 percent of the model year 2019 standards stringency level in model years 

2014-2015-2016-2017-2018-2019, respectively. This compliance alternative parallels 

and is equivalent to NHTSA’s first alternative described below.

 

34 The Light-duty FTP is a vehicle driving cycle that was originally developed for certifying light-duty

vehicles and subsequently applied to HD chassis testing for criteria pollutants. This contrasts with the 

Heavy-duty FTP, which refers to the transient engine test cycles used for certifying heavy-duty engines 

(with separate cycles specified for diesel and spark-ignition engines).

35 EISA requires CAFE standards for passenger cars and light trucks to be attribute-based; see 49 U.S.C. 

32902(b)(3)(A).
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

31 of

NHTSA is allowing manufacturers to select one of two fuel consumption standard 

alternatives for model years 2016 and later. The first alternative defines individual 

gasoline vehicle and diesel vehicle fuel consumption target curves that will not change 

for model years 2016-2018, and are equivalent to EPA’s 67-67-67-100 percent target 

curves in model years 2016-2017-2018-2019, respectively. The target curves for this 

alternative are presented in Section II.C. The second alternative uses target curves that 

are equivalent to the EPA’s 40-60-100 percent target curvesin model years 2016-2017-

2018, respectively. Stringency for the alternatives has been selected to allow a 

manufacturer, through the use of the credit and deficit carry-forward provisions that the 

agencies are also finalizing, to rely on the same product plans to satisfy either of these 

two alternatives, and also EPA requirements. If a manufacturer cannot meet an 

applicable standard in a given model year, it may make up its shortfall by overcomplying 

in a subsequent year, called reconciling a credit deficit. NHTSA is also allowing 

manufacturers to voluntarily opt into the NHTSA HD pickup and van program in model 

years 2014 or 2015. For these model years, NHTSA’s fuel consumption target curves are 

equivalent to EPA’s target curves.

The agencies received a number of comments suggesting that the standards for 

heavy-duty pickups and vans should be made more stringent for gasoline vehicles and 

that the phase-in timing of the standards should be accelerated to the 2016 model year 

(from 2018). We also received comments arguing that the proposed standards were 

aggressive and could only be met given the phase-in schedules proposed by the agencies. 

In response to these comments, we reviewed again the technology assessments from the 

2010 NAS report, our own joint light-duty 2012-2016 rulemaking, and information 

provided by the commenters relevant to the stringency of these standards. After 

reviewing all of the information, we continue to conclude that the proposed standards and 

associated phase-in schedules represent technically stringent but reasonable standards 

considering the available lead time and costs to bring the necessary technologies to 

market and our own assessments of the efficacy of the technologies when applied to 

heavy-duty pickup trucks and vans. Further detail on the feasibility of the standards and 

the agencies’ choices among alternative standards is found in Section III.C below.

The form and stringency of the EPA and NHTSA standards curves are based on a 

set of vehicle, engine, and transmission technologies expected to be used to meet the 

recently established GHG emissions and fuel economy standards for model year 2012-

2016 light-duty vehicles, with full consideration of how these technologies are likely to

perform in heavy-duty vehicle testing and use. All of these technologies are already in 

use or have been announced for upcoming model years in some light-duty vehicle 

models, and some are in use in a portion of HD pickups and vans as well. The 

technologies include:

 advanced 8-speed automatic transmissions

 aerodynamic improvements

 electro-hydraulic power steering

 engine friction reductions
32 of 

 improved accessories

 low friction lubricants in powertrain components

 lower rolling resistance tires

 lightweighting

 gasoline direct injection

 diesel aftertreatment optimization

 air conditioning system leakage reduction (for EPA program only)

See Section III.B for a detailed analysis of these and other potential technologies, 

including their feasibility, costs, and effectiveness when employed for reducing fuel 

consumption and CO2 emissions in HD pickups and vans.

A relatively small number of HD pickups and vans are sold by vehicle 

manufacturers as incomplete vehicles, without the primary load-carrying device or 

container attached. We are generally regulating these vehicles as Class 2b through 8 

vocational vehicles but are also allowing manufacturers the option to choose to comply

with heavy-duty pickup or van standards, as described in Section I.C.(2)(c). Although, as 

with vocational vehicles generally, we have little information on baseline aerodynamic 

performance and opportunities for improvement, a sizeable subset of these incomplete 

vehicles, often called cab-chassis vehicles, are sold by the vehicle manufacturers in 

configurations with many of the components that affect GHG emissions and fuel 

consumption identical to those on complete pickup truck or van counterparts — including 

engines, cabs, frames, transmissions, axles, and wheels. We are including provisions that 

will allow manufacturers to include these vehicles, as well as some Class 4 and 5 

vehicles, to be regulated under the chassis-based HD pickup and van program (i.e. subject 

to the standards for HD pickups and vans), rather than the vocational vehicle program. 

These provisions are described in Section V.B(1)(e). 

In addition to the EPA CO2 emission standards and the NHTSA fuel consumption 

standards for HD pickups and vans, EPA is also finalizing standards for two additional 

GHGs, N2O and CH4, as well as standards for air conditioning-related HFC emissions. 

These standards are discussed in more detail in Section II.E. Finally, EPA is finalizing 

standards that will apply to HD pickups and vans in use. All of the standards for these 

HD pickups and vans, as well as details about the provisions for certification and 

implementation of these standards, are discussed in Section II.C.

(c) Class 2b-8 Vocational Vehicles

Class 2b-8 vocational vehicles consist of a wide variety of vehicle types. Some of 

the primary applications for vehicles in this segment include delivery, refuse, utility,

dump, and cement trucks; transit, shuttle, and school buses; emergency vehicles, motor 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

33 of

homes,36 tow trucks, among others. These vehicles and their engines contribute 

approximately 20 percent of today’s heavy-duty truck sector GHG emissions. 

Manufacturing of vehicles in this segment of the industry is organized in a more 

complex way than that of the other heavy-duty categories. Class 2b-8 vocational vehicles 

are often built as a chassis with an installed engine and an installed transmission. Both 

the engine and transmissions are typically manufactured by other manufacturers and the 

chassis manufacturer purchases and installs them. Many of the same companies that 

build Class 7 and 8 tractors are also in the Class 2b-8 chassis manufacturing market. The 

chassis is typically then sent to a body manufacturer, which completes the vehicle by

installing the appropriate feature -- such as dump bed, delivery box, or utility bucket --

onto the chassis. Vehicle body manufacturers tend to be small businesses that specialize 

in specific types of bodies or specialized features. 

EPA and NHTSA proposed that in this vocational vehicle category the proposed 

GHG and fuel consumption standards apply to chassis manufacturers. Chassis 

manufacturers play a central role in the manufacturing process. The product they

produce – the chassis with engine and transmission – includes the primary technologies 

that affect GHG emissions and fuel consumption. They also constitute a much more 

limited group of manufacturers for purposes of developing and implementing a 

regulatory program. The agencies believe that a focus on the body manufacturers would 

be much less practical, since they represent a much more diverse set of manufacturers, 

many of whom are small businesses. Further, the part of the vehicle that they add affords 

very few opportunities to reduce GHG emissions and fuel consumption (given the limited 

role that aerodynamics plays in many types of lower speed and stop-and-go operation 

typically found with vocational vehicles.) Therefore, the agencies proposed that the 

standards in this vocational vehicle category would apply to the chassis manufacturers of 

all heavy-duty vehicles not otherwise covered by the HD pickup and van standards or 

Class 7 and 8 combination tractor standards discussed above. The agencies requested 

comment on the proposed focus on chassis manufacturers.

Volvo commented that the EISA does not speak to the regulation of subsystems, 

such as incomplete vehicles, and argued that on the other hand, Section 32902(k)(2) 

prescribes the regulation of vehicles. Volvo further stated that precedent for the 

regulation of complete vehicles exists in the light-duty fuel economy rule. As noted 

above, NHTSA does not believe that EISA mandates a particular regulatory approach, 

but rather gives the agency wide latitude and explicitly leaves that determination to the 

agency. NHTSA also notes that its heavy-duty rule creates a new fuel efficiency program 

for which the light-duty program does not necessarily serve as a useful precedent for 

considerations of its structure. Unlike the light-duty fuel economy program, MD/HD 

vehicles are produced in widely diverse stages. Further, given the MD/HD market 

structure, where the complete vehicle manufacturers are numerous, diverse, and often 

small businesses, the regulation of complete vehicles would create unique difficulties for 

 

36 NHTSA’s final fuel consumption standards will not apply to recreational vehicles, as discussed in earlier 

in this preamble section.
34 of 

the application of appropriate and feasible technologies. These same considerations 

justify EPA’s determination, pursuant to CAA section 202 (a), to regulate only chassis 

manufacturers in this first stage of GHG rules for the heavy-duty sector. NHTSA also 

notes that this rule does not represent the first time that the agency has regulated 

incomplete vehicles. Rather, incomplete vehicles have a history of regulation under the 

Federal Motor Vehicle Safety Standards.37 For this first phase of the HD National 

Program, NHTSA and EPA believe that given the complexity of the manufacturing 

process for vocational vehicles, and given the wide range of entities that participate in 

that process, vehicle fuel consumption standards would be most appropriately applied to 

chassis manufacturers and not to body builders. 

The agencies continue to believe that regulation of the chassis manufacturers for 

this vocational vehicle category will achieve the maximum feasible improvement in fuel 

efficiency for purposes of EISA and appropriate emissions reductions for purposes of the 

CAA. Therefore, consistent with our proposal the final standards in this vocational 

vehicle category apply to the chassis manufacturers of all heavy-duty vehicles not 

otherwise covered by the HD pickup and van standards or Class 7 and 8 combination 

tractor standards discussed above. As discussed above, EPA and NHTSA have concluded 

that reductions in GHG emissions and fuel consumption require addressing both the 

vehicle and the engine. As discussed above for Class 7 and 8 combination tractors, the 

agencies are each finalizing two sets of standards for Class 2b-8 vocational vehicles. For 

vehicle-related emissions and fuel consumption, the agencies are adopting standards for 

chassis manufacturers: EPA CO2 (g/ton-mile) standards and NHTSA fuel consumption 

(gal/1,000 ton-mile) standards). While the agencies believe that a freight-based metric is 

broadly appropriate for vocational vehicles because the vocational vehicle population is 

dominated by freight trucks and maintain that it is appropriate for the first phase of the 

program, the agencies may consider other metrics for future phases of a HD program. 

Manufacturers will use GEM, the same customized vehicle simulation model used for 

Class 7 and 8 tractors, to determine compliance with the vocational vehicle standards

finalized in this action. The primary manufacturer-generated input into the GEM for this 

category of trucks will be a measure of tire rolling resistance, as discussed further below, 

because tire improvements are the primary means of vehicle improvement available at 

this time for vocational vehicles. The model also assumes the use of a typical 

representative, compliant engine in the simulation, resulting in an overall value for CO2

emissions and one for fuel consumption. This is done for the same reason as for 

combination tractors. As is the case for combination tractors, the manufacturers of the 

engines intended for vocational vehicles will be subject to separate engine-based 

standards.

(i) Final Standards for Class 2b-8 Vocational Vehicles and their Engines

Based on our analysis and research, the agencies believe that the primary

opportunity for reductions in vocational vehicle GHG emissions and fuel consumption 

will be through improved engine technologies and improved tire rolling resistance. For 

engines, EPA and NHTSA are adopting separate standards for the manufacturers of 

 

37 See 49 U.S.C. §§ 567.5 and 568.4
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engines used in Class 2b-8 vocational vehicles (the same approach as for combination 

tractors and engines intended for use in those tractors). EPA’s final engine-based CO2

standards and NHTSA’s final engine-based fuel consumption standards vary based on the 

expected weight class and usage of the truck into which the engine will be installed. Tire 

rolling resistance is closely related to the weight of the vehicle. Therefore, we are 

adopting vehicle-based standards for these trucks which vary according to one key

attribute, GVWR. For this initial HD rulemaking, we are adopting standards based on the 

same groupings of truck weight classes used for the engine standards -- light heavy-duty,

medium heavy-duty, and heavy heavy-duty. These groupings are appropriate for the final 

vehicle-based standards because they parallel the general divisions among key engine 

characteristics, as discussed in Section II.

The agencies are also finalizing an interim alternative compression ignition 

(diesel) engine standard for model years 2014-2016, again analogous to the alternative 

standards for compression ignition engines use in combination tractors. The need for 

this provision and our considerations in adopting it are the same for the engines used in 

vocational vehicles as for the engines used in combination tractors. As we proposed, 

these alternative standards will only be available through model year 2016. In addition, 

manufacturers that use the interim alternative diesel engine standards for model years 

2014-2016 under the EPA program must use equivalent fuel consumption standards 

under the NHTSA program. 

For the 2014 to 2016 model years, manufacturers may also choose to meet 

alternative engine standards that are phased-in over the model years to coincide with new 

EPA On Board Diagnostic (OBD) requirements applicable for these same model years. 

See Sections II.B and II.D below.

The agencies received a significant number of comments arguing that our 

proposed standards for vocational vehicles did not reflect all of the technologies 

identified in the 2010 NAS report. The commenters encouraged the agencies to expand 

the program to bring in additional reductions through the use of new transmission 

technologies, vehicle weight reductions and hybrid drivetrains. In general, the agencies 

agree with the commenters’ central contention that there are additional technologies to 

improve the fuel efficiency of vocational vehicles. As discussed later, we are finalizing 

provisions to allow new technologies to be brought into the program through the 

innovative technology credit program. More specifically, we are including provisions to 

account for and credit the use of hybrid technology as a technology that can reduce 

emissions and fuel consumption. Hybrid technology can currently be a cost-effective 

technology in certain specific vocational applications, and the agencies want to recognize 

and promote the use of this technology. (See Sections I.E and IV below.) However, we 

are not finalizing standards that are premised on the use of these additional technologies 

because we have not been able to develop the test procedures, regulatory mechanisms and 

baseline performance data necessary to adopt a more comprehensive approach to 

controlling fuel efficiency and GHG emissions from vocational vehicles. In concept, the 

agencies would need to know the baseline weight, aerodynamic performance, and 

transmission configuration for the wide range of vocational vehicles produced today. We 
36 of 

do not have this information even for relatively small portions of this market (e.g. 

concrete mixers) nor are we well informed regarding the potential tradeoffs to changes to 

vehicle utility that might exist for changes to concrete mixer designs in response to a 

regulation. Nor did the commenters provide any such information. Absent this 

information and the necessary regulatory tools, we believe the standards we are finalizing 

for vocational vehicles represent the most appropriate standards for this segment during 

the model years of the first phase of the program. We intend to address fuel consumption 

and GHG emissions from these vehicles in a more comprehensive manner through future 

regulation and look forward to working with all stakeholders on this important segment 

in the future. 

The agencies are setting standards beginning in the 2014 model year and 

establishing more stringent standards in the 2017 model year. Table I-3 presents EPA’s 

final CO2 standards and NHTSA’s final fuel consumption standards for chassis 

manufacturers of Class 2b through Class 8 vocational vehicles for the 2017 model year. 

The 2017 model year standards represent a 6 to 9 percent reduction in CO2 emissions and 

fuel consumption over a 2010 model year vehicle.

Table I-3: Final 2017 Class 2b-8 Vocational Vehicle EPA CO2 Standards and NHTSA Fuel 

Consumption Standards

EPA CO2 (gram/ton-mile) Standard Effective 2017 Model Year

Light Heavy-Duty 

Class 2b-5

Medium HeavyDuty

Class 6-7

Heavy Heavy-Duty

Class 8

CO2 Emissions 373 225 222

NHTSA Fuel Consumption (gallon per 1,000 ton-mile) Standard Effective 2017 Model 

Year

Light Heavy-Duty 

Class 2b-5

Medium HeavyDuty

Class 6-7

Heavy Heavy-Duty

Class 8

Fuel Consumption 36.7 22.1 21.8

 As mentioned above for Class 7 and 8 combination tractors, EPA believes that 

N2O and CH4 emissions are technologically related solely to the engine, fuel, and 

emissions aftertreatment systems, and the agency is not aware of any influence of 

vehicle-based technologies on these emissions. Therefore, for Class 2b-8 vocational 

vehicles, EPA’s final N2O and CH4 standards cover manufacturers of the engines to be 

used in vocational vehicles. EPA did not propose, nor are we adopting separate vehiclebased standards for these GHGs. As for the engines used in Class 7 and 8 tractors, we are 

finalizing a somewhat higher N2O and CH4 emission standards reflecting new data 

submitted to the agencies during the public comment period. EPA expects that 

manufacturers of current engine technologies will be able to comply with the final “cap” 

standards with little or no technological improvements; the value of the standards is that 

they will prevent significant increases in these emissions as alternative technologies are 

developed and introduced in the future. Compliance with the final EPA engine-based 

CO2 standards and the final NHTSA fuel consumption standards, as well as the final EPA 
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37 of

N2O and CH4 standards, will be determined using the appropriate EPA engine test 

procedure, as discussed in Section II below. 

As with the other regulatory categories of heavy-duty vehicles, EPA and NHTSA 

are adopting standards that apply to Class 2b-8 vocational vehicles at the time of 

production, and EPA is adopting standards for a specified period of time in use. All of 

the standards for these trucks, as well as details about the final provisions for certification 

and implementation of these standards, are discussed in more detail later in this notice 

and in the RIA.

EPA did not propose, nor is it adopting A/C refrigerant leakage standards for 

Class 2b-8 vocational vehicles, primarily because of the number of entities involved in 

their manufacture and thus the potential for different entities besides the chassis 

manufacturer to be involved in the A/C system production and installation. 

(d) What Manufacturers Are Not Covered by the Final Standards?

The NPRM proposed to defer temporarily greenhouse gas emissions and fuel 

consumption standards for any manufacturers of heavy-duty engines, manufacturers of 

combination tractors, and chassis manufacturers for vocational vehicles that meet the 

“small business” size criteria set by the Small Business Administration (SBA). 13 CFR 

121.201 defines a small business by the maximum number of employees; for example, 

this is currently 1,000 for heavy-duty vehicle manufacturing and 750 for engine 

manufacturing.38 The agencies stated that they would instead consider appropriate GHG 

and fuel consumption standards for these entities as part of a future regulatory action. 

This includes both U.S.-based and foreign small-volume heavy-duty manufacturers. To 

ensure that the agencies are aware of which companies would be exempt, the agencies 

proposed to require that such entities submit a declaration describing how it qualifies as a 

small entity under the provisions of 13 CFR 121.201 to EPA and NHTSA as prescribed 

in Section V below.

EPA and NHTSA were not aware of any manufacturers of HD pickups and vans 

that meet these criteria. For each of the other categories and for engines, the agencies 

identified a small number of manufacturers that would appear to qualify as small 

businesses under the SBA size criterion, which were estimated to comprise a negligible 

percentage of the U.S. market.39 Therefore, the agencies believed that deferring the 

standards for these companies at this time would have a negligible impact on the GHG 

emission reductions and fuel consumption reductions that the program would otherwise 

achieve. The agencies proposed to consider appropriate GHG emissions and fuel 

consumption standards for these entities as part of a future regulatory action. 

 

38 See §1036.150 and §1037.150 

39 Two heavy-duty combination tractor and ten chassis manufacturers each comprising less than 0.5 percent 

of the total tractor and vocational market based on Polk Registration Data from 2003 through 2007, and 

three engine manufacturing entities based on company information included in Hoover’s, comprising less 

than 0.1 percent of the total heavy-duty engine sales in the United States based on 2009 and 2010 EPA 

certification information.
38 of 

The Institute for Policy Integrity (IPI) commented that the small business 

exemption proposed in the NPRM was based on the improper framework of whether the 

exemption would have a negligible impact, and did not adequately explain why the 

regulation of small businesses would face special compliance and administrative burdens. 

IPI argued that the only proper basis for this exemption would be if the agencies could 

explain how these burdens create costs that exceeded the benefits of regulation. 

NHTSA believes that developing standards that are “appropriate, cost-effective, 

and technologically feasible” under 49 USC 32902(k)(2) includes the authority to 

exclude certain manufacturers if their inclusion would work against these statutory

factors. Similarly, under section 202 (a) of the CAA, EPA may reasonably choose to 

defer regulation of industry segments based on considerations of cost, cost-effectiveness 

and available lead time for standards. As noted above, small businesses make up a very

small percentage of the market and are estimated to have a negligible impact on the 

emissions and fuel consumption goals of this program. The short lead time before the 

CO2 standards take effect, the extremely small fuel savings and emissions contribution of 

these entities, and the potential need to develop a program that would be structured 

differently for them (which would require more time to determine and adopt), all led to 

the decision that the inclusion of small businesses would not be appropriate at this time. 

Therefore, the final rule exempts small businesses as proposed. 

Volvo and EMA stated that by exempting small businesses based on the definition 

from SBA, the rules would create a competitive advantage for small businesses over 

larger entities. EMA commented that the exemption should not apply to market segments 

where a small business has a significant share of a particular HD market. Volvo argued 

that the exempted businesses could expand their product offerings or sell vehicles on 

behalf of larger entities, thereby inappropriately increasing the scope of the exclusion. 

The agencies anticipate that the gain a manufacturer might achieve by restructuring its 

practices and products to circumvent the standard (which for vocational vehicles simply

means installing low rolling resistance tires) in the first few years of this program will be 

outweighed by the costs, particularly as small businesses anticipate their potential 

inclusion in the next rulemaking. 

Volvo also commented that the agencies should elaborate on the requirements for 

the exemption in greater detail. The agencies agree that this may help to clarify the 

process. As suggested by Volvo, the agencies will consider affiliations to other 

companies and evidence of spin-offs for the purpose of circumventing the standards in 

determining whether a business qualifies as a small entity for this exclusion. Each 

declaration must be submitted in writing to EPA and NHTSA as prescribed in Section V 

below, and a manufacturer would not be considered exempt until EPA and NHTSA have 

made a formal determination as to their status in writing. As the agencies gain more 

experience with this exemption, these clarifications may be codified in the regulatory text 

of a future rulemaking.

Volvo further commented that the agencies were adopting an exemption of “small 

businesses” in order to avoid doing a Small Business Regulatory Enforcement Fairness 

Act (SBREFA) and Regulatory Flexibility Act (RFA) analysis. The agencies would like 
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39 of

to reiterate that they have decided not to include small businesses at this time due to the 

factors described above. The discussion on an RFA analysis is laid out in Section IX(4). 

The agencies continue to believe that deferring the standards for these companies 

at this time will have a negligible impact on the GHG emission reductions and fuel 

consumption reductions that the program would otherwise achieve. Therefore, the final 

rules include the small business exemption as proposed.The specific deferral provisions 

are discussed more detail in Section II.

The agencies will consider appropriate GHG emissions and fuel consumption 

standards for these entities as part of a future regulatory action. 

(e) Light-duty Vehicle CH4 and N2O Standards Flexibility 

After finalization of the N2O and CH4 standards for light-duty vehicles as part of 

the 2012-2016 MY program, some manufacturers raised concerns that they may have 

difficulty meeting those standards across their light-duty vehicle fleets. In response to 

these concerns, as part of the same Federal Register notice as the heavy-duty proposal, 

EPA requested comments on additional options for manufacturers to comply with lightduty vehicle N2O and CH4 standards to provide additional near-term flexibility. 

Commenters providing comment on this issue supported additional flexibility for 

manufacturers. EPA is finalizing provisions allowing manufacturers to use CO2 credits, 

on a CO2-equivalent basis, to meet the N2O and CH4 standards, which is consistent with 

many commenters’ preferred approach. Manufacturers will have the option of using CO2

credits to meet N2O and CH4 standards on a test group basis as needed for MYs 2012-

2016.

(f) Alternative Fuel Engines and Vehicles

The agencies believe that it is also appropriate to take steps to recognize the 

benefits of flexible-fueled vehicles (FFVs) and dedicated alternative-fueled vehicles. In 

the NPRM, EPA proposed to determine the emissions performance of dedicated 

alternative fuel engines and pickup trucks and vans by measuring tailpipe CO2 emissions. 

NHTSA proposed to determine fuel consumption performance of non-electric dedicated 

alternative fuel engines and pickup trucks and vans by measuring fuel consumption with 

the alternative fuel and then calculating a petroleum equivalent fuel consumption using a 

Petroleum Equivalency Factor (PEF) that is determined by the Department of Energy. 

NHTSA proposed to treat electric vehicles as having zero fuel consumption, comparable 

to the EPA proposal. Both agencies proposed to determine FFV performance in the same 

way as for GHG emissions for light-duty vehicles, with a 50-50 weighting of alternative 

and conventional fuel test results through MY 2015, and a weighting based on 

demonstrated fuel use in the real world after MY 2015 (defaulting to an assumption of 

100 percent conventional fuel use). This approach was considered to be a reasonable and 

logical way to properly credit alternative fuel use in FFVs in the real world without 

imposing a difficult burden of proof on manufacturers. However, unlike in the light-duty 

rule, the agencies do not believe it is appropriate to create a provision for additional 
40 of 

incentives similar to the 2012-2015 light-duty incentive program (see 49 USC 32904) 

because the HD sector does not have the incentives mandated in EISA for light-duty

FFVs, and so has not relied on the existence of such credits in devising compliance 

strategies for the early model years of this program. See 74 FR at 49531. In fact, 

manufacturers have not in the past produced FFV heavy-duty vehicles. On the other 

hand, the agencies sought comment on how to properly recognize the impact of the use of 

alternative fuels, and E85 in particular, in HD pickups and vans, including the proper 

accounting for alternative fuel use in FFVs in the real world.40 See 75 FR at 74198. 

The agencies received several comments from natural gas vehicle (NGV) interests 

arguing for greater crediting of NGVs than the proposed approach would have provided. 

Clean Energy, Hayday Farms, Border Valley, AGA, Ryder, Encana, and a group of NGV 

interests commented that the NPRM ignored Congress’ intent to incentivize the use of 

NGVs by not including the conversion factor that exists in the light-duty statutory

language. The commenters argued that Congress’ intent to incentivize NGVs is evident 

in the formula contained in 49 U.S.C. 32905, which deems a gallon equivalent of gaseous 

fuel to have a fuel content of 0.15 gallon of fuel. The commenters also argued that 

Congress implicitly intended NGVs to be incentivized in this rulemaking, as evidenced 

by the incentives in the light-duty statutory text. AGA and Hayday suggested that the 

agencies were not including the NGV incentive from light-duty because Congress did not 

explicitly include it in 49 U.S.C. 32902(k), and argued that this would contradict the 

agencies’ inclusion of other incentives similar to the light-duty rule. 

The American Trucking Association expressed support for estimating natural gas 

fuel efficiency by using carbon emissions from natural gas rather than energy content to 

estimate fuel consumption. ATA explained that two vehicles can achieve the same fuel 

efficiency, yet one operated on natural gas would have a lower carbon dioxide emissions 

rate. A natural gas conversion factor that uses carbon content versus energy content is a

more appropriate method for calculating fuel consumption, in the commenter’s view. A

number of other groups commented on the appropriate method to use in establishing fuel 

consumption from alternative fueled vehicles. A group of NGV interests, Ryder, Border 

Valley Trading, Waste Management, Robert Bosch and the Blue Green Alliance 

encouraged the agencies to adopt the 0.15 conversion factor in estimating fuel 

consumption for FFVs and alternative fuel vehicles finalized in the light-duty 2012-2016

MY vehicle standards. The suggested incentive would effectively reduces the calculated 

fuel consumption for FFVs and alternative fuel vehicles by a factor of 85 percent. The 

commenters argued that the incentive is needed for heavy-duty vehicles to encourage the 

use of natural gas and to reduce the nation’s dependence on petroleum. 

The agencies reassessed the options for treating the CO2 and fuel consumption 

performance of alternative fuel vehicles in response to comments and because the 

agencies recognized that the treatment of alternate fuel vehicles was one of the few 

provisions in the proposal where the EPA and NHTSA programs were not aligned. The 

agencies conducted an analysis comparing fuel consumption calculated based on CO2

 

40 E85 is a blended fuel consisting of nominally 15 percent gasoline and 85 percent ethanol.
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41 of

emissions41 to fuel consumption calculated based on gasoline or diesel energy 

equivalency to evaluate impacts of a consistent consumption measurement for all vehicle 

classes covered by this program and to further understand how alternative fuels would be 

impacted by this measurement methodology. In particular the agencies evaluated how 

measuring consumption via CO2 emissions would hinder or benefit the application of 

alternative fuels versus following similar alternative fuel incentivizing programs provided 

via statute for the Agency’s light-duty programs. The analysis showed measuring a 

vehicle’s CO2 output converted to fuel consumption provided a fuel consumption 

measurement benefit to those vehicles operating on fuels other than gasoline or diesel. 

For CNG, LNG and LPG the benefit is approximately 19 percent to 24 percent, for 

biodiesel and ethanol blends the benefit is approximately 1 percent to 3 percent, and for 

electricity and hydrogen fuels the benefit is 100 percent benefit, as fuel consumption is 

zero. The agencies also considered that the EPA Renewable Fuel Standard,42 a separate 

program, requires an increase in the volume of renewable fuels used in the U.S. 

transportation sector. For the fuels covered by the Renewable Fuels Standard additional 

incentives are not needed in this regulation given the large volume increases required 

under RFS.

The agencies continue to believe that alternative-fueled vehicles, including 

NGVs, provide fuel consumption benefits that should be accounted for in this program. 

However, the agencies do not agree with the commenters’ claim that the NGV incentive 

contained in EISA, and reflected in the light-duty program, is an explicit Congressional 

directive that must also be applied to the heavy-duty program, nor that the light-duty 

incentive for NGVs should be interpreted as an implicit Congressional directive for 

NGVs to be incentivized in the heavy-duty program. Further, the agencies believe that 

the fuel consumption benefits that alternative fuel vehicles would obtain through 

measuring CO2 emissions for the EPA program and converting CO2 emissions to fuel 

consumption for the NHTSA program accurately reflects their energy benefits. This, in 

conjunction with the volumetric increases required by the Renewable Fuels Standard,

provides sufficient incentives for these vehicles. The agencies continue to believe that 

the light-duty conversion factor is not appropriate for this program. Instead, the agencies 

are finalizing measuring the performance of alternative fueled vehicles by measuring CO2

emissions for the EPA program and converting CO2 emissions to fuel consumption for 

the NHTSA program. The agencies are also finalizing measuring FFV performance with 

a 50-50 weighting of alternative and conventional fuel test results through MY 2015, and 

an agency- or manufacturer-determined weighting based on demonstrated fuel use in the 

real world after MY 2015 (defaulting to an assumption of 100 percent conventional fuel 

use). 

 

41 Fuel consumption calculated from measured CO2 using conversion factors of 8,887 g CO2/gallon for 

gasoline (for alternative fuel engines that are derived from gasoline engines), and 10,180 g CO2/gallon for 

diesel fuel (for alternative fuel engines that are derived from diesel engines).

42 EPA is responsible for developing and implementing regulations to ensure that transportation fuel sold in 

the United States contains a minimum volume of renewable fuel. The RFS program was created under the 

Energy Policy Act (EPAct) of 2005, and expanded under the Energy Independence and Security Act 

(EISA) of 2007. 
42 of 

The agencies believe this structure accurately reflects the fuel consumption of the 

vehicles while at the same time providing an incentive for the alternative fuel use. (For 

example, natural gas heavy duty engines perform 20 to 30 percent better than their diesel 

and gasoline counterparts from a CO2 perspective, and so meet the standards adopted in 

these rules without cost, and indeed will be credit generators without cost.) We believe 

this is a substantial enough advantage to spur the market for these vehicles. The 

calculation at the same time does not overestimate the benefit from these technologies, 

which could reduce the effectiveness of the regulation. Therefore, the final rules do not 

include the light-duty 0.15 conversion factor for NGVs. The agencies would like to 

clarify that the decision not to include an NGV incentive was based on this policy

determination, not on a belief that incentives present in the light-duty rule could not be 

developed for the heavy-duty sector because they were not explicitly included in Section 

32902(k).

NHTSA recognizes that EPCA/EISA promotes incentives for alternative fueled 

vehicles for different purposes than does the CAA, and that there may be additional 

energy and national security benefits that could be achieved through increasing fleet 

percentages of natural gas and other alternative-fueled vehicles. More alternative-fueled 

vehicles on road would arguably displace petroleum-fueled vehicles, and thereby increase 

both U.S. energy and national security by reducing the nation’s dependence on foreign 

oil. However, the agencies believe that the benefits of harmonization would outweigh 

any potential gains in this area. In addition to reducing industry burden and creating 

regulatory efficiency, a harmonization rule both adheres to the President’s May 2010 

memorandum calling for a joint rulemaking,43 and Executive Order 13563.44

The agencies believe that a divergence of standards in this area would have 

significant negative consequences. Dis-harmonization would effectively make the 

NHTSA program irrelevant, but would increase burdens for both manufacturers and the 

agencies in the areas of compliance and reporting. Further, dis-harmonized standards 

would likely lead to credit excesses in NHTSA’s program for which there would be no 

demand.

On the other hand, achieving harmonized standards has many benefits for the 

public, the regulated industries, and the agencies. By reducing regulatory inefficiency, 

harmonization decreases costs for all parties involved, including taxpayers. 

Harmonization also allows manufacturers to project clear benefits for the application of 

GHG-reduction and fuel efficiency technologies, thus spurring their adoption, and 

 

43 Improving Energy Security, American Competitiveness and Job Creation, and Environmental Protection 

Through a Transformation of Our Nation’s Fleet of Cars And Trucks,” Issued May 21, 2010, published at 

75 FR 29399, May 26, 2010.

44 EO 13563 states that an agency shall “tailor its regulations to impose the least burden on 

society, consistent with obtaining regulatory objectives, taking into account, among other things, and 

to the extent practicable, the costs of cumulative regulations,” and “promote such coordination, 

simplification, and harmonization” as will reduce redundancy, inconsistency, and costs of multiple 

regulatory requirements.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

43 of

reduces incentives for gaming the regulatory system instead of achieving real GHG and 

fuel efficiency benefits.

This combined rulemaking by EPA and NHTSA is designed to regulate two 

separate characteristics of heavy duty vehicles: greenhouse gas emissions (GHG) and fuel 

consumption. In the case of diesel or gasoline powered vehicles, there is a one-to-one 

relationship between these two characteristics. Each gallon of gasoline combusted by a 

truck engine generates approximately 8,887 grams of CO2; and each gallon of diesel fuel 

burned generates about 10,180 grams of CO2. Because no available technologies reduce 

CO2 emissions per gallon of fuel combusted, any rule that limits CO2 emissions is 

effectively identical to a rule that limits fuel consumption. Compliance by a truck 

manufacturer with the NHTSA fuel economy rule assures compliance with the EPA rule, 

and vice versa. 

For alternatively fueled vehicles, which use no petroleum, the situation is 

different. For example, a natural gas vehicle that achieves approximately the same fuel 

economy as a diesel powered vehicle would emit 20 percent less CO2; and a natural gas 

vehicle with the same fuel economy as a gasoline vehicle would emit 30 percent less 

CO2. Yet natural gas vehicles consume no petroleum. To the extent that the goal of the 

NHTSA fuel economy portion of this rulemaking is to curb petroleum use, then natural 

gas vehicles should be credited with zero fuel consumption per mile. Similar differences 

between oil consumption and GHG would apply to electric vehicles, hybrid electric 

vehicles, and biofuel-powered vehicles. 

NHTSA notes that the purpose of EPCA/EISA is not merely to curb petroleum 

use – it is more generally to secure energy independence, which can be achieved by

reducing petroleum use. The value of incentivizing natural gas, electric vehicles, 

biofuels, hydrogen, or other alt fuel vehicles for energy independence is limited to the 

extent that the alternative fuels may be imported. 

In recent rulemakings for light-duty vehicles, EPA and NHTSA have followed the 

light-duty specific statutory provision that treats one gallon of alternative fuel as 

equivalent to 0.15 gallons of gasoline. Following that precedent in this heavy duty rule 

would mean that, for example, a natural gas powered truck would have attributed to it 20 

percent less CO2 emissions than a comparable diesel powered truck, but 85 percent less 

fuel consumption. Engine manufacturers with a relatively large share of alternative-fuel 

products would likely have an easier time complying with NHTSAs average fuel 

economy standard than EPAs GHG standard. Similarly, engine manufacturers with a 

relatively small share of alternative-fuel products would have a relatively easier time 

complying with EPA’s CO2 standard than with NHTSA’s fuel economy standard. In that 

way, the rule would not differ from the light duty vehicle rules. 

Instead, in this rule, EPA and NHTSA are finalizing identical rules. Fuel 

consumption for alternatively-powered vehicles will be calculated according to their CO2 

emissions. In that way, there will be a one-to-one relationship between fuel economy and 

GHG emissions for all vehicles. To the extent that this rule relies upon reduced 
44 of 

petroleum consumption specifically to promote the goals of EPCA/EISA, there will be a 

one-to-one relationship between this reduction and greenhouse gas emissions, by design, 

whether or not that relationship accurately reflects reduced petroleum consumption and 

GHG emissions for all vehicles. In addition to the significant harmonization benefits 

noted above, this has the advantage of reducing some of the paperwork and compliance 

burden this rule will impose on the truck manufacturers. On the other hand, it has the 

disadvantage of discouraging some cost-effective means of reducing petroleum 

consumption by trucks, and the accompanying energy security costs. By attributing to 

natural gas engines only 20 percent less fuel consumption than comparable diesel 

engines, because they emit 20 percent less CO2, rather than attributing to them a much 

larger percentage reduction in fuel consumption, because they use no petroleum, this 

uniform rulemaking does not incentivize technologies that reduce consumption of 

petroleum-based fuels. 

Agencies are considering for future rulemakings writing harmonized standards 

in a way that also accurately reflect the true fuel consumption and greenhouse gas 

emissions. Under such standards, any given vehicle might “over comply” with the fuel 

economy standard, but might “under comply” with the CO2 standard. Therefore, in 

meeting the fleet-wide requirements, a manufacturer would need to meet both standards 

using all available options, such as credit trading and technology mix. Allowing for two 

distinct standards may enable manufacturers to achieve the twin goals of reducing 

greenhouse gas emissions and decreasing consumption of petroleum-based fuels in the 

most cost-effective manner. 

D. Summary of Costs and Benefits of the HD National Program

This section summarizes the projected costs and benefits of the final NHTSA fuel 

consumption and EPA GHG emissions standards. These projections helped to inform the 

agencies’ choices among the alternatives considered and provide further confirmation 

that the final standards are an appropriate choice within the spectrum of choices 

allowable under the agencies’ respective statutory criteria. NHTSA and EPA have used 

common projected costs and benefits as the bases for our respective standards.

The agencies have analyzed in detail the projected costs and benefits of the final

GHG and fuel consumption standards. Table I-4 shows estimated lifetime discounted 

program costs (including technological outlays), fuel savings, and benefits for all heavyduty vehicles projected to be sold in model years 2014-2018 over these vehicles’ lives. 

The benefits include impacts such as climate-related economic benefits from reducing 

emissions of CO2 (but not other GHGs) and reductions in energy security externalities 

caused by U.S. petroleum consumption and imports. The analysis also includes 

economic impacts stemming from additional heavy-duty vehicle use attributable to fuel 

savings, such as the economic damages caused by accidents, congestion and noise. Note 

that benefits reflect on estimated values for the social cost of carbon (SCC), as described 

in Section VIII.G. 

The costs and benefits summarized here are slightly higher than at proposal, 

reflecting the use of 2009 (versus 2008) dollars, some minor changes to our cost 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

45 of

estimates in response to comments, and a change to the 2011 Annual Energy Outlook 

(AEO) estimate of economic growth and future fuel prices. In aggregate, these changes 

lead to an increased estimate of the net benefits of the final action compared to the 

proposal.

Table I-4: Estimated Lifetime Discounted Costs, Benefits, and Net Benefits for 2014-2018 Model 

Year HD Vehicles assuming the Model Average, 3% Discount Rate SCC Valuea,b (2009 dollars)

Lifetime Present Valuec– 3% Discount Rate

Program Costs $8.1

Fuel Savings $50

Benefits $7.3

Net Benefitsd$49

Annualized Valuee– 3% Discount Rate

Annualized benefits $2.6

Annualized costs $0.4

Net benefits $2.2

Lifetime Present Valuec- 7% Discount Rate

Program Costs $8.1

Fuel Savings $34

Benefits $6.7

Net Benefitsd$33

Annualized Valuee– 7% Discount Rate

Annualized benefits $3.1

Annualized costs $0.6

Net benefits $2.5

Notes:

a The agencies estimated the benefits associated with four different values of a one ton 

CO2 reduction (model average at 2.5% discount rate, 3%, and 5%; 95th percentile at 3%), 

which each increase over time. For the purposes of this overview presentation of 

estimated costs and benefits, however, we are showing the benefits associated with the 

marginal value deemed to be central by the interagency working group on this topic: the 

model average at 3% discount rate, in 2009 dollars. Section VIII.F provides a complete 

list of values for the 4 estimates.

b Note that net present value of reduced GHG emissions is calculated differently than

other benefits. The same discount rate used to discount the value of damages from future 

emissions (SCC at 5, 3, and 2.5 percent) is used to calculate net present value of SCC for 

internal consistency. Refer to Section VIII.F for more detail.

c

Present value is the total, aggregated amount that a series of monetized costs or benefits 

that occur over time is worth now (in year 2009 dollar terms), discounting future values 

to the present.

d Net present benefits reflect the fuel savings plus benefits minus costs.

e The annualized value is the constant annual value through a given time period (2012 

through 2050 in this analysis) whose summed present value equals the present value from 

which it was derived.

Table I-5 shows the estimated lifetime reductions in CO2 emissions (in million 

metric tons (MMT)) and fuel consumption for all heavy-duty vehicles sold in the model 
46 of 

years 2014-2018. The values in Table I-5 are projected lifetime totals for each model 

year and are not discounted. The two agencies’ standards together comprise the HD 

National Program, and the agencies’ respective GHG emissions and fuel consumption 

standards, jointly, are the source of the benefits and costs of the HD National Program. 

Table I-5: Estimated Lifetime Reductions in Fuel Consumption and CO2 Emissions for 2014-2018 

Model Year HD Vehicles

All Heavy-Duty 

Vehicles

2014 MY 2015 MY 2016 MY 2017 MY 2018 MY Total

Fuel (billion gallons) 4.0 3.6 3.6 5.1 5.8 22.1

Fuel (billion barrels) 0.10 0.09 0.08 0.12 0.14 0.53

CO2 (MMT)a50.2 44.8 44.0 62.8 71.7 273

Note: aIncludes upstream and downstream CO2 reductions.

Table I-6 shows the estimated lifetime discounted benefits for all heavy-duty

vehicles sold in model years 2014-2018. Although the agencies estimated the benefits 

associated with four different values of a one ton CO2 reduction ($5, $22, $36, $66), for 

the purposes of this overview presentation of estimated benefits the agencies are showing

the benefits associated with one of these marginal values, $22 per ton of CO2, in 2009

dollars and 2010 emissions. Table I-6 presents benefits based on the $22 per ton of CO2

value. Section VIII.F presents the four marginal values used to estimate monetized 

benefits of CO2 reductions and Section VIII presents the program benefits using each of 

the four marginal values, which represent only a partial accounting of total benefits due 

to omitted climate change impacts and other factors that are not readily monetized. The 

values in the table are discounted values for each model year of vehicles throughout their 

projected lifetimes. The analysis includes other economic impacts such as fuel savings, 

energy security, and other externalities such as impacts on accidents, congestion and 

noise. However, the model year lifetime analysis supporting the program omits other 

impacts such as benefits related to non-GHG emission reductions.45 The lifetime 

discounted benefits are shown for one of four different SCC values considered by EPA 

and NHTSA. The values in Table I-6 do not include costs associated with new 

technology required to meet the GHG and fuel consumption standards.

Table I-6: Estimated Lifetime Discounted Benefits for 2014-2018 Model Year HD Vehicles Assuming 

the Model Average, 3% Discount Rate SCC Valuea,b,c (billions of 2009 dollars)

Discount Rate Model Year

2014 2015 2016 2017 2018 Total

3% $10.7 $9.4 $9.2 $13.2 $14.9 $57

7% $8.3 $6.9 $6.6 $9.2 $10.1 $41

Notes:

a The analysis includes impacts such as the economic value of reduced fuel consumption and 

accompanying climate-related economic benefits from reducing emissions of CO2 (but not other 

 

45 Non-GHG emissions and health-related impacts were estimated for the calendar year analysis. See 

Section VII for more information about non-GHG emission impacts and Section VIII for more information 

about non-GHG-related health impacts.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

47 of

GHGs), and reductions in energy security externalities caused by U.S. petroleum consumption and 

imports. The analysis also includes economic impacts stemming from additional heavy-duty vehicle 

use, such as the economic damages caused by accidents, congestion and noise.

b Note that net present value of reduced CO2 emissions is calculated differently than other benefits. 

The same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 

and 2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to 

Section VIII.F for more detail, including a list of all four SCC values, which increase over time.

c Benefits in this table include fuel savings.

Table I-7 shows the agencies’ estimated lifetime fuel savings, lifetime CO2

emission reductions, and the monetized net present values of those fuel savings and CO2

emission reductions. The gallons of fuel and CO2 emission reductions are projected 

lifetime values for all vehicles sold in the model years 2014-2018. The estimated fuel 

savings in billions of barrels and the GHG reductions in million metric tons of CO2

shown in Table I-7 are totals for the five model years throughout their projected lifetime 

and are not discounted. The monetized values shown in Table I-7 are the summed values 

of the discounted monetized-fuel consumption and monetized-CO2 reductions for the five 

model years 2014-2018 throughout their lifetimes. The monetized values in Table I-7

reflect both a 3 percent and a 7 percent discount rate as noted.

Table I-7: Estimated Lifetime Reductions and Associated Discounted Monetized Benefits for 2014-

2018 Model Year HD Vehicles (monetized values in 2009 dollars)

Amount $ value (billions)

Fuel Consumption Reductions 0.53 billion barrels $50.1, 3% discount rate

$34.4, 7% discount rate

CO2 Emission Reductionsa

Valued assuming $22/ton CO2 in 2010

273 MMT CO2 $5.8b

Notes:

a

Includes both upstream and downstream CO2 emission reductions.

b Note that net present value of reduced CO2 emissions is calculated differently than other benefits. The 

same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 

percent) is used to calculate net present value of SCC for internal consistency. Refer to Section VIII.F 

for more detail. 

Table I-8 shows the estimated incremental and total technology outlays for all 

heavy-duty vehicles for each of the model years 2014-2018. The technology outlays 

shown in Table I-8 are for the industry as a whole and do not account for fuel savings 

associated with the program.
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Table I-8: Estimated Incremental Technology Outlays for 2014-2018 Model Year HD Vehicles

(billions of 2009 dollars)

2014

MY

2015

MY

2016

MY

2017

MY

2018

MY

Total

All HeavyDuty Vehicles $1.6 $1.4 $1.5 $1.6 $2.0 $8.1

Table I-9 shows the agencies’ estimated incremental cost increase of the average 

new heavy-duty vehicle for each model year 2014-2018. The values shown are 

incremental to a baseline vehicle and are not cumulative. 

Table I-9: Estimated Incremental Increase in Average Cost for 2014-2018 Model Year HD Vehicles

(2009 dollars per unit)

2014

MY

2015

MY

2016

MY

2017

MY

2018 MY

Combination Tractors $6,019 $5,871 $5,677 $6,413 $6,215

HD Pickups &Vans $165 $215 $422 $631 $1,048

Vocational Vehicles $329 $320 $397 $387 $378

Both costs and benefits presented in this section are in comparison to a reference 

case with no improvements in fuel consumption or greenhouse gas emissions in model 

years 2014 to 2018. 

E. Program Flexibilities

For each of the heavy-duty vehicle and heavy-duty engine categories for which 

we are adopting respective standards, EPA and NHTSA are also finalizing provisions 

designed to give manufacturers a degree of flexibility in complying with the standards. 

These final provisions have enabled the agencies to consider overall standards that are 

more stringent and that will become effective sooner than we could consider with a more 

rigid program, one in which all of a manufacturer’s similar vehicles or engines would be 

required to achieve the same emissions or fuel consumption levels, and at the same time.

46

 We believe that incorporating carefully structured regulatory flexibility provisions into 

the overall program is an important way to achieve each agency’s goals for the program. 

NHTSA’s and EPA’s flexibility provisions are essentially identical in structure 

and function. For combination tractor and vocational vehicle categories and for heavyduty engines, we are finalizing four primary types of flexibility: averaging, banking, and 

trading (ABT) provisions; early credits; advanced technology credits (including hybrid 

powertrains); and innovative technology credit provisions. The final ABT provisions are 

 

46 NHTSA notes that it has greater flexibility in the HD program to include consideration of credits and 

other flexibilities in determining appropriate and feasible levels of stringency than it does in the light-duty 

CAFE program. Cf. 49 U.S.C. 32902(h), which applies to light-duty CAFE but not heavy-duty fuel 

efficiency under 49 U.S.C. 32902(k).
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49 of

patterned on existing EPA and NHTSA ABT programs and will allow a vehicle 

manufacturer to reduce CO2 emission and fuel consumption levels further than the level 

of the standard for one or more vehicles to generate ABT credits. The manufacturer can 

use those credits to offset higher emission or fuel consumption levels in the same 

averaging set, “bank” the credits for later use, or “trade” the credits to another 

manufacturer. For HD pickups and vans, we are finalizing a fleet averaging system very

similar to the light-duty GHG and CAFE fleet averaging system.

At proposal, we restricted the use of the ABT provisions of the program to 

vehicles or engines within the same regulatory subcategory. This meant that credit 

exchanges could only happen between similar vehicles meeting the same standards. We 

proposed this approach for two reasons. First, we were concerned about a level playing 

field between different manufacturers who may not participate equally in the various 

truck and engine markets covered in the regulation. Second, we were concerned about 

the uncertainties inherent in credit calculations that are based on projections of lifetime 

emissions for different vehicles in wholly different vehicle markets. In response to 

comments, we have revised our ABT provisions to provide greater flexibility while 

continuing to provide assurance that the projected reductions in fuel consumption and 

GHG emissions will be achieved. We are relaxing the restriction on averaging, banking, 

and trading of credits between the various regulatory subcategories, by defining three HD 

vehicle averaging sets: Light Heavy-Duty (Classes 2b-5); Medium Heavy-Duty (Class 6-

7); and Heavy Heavy-Duty (Class 8). This allows the use of credits between vehicles 

within the same weight class. This means that a Class 8 day cab tractor can exchange 

credits with a Class 8 high roof sleeper tractor but not with a smaller Class 7 tractor. 

Also, a Class 8 vocational vehicle can exchange credits with a Class 8 tractor. We are 

adopting these revisions based on comments from the regulated industry that convinced 

us these changes would allow the broadest trading possible while maintaining a level 

playing field among the various market segments. 

The agencies believe that restricting trading to within the same eight classes as 

EPA’s existing criteria pollutant program (i.e. Heavy-Heavy Duty, Light Heavy-Duty, 

Medium Heavy-Duty), but not restricting trade between vehicle or engine type (such as 

vocational), is appropriate and reasonable. We do not expect emissions from engines and 

vehicles – when restricted by weight class – to be dissimilar. We therefore expect that 

the lifetime vehicle performance and emissions levels will be very similar across these 

defined categories, and the estimated credit calculations will fairly ensure the expected 

fuel consumption and GHG reductions. 

The agencies considered even broader trading provisions, but decided that in this 

first phase of regulation it would be prudent to start with a program that aligned with the 

current market structure and the well-established criteria pollutant trading provisions. 

We intend to investigate whether additional cost savings could be realized through 

broader trading provisions and whether through improved test procedures and trading 

mechanisms our concerns regarding potential fuel efficiency and environmental loss 

could be addressed or lessened. Reducing the cost of regulation through broader use of 

market tools is a priority for the Administration. Therefore, we intend to seek public 
50 of 

comment after credit trading begins in 2013, the first year we expect manufacturers to 

begin certifying 2014 model year vehicles. We believe that input will be better informed 

by the work the agencies and the regulated industry will have put into implementing this 

first phase of heavy-duty regulations. Using this input, the agencies intend to consider 

whether broader credit trading is more appropriate in developing the next phase of heavyduty regulations.

This program does not allow credits to be exchanged between heavy-duty

vehicles and light-duty vehicles, nor can credits be traded from heavy-duty vehicle fleets 

to light-duty vehicle fleets or vice versa.

The engine ABT provisions are also changed from the proposal and now are the 

same as in EPA’s existing criteria pollutant emission rules. The agencies have broadened 

the averaging sets to include both FTP-certified and SET-certified engines in the same 

averaging set. For example, a SET-certified engine intended for a Class 8 tractor can 

exchange credits with a FTP-certified engine intended for a Class 8 vocational vehicle. 

The agencies are finalizing three year deficit carry-forward provisions for heavyduty engines and vehicles within a limited time frame. This flexibility is expected to 

provide an opportunity for manufacturers to make necessary technological improvements 

and reduce the overall cost of the program without compromising overall environmental 

and fuel economy objectives. This flexibility, similar to the flexibility the agencies have 

offered under the light-duty vehicle program, is intended to assist the broad goal of 

harmonizing the two agencies’ standards while preserving the flexibility of manufacturers 

of vehicles and engines in meeting the standards, to the extent appropriate and required 

by law. During the MYs 2014–2018 manufacturers are expected to go through the 

normal business cycle of redesigning and upgrading their heavy-duty engine and vehicle 

products, and in some cases introducing entirely new vehicles and engines not on the 

market today. As explained in the following paragraph, the carry-forward provision will

allow manufacturers the time needed to incorporate technology to achieve GHG 

reductions and improve fuel economy during the vehicle redesign process.

We received comments from (Center for Biological Diversity) against the need to 

offer the deficit carry-forward flexibility. (CBD) has stated that allowing manufacturers 

to carry-forward deficits for up to three years would incentivize delays in investment and 

technological innovation and allow for the generation of additional tons of GHG 

emissions that may be prevented today. However, the deficit carry-forward flexibility (as 

well as ABT generally) has enabled the agencies to consider overall standards that are 

more stringent and that will become effective at an earlier period than we could consider 

with a more rigid program. The agencies also believe this flexibility is an important 

aspect of the program, as it avoids the much higher costs that would occur if 

manufacturers needed to add or change technology at times other than their scheduled 

redesigns, i.e. the cost of adopting a new engine or vehicle platform mid-production or 

mid-design. This time period would also provide manufacturers the opportunity to plan 

for compliance using a multi-year time frame, again consistent with normal business 

practice. Over these four model years, there would be an opportunity for manufacturers to 
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51 of

evaluate practically all of their vehicle and engine model platforms and add technology in 

a cost effective way to control GHG emissions and improve fuel economy. 

As noted above, in addition to ABT, the other primary flexibility provisions in 

this program involve opportunities to generate early credits, advanced technology credits 

(including for use of hybrid powertrains), and innovative technology credits. For the 

early credits and advanced technology credits, the agencies sought comment on the 

appropriateness of providing a 1.5x multiplier as an incentive for their use. We received 

a number of comments supporting the idea of a credit multiplier, arguing it was an 

appropriate means to incentivize the early compliance and advanced technologies the 

agencies sought. We received other comments suggesting a multiplier was unnecessary. 

After considering the comments, the agencies have decided to finalize a 1.5x multiplier 

consistent with our request for comments. We believe that given the very short lead time

of the program and the nascent nature of the advanced technologies identified in the 

proposal, that a 1.5x multiplier is an effective means to bring technology forward into the 

heavy-duty sector sooner than would otherwise occur. In addition, advanced technology

credits could be used anywhere within the heavy duty sector (including both vehicles and 

engines), but early credits would be restricted to use within the same defined averaging 

set generating the credit.

For other technologies which can reduce CO2 and fuel consumption, but for 

which there do not yet exist established methods for quantifying reductions, the agencies 

still wish to encourage the development of such innovative technologies, and are 

therefore adopting special “innovative technology” credits. These innovative technology

credits will apply to technologies that are shown to produce emission and fuel 

consumption reductions that are not adequately recognized on the current test procedures 

and that are not yet in widespread use in the heavy-duty sector. Manufacturers will need 

to quantify the reductions in fuel consumption and CO2 emissions that the technology is 

expected to achieve, above and beyond those achieved on the existing test procedures. 

As with ABT, the use of innovative technology credits will only be allowed for use 

among vehicles and engines of the same defined averaging set generating the credit, as 

described above. The credit multiplier will not be used for innovative technology credits.

CBD argued that including any opportunities for manufacturers to earn credits in 

the final rule would violate NHTSA’s statutory mandate to implement a program 

designed to achieve the maximum feasible improvement. 

NHTSA strongly believes that creating credit flexibilities for manufacturers for 

this first phase of the HD National Program is fully consistent with the agency’s 

obligation to develop a fuel efficiency improvement program designed to achieve the 

maximum feasible improvement. EISA gives NHTSA broad authority to develop 

“compliance and enforcement protocols” that are “appropriate, cost-effective, and 

technologically feasible,” and the agency believes that compliance flexibilities such as 

the opportunity to earn and use credits to meet the standards are a reasonable and 

appropriate interpretation of that authority, along with the other compliance and 

enforcement provisions developed for this final rule. Unlike in NHTSA’s light-duty 
52 of 

program, where the agency is restricted from considering the availability of credits in 

determining the maximum feasible level of stringency for the fuel economy standards,47

in this HD National Program, NHTSA and EPA have based the levels of stringency in 

part on our assumptions of the use of available flexibilities that have been built into the 

program to incentivize over-compliance in some respects, to balance out potential undercompliance in others. 

By assuming the use of credits for compliance, the agencies were able to set the 

fuel consumption/GHG standards at more stringent levels than would otherwise have 

been feasible. Greater improvements in fuel efficiency will occur under more stringent 

standards; manufacturers will simply have greater flexibility to determine where and how 

to make those improvements than they would have without credit options. Further, this is 

consistent with EOs 12866 and 13563, which encourage agencies to design regulations 

that promote innovation and flexibility where possible.48

A detailed discussion of each agency’s ABT, early credit, advanced technology, 

and innovative technology provisions for each regulatory category of heavy-duty vehicles 

and engines is found in Section IV below.

VI. How Will This Program Impact Fuel Consumption, GHG 

Emissions, and Climate Change?

A. What Methodologies Did the Agencies Use to Project GHG 

Emissions and Fuel Consumption Impacts?

EPA and NHTSA used EPA’s official mobile source emissions inventory model 

named Motor Vehicle Emissions Simulator (MOVES2010)49, to estimate emission and 

fuel consumption impacts of these final rules. MOVES has the capability to take in user 

inputs to modify default data to better estimate emissions for different scenarios, such as 

different regulatory alternatives, state implementation plans (SIPs), geographic locations, 

vehicle activity, and microscale projects. 

The agencies performed multiple MOVES runs to establish reference case and 

control case emission inventories and fuel consumption values. The agencies ran 

MOVES with user input databases that reflected characteristics of the final rules, such as 

 

47 49 U.S.C. 32902(h).

48 EO 12866 states that an agency must “design its regulations in the most cost-effective manner to achieve 

the regulatory objective... consider[ing] incentives for innovation... [and] flexibility,” among other 

factors; EO 13563 directs agencies to “seek to identify, as appropriate, means to achieve regulatory goals 

that are designed to promote innovation,” and “identify and consider regulatory approaches that... 

maintain flexibility.”

49 MOVES homepage: http://www.epa.gov/otaq/models/moves/index.htm. Version MOVES2010 was used 

for emissions impacts analysis for this action. Current version as of September 14, 2010 is an updated 

version named MOVES2010a, available directly from the MOVES homepage. To replicate results from 

this action, MOVES2010 must be used.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

53 of

emissions improvements and recent sales projections. Some post-processing of the model 

output was required to ensure proper results. The agencies ran MOVES for non-GHGs, 

CO2, CH4, and N2O for calendar years 2005, 2018, 2030, and 2050. Additional runs were 

performed for just the three greenhouse gases and for fuel consumption for every

calendar year from 2014 to 2050, inclusive, which fed the economy-wide modeling, 

monetized greenhouse gas benefits estimation, and climate impacts analyses.

The agencies also used MOVES to estimate emissions and fuel consumption 

impacts for the other alternatives considered and described in Section IX.

B. MOVES Analysis

(1) Inputs and Assumptions

The analysis performed for the final action mirrors what was done for the 

proposal. The methods and models are the same, with differences lying primarily in the 

inputs, as a result of updates in the program, standards, and baseline data.

(a) Reference Run Updates

Since MOVES2010a vehicle sales and activity data were developed from 

AEO2009, EPA first updated these data using sales and activity estimates from 

AEO2011. MOVES2010a defaults were used for all other parameters to estimate the 

reference case emissions inventories. 

(b) Control Run Updates

EPA developed additional user input data for MOVES runs to estimate control 

case inventories. To account for improvements of engine and vehicle efficiency, EPA 

developed several user inputs to run the control case in MOVES. As explained at 

proposal, since MOVES does not operate based on Heavy-duty FTP cycle results, EPA 

used the percent reduction in engine CO2 emissions expected due to the final rules to 

develop energy inputs for the control case runs. 75 FR at 74280. Also, EPA used the 

percent reduction in aerodynamic drag and tire rolling resistance coefficients and 

reduction in average total running weight (gross combined weight) expected from the 

final rules to develop road load input for the control case. The sales and activity data

updates used in the reference case were used in the control case. Details of all the 

MOVES runs, input data tables, and post-processing steps are available in the docket 

(EPA-HQ-OAR-2010-0162).

Table VI-1 and Table VI-2 describe the estimated expected reductions from these 

final rules, which were input into MOVES for estimating control case emissions 

inventories.
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Table VI-1: Estimated Reductions in Engine CO2 Emission Rates50

GVWR Class Fuel Model Years CO2 Reduction from 

2010 MY

HHD (8a-8b) Diesel 2014-2016 3%

2017+ 6%

MHD (6-7) and LHD 4-5 Diesel 2014-2016 5%

2017+ 9%

Gasoline 2016+ 5%

Table VI-2: Estimated Reductions in Rolling Resistance Coefficient, Aerodynamic Drag Coefficient, 

and Gross Combined Weight

TRUCK TYPE REDUCTION IN 

TIRE ROLLING 

RESISTANCE 

COEFFICIENT 

FROM BASELINE

REDUCTION IN 

AERODYNAMIC 

DRAG COEFFICIENT 

FROM BASELINE

WEIGHT 

REDUCTION 

(LBS.)

Combination long-haul 9.6% 12.1% 400 

Combination shorthaul7.0% 5.9% 321

Straight trucks, refuse 

trucks, motor homes, 

transit buses, and other 

vocational vehicles

5.0% 0% 0

Since nearly all HD pickup trucks and vans will be certified on a chassis 

dynamometer, the CO2 reductions for these vehicles will not be represented as engine and 

road load reduction components, but rather as total vehicle CO2 reductions. These 

estimated reductions are described in Table VI-3.

 

50 Section II of this preamble discusses an alternative engine standard for the HD diesel engines in the 

2014, 2015, and 2016 model years. To the extent that engines using this alternative are expected to have 

baseline emissions greater than the industry average, the reduction from the industry average projected in 

this program would be reduced.
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55 of

Table VI-3: Estimated Total Vehicle CO2 Reductions for HD Pickup Trucks and Vans

GVWR Class Fuel Model year CO2 Reduction from 

Baseline

HD Pickup 

Trucks and Vans

Gasoline 2014 1.5%

2015 2%

2016 4%

2017 6%

2018+ 10%

Diesel 2014 2.3%

2015 3%

2016 6%

2017 9%

2018+ 15%

C. What Are the Projected Reductions in Fuel Consumption and GHG 

Emissions?

EPA and NHTSA expect significant reductions in GHG emissions and fuel 

consumption from these final rules – emission reductions from both downstream 

(tailpipe) and upstream (fuel production and distribution) sources, and fuel consumption 

reductions from more efficient vehicles. Increased vehicle efficiency and reduced vehicle 

fuel consumption will also reduce GHG emissions from upstream sources. The following 

subsections summarize the GHG emissions and fuel consumption reductions expected 

from these final rules.

(1) Downstream (Tailpipe)

Consistent with the proposal, EPA used MOVES to estimate downstream GHG 

inventories from these final rules. We expect reductions in CO2 from all heavy-duty 

vehicle categories. The reductions come from engine and vehicle improvements. EPA 

expects N2O emissions to increase very slightly because of a rebound in vehicle miles 

traveled (VMT) and because significant vehicle emissions reductions are not expected 

from these final rules. In the proposal, we did not account for differences in methane 

emissions from use of auxiliary power units (APUs) during extended idling from sleeper 

cab combination tractors. After accounting for these differences, EPA expects methane 

emissions to decrease primarily due to differences in hydrocarbon emission 

characteristics between on-road diesel engines and APUs. The amount of methane 

emitted as a fraction of total hydrocarbons is significantly less for APUs than for diesel 

engines equipped with diesel particulate filters. Overall, downstream GHG emissions 

will be reduced significantly and are described in the following subsections. 
56 of 

For CO2 and fuel consumption, the total energy consumption “pollutant” was run 

in MOVES rather than CO2 itself. The energy was converted to fuel consumption based 

on fuel heating values assumed in the Renewable Fuels Standard and used in the 

development of MOVES emission and energy rates. These values are 117,250 kJ/gallon 

for gasoline blended with ten percent ethanol (E10)

51 and 138,451 kJ/gallon for diesel.52

 

To calculate CO2, the agencies assumed a CO2 content of 8,576 g/gallon for E10 and 

10,180 g/gallon for diesel. Table VI-4 shows the fleet-wide GHG reductions and fuel 

savings from reference case to control case through the lifetime of model year 2014 

through 2018 heavy-duty vehicles. Table VI-5 shows the downstream GHG emissions 

reductions and fuel savings in 2018, 2030, and 2050. The analysis follows what was 

done for the proposal. We did not receive comments indicating that this analysis was 

inappropriate or insufficient for estimating downstream emissions impacts of this 

program.

Table VI-4 Model Year 2014 through 2018 Lifetime GHG Reductions and Fuel Savings by Heavyduty Truck Category 

Downstream GHG 

Reductions (MMT CO2eq)

Fuel Savings (billion 

gallons)

HD pickups/vans 18 1.9

Vocational 24 2.4

Combination short-haul 

(Day cabs)

50 4.9

Combination long-haul 

(Sleeper cabs)

135 12.9

Table VI-5: Annual Downstream GHG Emissions Reductions and Fuel Savings in 2018, 2030, and 

2050

Downstream GHG 

Reductions (MMT 

CO2eq)

Diesel Savings 

(million gallons)

Gasoline Savings 

(million gallons)

2018 22 2,123 59

2030 61 5,670 349

2050 89 8,158 522

(2) Upstream (Fuel Production and Distribution)

Using the same approach as used in the NPRM, the upstream GHG emission 

reductions associated with the production and distribution of fuel were projected using 

 

51 Renewable Fuels Standards assumptions of 115,000 BTU/gallon gasoline (E0) and 76,330 BTU/gallon 

ethanol (E100) weighted 90% and 10%, respectively, and converted to kJ at 1.055 kJ/BTU.

52 MOVES2004 Energy and Emission Inputs. EPA420-P-05-003, March 2005. 

http://www.epa.gov/otaq/models/ngm/420p05003.pdf
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57 of

emission factors from DOE’s “Greenhouse Gases, Regulated Emissions, and Energy Use 

in Transportation” (GREET1.8) model, with some modifications consistent with the 

Light-Duty 2012-2016 MY vehicle rule. More information regarding these modifications 

can be found in the RIA Chapter 5. These estimates include both international and 

domestic emission reductions, since reductions in foreign exports of finished gasoline 

and/or crude make up a significant share of the fuel savings resulting from the GHG 

standards. Thus, significant portions of the upstream GHG emission reductions will 

occur outside of the United States; a breakdown and discussion of projected international 

versus domestic reductions is included in the RIA Chapter 5. GHG emission reductions 

from upstream sources can be found in Table VI-6.

Table VI-6: Annual Upstream GHG Emissions Reductions in 2018, 2030, and 2050

CO2 (MMT) CH4 (MMT 

CO2eq)

N2O (MMT 

CO2eq)

Total GHG (MMT 

CO2eq)

2018 5.1 0.9 0.02 6.0

2030 12.2 1.9 0.06 14.2

2050 16.4 2.5 0.08 19.0

(3) HFC Emissions

Based on projected HFC emission reductions due to the final AC leakage 

standards, EPA estimates the HFC reductions to be 120,000 metric tons of CO2eq in 

2018, 440,000 metric tons of CO2eq emissions in 2030 and 600,000 metric tons CO2eq in 

2050, as detailed in RIA Chapter 5.3.4.

(4) Total (Upstream + Downstream + HFC)

Table VI-7 combines downstream results from Table VI-5, upstream results Table 

VI-6, and HFC results to show total GHG reductions for calendar years 2018, 2030, and 

2050.

Table VI-7: Annual Total GHG Emissions Reductions in 2018, 2030, and 2050

GHG Reductions (MMT 

CO2eq)

2018 29

2030 76

2050 108

D. Overview of Climate Change Impacts from GHG Emissions

Once emitted, GHGs that are the subject of this regulation can remain in the 

atmosphere for decades to millenia, meaning that 1) their concentrations become wellmixed throughout the global atmosphere regardless of emission origin, and 2) their 

effects on climate are long lasting. GHG emissions come mainly from the combustion of 
58 of 

fossil fuels (coal, oil, and gas), with additional contributions from the clearing of forests 

and agricultural activities. Transportation activities, in aggregate, are the second largest 

contributor to total U.S. GHG emissions (27 percent of total emissions) despite a decline 

in emissions from this sector during 2008.

53

This section provides a summary of observed and projected changes in GHG 

emissions and associated climate change impacts. The source document for the section 

below is the Technical Support Document (TSD)54 for EPA’s Endangerment and Cause 

or Contribute Findings Under the Clean Air Act (74 FR 66496, December 15, 2009).

Below is the Executive Summary of the TSD which provides technical support for the 

endangerment and cause or contribute analyses concerning GHG emissions under section 

202(a) of the CAA. The TSD reviews observed and projected changes in climate based 

on current and projected atmospheric GHG concentrations and emissions, as well as the 

related impacts and risks from climate change that are projected in the absence of GHG 

mitigation actions, including this program and other U.S. and global actions. The TSD 

was updated and revised based on expert technical review and public comment as part of 

EPA’s rulemaking process for the final Endangerment Findings. The key findings 

synthesized here and the information throughout the TSD are primarily drawn from the 

assessment reports of the Intergovernmental Panel on Climate Change (IPCC), the U.S. 

Climate Change Science Program (CCSP), the U.S. Global Change Research Program 

(USGCRP), and NRC.55

In May 2010, the NRC published its comprehensive assessment, “Advancing the 

Science of Climate Change.”56 It concluded that “climate change is occurring, is caused 

largely by human activities, and poses significant risks for—and in many cases is already 

affecting—a broad range of human and natural systems.” Furthermore, the NRC stated 

that this conclusion is based on findings that are “consistent with the conclusions of 

recent assessments by the U.S. Global Change Research Program, the Intergovernmental 

Panel on Climate Change’s Fourth Assessment Report, and other assessments of the state 

of scientific knowledge on climate change.” These are the same assessments that served 

as the primary scientific references underlying the Administrator’s Endangerment 

Finding. Importantly, this recent NRC assessment represents another independent and 

critical inquiry of the state of climate change science, separate and apart from the 

previous IPCC and USGCRP assessments

(1) Observed Trends in Greenhouse Gas Emissions and Concentrations

The primary long-lived GHGs directly emitted by human activities include CO2, 

CH4, N2O, HFCs, PFCs, and SF6. Greenhouse gases have a warming effect by trapping 

 

53 U.S. EPA (2010) Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990–2007. EPA-430-R-10-

006, Washington, DC.

54 See Endangerment TSD, Note 12 above.

55 For a complete list of core references from IPCC, USGCRP/CCSP, NRC and others relied upon for 

development of the TSD for EPA’s Endangerment and Cause or Contribute Findings see section 1(b), 

specifically, Table 1.1 of the TSD Docket: EPA-HQ-OAR-2009-0171-11645. 

56 National Research Council (NRC) (2010). Advancing the Science of Climate Change. National 

Academy Press. Washington, DC.
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heat in the atmosphere that would otherwise escape to space. In 2007, U.S. GHG 

emissions were 7,150 teragrams57 of CO2 equivalent58 (TgCO2eq). The dominant gas 

emitted is CO2, mostly from fossil fuel combustion. Methane is the second largest 

component of U.S. emissions, followed by N2O and the fluorinated gases (HFCs, PFCs, 

and SF6). Electricity generation is the largest emitting sector (34% of total U.S. GHG 

emissions), followed by transportation (27%) and industry (19%). 

Transportation sources under section 202(a)59 of the CAA (passenger cars, lightduty trucks, other trucks and buses, motorcycles, and passenger cooling) emitted 1,649 

TgCO2eq in 2007, representing 23% of total U.S. GHG emissions. U.S. transportation 

sources under section 202(a) made up 4.3% of total global GHG emissions in 2005,60

which, in addition to the United States as a whole, ranked only behind total GHG 

emissions from China, Russia, and India but ahead of Japan, Brazil, Germany, and the 

rest of the world’s countries. In 2005, total U.S. GHG emissions were responsible for 

18% of global emissions, ranking only behind China, which was responsible for 19% of 

global GHG emissions. The scope of this final action focuses on GHG emissions under 

section 202(a) from heavy-duty source categories (see Section II). 

The global atmospheric CO2 concentration has increased about 38% from preindustrial levels to 2009, and almost all of the increase is due to anthropogenic emissions. 

The global atmospheric concentration of CH4 has increased by 149% since pre-industrial 

levels (through 2007); and the N2O concentration has increased by 23% (through 2007). 

The observed concentration increase in these gases can also be attributed primarily to 

anthropogenic emissions. The industrial fluorinated gases, HFCs, PFCs, and SF6, have 

relatively low atmospheric concentrations but the total radiative forcing due to these 

gases is increasing rapidly; these gases are almost entirely anthropogenic in origin. 

Historic data show that current atmospheric concentrations of the two most 

important directly emitted, long-lived GHGs (CO2 and CH4) are well above the natural 

range of atmospheric concentrations compared to at least the last 650,000 years. 

Atmospheric GHG concentrations have been increasing because anthropogenic emissions 

have been outpacing the rate at which GHGs are removed from the atmosphere by natural 

processes over timescales of decades to centuries.

 

57 One teragram (Tg) = 1 million metric tons. 1 metric ton = 1,000 kilograms = 1.102 short tons = 2,205 

pounds.

58 Long-lived GHGs are compared and summed together on a CO2-equivalent basis by multiplying each gas 

by its global warming potential (GWP), as estimated by IPCC. In accordance with United Nations 

Framework Convention on Climate Change (UNFCCC) reporting procedures, the U.S. quantifies GHG 

emissions in the official U.S. greenhouse gas inventory submission to the UNFCCC using the 100-year 

time frame values for GWPs established in the 1996 IPCC Second Assessment Report.

59 Source categories under Section 202(a) of the CAA are a subset of source categories considered in the 

transportation sector and do not include emissions from non-highway sources such as boats, rail, aircraft, 

agricultural equipment, construction/mining equipment, and other off-road equipment.

60 More recent emission data are available for the United States and other individual countries, but 2005 is 

the most recent year for which data for all countries and all gases are available.
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(2) Observed Effects Associated With Global Elevated Concentrations of 

GHGs

Greenhouse gases, at current (and projected) atmospheric concentrations, remain 

well below published exposure thresholds for any direct adverse health effects and are 

not expected to pose exposure risks (i.e., from breathing/inhalation).

The global average net effect of the increase in atmospheric GHG concentrations, 

plus other human activities (e.g., land-use change and aerosol emissions), on the global 

energy balance since 1750 has been one of warming. This total net heating effect, 

referred to as forcing, is estimated to be +1.6 (+0.6 to +2.4) watts per square meter 

(W/m2), with much of the range surrounding this estimate due to uncertainties about the 

cooling and warming effects of aerosols. However, as aerosol forcing has more regional 

variability than the well-mixed, long-lived GHGs, the global average might not capture 

some regional effects. The combined radiative forcing due to the cumulative (i.e., 1750 to 

2005) increase in atmospheric concentrations of CO2, CH4, and N2O is estimated to be 

+2.30 (+2.07 to +2.53) W/m2. The rate of increase in positive radiative forcing due to 

these three GHGs during the industrial era is very likely to have been unprecedented in 

more than 10,000 years.

Warming of the climate system is unequivocal, as is now evident from 

observations of increases in global average air and ocean temperatures, widespread 

melting of snow and ice, and rising global average sea level. Global mean surface 

temperatures have risen by 1.3 ± 0.32F (0.74°C ± 0.18C) over the last 100 years. Nine

of the 10 warmest years on record have occurred since 2001. Global mean surface 

temperature was higher during the last few decades of the 20th century than during any

comparable period during the preceding four centuries. 

Most of the observed increase in global average temperatures since the mid-20th 

century is very likely due to the observed increase in anthropogenic GHG concentrations. 

Climate model simulations suggest natural forcing alone (i.e., changes in solar irradiance) 

cannot explain the observed warming. 

U.S. temperatures also warmed during the 20th and into the 21st century;

temperatures are now approximately 1.3°F (0.7°C) warmer than at the start of the 20th

century, with an increased rate of warming over the past 30 years. Both the IPCC61 and 

the CCSP reports attributed recent North American warming to elevated GHG 

concentrations. In the CCSP (2008) report,62 the authors find that for North America, 

 

61 Hegerl, G.C. et al. (2007) Understanding and Attributing Climate Change. In: Climate Change 2007: The 

Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the 

Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, 

K.B. Averyt, M. Tignor, and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom 

and New York, NY, USA.

62 CCSP (2008) Reanalysis of Historical Climate Data for Key Atmospheric Features: Implications for 

Attribution of Causes of Observed Change. A Report by the U.S. Climate Change Science Program and the 

Subcommittee on Global Change Research [Randall Dole, Martin Hoerling, and Siegfried Schubert (eds.)]. 

National Oceanic and Atmospheric Administration, National Climatic Data Center, Asheville, NC, 156 pp.
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“more than half of this warming [for the period 1951-2006] is likely the result of humancaused greenhouse gas forcing of climate change.” 

Observations show that changes are occurring in the amount, intensity, frequency

and type of precipitation. Over the contiguous United States, total annual precipitation 

increased by 6.1% from 1901 to 2008. It is likely that there have been increases in the 

number of heavy precipitation events within many land regions, even in those where 

there has been a reduction in total precipitation amount, consistent with a warming 

climate.

There is strong evidence that global sea level gradually rose in the 20th century

and is currently rising at an increased rate. It is not clear whether the increasing rate of 

sea level rise is a reflection of short-term variability or an increase in the longer-term 

trend. Nearly all of the Atlantic Ocean shows sea level rise during the last 50 years with 

the rate of rise reaching a maximum (over 2 millimeters [mm] per year) in a band along 

the U.S. east coast running east-northeast.

Satellite data since 1979 show that annual average Arctic sea ice extent has 

shrunk by 4.1% per decade. The size and speed of recent Arctic summer sea ice loss is 

highly anomalous relative to the previous few thousands of years.

Widespread changes in extreme temperatures have been observed in the last 50 

years across all world regions, including the United States. Cold days, cold nights, and 

frost have become less frequent, while hot days, hot nights, and heat waves have become 

more frequent.

Observational evidence from all continents and most oceans shows that many

natural systems are being affected by regional climate changes, particularly temperature 

increases. However, directly attributing specific regional changes in climate to emissions 

of GHGs from human activities is difficult, especially for precipitation.

Ocean CO2 uptake has lowered the average ocean pH (increased acidity) level by

approximately 0.1 since 1750. Consequences for marine ecosystems can include reduced 

calcification by shell-forming organisms, and in the longer term, the dissolution of 

carbonate sediments.

Observations show that climate change is currently affecting U.S. physical and 

biological systems in significant ways. The consistency of these observed changes in 

physical and biological systems and the observed significant warming likely cannot be 

explained entirely due to natural variability or other confounding non-climate factors.

(3) Projections of Future Climate Change with Continued Increases in 

Elevated GHG Concentrations

Most future scenarios that assume no explicit GHG mitigation actions (beyond 

those already enacted) project increasing global GHG emissions over the century, with 

climbing GHG concentrations. Carbon dioxide is expected to remain the dominant 
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anthropogenic GHG over the course of the 21st century. The radiative forcing associated 

with the non-CO2 GHGs is still significant and increasing over time. 

Future warming over the course of the 21st century, even under scenarios of lowemission growth, is very likely to be greater than observed warming over the past 

century. According to climate model simulations summarized by the IPCC,

63 through 

about 2030, the global warming rate is affected little by the choice of different future 

emissions scenarios. By the end of the 21st century, projected average global warming 

(compared to average temperature around 1990) varies significantly depending on the 

emission scenario and climate sensitivity assumptions, ranging from 3.2 to 7.2F (1.8 to 

4.0C), with an uncertainty range of 2.0 to 11.5F (1.1 to 6.4C).

All of the United States is very likely to warm during this century, and most areas 

of the United States are expected to warm by more than the global average. The largest 

warming is projected to occur in winter over northern parts of Alaska. In western, central 

and eastern regions of North America, the projected warming has less seasonal variation 

and is not as large, especially near the coast, consistent with less warming over the 

oceans. 

It is very likely that heat waves will become more intense, more frequent, and 

longer lasting in a future warm climate, whereas cold episodes are projected to decrease 

significantly.

Increases in the amount of precipitation are very likely in higher latitudes, while 

decreases are likely in most subtropical latitudes and the southwestern United States, 

continuing observed patterns. The mid-continental area is expected to experience drying 

during summer, indicating a greater risk of drought. 

Intensity of precipitation events is projected to increase in the United States and 

other regions of the world. More intense precipitation is expected to increase the risk of 

flooding and result in greater runoff and erosion that has the potential for adverse water 

quality effects. 

It is likely that hurricanes will become more intense, with stronger peak winds 

and more heavy precipitation associated with ongoing increases of tropical sea surface 

temperatures. Frequency changes in hurricanes are currently too uncertain for confident 

projections.

By the end of the century, global average sea level is projected by IPCC64 to rise 

between 7.1 and 23 inches (18 and 59 centimeter [cm]), relative to around 1990, in the 

 

63 Meehl, G.A. et al. (2007) Global Climate Projections. In: Climate Change 2007: The Physical Science 

Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel 

on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and 

H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

64 IPCC (2007) Summary for Policymakers. In: Climate Change 2007: The Physical Science Basis. 

Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on 

Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and 

H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
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63 of

absence of increased dynamic ice sheet loss. Recent rapid changes at the edges of the 

Greenland and West Antarctic ice sheets show acceleration of flow and thinning. While 

an understanding of these ice sheet processes is incomplete, their inclusion in models 

would likely lead to increased sea level projections for the end of the 21st century. 

Sea ice extent is projected to shrink in the Arctic under all IPCC emissions 

scenarios. 

(4) Projected Risks and Impacts Associated With Future Climate Change

Risk to society, ecosystems, and many natural Earth processes increase with 

increases in both the rate and magnitude of climate change. Climate warming may

increase the possibility of large, abrupt regional or global climatic events (e.g., 

disintegration of the Greenland Ice Sheet or collapse of the West Antarctic Ice Sheet). 

The partial deglaciation of Greenland (and possibly West Antarctica) could be triggered 

by a sustained temperature increase of 2 to 7F (1 to 4oC) above 1990 levels. Such 

warming would cause a 13 to 20 feet (4 to 6 meter) rise in sea level, which would occur 

over a time period of centuries to millennia. 

The CCSP65 reports that climate change has the potential to accentuate the 

disparities already evident in the American health care system, as many of the expected 

health effects are likely to fall disproportionately on the poor, the elderly, the disabled, 

and the uninsured. The IPCC66 states with very high confidence that climate change 

impacts on human health in U.S. cities will be compounded by population growth and an 

aging population. 

Severe heat waves are projected to intensify in magnitude and duration over the 

portions of the United States where these events already occur, with potential increases in 

mortality and morbidity, especially among the elderly, young, and frail. 

Some reduction in the risk of death related to extreme cold is expected. It is not 

clear whether reduced mortality from cold will be greater or less than increased heatrelated mortality in the United States due to climate change. 

Increases in regional ozone pollution relative to ozone levels without climate 

change are expected due to higher temperatures and weaker circulation in the United 

States and other world cities relative to air quality levels without climate change. 

Climate change is expected to increase regional ozone pollution, with associated risks in 

 

65 Ebi, K.L., J. Balbus, P.L. Kinney, E. Lipp, D. Mills, M.S. O’Neill, and M. Wilson (2008) Effects of 

Global Change on Human Health. In: Analyses of the effects of global change on human health and welfare 

and human systems. A Report by the U.S. Climate Change Science Program and the Subcommittee on 

Global Change Research. [Gamble, J.L. (ed.), K.L. Ebi, F.G. Sussman, T.J. Wilbanks, (Authors)]. U.S. 

Environmental Protection Agency, Washington, DC, USA, pp. 2-1 to 2-78.

66 Field, C.B. et al. (2007) North America. In: Climate Change 2007: Impacts, Adaptation and 

Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental 

Panel on Climate Change [M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson 

(eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
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respiratory illnesses and premature death. In addition to human health effects, 

tropospheric ozone has significant adverse effects on crop yields, pasture and forest 

growth, and species composition. The directional effect of climate change on ambient 

particulate matter levels remains uncertain. 

Within settlements experiencing climate change, certain parts of the population 

may be especially vulnerable; these include the poor, the elderly, those already in poor 

health, the disabled, those living alone, and/or indigenous populations dependent on one 

or a few resources. Thus, the potential impacts of climate change raise environmental 

justice issues.

The CCSP67 concludes that, with increased CO2 and temperature, the life cycle of 

grain and oilseed crops will likely progress more rapidly. But, as temperature rises, these 

crops will increasingly begin to experience failure, especially if climate variability

increases and precipitation lessens or becomes more variable. Furthermore, the 

marketable yield of many horticultural crops (e.g., tomatoes, onions, fruits) is very likely 

to be more sensitive to climate change than grain and oilseed crops.

Higher temperatures will very likely reduce livestock production during the 

summer season in some areas, but these losses will very likely be partially offset by

warmer temperatures during the winter season.

Cold-water fisheries will likely be negatively affected; warm-water fisheries will 

generally benefit; and the results for cool-water fisheries will be mixed, with gains in the 

northern and losses in the southern portions of ranges.

Climate change has very likely increased the size and number of forest fires, 

insect outbreaks, and tree mortality in the interior West, the Southwest, and Alaska, and 

will continue to do so. Over North America, forest growth and productivity have been 

observed to increase since the middle of the 20th century, in part due to observed climate 

change. Rising CO2 will very likely increase photosynthesis for forests, but the increased 

photosynthesis will likely only increase wood production in young forests on fertile soils. 

The combined effects of expected increased temperature, CO2, nitrogen deposition, 

ozone, and forest disturbance on soil processes and soil carbon storage remain unclear.

Coastal communities and habitats will be increasingly stressed by climate change 

impacts interacting with development and pollution. Sea level is rising along much of the 

U.S. coast, and the rate of change will very likely increase in the future, exacerbating the 

impacts of progressive inundation, storm-surge flooding, and shoreline erosion. Storm 

impacts are likely to be more severe, especially along the Gulf and Atlantic coasts. Salt 

marshes, other coastal habitats, and dependent species are threatened by sea level rise, 

fixed structures blocking landward migration, and changes in vegetation. Population 

 

67 Backlund, P., A. Janetos, D.S. Schimel, J. Hatfield, M.G. Ryan, S.R. Archer, and D. Lettenmaier (2008) 

Executive Summary. In: The Effects of Climate Change on Agriculture, Land Resources, Water Resources, 

and Biodiversity in the United States. A Report by the U.S. Climate Change Science Program and the 

Subcommittee on Global Change Research. Washington, DC., USA, 362 pp.
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65 of

growth and rising value of infrastructure in coastal areas increases vulnerability to 

climate variability and future climate change.

Climate change will likely further constrain already over-allocated water 

resources in some regions of the United States, increasing competition among 

agricultural, municipal, industrial, and ecological uses. Although water management 

practices in the United States are generally advanced, particularly in the West, the 

reliance on past conditions as the basis for current and future planning may no longer be 

appropriate, as climate change increasingly creates conditions well outside of historical 

observations. Rising temperatures will diminish snowpack and increase evaporation, 

affecting seasonal availability of water. In the Great Lakes and major river systems, 

lower water levels are likely to exacerbate challenges relating to water quality, 

navigation, recreation, hydropower generation, water transfers, and binational 

relationships. Decreased water supply and lower water levels are likely to exacerbate 

challenges relating to aquatic navigation in the United States. 

Higher water temperatures, increased precipitation intensity, and longer periods of 

low flows will exacerbate many forms of water pollution, potentially making attainment 

of water quality goals more difficult. As waters become warmer, the aquatic life they

now support will be replaced by other species better adapted to warmer water. In the 

long term, warmer water and changing flow may result in deterioration of aquatic 

ecosystems. 

Ocean acidification is projected to continue, resulting in the reduced biological 

production of marine calcifiers, including corals. 

Climate change is likely to affect U.S. energy use and energy production and 

physical and institutional infrastructures. It will also likely interact with and possibly

exacerbate ongoing environmental change and environmental pressures in settlements, 

particularly in Alaska where indigenous communities are facing major environmental and 

cultural impacts. The U.S. energy sector, which relies heavily on water for hydropower 

and cooling capacity, may be adversely impacted by changes to water supply and quality 

in reservoirs and other water bodies. Water infrastructure, including drinking water and 

wastewater treatment plants, and sewer and stormwater management systems, will be at 

greater risk of flooding, sea level rise and storm surge, low flows, and other factors that 

could impair performance.

Disturbances such as wildfires and insect outbreaks are increasing in the United 

States and are likely to intensify in a warmer future with warmer winters, drier soils, and 

longer growing seasons. Although recent climate trends have increased vegetation 

growth, continuing increases in disturbances are likely to limit carbon storage, facilitate 

invasive species, and disrupt ecosystem services. 

Over the 21st century, changes in climate will cause species to shift north and to 

higher elevations and fundamentally rearrange U.S. ecosystems. Differential capacities 

for range shifts and constraints from development, habitat fragmentation, invasive 
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species, and broken ecological connections will alter ecosystem structure, function, and 

services.

(5) Present and Projected U.S. Regional Climate Change Impacts

Climate change impacts will vary in nature and magnitude across different 

regions of the United States. 

Sustained high summer temperatures, heat waves, and declining air quality are 

projected in the Northeast,68 Southeast,69 Southwest,70 and Midwest.71 Projected climate 

change would continue to cause loss of sea ice, glacier retreat, permafrost thawing, and 

coastal erosion in Alaska.

Reduced snowpack, earlier spring snowmelt, and increased likelihood of seasonal 

summer droughts are projected in the Northeast, Northwest,72 and Alaska. More severe, 

sustained droughts and water scarcity are projected in the Southeast, Great Plains,73 and 

Southwest. 

The Southeast, Midwest, and Northwest in particular are expected to be impacted 

by an increased frequency of heavy downpours and greater flood risk. 

Ecosystems of the Southeast, Midwest, Great Plains, Southwest, Northwest, and 

Alaska are expected to experience altered distribution of native species (including local 

extinctions), more frequent and intense wildfires, and an increase in insect pest outbreaks 

and invasive species. 

Sea level rise is expected to increase storm surge height and strength, flooding, 

erosion, and wetland loss along the coasts, particularly in the Northeast, Southeast, and 

islands. 

Warmer water temperatures and ocean acidification are expected to degrade 

important aquatic resources of islands and coasts such as coral reefs and fisheries. 

A longer growing season, low levels of warming, and fertilization effects of 

carbon dioxide may benefit certain crop species and forests, particularly in the Northeast 

and Alaska. Projected summer rainfall increases in the Pacific islands may augment 

limited freshwater supplies. Cold-related mortality is projected to decrease, especially in 

 

68 Northeast includes West Virginia, Maryland, Delaware, Pennsylvania, New Jersey, New York, 

Connecticut, Rhode Island, Massachusetts, Vermont, New Hampshire, and Maine.

69 Southeast includes Kentucky, Virginia, Arkansas, Tennessee, North Carolina, South Carolina, southeast 

Texas, Louisiana, Mississippi, Alabama, Georgia, and Florida.

70 Southwest includes California, Nevada, Utah, western Colorado, Arizona, New Mexico (except the 

extreme eastern section), and southwest Texas.

71 The Midwest includes Minnesota, Wisconsin, Michigan, Iowa, Illinois, Indiana, Ohio, and Missouri.

72 The Northwest includes Washington, Idaho, western Montana, and Oregon.

73 The Great Plains includes central and eastern Montana, North Dakota, South Dakota, Wyoming, 

Nebraska, eastern Colorado, Nebraska, Kansas, extreme eastern New Mexico, central Texas, and 

Oklahoma
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67 of

the Southeast. In the Midwest in particular, heating oil demand and snow-related traffic 

accidents are expected to decrease.

Climate change impacts in certain regions of the world may exacerbate problems 

that raise humanitarian, trade, and national security issues for the United States. The 

IPCC74 identifies the most vulnerable world regions as the Arctic, because of the effects 

of high rates of projected warming on natural systems; Africa, especially the sub-Saharan 

region, because of current low adaptive capacity as well as climate change; small islands, 

due to high exposure of population and infrastructure to risk of sea level rise and 

increased storm surge; and Asian mega-deltas, such as the Ganges-Brahmaputra and the 

Zhujiang, due to large populations and high exposure to sea level rise, storm surge and 

river flooding. Climate change has been described as a potential threat multiplier with 

regard to national security issues.

E. Changes in Atmospheric CO2 Concentrations, Global Mean 

Temperature, Sea Level Rise, and Ocean pH Associated with the 

Program’s GHG Emissions Reductions

EPA examined75 the reductions in CO2 and other GHGs associated with this

rulemaking and analyzed the projected effects on atmospheric CO2 concentrations, global 

mean surface temperature, sea level rise, and ocean pH which are common variables used 

as indicators of climate change. The analysis projects that the preferred alternative of this 

program will reduce atmospheric concentrations of CO2, global climate warming and sea 

level rise relative to the reference case. Although the projected reductions and 

improvements are small in comparison to the total projected climate change, they are 

quantifiable, directionally consistent, and will contribute to reducing the risks associated 

with climate change. Climate change is a global phenomenon and EPA recognizes that 

this one national action alone will not prevent it: EPA notes this would be true for any 

given GHG mitigation action when taken alone. EPA also notes that a substantial portion 

of CO2 emitted into the atmosphere is not removed by natural processes for millennia, 

and therefore each unit of CO2 not emitted into the atmosphere due to this program

avoids essentially permanent climate change on centennial time scales.

EPA determines that the projected reductions in atmospheric CO2, global mean 

temperature and sea level rise are meaningful in the context of this final action. In 

addition, EPA has conducted an analysis to evaluate the projected changes in ocean pH in 

the context of the changes in emissions from this rulemaking. The results of the analysis 

demonstrate that relative to the reference case, projected atmospheric CO2 concentrations 

 

74 Parry, M.L. et al. (2007) Technical Summary. In: Climate Change 2007: Impacts, Adaptation and 

Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental 

Panel on Climate Change [M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden, and C.E. Hanson 

(eds.)], Cambridge University Press, Cambridge, United Kingdom, pp. 23S78.

75 Using the Model for the Assessment of Greenhouse Gas Induced Climate Change (MAGICC) 5.3v2, 

http://www.cgd.ucar.edu/cas/wigley/magicc/), EPA estimated the effects of this rulemaking’s greenhouse 

gas emissions reductions on global mean temperature and sea level. Please refer to Chapter 8.4 of the RIA 

for additional information.
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are estimated to be reduced by 0.691 to 0.787 part per million by volume (ppmv), global 

mean temperature is estimated to be reduced by 0.0017 to 0.0042°C, and sea-level rise is 

projected to be reduced by approximately 0.017-0.040 cm by 2100, based on a range of 

climate sensitivities. The analysis also demonstrates that ocean pH will increase by

0.0003 pH units by 2100 relative to the reference case. 

(1) Estimated Projected Reductions in Atmospheric CO2 Concentration, 

Global Mean Surface Temperatures, Sea Level Rise, and Ocean pH

EPA estimated changes in the atmospheric CO2 concentration, global mean 

temperature, and sea level rise out to 2100 resulting from the emissions reductions in this 

rulemaking using the GCAM (Global Change Assessment Model, formerly MiniCAM),

integrated assessment model76 coupled with the Model for the Assessment of Greenhouse 

Gas Induced Climate Change (MAGICC, version 5.3v2).77 GCAM was used to create the 

globally and temporally consistent set of climate relevant variables required for running 

MAGICC. MAGICC was then used to estimate the projected change in these variables

over time. Given the magnitude of the estimated emissions reductions associated with 

this action, a simple climate model such as MAGICC is reasonable for estimating the 

atmospheric and climate response. This widely-used, peer reviewed modeling tool was 

also used to project temperature and sea level rise under different emissions scenarios in 

the Third and Fourth Assessments of the IPCC. 

The integrated impact of the following pollutant and greenhouse gas emissions 

changes are considered: CO2, CH4, N2O, HFC-134a, NOX, CO2 and SO2, and volatile 

organic compounds (VOC). For CO2, CH4, HFC-134a, and N2O an annual time-series of 

(upstream + downstream) emissions reductions estimated from the rulemaking were input 

directly. The GHG emissions reductions, from Section VI.C, were applied as net 

reductions to a global reference case (or baseline) emissions scenario in GCAM to 

generate an emissions scenario specific to this rulemaking. For CO, VOCs, SO2, and 

NOX, emissions reductions were estimated for 2018, 2030, and 2050 (provided in Section 

VII.A). EPA then linearly scaled emissions reductions for these gases between a zero 

input value in 2013 and the value supplied for 2018 to produce the reductions for 2014-

2018. A similar scaling was used for 2019-2029 and 2031-2050. The emissions 

reductions past 2050 for all gases were scaled with total U.S. road transportation fuel 

consumption from the GCAM reference scenario. Road transport fuel consumption past 

2050 does not change significantly and thus emissions reductions remain relatively

 

76 GCAM is a long-term, global integrated assessment model of energy, economy, agriculture and land use, 

that considers the sources of emissions of a suite of GHG’s, emitted in 14 globally disaggregated regions, 

the fate of emissions to the atmosphere, and the consequences of changing concentrations of greenhouse 

related gases for climate change. GCAM begins with a representation of demographic and economic 

developments in each region and combines these with assumptions about technology development to 

describe an internally consistent representation of energy, agriculture, land-use, and economic 

developments that in turn shape global emissions. 

Brenkert A, S. Smith, S. Kim, and H. Pitcher, 2003: Model Documentation for the MiniCAM. PNNL14337, Pacific Northwest National Laboratory, Richland, Washington.

77 Wigley, T.M.L. 2008. MAGICC 5.3.v2 User Manual. UCAR – Climate and Global Dynamics Division, 

Boulder, Colorado. http://www.cgd.ucar.edu/cas/wigley/magicc/
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69 of

constant from 2050 through 2100. Specific details about the GCAM reference case 

scenario can be found in Chapter 8.4 of the RIA that accompanies this preamble. 

MAGICC calculates the forcing response at the global scale from changes in 

atmospheric concentrations of CO2, CH4, N2O, HFCs, and tropospheric ozone. It also 

includes the effects of temperature changes on stratospheric ozone and the effects of CH4

emissions on stratospheric water vapor. Changes in CH4, NOX, VOC, and CO emissions 

affect both O3 concentrations and CH4 concentrations. MAGICC includes the relative 

climate forcing effects of changes in sulfate concentrations due to changing SO2

emissions, including both the direct effect of sulfate particles and the indirect effects 

related to cloud interactions. However, MAGICC does not calculate the effect of changes 

in concentrations of other aerosols such as nitrates, black carbon, or organic carbon, 

making the assumption that the sulfate cooling effect is a proxy for the sum of all the 

aerosol effects. Therefore, the climate effects of changes in PM2.5 emissions and 

precursors (besides SO2) which are presented in the RIA Chapter 5 were not included in 

the calculations in this section. MAGICC also calculates all climate effects at the global 

scale. This global scale captures the climate effects of the long-lived, well-mixed 

greenhouse gases, but does not address the fact that short-lived climate forcers such as 

aerosols and ozone can have effects that vary with location and timing of emissions. 

Black carbon in particular is known to cause a positive forcing or warming effect by 

absorbing incoming solar radiation, but there are uncertainties about the magnitude of 

that warming effect and the interaction of black carbon (and other co-emitted aerosol 

species) with clouds. While black carbon is likely to be an important contributor to 

climate change, it would be premature to include quantification of black carbon climate 

impacts in an analysis of the final standards at this time.

Changes in atmospheric CO2 concentration, global mean temperature, and sea

level rise for both the reference case and the emissions scenarios associated with this 

action were computed using MAGICC. To calculate the reductions in the atmospheric 

CO2 concentrations as well as in temperature and sea level resulting from this action, the 

output from the policy scenario associated with the preferred approach of this action was 

subtracted from an existing Global Change Assessment Model (GCAM, formerly 

MiniCAM) reference emission scenario. To capture some key uncertainties in the climate 

system with the MAGICC model, changes in atmospheric CO2, global mean temperature 

and sea level rise were projected across the most current IPCC range of climate 

sensitivities, from 1.5°C to 6.0°C.

78

 This range reflects the uncertainty for equilibrium 

climate sensitivity for how much global mean temperature would rise if the concentration 

of carbon dioxide in the atmosphere were to double. The information for this range come 

from constraints from past climate change on various time scales, and the spread of 

 

78 In IPCC reports, equilibrium climate sensitivity refers to the equilibrium change in the annual mean 

global surface temperature following a doubling of the atmospheric equivalent carbon dioxide 

concentration. The IPCC states that climate sensitivity is “likely” to be in the range of 2°C to 4.5°C, “very 

unlikely” to be less than 1.5°C, and “values substantially higher than 4.5°C cannot be excluded.” IPCC 

WGI, 2007, Climate Change 2007 - The Physical Science Basis, Contribution of Working Group I to the 

Fourth Assessment Report of the IPCC, http://www.ipcc.ch/
70 of 

results for climate sensitivity from ensembles of models.79 Details about this modeling 

analysis can be found in the RIA Chapter 8.4.

The results of this modeling, summarized in Table VI-8, show small, but 

quantifiable, reductions in atmospheric CO2 concentrations, projected global mean 

temperature and sea level resulting from this action, across all climate sensitivities. As a 

result of the emission reductions from the final standards for this action, relative to the 

reference case the atmospheric CO2 concentration is projected to be reduced by 0.691-

0.787 ppmv, the global mean temperature is projected to be reduced by approximately

0.0017-0.0042°C by 2100, and global mean sea level rise is projected to be reduced by 

approximately 0.017-0.040 cm by 2100. The range of reductions in global mean 

temperature and sea level rise is larger than that for CO2 concentrations because CO2

concentrations are only weakly coupled to climate sensitivity through the dependence on 

temperature of the rate of ocean absorption of CO2, whereas the magnitude of 

temperature change response to CO2 changes (and therefore sea level rise) is more tightly

coupled to climate sensitivity in the MAGICC model. 

Table VI-8: Impact of GHG Emissions Reductions on Projected Changes in Global Climate 

Associated with the Final Rulemaking (Based on a range of climate sensitivities from 1.5-6°C)

Variable Units Year Projected Change

Atmospheric CO2 Concentration ppmv 2100 -0.691 to -0.787

Global Mean Surface Temperature o C 2100 -0.0017 to -0.0042

Sea Level Rise cm 2100 -0.017 to -0.040

Ocean pH pH units 2100 0.0003a

Note:

a The value for projected change in ocean pH is based on a climate sensitivity of 3.0.

The projected reductions are small relative to the change in temperature (1.8 – 4.8

oC), sea level rise (27 – 51 cm), and ocean acidity (-0.30 pH units) from 1990 to 2100 

from the MAGICC simulations for the GCAM reference case. However, this is to be 

expected given the magnitude of emissions reductions expected from the program in the 

context of global emissions. This uncertainty range does not include the effects of 

uncertainty in future emissions. It should also be noted that the calculations in MAGICC 

do not include the possible effects of accelerated ice flow in Greenland and/or Antarctica: 

the recent NRC report estimated a likely sea level increase for the A1B SRES scenario of 

0.5 to 1.0 meters.80 Further discussion of EPA’s modeling analysis is found in the RIA, 

Chapter 8.

 

79 Meehl, G.A. et al. (2007) Global Climate Projections. In: Climate Change 2007: The Physical Science 

Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel 

on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and 

H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

80 National Research Council, 2011. Climate Stabilization Targets: Emissions, Concentrations, and Impacts 

over Decades to Millenia. Washington, DC: National Academies Press.
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71 of

EPA used the Program CO2SYS,81 version 1.05 to estimate projected changes in 

ocean pH for tropical waters based on the atmospheric CO2 concentration change 

(reduction) resulting from this action. The program performs calculations relating 

parameters of the CO2 system in seawater. EPA used the program to calculate ocean pH 

as a function of atmospheric CO2 concentrations, among other specified input conditions. 

Based on the projected atmospheric CO2 concentration reductions resulting from this 

action, the program calculates an increase in ocean pH of 0.0003 pH units in 2100 

relative to the reference case (compared to a decrease of 0.3 pH units from 1990 to 2100 

in the reference case). Thus, this analysis indicates the projected decrease in atmospheric 

CO2 concentrations from the program will result in an increase in ocean pH. For 

additional validation, results were generated using different known constants from the 

literature. A comprehensive discussion of the modeling analysis associated with ocean 

pH is provided in the RIA, Chapter 8. 

(2) Program’s Effect on Climate

As a substantial portion of CO2 emitted into the atmosphere is not removed by 

natural processes for millennia, each unit of CO2 not emitted into the atmosphere avoids 

essentially permanent climate change on centennial time scales. Reductions in emissions 

in the near-term are important in determining long-term climate stabilization and 

associated impacts experienced not just over the next decades but in the coming centuries 

and millennia.82 Though the magnitude of the avoided climate change projected here is 

small in comparison to the total projected changes, these reductions represent a reduction 

in the adverse risks associated with climate change (though these risks were not formally 

estimated for this action) across a range of equilibrium climate sensitivities.

EPA’s analysis of the program’s impact on global climate conditions is intended 

to quantify these potential reductions using the best available science. EPA’s modeling 

results show repeatable, consistent reductions relative to the reference case in changes of 

CO2 concentration, temperature, sea-level rise, and ocean pH over the next century.

 

81 Lewis, E., and D. W. R. Wallace. 1998. Program Developed for CO2 System Calculations. 

ORNL/CDIAC-105. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. 

Department of Energy, Oak Ridge, Tennessee.

82 See NRC 2011, Note 80.83 Although the net impact is small when aggregated to the national level, it is 

unlikely that the geographic location of increases in downstream PM2.5 emissions will coincide with the 

location of decreases in upstream PM2.5 emissions. Impacts of the emissions changes are included in the air 

quality modeling, discussed in Section VII.D of this preamble and in Chapter 8 of the RIA.
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VII. How Will This Final Action Impact Non-GHG Emissions 

and Their Associated Effects?

A. Emissions Inventory Impacts

(1) Upstream Impacts of the Program

Increasing efficiency in heavy-duty vehicles will result in reduced fuel demand 

and therefore reductions in the emissions associated with all processes involved in getting 

petroleum to the pump. These projected upstream emission impacts on criteria pollutants 

are summarized in Table VII-1. Table VII-2 shows the corresponding projected impacts 

on upstream air toxic emissions in 2030. 

Table VII-1: Overall estimated upstream impacts on criteria pollutants for calendar years 2018, 

2030, and 2050 (short tons)

Calendar Year NOX VOC CO PM2.5 

2018 -6,475 -1,765 -2,217 -971

2030 -9,975 -4,367 -3,331 -1,379

2050 -14,243 -6,379 -4,785 -1,998

Table VII-2: Overall estimated upstream impacts on air toxics for calendar years 2018, 2030, and 

2050 (short tons)

Calendar Year Benzene 1,3-butadiene Formaldehyde Acetaldehyde Acrolein

2018 -12 -0.6 -12 -1 -0.2

2030 -19 -0.9 -26 -3 -0.5

2050 -28 -1.2 -35 -5 -0.6

To project these impacts, EPA estimated the impact of reduced petroleum 

volumes on the extraction and transportation of crude oil as well as the production and 

distribution of finished gasoline and diesel. For the purpose of assessing domestic-only

emission reductions it was necessary to estimate the fraction of fuel savings attributable

to domestic finished gasoline and diesel, and of this fuel what fraction is produced from 

domestic crude. For this analysis EPA estimated that 50 percent of fuel savings is 

attributable to domestic finished gasoline and diesel and that 90 percent of this gasoline

and diesel originated from imported crude. Emission factors for most upstream emission 

sources are based on the GREET1.8 model, developed by DOE’s Argonne National 

Laboratory but in some cases the GREET values were modified or updated by EPA to be

consistent with the National Emission Inventory. These updates are consistent with those 

used for the upstream analysis included in the Light-Duty GHG rulemaking. More 

information on the development of the emission factors used in this analysis can be found 

in RIA Chapter 5.
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73 of

(2) Downstream Impacts of the Program

While these final rules do not regulate non-GHG pollutants, EPA expects 

reductions in downstream emissions of most non-GHG pollutants. These pollutants 

include NOX, SO2, VOC, CO, and PM. The primary reasons for this are the 

improvements in road load (aerodynamics and tire rolling resistance) under the program 

and the agency’s anticipation of increased use of APUs in combination tractors for GHG 

reduction purposes during extended idling. APUs exhibit different non-GHG emissions 

characteristics compared to the on-road engines they would replace during extended 

idling. Another reason is that emissions from certain pollutants (e.g., SO2) are 

proportional to fuel consumption. For vehicle types not affected by road load 

improvements, non-GHG emissions may increase very slightly due to VMT rebound. 

EPA used MOVES to determine non-GHG emissions inventories for baseline and control 

cases. Further information about the MOVES analysis is available in Section VI and RIA 

Chapter 5. The improvements in road load, use of APUs, and VMT rebound were 

included in the MOVES runs and post-processing. Table VII-3 summarizes the 

downstream criteria pollutant impacts of this program. Most of the impacts shown are 

through projected increased APU use. Because APUs are required to meet much less 

stringent PM2.5 standards than on-road engines, the projected widespread use of APUs 

leads to higher PM2.5. Table VII-4 summarizes the downstream air toxics impacts of this 

program. 

Table VII-3: Overall Estimated Downstream Impacts on Criteria Pollutants (short tons)

Calendar 

Year

Downstream 

NOX

Downstream 

VOC

Downstream 

SO2

Downstream 

CO

Downstream 

PM2.5 

a

2018 -107,135 -12,951 -145 -25,614 803

2030 -235,046 -25,502 -423 -52,212 1,751

2050 -326,413 -35,126 -614 -72,049 2,441

Note:

a

Positive number means emissions would increase from baseline to control case. PM2.5 from tire wear and 

brake wear is included. 

Table VII-4: Overall Estimated Downstream Impacts on Air Toxics (short tons)

Calendar Year Benzene 1,3-butadiene Formaldehyde Acetaldehyde Acrolein

2018 -158 -0.3 -2,853 -871 -120

2030 -341 0.4 -6,255 -1,908 -263

2050 -472 0.8 -8,689 -2,650 -365

(3) Total Impacts of the Program

As shown in Table VII-5 and Table VII-6, the agencies estimate that this program 

would result in reductions of NOX, VOC, CO, PM, and air toxics. For NOX, VOC, and 

CO, much of the net reductions are realized through the use of APUs, which emit these 
74 of 

pollutants at a lower rate than on-road engines during extended idle operation. 

Additional reductions are achieved in all pollutants through reduced road load (improved 

aerodynamics and tire rolling resistance), which reduces the amount of work required to 

travel a given distance. For SOX, downstream emissions are roughly proportional to fuel 

consumption; therefore a decrease is seen in both upstream and downstream sources. The 

downstream increase in PM2.5 due to APU use is mostly negated by upstream PM2.5

reductions, though our calculations show a slight net increase in 2030 and 2050.83 

Table VII-5: Overall Estimated Total Impacts (Upstream Plus Downstream) on Criteria Pollutants 

Results are shown in both short tons and percent change from baseline to control case.

CY NOX VOC SO2 CO PM2.5

short 

tons

% short 

tons

% short 

tons

% short tons % short 

tons

%

2018 -113,610 6.2 -14,715 5.6 -4,566 -4.5 -27,832 1.0

-

167 0.2

2030 -245,129 21.0 -29,932 16.0 -6,888 -10.1 -55,579 2.1

3

56 0.1

2050 -340,656 23.7 -41,506 18.3 -9,857 -11.0 -76,834 2.2

4

43 0.1

Table VII-6: Overall Estimated Total Impacts (Upstream Plus Downstream) Impacts on Air Toxics

CY Benzene 1,3-butadiene Formaldehyde Acetaldehyde Acrolein

short 

tons

% short 

tons

% short 

tons

% short 

tons

% short 

tons

%

2018 -170 -4.8 -0.9 -0.1 -2,865 -18.3 -873 -13.9 -120.0 -12.4

2030 -359 -15.0 -0.5 -0.1 -6,282 -46.2 -1,912 -40.2 -263.0 -40.0

2050 -500 -17.4 -0.4 -0.1 -8,725 -49.5 -2,655 -44.2 -365.4 -44.5

B. Health Effects of Non-GHG Pollutants

In this section we discuss health effects associated with exposure to some of the 

criteria and air toxic pollutants impacted by the final heavy-duty vehicle standards. 

(1) Particulate Matter

(a) Background

Particulate matter is a generic term for a broad class of chemically and physically 

diverse substances. It can be principally characterized as discrete particles that exist in the 

condensed (liquid or solid) phase spanning several orders of magnitude in size. Since 

1987, EPA has delineated that subset of inhalable particles small enough to penetrate to 

 

83 Although the net impact is small when aggregated to the national level, it is unlikely that the geographic 

location of increases in downstream PM2.5 emissions will coincide with the location of decreases in 

upstream PM2.5 emissions. Impacts of the emissions changes are included in the air quality modeling,

discussed in Section VII.D of this preamble and in Chapter 8 of the RIA.
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75 of

the thoracic region (including the tracheobronchial and alveolar regions) of the 

respiratory tract (referred to as thoracic particles). Current National Ambient Air Quality

Standards (NAAQS) use PM2.5 as the indicator for fine particles (with PM2.5 referring to 

particles with a nominal mean aerodynamic diameter less than or equal to 2.5 μm), and 

use PM10 as the indicator for purposes of regulating the coarse fraction of PM10 (referred 

to as thoracic coarse particles or coarse-fraction particles; generally including particles 

with a nominal mean aerodynamic diameter greater than 2.5 μm and less than or equal to 

10 μm, or PM10-2.5). Ultrafine particles are a subset of fine particles, generally less than 

100 nanometers (0.1 μm) in aerodynamic diameter. 

Fine particles are produced primarily by combustion processes and by 

transformations of gaseous emissions (e.g., SOX, NOX, and VOC) in the atmosphere. The 

chemical and physical properties of PM2.5 may vary greatly with time, region, 

meteorology, and source category. Thus, PM2.5 may include a complex mixture of 

different pollutants including sulfates, nitrates, organic compounds, elemental carbon and 

metal compounds. These particles can remain in the atmosphere for days to weeks and 

travel hundreds to thousands of kilometers.

(b) Health Effects of PM

Scientific studies show ambient PM is associated with a series of adverse health 

effects. These health effects are discussed in detail in EPA’s Integrated Science 

Assessment for Particulate Matter (ISA).

84

 Further discussion of health effects associated 

with PM can also be found in the RIA for this final action. The ISA summarizes 

evidence associated with PM2.5, PM10-2.5, and ultrafine particles.

The ISA concludes that health effects associated with short-term exposures (hours 

to days) to ambient PM2.5 include mortality, cardiovascular effects, such as altered 

vasomotor function and hospital admissions and emergency department visits for 

ischemic heart disease and congestive heart failure, and respiratory effects, such as 

exacerbation of asthma symptoms in children and hospital admissions and emergency

department visits for chronic obstructive pulmonary disease and respiratory infections.

85

 

The ISA notes that long-term exposure to PM2.5 (months to years) is associated with the 

development/progression of cardiovascular disease, premature mortality, and respiratory

effects, including reduced lung function growth, increased respiratory symptoms, and 

asthma development.86 The ISA concludes that the currently available scientific evidence 

from epidemiologic, controlled human exposure, and toxicological studies supports a 

causal association between short- and long-term exposures to PM2.5 and cardiovascular 

effects and mortality. Furthermore, the ISA concludes that the collective evidence 

supports likely causal associations between short- and long-term PM2.5 exposures and 

respiratory effects. The ISA also concludes that the scientific evidence is suggestive of a 

 

84 U.S. EPA (2009) Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, Docket EPA-HQ-OAR-2010-

0162.

85 See U.S. EPA, 2009 Final PM ISA, Note 84, at Section 2.3.1.1.

86 See U.S. EPA 2009 Final PM ISA, Note 84, at page 2-12, Sections 7.3.1.1 and 7.3.2.1.
76 of 

causal association for reproductive and developmental effects and cancer, mutagenicity, 

and genotoxicity and long-term exposure to PM2.5.

87

For PM10-2.5, the ISA concludes that the current evidence is suggestive of a causal 

relationship between short-term exposures and cardiovascular effects, such as 

hospitalization for ischemic heart disease. There is also suggestive evidence of a causal 

relationship between short-term PM10-2.5 exposure and mortality and respiratory effects. 

Data are inadequate to draw conclusions regarding the health effects associated with 

long-term exposure to PM10-2.5.

88

For ultrafine particles, the ISA concludes that there is suggestive evidence of a 

causal relationship between short-term exposures and cardiovascular effects, such as 

changes in heart rhythm and blood vessel function. It also concludes that there is 

suggestive evidence of association between short-term exposure to ultrafine particles and 

respiratory effects. Data are inadequate to draw conclusions regarding the health effects 

associated with long-term exposure to ultrafine particles.89

(2) Ozone

(a) Background

Ground-level ozone pollution is typically formed by the reaction of VOC and 

NOX in the lower atmosphere in the presence of sunlight. These pollutants, often referred 

to as ozone precursors, are emitted by many types of pollution sources, such as highway

and nonroad motor vehicles and engines, power plants, chemical plants, refineries, 

makers of consumer and commercial products, industrial facilities, and smaller area 

sources.

The science of ozone formation, transport, and accumulation is complex. 

Ground-level ozone is produced and destroyed in a cyclical set of chemical reactions, 

many of which are sensitive to temperature and sunlight. When ambient temperatures 

and sunlight levels remain high for several days and the air is relatively stagnant, ozone 

and its precursors can build up and result in more ozone than typically occurs on a single 

high-temperature day. Ozone can be transported hundreds of miles downwind from 

precursor emissions, resulting in elevated ozone levels even in areas with low local VOC 

or NOX emissions.

(b) Health Effects of Ozone

The health and welfare effects of ozone are well documented and are assessed in 

EPA’s 2006 Air Quality Criteria Document and 2007 Staff Paper.90,91 People who are 

 

87 See U.S. EPA 2009 Final PM ISA, Note 84, at Section 2.3.2.

88 See U.S. EPA 2009 Final PM ISA, Note 84, at Section 2.3.4, Table 2-6.

89 See U.S. EPA 2009 Final PM ISA, Note 84, at Section 2.3.5, Table 2-6.

90 U.S. EPA. (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). 

EPA/600/R-05/004aF-cF. Washington, DC: U.S. EPA. Docket EPA-HQ-OAR-2010-0162.
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more susceptible to effects associated with exposure to ozone can include children, the 

elderly, and individuals with respiratory disease such as asthma. Those with greater 

exposures to ozone, for instance due to time spent outdoors (e.g., children and outdoor 

workers), are of particular concern. Ozone can irritate the respiratory system, causing 

coughing, throat irritation, and breathing discomfort. Ozone can reduce lung function 

and cause pulmonary inflammation in healthy individuals. Ozone can also aggravate 

asthma, leading to more asthma attacks that require medical attention and/or the use of 

additional medication. Thus, ambient ozone may cause both healthy and asthmatic 

individuals to limit their outdoor activities. In addition, there is suggestive evidence of a 

contribution of ozone to cardiovascular-related morbidity and highly suggestive evidence 

that short-term ozone exposure directly or indirectly contributes to non-accidental and 

cardiopulmonary-related mortality, but additional research is needed to clarify the 

underlying mechanisms causing these effects. In a recent report on the estimation of 

ozone-related premature mortality published by NRC, a panel of experts and reviewers 

concluded that short-term exposure to ambient ozone is likely to contribute to premature 

deaths and that ozone-related mortality should be included in estimates of the health 

benefits of reducing ozone exposure.92 Animal toxicological evidence indicates that with 

repeated exposure, ozone can inflame and damage the lining of the lungs, which may lead 

to permanent changes in lung tissue and irreversible reductions in lung function. The 

respiratory effects observed in controlled human exposure studies and animal studies are 

coherent with the evidence from epidemiologic studies supporting a causal relationship 

between acute ambient ozone exposures and increased respiratory-related emergency

room visits and hospitalizations in the warm season. In addition, there is suggestive 

evidence of a contribution of ozone to cardiovascular-related morbidity and nonaccidental and cardiopulmonary mortality.

(3) Nitrogen Oxides and Sulfur Oxides

(a) Background

Nitrogen dioxide (NO2) is a member of the NOX family of gases. Most NO2 is 

formed in the air through the oxidation of nitric oxide (NO) emitted when fuel is burned 

at a high temperature. SO2, a member of the sulfur oxide (SOX) family of gases, is 

formed from burning fuels containing sulfur (e.g., coal or oil derived), extracting gasoline 

from oil, or extracting metals from ore. 

SO2 and NO2 can dissolve in water droplets and further oxidize to form sulfuric 

and nitric acid which react with ammonia to form sulfates and nitrates, both of which are 

important components of ambient PM. The health effects of ambient PM are discussed in 

 

91 U.S. EPA. (2007). Review of the National Ambient Air Quality Standards for Ozone: Policy Assessment 

of Scientific and Technical Information, OAQPS Staff Paper. EPA-452/R-07-003. Washington, DC, U.S. 

EPA. Docket EPA-HQ-OAR-2010-0162.

92 National Research Council (NRC), 2008. Estimating Mortality Risk Reduction and Economic Benefits 

from Controlling Ozone Air Pollution. The National Academies Press: Washington, D.C. Docket EPAHQ-OAR-2010-0162
78 of 

Section VII. B. (1) (b) of this preamble. NOX and NMHC are the two major precursors 

of ozone. The health effects of ozone are covered in Section VII. B. (2) (b).

(b) Health Effects of NO2

Information on the health effects of NO2 can be found in the EPA Integrated 

Science Assessment (ISA) for Nitrogen Oxides.93 The EPA has concluded that the 

findings of epidemiologic, controlled human exposure, and animal toxicological studies 

provide evidence that is sufficient to infer a likely causal relationship between respiratory

effects and short-term NO2 exposure. The ISA concludes that the strongest evidence for 

such a relationship comes from epidemiologic studies of respiratory effects including 

symptoms, emergency department visits, and hospital admissions. The ISA also draws 

two broad conclusions regarding airway responsiveness following NO2 exposure. First, 

the ISA concludes that NO2 exposure may enhance the sensitivity to allergen-induced 

decrements in lung function and increase the allergen-induced airway inflammatory

response following 30-minute exposures of asthmatics to NO2 concentrations as low as 

0.26 ppm. In addition, small but significant increases in non-specific airway

hyperresponsiveness were reported following 1-hour exposures of asthmatics to 0.1 ppm 

NO2. Second, exposure to NO2 has been found to enhance the inherent responsiveness of 

the airway to subsequent nonspecific challenges in controlled human exposure studies of 

asthmatic subjects. Enhanced airway responsiveness could have important clinical 

implications for asthmatics since transient increases in airway responsiveness following 

NO2 exposure have the potential to increase symptoms and worsen asthma control. 

Together, the epidemiologic and experimental data sets form a plausible, consistent, and 

coherent description of a relationship between NO2 exposures and an array of adverse 

health effects that range from the onset of respiratory symptoms to hospital admission. 

Although the weight of evidence supporting a causal relationship is somewhat 

less certain than that associated with respiratory morbidity, NO2 has also been linked to 

other health endpoints. These include all-cause (nonaccidental) mortality, hospital 

admissions or emergency department visits for cardiovascular disease, and decrements in 

lung function growth associated with chronic exposure.

(c) Health Effects of SO2

Information on the health effects of SO2 can be found in the EPA Integrated 

Science Assessment for Sulfur Oxides.94 SO2 has long been known to cause adverse 

respiratory health effects, particularly among individuals with asthma. Other potentially 

sensitive groups include children and the elderly. During periods of elevated ventilation, 

asthmatics may experience symptomatic bronchoconstriction within minutes of exposure. 

Following an extensive evaluation of health evidence from epidemiologic and laboratory

studies, the EPA has concluded that there is a causal relationship between respiratory

 

93 U.S. EPA (2008). Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Final 

Report). EPA/600/R-08/071. Washington, DC: U.S.EPA. Docket EPA-HQ-OAR-2010-0162 .

94 U.S. EPA. (2008). Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria (Final 

Report). EPA/600/R-08/047F. Washington, DC: U.S. Environmental Protection Agency. Docket EPA-HQOAR-2010-0162.
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health effects and short-term exposure to SO2. Separately, based on an evaluation of the 

epidemiologic evidence of associations between short-term exposure to SO2 and 

mortality, the EPA has concluded that the overall evidence is suggestive of a causal 

relationship between short-term exposure to SO2 and mortality.

(4) Carbon Monoxide

Information on the health effects of CO can be found in the EPA Integrated 

Science Assessment (ISA) for Carbon Monoxide.

95

 The ISA concludes that ambient 

concentrations of CO are associated with a number of adverse health effects.96 This 

section provides a summary of the health effects associated with exposure to ambient 

concentrations of CO.

97

 

Human clinical studies of subjects with coronary artery disease show a decrease 

in the time to onset of exercise-induced angina (chest pain) and electrocardiogram 

changes following CO exposure. In addition, epidemiologic studies show associations 

between short-term CO exposure and cardiovascular morbidity, particularly increased 

emergency room visits and hospital admissions for coronary heart disease (including 

ischemic heart disease, myocardial infarction, and angina). Some epidemiologic 

evidence is also available for increased hospital admissions and emergency room visits 

for congestive heart failure and cardiovascular disease as a whole. The ISA concludes 

that a causal relationship is likely to exist between short-term exposures to CO and 

cardiovascular morbidity. It also concludes that available data are inadequate to conclude 

that a causal relationship exists between long-term exposures to CO and cardiovascular 

morbidity. 

Animal studies show various neurological effects with in-utero CO exposure. 

Controlled human exposure studies report inconsistent neural and behavioral effects 

following low-level CO exposures. The ISA concludes the evidence is suggestive of a 

causal relationship with both short- and long-term exposure to CO and central nervous 

system effects.

A number of epidemiologic and animal toxicological studies cited in the ISA have 

evaluated associations between CO exposure and birth outcomes such as preterm birth or 

cardiac birth defects. The epidemiologic studies provide limited evidence of a COinduced effect on preterm births and birth defects, with weak evidence for a decrease in 

birth weight. Animal toxicological studies have found associations between perinatal CO 

 

95 U.S. EPA, 2010. Integrated Science Assessment for Carbon Monoxide (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-09/019F, 2010. Available at

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=218686. Docket EPA-HQ-OAR-2010-0162

96 The ISA evaluates the health evidence associated with different health effects, assigning one of five 

“weight of evidence” determinations: causal relationship, likely to be a causal relationship, suggestive of a 

causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship. For 

definitions of these levels of evidence, please refer to Section 1.6 of the ISA. 

97 Personal exposure includes contributions from many sources, and in many different environments. Total 

personal exposure to CO includes both ambient and nonambient components; and both components may 

contribute to adverse health effects.
80 of 

exposure and decrements in birth weight, as well as other developmental outcomes. The 

ISA concludes these studies are suggestive of a causal relationship between long-term 

exposures to CO and developmental effects and birth outcomes.

Epidemiologic studies provide evidence of effects on respiratory morbidity such 

as changes in pulmonary function, respiratory symptoms, and hospital admissions 

associated with ambient CO concentrations. A limited number of epidemiologic studies 

considered copollutants such as ozone, SO2, and PM in two-pollutant models and found 

that CO risk estimates were generally robust, although this limited evidence makes it 

difficult to disentangle effects attributed to CO itself from those of the larger complex air 

pollution mixture. Controlled human exposure studies have not extensively evaluated the 

effect of CO on respiratory morbidity. Animal studies at levels of 50-100 ppm CO show 

preliminary evidence of altered pulmonary vascular remodeling and oxidative injury. 

The ISA concludes that the evidence is suggestive of a causal relationship between shortterm CO exposure and respiratory morbidity, and inadequate to conclude that a causal 

relationship exists between long-term exposure and respiratory morbidity. 

Finally, the ISA concludes that the epidemiologic evidence is suggestive of a 

causal relationship between short-term exposures to CO and mortality. Epidemiologic 

studies provide evidence of an association between short-term exposure to CO and 

mortality, but limited evidence is available to evaluate cause-specific mortality outcomes 

associated with CO exposure. In addition, the attenuation of CO risk estimates which 

was often observed in copollutant models contributes to the uncertainty as to whether CO 

is acting alone or as an indicator for other combustion-related pollutants. The ISA also 

concludes that there is not likely to be a causal relationship between relevant long-term 

exposures to CO and mortality.

(5) Air Toxics

Heavy-duty vehicle emissions contribute to ambient levels of air toxics known or 

suspected as human or animal carcinogens, or that have noncancer health effects. The 

population experiences an elevated risk of cancer and other noncancer health effects from 

exposure to the class of pollutants known collectively as “air toxics.”98 These 

compounds include, but are not limited to, benzene, 1,3-butadiene, formaldehyde, 

acetaldehyde, acrolein, diesel particulate matter and exhaust organic gases, polycyclic 

organic matter, and naphthalene. These compounds were identified as national or 

regional risk drivers or contributors in the 2005 National-scale Air Toxics Assessment 

and have significant inventory contributions from mobile sources.99 

(a) Diesel Exhaust

Heavy-duty diesel engines emit diesel exhaust, a complex mixture composed of 

carbon dioxide, oxygen, nitrogen, water vapor, carbon monoxide, nitrogen compounds, 

 

98 U. S. EPA. 2002 National-Scale Air Toxics Assessment. 

http://www.epa.gov/ttn/atw/nata12002/risksum.html Docket EPA-HQ-OAR-2010-0162

99 U.S. EPA 2009. National-Scale Air Toxics Assessment for 2002. http://www.epa.gov/ttn/atw/nata2002/ 

Docket EPA-HQ-OAR-2010-0162
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sulfur compounds and numerous low-molecular-weight hydrocarbons. A number of 

these gaseous hydrocarbon components are individually known to be toxic, including 

aldehydes, benzene and 1,3-butadiene. The diesel particulate matter present in diesel 

exhaust consists mostly of fine particles (< 2.5 μm), including a significant fraction of 

ultrafine particles (< 0.1 μm). These particles have a large surface area which makes 

them an excellent medium for adsorbing organics and their small size makes them highly 

respirable. Many of the organic compounds present in the gases and on the particles, such 

as polycyclic organic matter, are individually known to have mutagenic and carcinogenic 

properties. 

Diesel exhaust varies significantly in chemical composition and particle sizes 

between different engine types (heavy-duty, light-duty), engine operating conditions 

(idle, accelerate, decelerate), and fuel formulations (high/low sulfur fuel). Also, there are 

emissions differences between on-road and nonroad engines because the nonroad engines 

are generally of older technology. After being emitted in the engine exhaust, diesel 

exhaust undergoes dilution as well as chemical and physical changes in the atmosphere. 

The lifetime for some of the compounds present in diesel exhaust ranges from hours to 

days.100

(i) Diesel Exhaust: Potential Cancer Effects

In EPA’s 2002 Diesel Health Assessment Document (Diesel HAD),101 exposure 

to diesel exhaust was classified as likely to be carcinogenic to humans by inhalation from 

environmental exposures, in accordance with the revised draft 1996/1999 EPA cancer 

guidelines. A number of other agencies (National Institute for Occupational Safety and 

Health, the International Agency for Research on Cancer, the World Health Organization, 

California EPA, and the U.S. Department of Health and Human Services) have made 

similar classifications. However, EPA also concluded in the Diesel HAD that it is not 

possible currently to calculate a cancer unit risk for diesel exhaust due to a variety of 

factors that limit the current studies, such as limited quantitative exposure histories in 

occupational groups investigated for lung cancer.

For the Diesel HAD, EPA reviewed 22 epidemiologic studies on the subject of the 

carcinogenicity of workers exposed to diesel exhaust in various occupations, finding 

increased lung cancer risk, although not always statistically significant, in 8 out of 10 

cohort studies and 10 out of 12 case-control studies within several industries. Relative 

risk for lung cancer associated with exposure ranged from 1.2 to 1.5, although a few 

studies show relative risks as high as 2.6. Additionally, the Diesel HAD also relied on 

two independent meta-analyses, which examined 23 and 30 occupational studies 

respectively, which found statistically significant increases in smoking-adjusted relative 

lung cancer risk associated with exposure to diesel exhaust of 1.33 to 1.47. These metaanalyses demonstrate the effect of pooling many studies and in this case show the 

 

100 U.S. EPA (2002). Health Assessment Document for Diesel Engine Exhaust. EPA/600/8-90/057F Office 

of Research and Development, Washington DC. Retrieved on March 17, 2009 from 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060. Docket EPA-HQ-OAR-2010-0162

101 See U.S. EPA (2002) Diesel HAD, Note 100, at pp. 1-1, 1-2.
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positive relationship between diesel exhaust exposure and lung cancer across a variety of 

diesel exhaust-exposed occupations.102,103

In the absence of a cancer unit risk, the Diesel HAD sought to provide additional 

insight into the significance of the diesel exhaust-cancer hazard by estimating possible 

ranges of risk that might be present in the population. An exploratory analysis was used 

to characterize a possible risk range by comparing a typical environmental exposure level 

for highway diesel sources to a selected range of occupational exposure levels. The 

occupationally observed risks were then proportionally scaled according to the exposure 

ratios to obtain an estimate of the possible environmental risk. A number of calculations 

are needed to accomplish this, and these can be seen in the EPA Diesel HAD. The 

outcome was that environmental risks from diesel exhaust exposure could range from a 

low of 10-4to 10-5to as high as 10-3, reflecting the range of occupational exposures that 

could be associated with the relative and absolute risk levels observed in the occupational 

studies. Because of uncertainties, the analysis acknowledged that the risks could be 

lower than 10-4or 10-5, and a zero risk from diesel exhaust exposure was not ruled out.

(ii) Diesel Exhaust: Other Health Effects

Noncancer health effects of acute and chronic exposure to diesel exhaust 

emissions are also of concern to the EPA. EPA derived a diesel exhaust reference

concentration (RfC) from consideration of four well-conducted chronic rat inhalation 

studies showing adverse pulmonary effects.104,105,106,107 The RfC is 5 μg/m3for diesel 

exhaust as measured by diesel particulate matter. This RfC does not consider allergenic 

effects such as those associated with asthma or immunologic effects. There is growing 

evidence, discussed in the Diesel HAD, that exposure to diesel exhaust can exacerbate 

these effects, but the exposure-response data are presently lacking to derive an RfC. The 

EPA Diesel HAD states, “With [diesel particulate matter] being a ubiquitous component 

of ambient PM, there is an uncertainty about the adequacy of the existing [diesel exhaust] 

noncancer database to identify all of the pertinent [diesel exhaust]-caused noncancer 

health hazards.” (p. 9-19). The Diesel HAD concludes “that acute exposure to [diesel 

exhaust] has been associated with irritation of the eye, nose, and throat, respiratory

 

102 Bhatia, R., Lopipero, P., Smith, A. (1998). Diesel exposure and lung cancer. Epidemiology, 9(1), 84-91. 

Docket EPA-HQ-OAR-2010-0162

103 Lipsett, M. Campleman, S. (1999). Occupational exposure to diesel exhaust and lung cancer: a metaanalysis. Am J Public Health, 80(7), 1009-1017. Docket EPA-HQ-OAR-2010-0162

104 Ishinishi, N. Kuwabara, N. Takaki, Y., et al. (1988). Long-term inhalation experiments on diesel 

exhaust. In: Diesel exhaust and health risks. Results of the HERP studies. Ibaraki, Japan: Research 

Committee for HERP Studies; pp.11-84. Docket EPA-HQ-OAR-2010-0162

105 Heinrich, U., Fuhst, R., Rittinghausen, S., et al. (1995). Chronic inhalation exposure of Wistar rats and 

two different strains of mice to diesel engine exhaust, carbon black, and titanium dioxide. Inhal Toxicol, 7,

553-556. Docket EPA-HQ-OAR-2010-0162

106 Mauderly, J.L., Jones, R.K., Griffith, W.C., et al. (1987). Diesel exhaust is a pulmonary carcinogen in 

rats exposed chronically by inhalation. Fundam. Appl. Toxicol., 9, 208-221. Docket EPA-HQ-OAR-2010-

0162

107 Nikula, K.J., Snipes, M.B., Barr, E.B., et al. (1995). Comparative pulmonary toxicities and 

carcinogenicities of chronically inhaled diesel exhaust and carbon black in F344 rats. Fundam. Appl. 

Toxicol, 25, 80-94.. Docket EPA-HQ-OAR-2010-0162
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83 of

symptoms (cough and phlegm), and neurophysiological symptoms such as headache, 

lightheadedness, nausea, vomiting, and numbness or tingling of the extremities.”108

(iii) Ambient PM2.5 Levels and Exposure to Diesel Exhaust PM

The Diesel HAD also briefly summarizes health effects associated with ambient 

PM and discusses the EPA’s annual PM2.5 NAAQS of 15 μg/m3. There is a much more 

extensive body of human data showing a wide spectrum of adverse health effects 

associated with exposure to ambient PM, of which diesel exhaust is an important 

component. The PM2.5 NAAQS is designed to provide protection from the noncancer 

and premature mortality effects of PM2.5 as a whole.

(iv) Diesel Exhaust PM Exposures

Exposure of people to diesel exhaust depends on their various activities, the time 

spent in those activities, the locations where these activities occur, and the levels of diesel 

exhaust pollutants in those locations. The major difference between ambient levels of 

diesel particulate and exposure levels for diesel particulate is that exposure accounts for a 

person moving from location to location, proximity to the emission source, and whether 

the exposure occurs in an enclosed environment.

Occupational Exposures

Occupational exposures to diesel exhaust from mobile sources can be several 

orders of magnitude greater than typical exposures in the non-occupationally exposed 

population.

Over the years, diesel particulate exposures have been measured for a number of 

occupational groups. A wide range of exposures have been reported, from 2 μg/m3to 

1,280 μg/m3, for a variety of occupations. As discussed in the Diesel HAD, the National 

Institute of Occupational Safety and Health has estimated a total of 1,400,000 workers 

are occupationally exposed to diesel exhaust from on-road and nonroad vehicles.

Elevated Concentrations and Ambient Exposures in Mobile Source-Impacted Areas

Regions immediately downwind of highways or truck stops may experience 

elevated ambient concentrations of directly-emitted PM2.5 from diesel engines. Due to 

the unique nature of highways and truck stops, emissions from a large number of diesel 

engines are concentrated in a small area. Studies near roadways with high truck traffic 

indicate higher concentrations of components of diesel PM than other locations.109,110,111 

 

108 See U.S. EPA (2002), Diesel HAD at Note 100, at p. 9-9.

109 Zhu, Y.; Hinds, W.C.; Kim, S.; Shen, S.; Sioutas, C. (2002) Study of ultrafine particles near a major 

highway with heavy-duty diesel traffic. Atmospheric Environment 36: 4323-4335. Docket EPA-HQOAR-2010-0162

110 Lena, T.S; Ochieng, V.; Holguín-Veras, J.; Kinney, P.L. (2002) Elemental carbon and PM2.5 levels in 

an urban community heavily impacted by truck traffic. Environ Health Perspect 110: 1009-1015. Docket 

EPA-HQ-OAR-2010-0162
84 of 

High ambient particle concentrations have also been reported near trucking terminals, 

truck stops, and bus garages.112,113,114 Additional discussion of exposure and health 

effects associated with traffic is included below in Section VII. B. (5) (j). 

(b) Benzene

The EPA’s Integrated Risk Information System (IRIS) database lists benzene as a 

known human carcinogen (causing leukemia) by all routes of exposure, and concludes 

that exposure is associated with additional health effects, including genetic changes in 

both humans and animals and increased proliferation of bone marrow cells in 

mice.

115,116,117 EPA states in its IRIS database that data indicate a causal relationship 

between benzene exposure and acute lymphocytic leukemia and suggest a relationship 

between benzene exposure and chronic non-lymphocytic leukemia and chronic 

lymphocytic leukemia. The International Agency for Research on Carcinogens (IARC)

has determined that benzene is a human carcinogen and the U.S. Department of Health 

and Human Services (DHHS) has characterized benzene as a known human 

carcinogen.118,119

A number of adverse noncancer health effects including blood disorders, such as 

preleukemia and aplastic anemia, have also been associated with long-term exposure to 

benzene.120,121 The most sensitive noncancer effect observed in humans, based on current 

data, is the depression of the absolute lymphocyte count in blood.122, 123 In addition, 

 

111 Soliman, A.S.M.; Jacko, J.B.; Palmer, G.M. (2006) Development of an empirical model to estimate realworld fine particulate matter emission factors: the Traffic Air Quality model. J Air & Waste Manage 

Assoc 56: 1540-1549. Docket EPA-HQ-OAR-2010-0162

112 Davis, M.E.; Smith, T.J.; Laden, F.; Hart, J.E.; Ryan, L.M.; Garshick, E. (2006) Modeling particle 

exposure in U.S. trucking terminals. Environ Sci Techol 40: 4226-4232. Docket EPA-HQ-OAR-2010-

0162

113 Miller, T.L.; Fu, J.S.; Hromis, B.; Storey, J.M. (2007) Diesel truck idling emissions – measurements at a 

PM2.5 hot spot. Proceedings of the Annual Conference of the Transportation Research Board, paper no. 07-

2609. Docket EPA-HQ-OAR-2010-0162

114 Ramachandran, G.; Paulsen, D.; Watts, W.; Kittelson, D. (2005) Mass, surface area, and number metrics 

in diesel occupational exposure assessment. J Environ Monit 7: 728-735. Docket EPA-HQ-OAR-2010-

0162

115 U.S. EPA. 2000. Integrated Risk Information System File for Benzene. This material is available 

electronically at http://www.epa.gov/iris/subst/0276.htm. Docket EPA-HQ-OAR-2010-0162.

116 International Agency for Research on Cancer. 1982. Monographs on the evaluation of carcinogenic risk 

of chemicals to humans, Volume 29. Some industrial chemicals and dyestuffs, World Health Organization, 

Lyon, France, p. 345-389. Docket EPA-HQ-OAR-2010-0162

117 Irons, R.D.; Stillman, W.S.; Colagiovanni, D.B.; Henry, V.A. 1992. Synergistic action of the benzene 

metabolite hydroquinone on myelopoietic stimulating activity of granulocyte/macrophage colonystimulating factor in vitro, Proc. Natl. Acad. Sci. 89:3691-3695. Docket EPA-HQ-OAR-2010-0162.

118 See IARC, Note 116, above.

119 U.S. Department of Health and Human Services National Toxicology Program 11th Report on 

Carcinogens available at: http://ntp.niehs.nih.gov/go/16183. Docket EPA-HQ-OAR-2010-0162

120 Aksoy, M. (1989). Hematotoxicity and carcinogenicity of benzene. Environ. Health Perspect. 82: 193-

197. Docket EPA-HQ-OAR-2010-0162.

121 Goldstein, B.D. (1988). Benzene toxicity. Occupational medicine. State of the Art Reviews. 3: 541-554. 

Docket EPA-HQ-OAR-2010-0162.

122 Rothman, N., G.L. Li, M. Dosemeci, W.E. Bechtold, G.E. Marti, Y.Z. Wang, M. Linet, L.Q. Xi, W. Lu, 

M.T. Smith, N. Titenko-Holland, L.P. Zhang, W. Blot, S.N. Yin, and R.B. Hayes (1996) Hematotoxicity 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

85 of

recent work, including studies sponsored by the Health Effects Institute (HEI), provides 

evidence that biochemical responses are occurring at lower levels of benzene exposure 

than previously known.124,125,126,127 EPA’s IRIS program has not yet evaluated these new 

data.

(c) 1,3-Butadiene

EPA has characterized 1,3-butadiene as carcinogenic to humans by

inhalation.128,129 The IARC has determined that 1,3-butadiene is a human carcinogen and 

the U.S. DHHS has characterized 1,3-butadiene as a known human carcinogen.130,131 

There are numerous studies consistently demonstrating that 1,3-butadiene is metabolized 

into genotoxic metabolites by experimental animals and humans. The specific 

mechanisms of 1,3-butadiene-induced carcinogenesis are unknown; however, the 

scientific evidence strongly suggests that the carcinogenic effects are mediated by 

genotoxic metabolites. Animal data suggest that females may be more sensitive than 

males for cancer effects associated with 1,3-butadiene exposure; there are insufficient 

data in humans from which to draw conclusions about sensitive subpopulations. 1,3-

 

among Chinese workers heavily exposed to benzene. Am. J. Ind. Med. 29: 236-246. Docket EPA-HQOAR-2010-0162.

123 U.S. EPA (2002) Toxicological Review of Benzene (Noncancer Effects). Environmental Protection 

Agency, Integrated Risk Information System, Research and Development, National Center for 

Environmental Assessment, Washington DC. This material is available electronically at 

http://www.epa.gov/iris/subst/0276.htm. Docket EPA-HQ-OAR-2010-0162.

124 Qu, O.; Shore, R.; Li, G.; Jin, X.; Chen, C.L.; Cohen, B.; Melikian, A.; Eastmond, D.; Rappaport, S.; Li, 

H.; Rupa, D.; Suramaya, R.; Songnian, W.; Huifant, Y.; Meng, M.; Winnik, M.; Kwok, E.; Li, Y.; Mu, 

R.; Xu, B.; Zhang, X.; Li, K. (2003) HEI Report 115, Validation & Evaluation of Biomarkers in Workers 

Exposed to Benzene in China. Docket EPA-HQ-OAR-2010-0162. 

125 Qu, Q., R. Shore, G. Li, X. Jin, L.C. Chen, B. Cohen, et al. (2002) Hematological changes among 

Chinese workers with a broad range of benzene exposures. Am. J. Industr. Med. 42: 275-285. Docket 

EPA-HQ-OAR-2010-0162.

126 Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. (2004) Hematotoxically in Workers Exposed to Low

Levels of Benzene. Science 306: 1774-1776. Docket EPA-HQ-OAR-2010-0162.

127 Turtletaub, K.W. and Mani, C. (2003) Benzene metabolism in rodents at doses relevant to human 

exposure from Urban Air. Research Reports Health Effect Inst. Report No.113. Docket EPA-HQ-OAR2010-0162.

128 U.S. EPA (2002) Health Assessment of 1,3-Butadiene. Office of Research and Development, National 

Center for Environmental Assessment, Washington Office, Washington, DC. Report No. EPA600-P-98-

001F. This document is available electronically at http://www.epa.gov/iris/supdocs/buta-sup.pdf. Docket 

EPA-HQ-OAR-2010-0162.

129 U.S. EPA (2002) Full IRIS Summary for 1,3-butadiene (CASRN 106-99-0). Environmental Protection 

Agency, Integrated Risk Information System (IRIS), Research and Development, National Center for 

Environmental Assessment, Washington, DC http://www.epa.gov/iris/subst/0139.htm. Docket EPA-HQOAR-2010-0162

130 International Agency for Research on Cancer (1999) Monographs on the evaluation of carcinogenic risk 

of chemicals to humans, Volume 71, Re-evaluation of some organic chemicals, hydrazine and hydrogen 

peroxide and Volume 97 (in preparation), World Health Organization, Lyon, France. Docket EPA-HQOAR-2010-0162

131 U.S. Department of Health and Human Services (2005) National Toxicology Program 11th Report on 

Carcinogens available at: ntp.niehs.nih.gov/index.cfm?objectid=32BA9724-F1F6-975E7FCE50709CB4C932. Docket EPA-HQ-OAR-2010-0162
86 of 

butadiene also causes a variety of reproductive and developmental effects in mice; no 

human data on these effects are available. The most sensitive effect was ovarian atrophy 

observed in a lifetime bioassay of female mice.132

(d) Formaldehyde

Since 1987, EPA has classified formaldehyde as a probable human carcinogen 

based on evidence in humans and in rats, mice, hamsters, and monkeys.133 EPA is 

currently reviewing recently published epidemiological data. For instance, research 

conducted by the National Cancer Institute found an increased risk of nasopharyngeal 

cancer and lymphohematopoietic malignancies such as leukemia among workers exposed 

to formaldehyde.134, 135 In an analysis of the lymphohematopoietic cancer mortality from 

an extended follow-up of these workers, the National Cancer Institute confirmed an 

association between lymphohematopoietic cancer risk and peak exposures.136 A recent 

National Institute of Occupational Safety and Health study of garment workers also found 

increased risk of death due to leukemia among workers exposed to formaldehyde.137 

Extended follow-up of a cohort of British chemical workers did not find evidence of an 

increase in nasopharyngeal or lymphohematopoietic cancers, but a continuing statistically 

significant excess in lung cancers was reported.138 Recently, the IARC re-classified 

formaldehyde as a human carcinogen (Group 1).139 

Formaldehyde exposure also causes a range of noncancer health effects, including 

irritation of the eyes (burning and watering of the eyes), nose and throat. Effects from 

repeated exposure in humans include respiratory tract irritation, chronic bronchitis and 

nasal epithelial lesions such as metaplasia and loss of cilia. Animal studies suggest that 

formaldehyde may also cause airway inflammation – including eosinophil infiltration into 

 

132 Bevan, C.; Stadler, J.C.; Elliot, G.S.; et al. (1996) Subchronic toxicity of 4-vinylcyclohexene in rats and 

mice by inhalation. Fundam. Appl. Toxicol. 32:1-10. Docket EPA-HQ-OAR-2010-0162.

133 U.S. EPA (1987) Assessment of Health Risks to Garment Workers and Certain Home Residents from 

Exposure to Formaldehyde, Office of Pesticides and Toxic Substances, April 1987. Docket EPA-HQ-OAR2010-0162.

134 Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2003. Mortality from 

lymphohematopoetic malignancies among workers in formaldehyde industries. Journal of the National 

Cancer Institute 95: 1615-1623. Docket EPA-HQ-OAR-2010-0162.

135 Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2004. Mortality from solid 

cancers among workers in formaldehyde industries. American Journal of Epidemiology 159: 1117-1130. 

Docket EPA-HQ-OAR-2010-0162.

136 Beane Freeman, L. E.; Blair, A.; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Hoover, R. N.; Hauptmann, 

M. 2009. Mortality from lymphohematopoietic malignancies among workers in formaldehyde industries: 

The National Cancer Institute cohort. J. National Cancer Inst. 101: 751-761. Docket EPA-HQ-OAR-2010-

0162.

137 Pinkerton, L. E. 2004. Mortality among a cohort of garment workers exposed to formaldehyde: an 

update. Occup. Environ. Med. 61: 193-200. Docket EPA-HQ-OAR-2010-0162.

138 Coggon, D, EC Harris, J Poole, KT Palmer. 2003. Extended follow-up of a cohort of British chemical 

workers exposed to formaldehyde. J National Cancer Inst. 95:1608-1615. Docket EPA-HQ-OAR-2010-

0162.

139 International Agency for Research on Cancer. 2006. Formaldehyde, 2-Butoxyethanol and 1-tertButoxypropan-2-ol. Volume 88. (in preparation), World Health Organization, Lyon, France. Docket EPAHQ-OAR-2010-0162
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87 of

the airways. There are several studies that suggest that formaldehyde may increase the 

risk of asthma – particularly in the young.140,141

(e) Acetaldehyde

Acetaldehyde is classified in EPA’s IRIS database as a probable human 

carcinogen, based on nasal tumors in rats, and is considered toxic by the inhalation, oral, 

and intravenous routes.

142

 Acetaldehyde is reasonably anticipated to be a human 

carcinogen by the U.S. DHHS in the 11th Report on Carcinogens and is classified as 

possibly carcinogenic to humans (Group 2B) by the IARC.143,144 EPA is currently

conducting a reassessment of cancer risk from inhalation exposure to acetaldehyde.

The primary noncancer effects of exposure to acetaldehyde vapors include 

irritation of the eyes, skin, and respiratory tract.145 In short-term (4 week) rat studies, 

degeneration of olfactory epithelium was observed at various concentration levels of

acetaldehyde exposure.

146, 147

 Data from these studies were used by EPA to develop an 

inhalation reference concentration. Some asthmatics have been shown to be a sensitive 

subpopulation to decrements in functional expiratory volume (FEV1 test) and 

bronchoconstriction upon acetaldehyde inhalation.148 The agency is currently conducting 

a reassessment of the health hazards from inhalation exposure to acetaldehyde. 

 

140 Agency for Toxic Substances and Disease Registry (ATSDR). 1999. Toxicological profile for 

Formaldehyde. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. 

http://www.atsdr.cdc.gov/toxprofiles/tp111.html Docket EPA-HQ-OAR-2010-0162.

141 WHO (2002) Concise International Chemical Assessment Document 40: Formaldehyde. Published 

under the joint sponsorship of the United Nations Environment Programme, the International Labour 

Organization, and the World Health Organization, and produced within the framework of the InterOrganization Programme for the Sound Management of Chemicals. Geneva. Docket EPA-HQ-OAR-2010-

0162.

142 U.S. EPA. 1991. Integrated Risk Information System File of Acetaldehyde. Research and Development, 

National Center for Environmental Assessment, Washington, DC. Available at

http://www.epa.gov/iris/subst/0290.htm. Docket EPA-HQ-OAR-2010-0162.

143 U.S. Department of Health and Human Services National Toxicology Program 11th Report on 

Carcinogens available at: ntp.niehs.nih.gov/index.cfm?objectid=32BA9724-F1F6-975E7FCE50709CB4C932. Docket EPA-HQ-OAR-2010-0162.

144 International Agency for Research on Cancer. 1999. Re-evaluation of some organic chemicals, 

hydrazine, and hydrogen peroxide. IARC Monographs on the Evaluation of Carcinogenic Risk of 

Chemical to Humans, Vol 71. Lyon, France. Docket EPA-HQ-OAR-2010-0162

145 See Integrated Risk Information System File of Acetaldehyde, Note 142, above.

146 Appleman, L. M., R. A. Woutersen, V. J. Feron, R. N. Hooftman, and W. R. F. Notten. 1986. Effects 

of the variable versus fixed exposure levels on the toxicity of acetaldehyde in rats. J. Appl. Toxicol. 6: 331-

336. Docket EPA-HQ-OAR-2010-0162

147 Appleman, L.M., R.A. Woutersen, and V.J. Feron. 1982. Inhalation toxicity of acetaldehyde in rats. I. 

Acute and subacute studies. Toxicology. 23: 293-297. Docket EPA-HQ-OAR-2010-0162.

148 Myou, S.; Fujimura, M.; Nishi K.; Ohka, T.; and Matsuda, T. 1993. Aerosolized acetaldehyde induces 

histamine-mediated bronchoconstriction in asthmatics. Am. Rev. Respir.Dis.148(4 Pt 1): 940-3. Docket 

EPA-HQ-OAR-2010-0162
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(f) Acrolein

Acrolein is extremely acrid and irritating to humans when inhaled, with acute 

exposure resulting in upper respiratory tract irritation, mucus hypersecretion and 

congestion. The intense irritancy of this carbonyl has been demonstrated during 

controlled tests in human subjects, who suffer intolerable eye and nasal mucosal sensory

reactions within minutes of exposure.149 These data and additional studies regarding 

acute effects of human exposure to acrolein are summarized in EPA’s 2003 IRIS Human 

Health Assessment for acrolein.150 Evidence available from studies in humans indicate 

that levels as low as 0.09 ppm (0.21 mg/m3) for five minutes may elicit subjective 

complaints of eye irritation with increasing concentrations leading to more extensive eye, 

nose and respiratory symptoms.151 Lesions to the lungs and upper respiratory tract of 

rats, rabbits, and hamsters have been observed after subchronic exposure to acrolein.152 

Acute exposure effects in animal studies report bronchial hyper-responsiveness.153 In a 

recent study, the acute respiratory irritant effects of exposure to 1.1 ppm acrolein were 

more pronounced in mice with allergic airway disease by comparison to non-diseased 

mice which also showed decreases in respiratory rate.154 Based on these animal data and 

demonstration of similar effects in humans (e.g., reduction in respiratory rate), 

individuals with compromised respiratory function (e.g., emphysema, asthma) are 

expected to be at increased risk of developing adverse responses to strong respiratory

irritants such as acrolein. 

EPA determined in 2003 that the human carcinogenic potential of acrolein could 

not be determined because the available data were inadequate. No information was 

available on the carcinogenic effects of acrolein in humans and the animal data provided 

inadequate evidence of carcinogenicity.

155

 The IARC determined in 1995 that acrolein 

was not classifiable as to its carcinogenicity in humans.

156

 

149 U.S. EPA (U.S. Environmental Protection Agency). (2003) Toxicological review of acrolein in support 

of summary information on Integrated Risk Information System (IRIS) National Center for Environmental 

Assessment, Washington, DC. EPA/635/R-03/003. p. 10. Available online at: 

http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf. Docket EPA-HQ-OAR-2010-0162

150 See U.S. EPA 2003 Toxicological review of acrolein, Note 149, above. 

151 See U.S. EPA 2003 Toxicological review of acrolein, Note 149, at p. 11.

152 Integrated Risk Information System File of Acrolein. Office of Research and Development, National 

Center for Environmental Assessment, Washington, DC. This material is available at 

http://www.epa.gov/iris/subst/0364.htm Docket EPA-HQ-OAR-2010-0162.

153 See U.S. 2003 Toxicological review of acrolein, Note 149, at p. 15. 

154 Morris JB, Symanowicz PT, Olsen JE, et al. 2003. Immediate sensory nerve-mediated respiratory 

responses to irritants in healthy and allergic airway-diseased mice. J Appl Physiol 94(4):1563-1571. Docket 

EPA-HQ-OAR-2010-0162.

155 U.S. EPA. 2003. Integrated Risk Information System File of Acrolein. Research and Development, 

National Center for Environmental Assessment, Washington, DC. This material is available at 

http://www.epa.gov/iris/subst/0364.htm Docket EPA-HQ-OAR-2010-0162.

156 International Agency for Research on Cancer. 1995. Monographs on the evaluation of carcinogenic risk 

of chemicals to humans, Volume 63. Dry cleaning, some chlorinated solvents and other industrial 

chemicals, World Health Organization, Lyon, France. Docket EPA-HQ-OAR-2010-0162
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(g) Polycyclic Organic Matter

The term polycyclic organic matter (POM) defines a broad class of compounds 

that includes the polycyclic aromatic hydrocarbon compounds (PAHs). One of these 

compounds, naphthalene, is discussed separately below. POM compounds are formed 

primarily from combustion and are present in the atmosphere in gas and particulate form. 

Cancer is the major concern from exposure to POM. Epidemiologic studies have 

reported an increase in lung cancer in humans exposed to diesel exhaust, coke oven 

emissions, roofing tar emissions, and cigarette smoke; all of these mixtures contain POM 

compounds.

157158

 Animal studies have reported respiratory tract tumors from inhalation 

exposure to benzo[a]pyrene and alimentary tract and liver tumors from oral exposure to 

benzo[a]pyrene. EPA has classified seven PAHs (benzo[a]pyrene, benz[a]anthracene, 

chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, dibenz[a,h]anthracene, and 

indeno[1,2,3-cd]pyrene) as Group B2, probable human carcinogens.159 Recent studies 

have found that maternal exposures to PAHs in a population of pregnant women were 

associated with several adverse birth outcomes, including low birth weight and reduced 

length at birth, as well as impaired cognitive development in preschool children (3 years 

of age).160,161 EPA has not yet evaluated these recent studies.

(h) Naphthalene

Naphthalene is found in small quantities in gasoline and diesel fuels. 

Naphthalene emissions have been measured in larger quantities in both gasoline and 

diesel exhaust compared with evaporative emissions from mobile sources, indicating it is 

primarily a product of combustion. EPA released an external review draft of a 

reassessment of the inhalation carcinogenicity of naphthalene based on a number of 

recent animal carcinogenicity studies.162 The draft reassessment completed external peer 

 

157 Agency for Toxic Substances and Disease Registry (ATSDR). 1995. Toxicological profile for Polycyclic 

Aromatic Hydrocarbons (PAHs). Atlanta, GA: U.S. Department of Health and Human Services, Public 

Health Service. Available electronically at http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=122&tid=25.

158 U.S. EPA (2002). Health Assessment Document for Diesel Engine Exhaust. EPA/600/8-90/057F Office 

of Research and Development, Washington DC. 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060. Docket EPA-HQ-OAR-2010-0162

159 U.S. EPA (1997). Integrated Risk Information System File of indeno(1,2,3-cd)pyrene. Research and 

Development, National Center for Environmental Assessment, Washington, DC. This material is available 

electronically at http://www.epa.gov/ncea/iris/subst/0457.htm.

160 Perera, F.P.; Rauh, V.; Tsai, W-Y.; et al. (2002) Effect of transplacental exposure to environmental 

pollutants on birth outcomes in a multiethnic population. Environ Health Perspect. 111: 201-205.

161 Perera, F.P.; Rauh, V.; Whyatt, R.M.; Tsai, W.Y.; Tang, D.; Diaz, D.; Hoepner, L.; Barr, D.; Tu, Y.H.; 

Camann, D.; Kinney, P. (2006) Effect of prenatal exposure to airborne polycyclic aromatic hydrocarbons 

on neurodevelopment in the first 3 years of life among inner-city children. Environ Health Perspect 114: 

1287-1292.

162 U. S. EPA. 2004. Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer Risk), 

Environmental Protection Agency, Integrated Risk Information System, Research and Development, 

National Center for Environmental Assessment, Washington, DC. This material is available electronically 

at http://www.epa.gov/iris/subst/0436.htm. Docket EPA-HQ-OAR-2010-0162.
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review.163 Based on external peer review comments received, additional analyses are 

being undertaken. This external review draft does not represent official agency opinion 

and was released solely for the purposes of external peer review and public comment. 

The National Toxicology Program listed naphthalene as "reasonably anticipated to be a 

human carcinogen" in 2004 on the basis of bioassays reporting clear evidence of 

carcinogenicity in rats and some evidence of carcinogenicity in mice.164 California EPA 

has released a new risk assessment for naphthalene, and the IARC has reevaluated 

naphthalene and re-classified it as Group 2B: possibly carcinogenic to humans.165 

Naphthalene also causes a number of chronic non-cancer effects in animals, including 

abnormal cell changes and growth in respiratory and nasal tissues.166

(i) Other Air Toxics

In addition to the compounds described above, other compounds in gaseous 

hydrocarbon and PM emissions from heavy-duty vehicles will be affected by this final 

action. Mobile source air toxic compounds that would potentially be impacted include 

ethylbenzene, propionaldehyde, toluene, and xylene. Information regarding the health 

effects of these compounds can be found in EPA’s IRIS database.167

(j) Exposure and Health Effects Associated with Traffic

Populations who live, work, or attend school near major roads experience 

elevated exposure concentrations to a wide range of air pollutants, as well as higher risks 

for a number of adverse health effects. While the previous sections of this preamble have 

focused on the health effects associated with individual criteria pollutants or air toxics, 

this section discusses the mixture of different exposures near major roadways, rather than 

the effects of any single pollutant. As such, this section emphasizes traffic-related air 

pollution, in general, as the relevant indicator of exposure rather than any particular 

pollutant.

Concentrations of many traffic-generated air pollutants are elevated for up to 300-

500 meters downwind of roads with high traffic volumes.168 Numerous sources on roads 

contribute to elevated roadside concentrations, including exhaust and evaporative 

 

163 Oak Ridge Institute for Science and Education. (2004). External Peer Review for the IRIS 

Reassessment of the Inhalation Carcinogenicity of Naphthalene. August 2004. 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=84403 Docket EPA-HQ-OAR-2010-0162.

164 National Toxicology Program (NTP). (2004). 11th Report on Carcinogens. Public Health Service, U.S. 

Department of Health and Human Services, Research Triangle Park, NC. Available from: http://ntpserver.niehs.nih.gov. Docket EPA-HQ-OAR-2010-0162.

165 International Agency for Research on Cancer. (2002). Monographs on the Evaluation of the 

Carcinogenic Risk of Chemicals for Humans. Vol. 82. Lyon, France. Docket EPA-HQ-OAR-2010-0162.

166 U. S. EPA. 1998. Toxicological Review of Naphthalene, Environmental Protection Agency, Integrated 

Risk Information System, Research and Development, National Center for Environmental Assessment, 

Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0436.htm 

Docket EPA-HQ-OAR-2010-0162.

167 U.S. EPA Integrated Risk Information System (IRIS) database is available at: www.epa.gov/iris 

168 Zhou, Y.; Levy, J.I. (2007) Factors influencing the spatial extent of mobile source air pollution impacts: 

a meta-analysis. BMC Public Health 7: 89. doi:10.1186/1471-2458-7-89 Docket EPA-HQ-OAR-2010-

0162.
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emissions, and resuspension of road dust and tire and brake wear. Concentrations of 

several criteria and hazardous air pollutants are elevated near major roads. Furthermore, 

different semi-volatile organic compounds and chemical components of particulate 

matter, including elemental carbon, organic material, and trace metals, have been 

reported at higher concentrations near major roads.

 Populations near major roads experience greater risk of certain adverse health 

effects. The Health Effects Institute published a report on the health effects of trafficrelated air pollution.169

 It concluded that evidence is “sufficient to infer the presence of a 

causal association” between traffic exposure and exacerbation of childhood asthma 

symptoms. The HEI report also concludes that the evidence is either “sufficient” or 

“suggestive but not sufficient” for a causal association between traffic exposure and new 

childhood asthma cases. A review of asthma studies by Salam et al. (2008) reaches 

similar conclusions.170 The HEI report also concludes that there is “suggestive” evidence 

for pulmonary function deficits associated with traffic exposure, but concluded that there 

is “inadequate and insufficient” evidence for causal associations with respiratory health 

care utilization, adult-onset asthma, chronic obstructive pulmonary disease symptoms, 

and allergy. A review by Holguin (2008) notes that the effects of traffic on asthma may 

be modified by nutrition status, medication use, and genetic factors.171

The HEI report also concludes that evidence is “suggestive” of a causal 

association between traffic exposure and all-cause and cardiovascular mortality. There is 

also evidence of an association between traffic-related air pollutants and cardiovascular 

effects such as changes in heart rhythm, heart attack, and cardiovascular disease. The 

HEI report characterizes this evidence as “suggestive” of a causal association, and an 

independent epidemiological literature review by Adar and Kaufman (2007) concludes 

that there is “consistent evidence” linking traffic-related pollution and adverse 

cardiovascular health outcomes.172

Some studies have reported associations between traffic exposure and other health 

effects, such as birth outcomes (e.g., low birth weight) and childhood cancer. The HEI 

report concludes that there is currently “inadequate and insufficient” evidence for a 

causal association between these effects and traffic exposure. A review by RaaschouNielsen and Reynolds (2006) concluded that evidence of an association between 

 

169 HEI Panel on the Health Effects of Air Pollution. (2010) Traffic-related air pollution: a critical review 

of the literature on emissions, exposure, and health effects. [Online at www.healtheffects.org] Docket 

EPA-HQ-OAR-2010-0162.

170 Salam, M.T.; Islam, T.; Gilliland, F.D. (2008) Recent evidence for adverse effects of residential 

proximity to traffic sources on asthma. Current Opin Pulm Med 14: 3-8. Docket EPA-HQ-OAR-2010-

0162

171 Holguin, F. (2008) Traffic, outdoor air pollution, and asthma. Immunol Allergy Clinics North Am 28: 

577-588. Docket EPA-HQ-OAR-2010-0162.

172 Adar, S.D.; Kaufman, J.D. (2007) Cardiovascular disease and air pollutants: evaluating and improving 

epidemiological data implicating traffic exposure. Inhal Toxicol 19: 135-149. Docket EPA-HQ-OAR2010-0162.
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childhood cancer and traffic-related air pollutants is weak, but noted the inability to draw 

firm conclusions based on limited evidence.173

There is a large population in the United States living in close proximity of major 

roads. According to the Census Bureau’s American Housing Survey for 2007, 

approximately 20 million residences in the United States, 15.6% of all homes, are located 

within 300 feet (91 m) of a highway with 4+ lanes, a railroad, or an airport.174 Therefore, 

at current population of approximately 309 million, assuming that population and housing 

are similarly distributed, there are over 48 million people in the United States living near 

such sources. The HEI report also notes that in two North American cities, Los Angeles 

and Toronto, over 40% of each city’s population live within 500 meters of a highway or 

100 meters of a major road. It also notes that about 33% of each city’s population resides 

within 50 meters of major roads. Together, the evidence suggests that a large U.S. 

population lives in areas with elevated traffic-related air pollution.

People living near roads are often socioeconomically disadvantaged. According 

to the 2007 American Housing Survey, a renter-occupied property is over twice as likely 

as an owner-occupied property to be located near a highway with 4+ lanes, railroad or 

airport. In the same survey, the median household income of rental housing occupants 

was less than half that of owner-occupants ($28,921/$59,886). Numerous studies in 

individual urban areas report higher levels of traffic-related air pollutants in areas with 

high minority or poor populations.175,176,177

Students may also be exposed in situations where schools are located near major 

roads. In a study of nine metropolitan areas across the United States, Appatova et al. 

(2008) found that on average greater than 33% of schools were located within 400 m of 

an Interstate, U.S., or state highway, while 12% were located within 100 m.178 The study

also found that among the metropolitan areas studied, schools in the Eastern United 

States were more often sited near major roadways than schools in the Western United 

States.

 

173 Raaschou-Nielsen, O.; Reynolds, P. (2006) Air pollution and childhood cancer: a review of the 

epidemiological literature. Int J Cancer 118: 2920-2929. Docket EPA-HQ-OAR-2010-0162

174 U.S. Census Bureau (2008) American Housing Survey for the United States in 2007. Series H-150 

(National Data), Table 1A-7. [Accessed at 

http://www.census.gov/hhes/www/housing/ahs/ahs07/ahs07.html on January 22, 2009] Docket EPA-HQOAR-2010-0162.

175 Lena, T.S.; Ochieng, V.; Carter, M.; Holguín-Veras, J.; Kinney, P.L. (2002) Elemental carbon and 

PM2.5 levels in an urban community heavily impacted by truck traffic. Environ Health Perspect 110: 

1009-1015. Docket EPA-HQ-OAR-2010-0162

176 Wier, M.; Sciammas, C.; Seto, E.; Bhatia, R.; Rivard, T. (2009) Health, traffic, and environmental 

justice: collaborative research and community action in San Francisco, California. Am J Public Health 99: 

S499-S504. Docket EPA-HQ-OAR-2010-0162

177 Forkenbrock, D.J. and L.A. Schweitzer, Environmental Justice and Transportation Investment Policy. 

Iowa City: University of Iowa, 1997. Docket EPA-HQ-OAR-2010-0162

178 Appatova, A.S.; Ryan, P.H.; LeMasters, G.K.; Grinshpun, S.A. (2008) Proximal exposure of public 

schools and students to major roadways: a nationwide U.S. survey. J Environ Plan Mgmt Docket EPAHQ-OAR-2010-0162
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Demographic studies of students in schools near major roadways suggest that this 

population is more likely than the general student population to be of non-white race or 

Hispanic ethnicity, and more often live in low socioeconomic status locations. 179,180,181 

There is some inconsistency in the evidence, which may be due to different local 

development patterns and measures of traffic and geographic scale used in the studies.178 

C. Environmental Effects of Non-GHG Pollutants

In this section we discuss some of the environmental effects of PM and its 

precursors such as visibility impairment, atmospheric deposition, and materials damage 

and soiling, as well as environmental effects associated with the presence of ozone in the 

ambient air, such as impacts on plants, including trees, agronomic crops and urban 

ornamentals, and environmental effects associated with air toxics.

(1) Visibility

Visibility can be defined as the degree to which the atmosphere is transparent to 

visible light.182 Visibility impairment is caused by light scattering and absorption by suspended 

particles and gases. Visibility is important because it has direct significance to people’s 

enjoyment of daily activities in all parts of the country. Individuals value good visibility

for the well-being it provides them directly, where they live and work, and in places 

where they enjoy recreational opportunities. Visibility is also highly valued in significant 

natural areas, such as national parks and wilderness areas, and special emphasis is given 

to protecting visibility in these areas. For more information on visibility see the final 

2009 PM ISA.183

EPA is pursuing a two-part strategy to address visibility impairment. First, EPA 

developed the regional haze program (64 FR 35714) which was put in place in July 1999 

to protect the visibility in Mandatory Class I Federal areas. There are 156 national parks, 

forests and wilderness areas categorized as Mandatory Class I Federal areas (62 FR 

38680-38681, July 18, 1997). These areas are defined in CAA section 162 as those 

national parks exceeding 6,000 acres, wilderness areas and memorial parks exceeding 

5,000 acres, and all international parks which were in existence on August 7, 1977. 

Second, EPA has concluded that PM2.5 causes adverse effects on visibility in other areas 

that are not protected by the Regional Haze Rule, depending on PM2.5 concentrations and 

other factors that control their visibility impact effectiveness such as dry chemical 

 

179 Green, R.S.; Smorodinsky, S.; Kim, J.J.; McLaughlin, R.; Ostro, B. (2004) Proximity of California 

public schools to busy roads. Environ Health Perspect 112: 61-66. Docket EPA-HQ-OAR-2010-0162

180 Houston, D.; Ong, P.; Wu, J.; Winer, A. (2006) Proximity of licensed child care facilities to nearroadway vehicle pollution. Am J Public Health 96: 1611-1617. Docket EPA-HQ-OAR-2010-0162

181 Wu, Y.; Batterman, S. (2006) Proximity of schools in Detroit, Michigan to automobile and truck traffic. 

J Exposure Sci Environ Epidemiol 16: 457-470. Docket EPA-HQ-OAR-2010-0162

182 National Research Council, 1993. Protecting Visibility in National Parks and Wilderness Areas. 

National Academy of Sciences Committee on Haze in National Parks and Wilderness Areas. National 

Academy Press, Washington, DC. Docket EPA-HQ-OAR-2010-0162. This book can be viewed on the 

National Academy Press Website at http://www.nap.edu/books/0309048443/html/

183 See U.S. EPA 2009 Final PM ISA, Note 84. 
94 of 

composition and relative humidity (i.e., an indicator of the water composition of the 

particles), and has set secondary PM2.5 standards to address these areas. The existing 

annual primary and secondary PM2.5 standards have been remanded and are being 

addressed in the currently ongoing PM NAAQS review. The secondary PM2.5 standards 

serve as a reasonable complement to the Regional Haze Program.

(2) Plant and Ecosystem Effects of Ozone

Elevated ozone levels contribute to environmental effects, with impacts to plants 

and ecosystems being of most concern. Ozone can produce both acute and chronic injury

in sensitive species depending on the concentration level and the duration of the 

exposure. Ozone effects also tend to accumulate over the growing season of the plant, so 

that even low concentrations experienced for a longer duration have the potential to 

create chronic stress on vegetation. Ozone damage to plants includes visible injury to 

leaves and impaired photosynthesis, both of which can lead to reduced plant growth and 

reproduction, resulting in reduced crop yields, forestry production, and use of sensitive 

ornamentals in landscaping. In addition, the impairment of photosynthesis, the process 

by which the plant makes carbohydrates (its source of energy and food), can lead to a 

subsequent reduction in root growth and carbohydrate storage below ground, resulting in 

other, more subtle plant and ecosystems impacts. 

These latter impacts include increased susceptibility of plants to insect attack, 

disease, harsh weather, interspecies competition and overall decreased plant vigor. The 

adverse effects of ozone on forest and other natural vegetation can potentially lead to 

species shifts and loss from the affected ecosystems, resulting in a loss or reduction in 

associated ecosystem goods and services. Lastly, visible ozone injury to leaves can result 

in a loss of aesthetic value in areas of special scenic significance like national parks and 

wilderness areas. The final 2006 Ozone Air Quality Criteria Document presents more 

detailed information on ozone effects on vegetation and ecosystems.

(3) Atmospheric Deposition

Wet and dry deposition of ambient particulate matter delivers a complex mixture 

of metals (e.g., mercury, zinc, lead, nickel, aluminum, cadmium), organic compounds 

(e.g., polycyclic organic matter, dioxins, furans) and inorganic compounds (e.g., nitrate, 

sulfate) to terrestrial and aquatic ecosystems. The chemical form of the compounds 

deposited depends on a variety of factors including ambient conditions (e.g., temperature, 

humidity, oxidant levels) and the sources of the material. Chemical and physical 

transformations of the compounds occur in the atmosphere as well as the media onto 

which they deposit. These transformations in turn influence the fate, bioavailability and 

potential toxicity of these compounds. Atmospheric deposition has been identified as a 

key component of the environmental and human health hazard posed by several 

pollutants including mercury, dioxin and PCBs.184

 

184 U.S. EPA (2000) Deposition of Air Pollutants to the Great Waters: Third Report to Congress. Office of 

Air Quality Planning and Standards. EPA-453/R-00-0005. Docket EPA-HQ-OAR-2010-0162.
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Adverse impacts on water quality can occur when atmospheric contaminants 

deposit to the water surface or when material deposited on the land enters a waterbody

through runoff. Potential impacts of atmospheric deposition to waterbodies include those 

related to both nutrient and toxic inputs. Adverse effects to human health and welfare 

can occur from the addition of excess nitrogen via atmospheric deposition. The nitrogennutrient enrichment contributes to toxic algae blooms and zones of depleted oxygen, 

which can lead to fish kills, frequently in coastal waters. Deposition of heavy metals or 

other toxics may lead to the human ingestion of contaminated fish, impairment of 

drinking water, damage to the marine ecology, and limits to recreational uses. Several 

studies have been conducted in U.S. coastal waters and in the Great Lakes Region in 

which the role of ambient PM deposition and runoff is investigated.185,186,187,188,189 

Atmospheric deposition of nitrogen and sulfur contributes to acidification, 

altering biogeochemistry and affecting animal and plant life in terrestrial and aquatic 

ecosystems across the United States. The sensitivity of terrestrial and aquatic ecosystems 

to acidification from nitrogen and sulfur deposition is predominantly governed by

geology. Prolonged exposure to excess nitrogen and sulfur deposition in sensitive areas 

acidifies lakes, rivers and soils. Increased acidity in surface waters creates inhospitable 

conditions for biota and affects the abundance and nutritional value of preferred prey

species, threatening biodiversity and ecosystem function. Over time, acidifying

deposition also removes essential nutrients from forest soils, depleting the capacity of 

soils to neutralize future acid loadings and negatively affecting forest sustainability. 

Major effects include a decline in sensitive forest tree species, such as red spruce (Picea 

rubens) and sugar maple (Acer saccharum), and a loss of biodiversity of fishes, 

zooplankton, and macro invertebrates.

In addition to the role nitrogen deposition plays in acidification, nitrogen 

deposition also leads to nutrient enrichment and altered biogeochemical cycling. In 

aquatic systems increased nitrogen can alter species assemblages and cause 

eutrophication. In terrestrial systems nitrogen loading can lead to loss of nitrogen 

sensitive lichen species, decreased biodiversity of grasslands, meadows and other 

sensitive habitats, and increased potential for invasive species. For a broader explanation 

of the topics treated here, refer to the description in Section 7.1.2 of the RIA.

 

185 U.S. EPA (2004) National Coastal Condition Report II. Office of Research and Development/ Office of 

Water. EPA-620/R-03/002. Docket EPA-HQ-OAR-2010-0162.

186 Gao, Y., E.D. Nelson, M.P. Field, et al. 2002. Characterization of atmospheric trace elements on 

PM2.5 particulate matter over the New York-New Jersey harbor estuary. Atmos. Environ. 36: 1077-1086. 

Docket EPA-HQ-OAR-2010-0162.

187 Kim, G., N. Hussain, J.R. Scudlark, and T.M. Church. 2000. Factors influencing the atmospheric 

depositional fluxes of stable Pb, 210Pb, and 7Be into Chesapeake Bay. J. Atmos. Chem. 36: 65-79. 

Docket EPA-HQ-OAR-2010-0162.

188 Lu, R., R.P. Turco, K. Stolzenbach, et al. 2003. Dry deposition of airborne trace metals on the Los 

Angeles Basin and adjacent coastal waters. J. Geophys. Res. 108(D2, 4074): AAC 11-1 to 11-24. Docket 

EPA-HQ-OAR-2010-0162.

189 Marvin, C.H., M.N. Charlton, E.J. Reiner, et al. 2002. Surficial sediment contamination in Lakes Erie 

and Ontario: A comparative analysis. J. Great Lakes Res. 28(3): 437-450. Docket EPA-HQ-OAR-2010-

0162.
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Adverse impacts on soil chemistry and plant life have been observed for areas 

heavily influenced by atmospheric deposition of nutrients, metals and acid species, 

resulting in species shifts, loss of biodiversity, forest decline and damage to forest 

productivity. Potential impacts also include adverse effects to human health through 

ingestion of contaminated vegetation or livestock (as in the case for dioxin deposition), 

reduction in crop yield, and limited use of land due to contamination. 

Atmospheric deposition of pollutants can reduce the aesthetic appeal of buildings 

and culturally important articles through soiling, and can contribute directly (or in 

conjunction with other pollutants) to structural damage by means of corrosion or erosion. 

Atmospheric deposition may affect materials principally by promoting and accelerating 

the corrosion of metals, by degrading paints, and by deteriorating building materials such 

as concrete and limestone. Particles contribute to these effects because of their 

electrolytic, hygroscopic, and acidic properties, and their ability to adsorb corrosive gases 

(principally sulfur dioxide). 

(4) Environmental Effects of Air Toxics

Emissions from producing, transporting and combusting fuel contribute to 

ambient levels of pollutants that contribute to adverse effects on vegetation. Volatile 

organic compounds, some of which are considered air toxics, have long been suspected to 

play a role in vegetation damage.190 In laboratory experiments, a wide range of tolerance 

to VOCs has been observed.191 Decreases in harvested seed pod weight have been 

reported for the more sensitive plants, and some studies have reported effects on seed 

germination, flowering and fruit ripening. Effects of individual VOCs or their role in 

conjunction with other stressors (e.g., acidification, drought, temperature extremes) have

not been well studied. In a recent study of a mixture of VOCs including ethanol and 

toluene on herbaceous plants, significant effects on seed production, leaf water content 

and photosynthetic efficiency were reported for some plant species.192

Research suggests an adverse impact of vehicle exhaust on plants, which has in 

some cases been attributed to aromatic compounds and in other cases to nitrogen 

oxides.193, 194, 195 The impacts of VOCs on plant reproduction may have long-term 

 

190 U.S. EPA. 1991. Effects of organic chemicals in the atmosphere on terrestrial plants. EPA/600/3-91/001. 

Docket EPA-HQ-OAR-2010-0162.

191 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. 2003. 

Effects of VOCs on herbaceous plants in an open-top chamber experiment. Environ. Pollut. 124:341-343. 

Docket EPA-HQ-OAR-2010-0162. 

192 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. 2003. 

Effects of VOCs on herbaceous plants in an open-top chamber experiment. Environ. Pollut. 124:341-343. 

Docket EPA-HQ-OAR-2010-0162. 

193 Viskari E-L. 2000. Epicuticular wax of Norway spruce needles as indicator of traffic pollutant 

deposition. Water, Air, and Soil Pollut. 121:327-337. Docket EPA-HQ-OAR-2010-0162.

194 Ugrekhelidze D, F Korte, G Kvesitadze. 1997. Uptake and transformation of benzene and toluene by 

plant leaves. Ecotox. Environ. Safety 37:24-29. Docket EPA-HQ-OAR-2010-0162.

195 Kammerbauer H, H Selinger, R Rommelt, A Ziegler-Jons, D Knoppik, B Hock. 1987. Toxic 

components of motor vehicle emissions for the spruce Picea abies. Environ. Pollut. 48:235-243. Docket 

EPA-HQ-OAR-2010-0162.
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implications for biodiversity and survival of native species near major roadways. Most of 

the studies of the impacts of VOCs on vegetation have focused on short-term exposure 

and few studies have focused on long-term effects of VOCs on vegetation and the 

potential for metabolites of these compounds to affect herbivores or insects.

D. Air Quality Impacts of Non-GHG Pollutants

Air quality modeling was performed to assess the impact of the heavy-duty 

vehicle standards on criteria and air toxic pollutants. In this section, we present 

information on current modeled levels of pollution as well as projections for 2030, with 

respect to ambient PM2.5, ozone, selected air toxics, visibility levels and nitrogen and 

sulfur deposition. The results are discussed in more detail in Section 8.2 of the RIA. 

We used the Community Multi-scale Air Quality (CMAQ) photochemical model, 

version 4.7.1, for our analysis. This version of CMAQ includes a number of 

improvements to previous versions of the model. These improvements are discussed in 

Section 8.2.2 of the RIA.

(1) Ozone

(a) Current Levels

8-hour ozone concentrations exceeding the level of the ozone NAAQS occur in 

many parts of the country. In 2008, the EPA amended the ozone NAAQS (73 FR 16436, 

March 27, 2008). The final 2008 ozone NAAQS rule set forth revisions to the previous 

1997 NAAQS for ozone to provide increased protection of public health and welfare. On 

January 6, 2010, EPA proposed to reconsider the 2008 ozone NAAQS to ensure that they

are requisite to protect public health with an ample margin of safety, and requisite to 

protect public welfare (75 FR 2938, January 19, 2010). EPA intends to complete the 

reconsideration by July 31, 2011. If, as a result of the reconsideration, EPA promulgates 

different ozone standards, the new 2011 ozone standards would replace the 2008 ozone 

standards and the requirement to designate areas for the replaced 2008 standards would 

no longer apply. 

As of April 21, 2011 there are 44 areas designated as nonattainment for the 1997 

8-hour ozone NAAQS, comprising 242 full or partial counties with a total population of 

over 118 million people. These numbers do not include the people living in areas where 

there is a future risk of failing to maintain or attain the 1997 8-hour ozone NAAQS. The 

numbers above likely underestimate the number of counties that are not meeting the 

ozone NAAQS because the nonattainment areas associated with the more stringent 2008 

8-hour ozone NAAQS have not yet been designated. Table VII-7 provides an estimate, 

based on 2006-08 air quality data, of the counties with design values greater than the 

2008 8-hour ozone NAAQS of 0.075 ppm. 
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Table VII-7 Counties with Design Values Greater Than the Ozone NAAQS

NUMBER OF 

COUNTIES

POPULATIONA

1997 Ozone Standard: counties within the 54 

areas currently designated as nonattainment 

(as of 1/6/10)

266 122,343, 799

2008 Ozone Standard: additional counties 

that would not meet the 2008 NAAQS (based 

on 2006-2008 air quality data)b

156 36,678,478

Total 422 159,022,277

Notes:

a

Population numbers are from 2000 census data.

b Area designations for the 2008 ozone NAAQS have not yet been made. Nonattainment for the 2008 

Ozone NAAQS would be based on three years of air quality data from later years. Also, the county 

numbers in this row include only the counties with monitors violating the 2008 Ozone NAAQS. The 

numbers in this table may be an underestimate of the number of counties and populations that will 

eventually be included in areas with multiple counties designated nonattainment.

(b) Projected Levels without this Final Action

States with 8-hour ozone nonattainment areas are required to take action to bring 

those areas into compliance in the future. Based on the final rule designating and 

classifying 8-hour ozone nonattainment areas for the 1997 standard (69 FR 23951, April 

30, 2004), most 8-hour ozone nonattainment areas will be required to attain the ozone 

NAAQS in the 2007 to 2013 time frame and then maintain the NAAQS thereafter. As 

noted, EPA is reconsidering the 2008 ozone NAAQS. If EPA promulgates different 

ozone NAAQS in 2011 as a result of the reconsideration, these standards would replace 

the 2008 ozone NAAQS and there would no longer be a requirement to designate areas 

for the 2008 NAAQS. Attainment dates for any 2011 ozone NAAQS would range from 3 

to 20 years from designation, depending on the area’s classification. 

EPA has already adopted many emission control programs that are expected to 

reduce ambient ozone levels and assist in reducing the number of areas that fail to 

achieve the ozone NAAQS. Even so, our air quality modeling projects that in 2030, with 

all current controls but excluding the impacts of the heavy-duty standards, up to 10

counties with a population of over 30 million may not attain the 2008 ozone standard of 

0.075 ppm (75 ppb). These numbers do not account for those areas that are close to (e.g., 

within 10 percent of) the 2008 ozone standard. These areas, although not violating the 

standards, will also be impacted by changes in ozone as they work to ensure long-term 

maintenance of the ozone NAAQS.

(c) Projected Levels with this Final Action

Our modeling indicates ozone design value concentrations will decrease in many

areas of the country. The decreases in ozone design values are likely due to projected 

tailpipe reductions in NOX and projected upstream emissions decreases in NOX and 

VOCs from reduced gasoline production. The majority of the ozone design value 
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99 of

decreases are less than 1 ppb. The maximum projected decrease in an 8-hour ozone 

design value is 1.57 ppb in Jefferson County, Tennessee. On a population-weighted 

basis, the average modeled 8-hour ozone design values are projected to decrease by 0.39 

ppb in 2030 and the design values for those counties that are projected to be above the 

2008 ozone standard in 2030 will see population-weighted decreases of 0.16 ppb due to 

the heavy-duty standards. 

(2) Particulate Matter

(a) Current Levels

PM2.5 concentrations exceeding the level of the PM2.5 NAAQS occur in many 

parts of the country. In 2005, EPA designated 39 nonattainment areas for the 1997 PM2.5

NAAQS (70 FR 943, January 5, 2005). These areas are composed of 208 full or partial 

counties with a total population exceeding 88 million. The 1997 PM2.5 NAAQS was 

revised in 2006 and the 2006 24-hour PM2.5 NAAQS became effective on December 18, 

2006. On October 8, 2009, the EPA issued final nonattainment area designations for the 

2006 24-hour PM2.5 NAAQS (74 FR 58688, November 13, 2009). These designations 

include 32 areas composed of 121 full or partial counties with a population of over 70 

million. In total, there are 54 PM2.5 nonattainment areas composed of 243 counties with a 

population of almost 102 million people.

(b) Projected Levels without this Final Action

States with PM2.5 nonattainment areas are required to take action to bring those 

areas into compliance in the future. Areas designated as not attaining the 1997 PM2.5

NAAQS will need to attain the 1997 standards in the 2010 to 2015 time frame, and then 

maintain them thereafter. The 2006 24-hour PM2.5 nonattainment areas will be required 

to attain the 2006 24-hour PM2.5 NAAQS in the 2014 to 2019 time frame and then be 

required to maintain the 2006 24-hour PM2.5 NAAQS thereafter. The heavy-duty 

standards finalized in this action become effective in 2012 and therefore may be useful to 

states in attaining or maintaining the PM2.5 NAAQS.

EPA has already adopted many emission control programs that are expected to 

reduce ambient PM2.5 levels and which will assist in reducing the number of areas that 

fail to achieve the PM2.5 NAAQS. Even so, our air quality modeling projects that in 

2030, with all current controls but excluding the impacts of the heavy-duty standards 

adopted here, at least 4 counties with a population of almost 7 million may not attain the 

1997 annual PM2.5 standard of 15 μg/m3and 22 counties with a population of over 33 

million may not attain the 2006 24-hour PM2.5 standard of 35 μg/m3. These numbers do 

not account for those areas that are close to (e.g., within 10 percent of) the PM2.5

standards. These areas, although not violating the standards, will also benefit from any

reductions in PM2.5 ensuring long-term maintenance of the PM2.5 NAAQS. 
100 of 

(c) Projected Levels with this Final Action

Air quality modeling performed for this final action shows that in 2030 the 

majority of the modeled counties will see decreases of less than 0.01 μg/m

3

in their 

annual PM2.5 design values. The decreases in annual PM2.5 design values that we see in 

some counties are likely due to emission reductions related to lower fuel production at 

existing oil refineries and/or reductions in PM2.5 precursor emissions (NOX, SOX, and 

VOCs) due to improvements in road load. The maximum projected decrease in an annual 

PM2.5 design value is 0.03 μg/m

3

in Allen County, Indiana and Canyon County, Idaho. 

On a population-weighted basis, the average modeled 2030 annual PM2.5 design value is 

projected to decrease by 0.01 μg/m

3

due to this final action. 

In addition to looking at annual PM2.5 design values, we also modeled the impact 

of the standards on 24-hour PM2.5 design values. Air quality modeling performed for this 

final action shows that in 2030 the majority of the modeled counties will see changes of 

between -0.05 μg/m

3

and 0 μg/m

3

in their 24-hour PM2.5 design values. The decreases in 

annual PM2.5 design values that we see in some counties are likely due to emission 

reductions related to lower fuel production at existing oil refineries and/or reductions in 

PM2.5 precursor emissions (NOX, SOX, and VOCs) due to improvements in road load. 

The maximum projected decrease in a 24-hour PM2.5 design value is 0.27 μg/m

3

in 

Canyon County, ID. There are also some counties that are projected to see increases of 

less than 0.1 μg/m

3

in their 24-hour PM2.5 design values. These small increases in 24-

hour PM2.5 design values are likely related to downstream emission increases from APUs. 

On a population-weighted basis, the average modeled 2030 24-hour PM2.5 design value is 

projected to decrease by 0.03 μg/m

3

due to this final action. Those counties that are 

projected to be above the 24-hour PM2.5 standard in 2030 will see slightly smaller 

population-weighted decreases of 0.01 μg/m

3

in their design values due to this final 

action. 

(3) Air Toxics

(a) Current Levels

The majority of Americans continue to be exposed to ambient concentrations of 

air toxics at levels which have the potential to cause adverse health effects.196 The levels 

of air toxics to which people are exposed vary depending on where people live and work 

and the kinds of activities in which they engage, as discussed in detail in U.S. EPA’s 

most recent Mobile Source Air Toxics Rule.197 According to the National Air Toxic 

Assessment (NATA) for 2005,

198 mobile sources were responsible for 43 percent of 

outdoor toxic emissions and over 50 percent of the cancer risk and noncancer hazard. 

Benzene is the largest contributor to cancer risk of all 124 pollutants quantitatively

 

196 U.S. Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile 

Sources; Final Rule. 72 FR 8434, February 26, 2007.

197 U. S. Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile 

Sources; Final Rule. 72 FR 8434, February 26, 2007. 

198 U. S. EPA. (2011) 2005 National-Scale Air Toxics Assessment. http://www.epa.gov/ttn/atw/nata2005/. 

Docket EPA-HQ-OAR-2010-0162. 
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101 of

assessed in the 2002 NATA and mobile sources were responsible for 59 percent of 

benzene emissions in 2002. Over the years, EPA has implemented a number of mobile 

source and fuel controls resulting in VOC reductions, which also reduce benzene and 

other air toxic emissions. 

(b) Projected Levels 

Our modeling indicates that the heavy-duty standards have relatively little impact 

on national average ambient concentrations of the modeled air toxics. Additional detail 

on the air toxics results can be found in Section 8.2.3.3 of the RIA. 

(4) Nitrogen and Sulfur Deposition

(a) Current Levels

Over the past two decades, the EPA has undertaken numerous efforts to reduce 

nitrogen and sulfur deposition across the U.S. Analyses of long-term monitoring data for 

the U.S. show that deposition of both nitrogen and sulfur compounds has decreased over 

the last 17 years although many areas continue to be negatively impacted by deposition. 

Deposition of inorganic nitrogen and sulfur species routinely measured in the U.S. 

between 2005 and 2007 were as high as 9.6 kilograms of nitrogen per hectare (kg N/ha) 

averaged over three years and 20.8 kilograms of sulfur per hectare (kg S/ha) averaged 

over three years.

199 The data show that reductions were more substantial for sulfur 

compounds than for nitrogen compounds. These numbers are generated by the U.S. 

national monitoring network and they likely underestimate nitrogen deposition because 

neither ammonia nor organic nitrogen is measured. In the eastern U.S., where data are 

most abundant, total sulfur deposition decreased by about 44% between 1990 and 2007,

while total nitrogen deposition decreased by 25% over the same time frame.200

(b) Projected Levels 

Our air quality modeling projects decreases in nitrogen deposition, especially in 

the Midwest, as a result of the heavy-duty standards required by this final action. The 

heavy-duty standards will result in annual percent decreases of 0.5% to more than 2% in 

some cities in the Midwest, Phoenix, Albuquerque, and some areas in Texas. The

remainder of the country will see only minimal changes in nitrogen deposition, ranging 

from decreases of less than 0.5% to increases of less than 0.5%. For a map of 2030 

 

199 U.S. EPA. U.S. EPA's Report on the Environment (Final Report). U.S. Environmental Protection 

Agency, Washington, D.C., EPA/600/R-07/045F (NTIS PB2008-112484). Docket EPA-HQ-OAR-2010-

0162. Updated data available online at: 

http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&ch=46&subtop=341&lv=list.listByChapter

&r=201744 

200 U.S. EPA. U.S. EPA’s 2008 Report on the Environment (Final Report). U.S. Environmental Protection 

Agency, Washington, D.C., EPA/600/R-07/045F (NTIS PB2008-112484). Docket EPA-HQ-OAR-2010-

0162. Updated data available online at: 

http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&ch=46&subtop=341&lv=list.listByChapter

&r=201744 
102 of 

nitrogen deposition impacts and additional information on these impacts, see Section

8.2.3.4 of the RIA. The impacts of the heavy-duty standards on sulfur deposition are 

minimal, ranging from decreases of up to 0.5% to increases of up to 0.5%.

(5) Visibility

(a) Current Levels

As mentioned in Section VII.D(1)(a) , millions of people live in nonattainment 

areas for the PM2.5 NAAQS. These populations, as well as large numbers of individuals 

who travel to these areas, are likely to experience visibility impairment. In addition, 

while visibility trends have improved in mandatory class I federal areas, the most recent 

data show that these areas continue to suffer from visibility impairment. In summary, 

visibility impairment is experienced throughout the U.S., in multi-state regions, urban 

areas, and remote mandatory class I federal areas.

(b) Projected Levels 

Air quality modeling conducted for this final action was used to project visibility

conditions in 138 mandatory class I federal areas across the U.S. in 2030. The results 

show that all the modeled areas will continue to have annual average deciview levels 

above background in 2030.201 The results also indicate that the majority of the modeled 

mandatory class I federal areas will see very little change in their visibility, but some 

mandatory class I federal areas will see improvements in visibility due to the heavy-duty 

standards and a few mandatory class I federal areas will see visibility decreases. The 

average visibility at all modeled mandatory class I federal areas on the 20% worst days is 

projected to improve by 0.01 deciviews, or 0.06%, in 2030. Section 8.2.3.5 of the RIA 

contains more detail on the visibility portion of the air quality modeling.

VIII. What are the Agencies’ Estimated Cost, Economic, and 

Other Impacts of the Final Program?

In this section, we present the costs and impacts of the final HD National 

Program. It is important to note that NHTSA’s final fuel consumption standards and 

EPA’s final GHG emissions standards will both be in effect, and each will lead to 

average fuel efficiency increases and GHG emission reductions. The two agencies’ final 

standards comprise the HD National Program.

The net benefits of the final HD National Program consist of the effects of the 

program on: 

 

201 The level of visibility impairment in an area is based on the light-extinction coefficient and a unitless

visibility index, called a “deciview,” which is used in the valuation of visibility. The deciview metric 

provides a scale for perceived visual changes over the entire range of conditions, from clear to hazy. Under 

many scenic conditions, the average person can generally perceive a change of one deciview. The higher 

the deciview value, the worse the visibility. Thus, an improvement in visibility is a decrease in deciview 

value.
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103 of

 the vehicle program costs (costs of complying with the vehicle CO2 standards)

 fuel savings associated with reduced fuel usage resulting from the program

 reductions in greenhouse gas emissions, 

 the reductions in other (non-GHG) pollutants, 

 costs associated with increases in noise, congestion, and accidents resulting from 

increased vehicle use, 

 improvements in U.S. energy security impacts,

 benefits associated with increased vehicle use due to the “rebound” effect. 

We also present the cost-effectiveness of the standards, or the cost per ton of 

emissions reduced. Where possible, we identify the uncertain aspects of these economic 

impacts and attempt to quantify them when/if possible (e.g., sensitivity ranges associated 

with quantified and monetized GHG impacts; probabilistic uncertainty associated with 

non-GHG health benefits). For some impacts, however, there is a lack of adequate 

information to inform a probabilistic assessment of uncertainty. EPA continues to work 

toward developing a comprehensive strategy for characterizing the aggregate impact of 

uncertainty in key elements of its analyses and we will continue to work to refine these 

uncertainty analyses in the future as time and resources permit.

The program may have other effects that are not included here. The agencies 

sought comment on whether any costs or benefits were omitted from this analysis, so that 

they could be explicitly recognized in the final rules. In particular, as discussed in 

Section III and in Chapter 2 of the RIA, the technology cost estimates developed here 

take into account the costs to hold other vehicle attributes, such as size and performance, 

constant. In addition, the analysis assumes that the full technology costs are passed along 

to vehicle buyers. With these assumptions, because welfare losses are monetary 

estimates of how much buyers would have to be compensated to be made as well off as in 

the absence of the change,202 the price increase measures the loss to the buyer.203 

Assuming that the full technology cost gets passed along to the buyer as an increase in 

price, the technology cost thus measures the welfare loss to the buyer. Increasing fuel 

efficiency would have to lead to other changes in the vehicles that buyers find 

undesirable for there to be additional losses not included in the technology costs. 

 

202 This approach describes the economic concept of compensating variation, a payment of money after a 

change that would make a consumer as well off after the change as before it. A related concept, equivalent 

variation, estimates the income change that would be an alternative to the change taking place. The 

difference between them is whether the consumer’s point of reference is her welfare before the change 

(compensating variation) or after the change (equivalent variation). In practice, these two measures are 

typically very close together. 

203 Indeed, it is likely to be an overestimate of the loss to the buyer, because the buyer has choices other 

than buying the same vehicle with a higher price; she could choose a different vehicle, or decide not to buy 

a new vehicle. The buyer would choose one of those options only if the alternative involves less loss than 

paying the higher price. Thus, the increase in price that the buyer faces would be the upper bound of loss 

of consumer welfare, unless there are other changes to the vehicle due to the fuel economy improvements 

that make the vehicle less desirable to buyers.
104 of 

The agencies sought comments, including supporting data and quantitative 

analyses, of any additional impacts of the final standards on vehicle attributes and 

performance, and other potential aspects that could positively or negatively affect the 

welfare implications of this final rulemaking, not addressed in this analysis. 

The comments received by the agencies did not provide any clear insights into 

this question. Some comments noted the diversity of the trucking industry and expressed 

a request that the program continue the great variety of options for the industry, because 

of the variation in needs for different customers. Additional comments noted that the 

separate engine and vehicle programs support the maintenance of variety and current 

market structure. Though a few commenters raised concerns, no information was offered 

to indicate that choice will in fact be limited by the program, or that other vehicle 

attributes are adversely affected.

The total monetized benefits (excluding fuel savings) under the program are 

projected to be $4.3 to $11.1 billion in 2030, depending on the value used for the social 

cost of carbon. These benefits are summarized below in Table VIII-31. The costs of the 

program in 2030 are estimated to be approximately $2.6 billion for new engine and truck 

technology, less $20.6 billion in savings realized by trucking operations through fewer 

fuel expenditures (calculated using pre-tax fuel prices). These costs are summarized 

below in Table VIII-29. The present value of the total monetized benefits (excluding fuel 

savings) under the program is expected to range from $48.7 billion to $180.1 billion with 

a 3% discount rate; with a 7% discount rate, the total monetized benefits are expected to 

range from $24.3 billion to $155.7 billion. These values, summarized in Table VIII-31, 

depend on the value used for the social cost of carbon. The present value of costs of the 

program for new engine and truck technology, in Table VIII-29, are expected to be $47.4

billion using a 3% discount rate, and $24.7 billion with a 7% discount rate, less fuel 

savings (calculated using pre-tax fuel prices) of $375.3 billion with a 3% discount rate, 

and $166.5 billion with a 7% discount rate. Total net present benefits (in Table VIII-32) 

are thus expected to range from $376.6 billion to $508 billion with a 3% discount rate, 

and $166.1 billion to $297.5 billion with a 7% discount rate.

The estimates developed here are measured against a baseline fuel efficiency

associated with MY 2010 vehicles. The agencies also considered an alternate baseline 

associated with AEO 2011 projections, which is further discussed in Section IX. All 

calculations presented in Section VIII use the constant 2010 vehicle baseline. The extent 

to which fuel efficiency improvements may have occurred in the absence of the rules 

affects the net benefits associated with the program. If trucks were to install technologies 

to achieve the fuel savings and reduced GHG emissions in the absence of this program, 

then both the costs and benefits of these fuel savings could be attributed to market forces, 

not the rules. As a baseline for estimates of the extent of fuel-saving technologies that 

might have been adopted in the absence of the program, the proposal used the level of 

these technologies in MY 2010 vehicles. We sought comment on whether the agencies 

should use an alternative baseline based on data provided by commenters to estimate the 

degree to which the technologies discussed in the proposal would have been adopted in 

the absence of these rules. No comments were received on this issue. One comment cites 

the EPA draft RIA as noting a historic 1% per year improvement in fuel efficiency, and 
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105 of

argues that the rules are therefore not needed; the actual figure in the draft RIA, however, 

was a 0.09% per year improvement.

EPA has undertaken an analysis of the economy-wide impacts of the final heavyduty truck fuel efficiency and GHG standards as an exploratory exercise that EPA 

believes could provide additional insights into the potential impacts of the program.204

These results were not a factor regarding the appropriateness of the final standards. It is 

important to note that the results of this modeling exercise are dependent on the 

assumptions associated with how manufacturers would make fuel efficiency 

improvements and how trucking operations would respond to increases in higher vehicle 

costs and improved vehicle fuel efficiency as a result of the final program. 

Further information on these and other aspects of the economic impacts of our 

rules are summarized in the following sections and are presented in more detail in the 

RIA for this final rulemaking.

A. Conceptual Framework for Evaluating Impacts

This regulation is motivated primarily by the goals of reducing emissions of 

greenhouse gases and promoting U.S. energy security by reducing consumption and 

imports of petroleum-based fuels. These motivations involve classic externalities, 

meaning that private decisions do not incorporate all of the costs associated with these 

problems; these costs are not borne completely by the households or businesses whose 

actions are responsible for them. In the absence of some mechanism to “internalize” 

these costs – that is, to transfer their burden to individuals or firms whose decisions 

impose them – individuals and firms will consume more petroleum-based fuels than is 

socially optimal. Externalities are a classic motivation for government intervention in 

markets. These externalities, as well as effects due to changes in emissions of other 

pollutants and other impacts, are discussed in Sections VIII.H – VIII.K. 

In some cases, these classic externalities are by themselves enough to justify the 

costs of imposing fuel efficiency standards. For some discount rates and some projected

social costs of carbon, however, the reductions in these external costs are less than the 

costs of new fuel saving technologies needed to meet the standards. (See Tables 9-18 and 

9-19 in the RIA.) Nevertheless, this regulation reduces trucking companies’ fuel costs; 

according to our estimates, these savings in fuel costs are by themselves sufficient to pay

for the technologies over periods of time considerably shorter than vehicles’ expected 

lifetimes under the assumptions used for this analysis (e.g., AEO 2011 projected fuel 

prices). If these estimates are correct, then the entire value of the reductions in external 

costs represents additional net benefits of the program, beyond those resulting from the 

fact that the value of fuel savings exceeds the costs of technologies necessary to achieve 

them.

 

204 See Memorandum to Docket, “Economy-Wide Impacts of Proposed Heavy-Duty Truck Greenhouse Gas 

Emissions and Fuel Efficiency Standards”, October 8, 2010. Docket EPA-HQ-OAR-2010-0162.
106 of 

It is often asserted that there are cost-effective fuel-saving technologies that 

markets do not take advantage of. This is commonly known as the “energy gap” or 

“energy paradox.” Standard economic theory suggests that in normally functioning 

competitive markets, interactions between vehicle buyers and producers would lead 

producers to incorporate all cost-effective technology into the vehicles that they offer, 

without government intervention. Unlike in the light-duty vehicle market, the vast 

majority of vehicles in the medium- and heavy-duty truck market are purchased and 

operated by businesses with narrow profit margins, and for which fuel costs represent a 

substantial operating expense. 

Even in the presence of uncertainty and imperfect information – conditions that 

hold to some degree in every market – we generally expect firms to attempt to minimize 

their costs in an effort to survive in a competitive marketplace, and therefore to make 

decisions that are in the best interest of the company and its owners and/or shareholders. 

In this case, the benefits of the rules would be due exclusively to reducing the economic 

costs of externalities resulting from fuel production and consumption. However, as 

discussed below in Section VIII.E, the agencies have estimated that the application of 

fuel-saving technologies in response to the final standards would, on average, yield 

private returns to truck owners of 140% to 420% (see Table VIII-21 below). The 

agencies have also estimated that the application of these technologies would be 

significantly lower in the absence of the final standards (i.e., under the “no action” 

regulatory alternative), meaning that truck buyers and operators ignore opportunities to 

make investments in higher fuel efficiency that appear to offer significant cost savings.

As discussed in the NPRM, there are several possible explanations in the 

economics literature for why trucking companies do not adopt technologies that would be 

expected to increase their profits: there could be a classic market failure in the trucking 

industry – market power, externalities, or asymmetric or incomplete (i.e., missing market)

information; there could be institutional or behavioral rigidities in the industry (union 

rules, standard operating procedures, statutory requirements, loss aversion, etc.), whereby 

participants collectively do not minimize costs; or the engineering estimates of fuel 

savings and costs for these technologies might overstate their benefits or understate their 

costs in real-world applications.

To try to understand why trucking companies have not adopted these seemingly 

cost-effective fuel-saving technologies, the agencies surveyed published literature about 

the energy paradox, and held discussions with numerous truck market participants. The 

proposal discussed five categories of possible explanations derived from these sources. 

Collectively, these five hypotheses may explain the apparent inconsistency between the 

engineering analysis, which finds a number of cost-effective methods of improving fuel 

efficiency, and the observation that many of these technologies are not widely adopted. 

These hypotheses include imperfect information in the original and resale 

markets, split incentives, uncertainty about future fuel prices, and adjustment and 

transactions costs. As the discussion indicated, some of these explanations suggest 

failures in the private market for fuel-saving technology in addition to the externalities 

caused by producing and consuming fuel that are the primary motivation for the rules. 
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107 of

Other explanations suggest market-based behaviors that may imply additional costs of 

regulating truck fuel efficiency that are not accounted for in this analysis. As noted 

above, an additional explanation – adverse effects on other vehicle attributes -- did not 

elicit supporting information in the public comments. Anecdotal evidence from various 

segments of the trucking industry suggests that many of the hypotheses discussed here 

may play a role in explaining the puzzle of why truck purchasers appear to under-invest 

in fuel efficiency, although different explanations may apply to different segments, or 

even different companies. The published literature does not appear to include empirical 

analysis or data related to this question.

The agencies invited comment on these explanations, and on any data or 

information that could be used to investigate the role of any or all of these five 

hypotheses in explaining this energy paradox as it applies specifically to trucks. Some 

comments expressed dissatisfaction about the explanations presented; they argued that 

these arguments were not sufficient to explain the phenomenon. These comments argued 

that the truck owners and operators are better judges of the appropriate amount of fuel 

efficiency than are government agencies; they choose not to invest because of warranted 

skepticism about these technologies. The agencies also requested comment and 

information regarding any other hypotheses that could explain the appearance that costeffective fuel-saving technologies have not been widely incorporated into trucks. The 

following discussion summarizes the fuller discussion provided in the NPRM and 

includes discussion of the comments received.

(1) Information Issues in the Original Sale Markets

One potential hypothesis for why the trucking industry does not adopt what 

appear to be inexpensive fuel saving technologies is that there is inadequate or unreliable 

information available about the effectiveness of many fuel-saving technologies for new 

vehicles. If reliable information on the effectiveness of many new technologies is absent, 

truck buyers will understandably be reluctant to spend additional money to purchase 

vehicles equipped with unproven technologies. 

This lack of information can manifest itself in multiple ways. For instance, the 

problem may arise purely because collecting reliable information on technologies is 

costly (also see Section VIII.A.5 on transaction costs). Moreover, information has 

aspects of a public good, in that no single firm has the incentive to do the costly

experimentation to determine whether or not particular technologies are cost-effective, 

while all firms benefit from the knowledge that would be gained from that 

experimentation. Similarly, if multiple firms must conduct the same tests to get the same 

information, costs could be reduced by some form of coordination of information 

gathering.

While its effect on information is indirect, we expect the requirement for the use 

of new technologies included in this program will circumvent these information issues, 

resulting in their adoption, thus providing more readily available information about their 

benefits. The agencies appreciate, however, that the diversity of truck uses, driving 
108 of 

situations, and driver behavior will lead to variation in the fuel savings that individual 

trucks or fleets experience from using specific technologies. 

One commenter noted that the SmartWay program targets semi-truck owners and 

thus should have the largest impact on that sector, rather than vocational or medium-duty

trucks. However, the gap between actual investment in fuel efficiency and the agencies’ 

estimates of optimal investment is largest for combination tractors. Some of the 

difference in magnitude is likely to be due to the higher vehicle miles traveled for semitrucks compared to medium-duty and vocational vehicles: more driving means more fuel 

savings. Additionally, not even a majority of semi-trucks are owned by participants in 

SmartWay; non-participants are unlikely to get all the benefits of participants. Other 

explanations, noted below, are also likely to play a role. This observation may also 

suggest some limitations of improved information provision as a means of addressing the 

“efficiency gap.”

(2) Information Issues in the Resale Market

In addition to issues in the new vehicle market, a second hypothesis for why 

trucking companies may not adopt what appear to be cost-effective technologies to save 

fuel is that the resale market may not adequately reward the addition of fuel-saving 

technology to vehicles to ensure their original purchase by new truck buyers. This 

inadequate payback for users beyond the original owner may contribute to the short 

payback period that new purchasers appear to expect.205 The agencies requested data and 

information on the extent to which costs of fuel saving equipment can be recovered in the 

resale truck market. No data were received. One reviewer disputed this theory on the 

basis that people are willing to pay more for better vehicles, new or used. It is not clear, 

however, whether buyers of used vehicles can tell which are the better vehicles.206

Some of this unwillingness to pay for fuel-saving technology may be due to the 

extension of the information problems in the new vehicle market into resale markets. 

Buyers in the resale market have no more reason to trust information on fuel-saving 

technologies than buyers in the original market. Because actual fuel efficiency of trucks 

on the road depends on many factors, including geography and driving styles or habits, 

even objective sources such as logs of truck performance for used vehicles may not 

provide reliable information about the fuel efficiency that potential purchasers of used 

trucks will experience.

A related possibility is that vehicles will be used for different purposes by their 

second owners than those for which they were originally designed, and the fuel-saving 

technology is therefore of less value. 

 

205 See NAS 2010, Note Error! Bookmark not defined.216, at p. 188.

206 Akerlof, George A. “The Market for ‘Lemons’” Quality Uncertainty and the Market Mechanism,” 

Quarterly Journal of Economics 84(3) (1970): 488-500 points out that asymmetric information – the seller 

has better information than the buyer – can potentially lead to complete failure of a market, even when both 

buyers and sellers would benefit from trade.
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109 of

It is possible, though, that the fuel savings experienced by the secondary

purchasers may not match those experienced by their original owners if the optimal 

secondary new use of the vehicle does not earn as many benefits from the technologies. 

One commenter asks whether the fuel-saving technology is unvalued because it is 

unproven or overrated. In that case, the premium for fuel-saving technology in the 

secondary market should accurately reflect its value to potential buyers participating in 

that market, even if it is lower than its value in the original market, and the market has 

not failed. Because the information necessary to optimize use in the secondary market 

may not be readily available or reliable, however, buyers in the resale market may have 

less ability than purchasers of new vehicles to identify and gain the advantages of new 

fuel-saving technologies, and may thus be even less likely to pay a premium for them.

For these reasons, purchasers’ willingness to pay for fuel efficiency technologies 

may be even lower in the resale market than in the original equipment market. Even 

when fuel-saving technologies will provide benefits in the resale markets, purchasers of 

used vehicles may not be willing to compensate their original owners fully for their 

remaining value. As a result, the purchasers of original equipment may expect the resale 

market to provide inadequate appropriate compensation for the new technologies, even 

when those technologies would reduce costs for the new buyers. This information issue 

may partially explain what appears to be the very short payback periods required for new 

technologies in the new vehicle market.

(3) Split Incentives in the Medium- and Heavy-Duty Truck Industry

A third hypothesis explaining the energy paradox as applied to trucking involves 

split incentives. When markets work effectively, signals provided by transactions in one 

market are quickly transmitted to related markets and influence the decisions of buyers 

and sellers in those related markets. For instance, in a well-functioning market system, 

changes in the expected future price of fuel should be transmitted rapidly to those who 

purchase trucks, who will then reevaluate the amount of fuel-saving technology to 

purchase for new vehicles. If for some reason a truck purchaser will not be directly

responsible for future fuel costs, or the individual who will be responsible for fuel costs 

does not decide which truck characteristics to purchase, then those price signals may not 

be transmitted effectively, and incentives can be described as “split.” 

One place where such a split may occur is between the owners and operators of 

trucks. Because they are generally responsible for purchasing fuel, truck operators have 

strong incentives to economize on its use, and are thus likely to support the use of fuelsaving technology. However, the owners of trucks or trailers are often different from 

operators, and may be more concerned about their longevity or maintenance costs than 

about their fuel efficiency, when purchasing vehicles. As a result, capital investments by

truck owners may be channeled into equipment that improves vehicles’ durability or 

reduces their maintenance costs, rather than into fuel-saving technology. If operators can 

choose freely among the trucks they drive, competition among truck owners to employ

operators would encourage owners to invest in fuel-saving technology. However, if truck 

owners have more ability to choose among operators, then market signals for improved 
110 of 

fuel savings that would normally be transmitted to truck owners may be muted. Truck 

fleets that rent their vehicles may provide an example: renters may observe the cost of 

renting the truck, but not its fuel efficiency; if so, then the purchasers will aim for 

vehicles with lower costs, to lower the cost of the rental. It might be possible to test this 

theory by comparing the fuel efficiency of trucks by owner-operators with those that are 

leased by operators. The agencies have not had the data to conduct such a test.

One commenter noted that there are always tradeoffs in an investment decision: a 

purchaser may prefer to invest in other vehicle attributes than fuel efficiency. In an 

efficient market, however, a purchaser should invest in fuel-saving technology as long as 

the increase in fuel-saving technology costs less than the expected fuel savings. This 

result should hold regardless of the level of investment in other attributes, unless there are 

constraints on a purchaser’s access to investment capital. The agencies believe that truck 

fleets do have an incentive to make investments in fuel efficiency, and that this 

assumption is reflected in the regulatory analysis. The agencies also believe, however, 

that sufficient evidence suggests that truck fleets are not availing themselves of all the 

opportunities for efficiency improvements.

 

In addition, the NAS report notes that split incentives can arise between tractor 

and trailer operators.207 Trailers affect the fuel efficiency of shipping, but trailer owners 

do not face strong incentives to coordinate with truck owners. EPA and NHTSA are not 

regulating trailers in this action.

By itself, information provision may be inadequate to address the potential 

underinvestment in fuel efficiency resulting from such split incentives. In this setting, 

regulation may contribute to fuel savings that otherwise may be difficult to achieve.

(4) Uncertainty About Future Cost Savings

Another hypothesis for the lack of adoption of seemingly fuel saving technologies 

may be uncertainty about future fuel prices or truck maintenance costs. When purchasers 

have less than perfect foresight about future operating expenses, they may implicitly

discount future savings in those costs due to uncertainty about potential returns from 

investments that reduce future costs. In contrast, the immediate costs of the fuel-saving 

or maintenance-reducing technologies are certain and immediate, and thus not subject to 

discounting. In this situation, both the expected return on capital investments in higher 

fuel efficiency and potential variance about its expected rate may play a role in a firm’s 

calculation of its payback period on such investments.

In the context of energy efficiency investments for the home, Metcalf and 

Rosenthal (1995) and Metcalf and Hassett (1995) observe that households weigh known, 

up-front costs that are essentially irreversible against an unknown stream of future fuel 

 

207 See NAS 2010, Note Error! Bookmark not defined.216, at p. 182.
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111 of

savings.208 Notably, in this situation, requiring households to adopt technologies more 

quickly may make them worse off by imposing additional risk on them.

Greene et al (2009) also finds support for this explanation in the context of lightduty fuel economy decisions: a loss-averse consumer’s expected net present value of 

increasing the fuel economy of a passenger car can be very close to zero, even if a riskneutral expected value calculation shows that its buyer can expect significant net benefits 

from purchasing a more fuel-efficient car.

209 Supporting this hypothesis is a finding by

Dasgupta et. al (2007) that consumers are more likely to lease than buy a vehicle with 

higher maintenance costs because it provides them with the option to return it before 

those costs become too high.210 However, the agencies know of no studies that have 

estimated the impact of uncertainty on perceived future savings for medium- and heavyduty vehicles.

Purchasers’ uncertainty about future fuel prices implies that mandating 

improvements in fuel efficiency can reduce the expected utility associated with truck 

purchases. This is because adopting such regulation requires purchasers to assume a 

greater level of risk than they would in its absence, even if the future fuel savings 

predicted by a risk-neutral calculation actually materialize. One commenter expressed 

support for this argument. Thus the mere existence of uncertainty about future savings in 

fuel costs does not by itself assure that regulations requiring improved fuel efficiency will 

necessarily provide economic benefits for truck purchasers and operators. On the other 

hand, because risk aversion reduces expected returns for businesses, competitive 

pressures can reduce risk aversion: risk-neutral companies can make higher average 

profits over time. Thus, significant risk aversion is unlikely to survive competitive 

pressures.

(5) Adjustment and Transactions Costs

Another hypothesis is that transactions costs of changing to new technologies 

(how easily drivers will adapt to the changes, e.g.) may slow or prevent their adoption. 

Because of the diversity in the trucking industry, truck owners and fleets may like to see 

how a new technology works in the field, when applied to their specific operations, 

before they adopt it. One commenter expressed support for this argument. If a 

conservative approach to new technologies leads truck buyers to adopt new technologies 

slowly, then successful new technologies are likely to be adopted over time without 

 

208 Metcalf, G., and D. Rosenthal (1995). “The ‘New’ View of Investment Decisions and Public Policy 

Analysis: An Application to Green Lights and Cold Refrigerators,” Journal of Policy Analysis and 

Management 14: 517–531. Hassett and Metcalf (1995). “Energy Tax Credits and Residential Conservation 

Investment: Evidence from Panel Data” Journal of Public Economics 57 (1995): 201-217. Metcalf, G., and 

K. Hassett (1999). “Measuring the Energy Savings from Home Improvement Investments: Evidence from 

Monthly Billing Data.” The Review of Economics and Statistics 81(3): 516-528.

209 Greene, D., J. German, and M. Delucchi (2009). “Fuel Economy: The Case for Market Failure” in 

Reducing Climate Impacts in the Transportation Sector, Sperling, D., and J. Cannon, eds. Springer Science.

210 Dasgupta, S., S. Siddarth, and J. Silva-Risso (2007). “To Lease or to Buy? A Structural Model of a 

Consumer’s Vehicle and Contract Choice Decisions.” Journal of Marketing Research 44: 490 – 502.
112 of 

market intervention, but with potentially significant delays in achieving fuel saving, 

environment, and energy security benefits.

In addition, there may be costs associated with training drivers to realize the 

potential fuel savings enabled by new technologies, or with accelerating fleet operators’ 

scheduled fleet turnover and replacement to hasten their acquisition of vehicles equipped 

with new fuel-saving technologies. Here, again, there may be no market failure; 

requiring the widespread use of these technologies may impose adjustment and 

transactions costs not included in this analysis. As in the discussion of the role of risk, 

these adjustment and transactions costs are typically immediate and undiscounted, while 

their benefits are future and uncertain; risk or loss aversion may further discourage 

companies from adopting new technologies.

To the extent that there may be transactions costs associated with the new 

technologies, then regulation gives all new truck purchasers a level playing field, because 

it will require all of them to adjust on approximately the same time schedule. If 

experience with the new technologies serves to reduce uncertainty and risk, the industry 

as a whole may become more accepting of new technologies. This could increase 

demand for future new technologies and induce additional benefits in the legacy fleet 

through complementary efforts such as SmartWay.

(6) Additional Hypotheses

In the public comments, two additional ideas were raised for the lack of adoption 

of what appears to be cost-effective fuel-saving technology. The first suggestion is that 

tighter diesel emissions standards caused fuel efficiency for diesel trucks to decline in the 

past decade. Because engine manufacturers would have to invest heavily (both 

financially and with personnel) in emissions reduction technologies, they would not 

invest in fuel efficiency. The costs associated with the decline in fuel efficiency due to 

the emissions regulations were accounted for in that rulemaking. 

A second suggestion is that a truck may be a “positional good” – that is, a good 

whose value depends on how it compares to the goods owned by others. If trucks confer 

status on their owners or operators, and if that status depends on easily observable 

characteristics, then owners may invest disproportionately in status-granting 

characteristics rather than less visible characteristics, such as fuel efficiency. Because 

status depends on comparisons to others, an “arms race” may develop in which all parties 

spend additional money on visible characteristics but may not manage to make 

themselves better off. In this case, regulation may improve welfare: by increasing the 

requirements for non-positional fuel efficiency, regulation could reduce expenditures 

made purely for competition rather than actual increase in welfare. In a competitive 

business, cost reduction provides a major opportunity cost to investing in status rather 

than in fuel-saving technology; thus, this argument may play less of a role in the heavyduty market than in the consumer market for vehicles.

Both these hypotheses leave open the question, though, why additional 

investments were not made in fuel efficiency if they would provide rapid payback. Truck 
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113 of

purchasers should, in principle, be willing to buy additional fuel-saving technology as 

long as it is cost-effective, regardless of other vehicle attributes. Limited access to 

capital, if it is a problem in this sector, might provide some reason for the “crowding out” 

of the purchase of fuel-saving technology. The agencies received no evidence indicating 

that constrained access to capital might explain the efficiency gap in this market.

(7) Summary

On the one hand, commercial vehicle operators are under competitive pressure to 

reduce operating costs, and thus their purchasers would be expected to pursue and rapidly 

adopt cost-effective fuel-saving technologies. On the other hand, the short payback 

period required by buyers of new trucks is a symptom that suggests some combination of 

uncertainty about future cost savings, transactions costs, and imperfectly functioning 

markets. In addition, widespread use of tractor-trailer combinations introduces the 

possibility that owners of trailers may have weaker incentives than truck owners or 

operators to adopt fuel-saving technology for their trailers. The market for medium- and 

heavy-duty trucks may face these problems, both in the new vehicle market and in the 

resale market.

Provision of information about fuel-saving technologies through voluntary

programs such as SmartWay will assist in the adoption of new cost-saving technologies, 

but diffusion of new technologies can still be obstructed. Those who are willing to 

experiment with new technologies expect to find cost savings, but those may be difficult 

to prove. As noted above, because individual results of new technologies vary, new truck 

purchasers may find it difficult to identify or verify the effects of fuel-saving 

technologies. Those who are risk-averse are likely to avoid new technologies out of 

concerns over the possibility of inadequate returns on the investment, or with other 

adverse impacts. Competitive pressures in the freight transport industry can provide a 

strong incentive to reduce fuel consumption and improve environmental performance. 

However, not every driver or trucking fleet operating today has the requisite ability or

interest to access the technical information, some of which is already provided by 

SmartWay, nor the resources necessary to evaluate this information within the context of 

his or her own freight operation.

It is unclear, as discussed above, whether some or many of the technologies 

would be adopted in the absence of the program. To the extent that they would have been 

adopted, the costs and the benefits attributed to those technologies may not in fact be due 

to the program and may therefore be overstated. Both baselines used project substantially

less adoption than the agencies consider to be cost-effective. The agencies will continue 

to explore reasons for this slow adoption of cost-effective technologies.

B. Costs Associated With the Final Program

In this section, the agencies present the estimated costs associated with the final 

program. The presentation here summarizes the costs associated with new technology

expected to be added to meet the new GHG and fuel consumption standards. The 
114 of 

analysis summarized here provides the estimate of incremental costs on a per truck basis 

and on an annual total basis. 

The presentation here summarizes the best estimate by EPA and NHTSA staff as 

to the technology mix expected to be employed for compliance. For details behind the 

cost estimates associated with individual technologies, the reader is directed to Section III 

of this preamble and to Chapter 2 of the RIA. 

With respect to the cost estimates presented here, the agencies note that, because 

these estimates relate to technologies which are in most cases already available, these 

cost estimates are technically robust. 

(1) Costs per Truck

For the heavy-duty pickup trucks and vans, the agencies have used a methodology

consistent with that used for our recent light-duty joint rulemaking since most of the 

technologies expected for heavy-duty pickup trucks and vans is consistent with that 

expected for the larger light-duty trucks. The cost estimates presented in the recent lightduty joint rulemaking were then scaled upward to account for the larger weight, towing 

capacity, and work demands of the trucks in these heavier classes. For details on that 

scaling process and the resultant costs for individual technologies, the reader is directed 

to Section III of this preamble and to Chapter 2 of the RIA. Note also that all cost 

estimates have been updated to 2009 dollars for this analysis while the heavy-duty GHG 

emissions and fuel efficiency proposal was presented in 2008 dollars and the light-duty 

rule was presented in 2007 dollars. 

For the loose heavy-duty gasoline engines, we have generally used engine-related 

costs from the heavy-duty pickup truck and van estimates since the loose heavy-duty 

gasoline engines are essentially the same engines as those sold into the heavy-duty

pickup truck and van market. 

For heavy-duty diesel engines, the agencies have estimated costs using a different 

methodology than that employed in the recent light-duty joint rulemaking. In the lightduty 2012-2016 MY vehicle rule, the fixed costs were included in the hardware costs via 

an indirect cost multiplier. As such, the hardware costs presented in that analysis, and in 

the cost estimates for Class 2b and 3 trucks, included both the actual hardware and the 

associated fixed costs. For this analysis, some of the fixed costs are estimated separately 

for HD diesel engines and are presented separately from the hardware costs. For details, 

the reader is directed to Chapter 2 of the RIA. Importantly, both methodologies after the 

figures are totaled account for all the costs associated with the program. As noted above, 

all costs are presented in 2009 dollars.

The estimates of vehicle compliance costs cover the years leading up to – 2012 

and 2013 – and including implementation of the program – 2014 through 2018. Also 

presented are costs for the years following implementation to shed light on the long term 

(2022 and later) cost impacts of the program. The year 2022 was chosen here consistent 

with the light-duty 2012-2016 MY vehicle rule. That year was considered long term in 
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115 of

that analysis because the short-term and long-term markup factors described shortly

below are applied in five year increments with the 2012 through 2016 implementation 

span and the 2017 through 2021 span both representing the short-term. Since many of 

the costs used in this analysis are based on costs in the light-duty rule analysis, 

consistency with that analysis seems appropriate. 

Some of the individual technology cost estimates are presented in brief in Section 

III, and account for both the direct and indirect costs incurred in the manufacturing and 

dealer industries (for a complete presentation of technology costs, please refer to Chapter 

2 of the RIA). To account for the indirect costs on Class 2b and 3 pickup trucks and 

vans, the agencies have applied an ICM factor to all of the direct costs to arrive at the 

estimated technology cost. The ICM factor used was 1.24 in the short-term (2014 

through 2021) to account for differences in the levels of R&D, tooling, and other indirect 

costs that will be incurred. Once the program has been fully implemented, some of the 

indirect costs will no longer be attributable to these standards and, as such, a lower ICM 

factor is applied to direct costs in 2022 and later. The agencies have also applied ICM 

factors to Class 4 through 8 trucks and to heavy-duty diesel engine technologies. Markup 

factors in these categories range from 1.15 to 1.30 in the short term (2014 through 2021) 

depending on the complexity of the given technology. We have modified the manner in 

which ICMs are applied in that they are no longer applied as a simple multiplicative 

factor on top of the direct manufacturing costs. Instead, we have broken out the warranty

cost portion of the ICM and apply it in a multiplicative manner then add the non-warranty 

cost portion of the ICM to that. The latter portion, that for non-warranty costs, is 

determined for a given year and held constant rather than decreasing year-over-year. 

This new approach, which responds to criticisms from some that the multiplicative 

approach used in the past essentially double counts learning effects, is discussed in 

Section VIII.C and is detailed in Chapter 2 of the RIA. Note that, for the HD diesel 

engines, the agencies have applied the ICMs to ensure that our estimates are conservative 

since we have estimated fixed costs separately for technologies applied to these 

categories -- effectively making the use of markups a double counting of indirect costs. 

For the details on the background and the concept behind our use of ICMs to calculate 

indirect costs, please refer to the report that has been placed in the docket for this final 

action.211

The agencies have also considered the impacts of manufacturer learning on the 

technology cost estimates by reflecting the phenomenon of volume-based learning curve 

cost reductions in our modeling using two algorithms depending on where in the learning 

cycle (i.e., on what portion of the learning curve) we consider a technology to be –

“steep” portion of the curve for newer technologies and “flat” portion of the curve for 

mature technologies. The observed phenomenon in the economic literature which 

supports manufacturer learning cost reductions are based on reductions in costs as 

production volumes increase, and the economic literature suggests these cost reductions 

occur indefinitely, though the absolute magnitude of the cost reductions decrease as 

production volumes increase (with the highest absolute cost reduction occurring with the 

 

211 RTI International. Heavy-duty Truck Retail Price Equivalent and Indirect Cost Multipliers. July 2010.
116 of 

first doubling of production). The agencies use the terminology “steep” and “flat” 

portion of the curve to distinguish among newer technologies and more mature 

technologies, respectively, and how learning cost reductions are applied in cost analyses. 

The steep learning algorithm applies for the early, steep portion of the learning curve and 

is estimated to result in 20 percent lower costs after two full years of implementation (i.e., 

a 2016 MY cost would be 20 percent lower than the 2014 and 2015 model year costs for 

a new technology being implemented in 2014). The flat learning algorithm applies for 

the flatter portion of the learning curve and is estimated to result in 3 percent lower costs 

in each of the five years following first introduction of a mature technology added in 

response to this final action. Once two steep learning steps have occurred (for 

technologies having steep learning applied), flat learning would begin. For technologies 

to which flat learning is applied, learning would begin in year 2 at 3 percent per year for 

5 years. Beyond 5 years of flat learning at 3 percent per year, 5 years of flat learning at 2 

percent per year, then 5 at 1 percent per year become effective. 

Learning impacts have been considered on most but not all of the technologies 

expected to be used because some of the expected technologies are already used rather 

widely in the industry and, presumably, learning impacts have already occurred. The 

agencies have applied the steep learning algorithm for only a handful of technologies 

considered to be new or emerging technologies such as energy recovery systems and 

thermal storage units which might one day be used on big trucks. For most technologies, 

the agencies have considered them to be more established and, hence, the agencies have 

applied the lower flat learning algorithm. For more discussion of the learning approach 

and the technologies to which each type of learning has been applied the reader is 

directed to Chapter 2 of the RIA.

The technology cost estimates discussed in Section III and detailed in Chapter 2 

of the RIA are used to build up technology package cost estimates. For each engine and 

truck class, a single package for each was developed capable of complying with the final 

standards and the costs for each package was generated. The technology packages and 

package costs are discussed in more detail in Chapter 2 of the RIA. The compliance cost 

estimates take into account all credits and trading programs and include costs associated 

with air conditioning controls. Table VIII-1 presents the average incremental costs per 

truck for this final action. For HD pickup trucks and vans (Class 2b and 3), costs 

increase as the standards become more stringent in 2014 through 2018. Following 2018, 

costs then decrease going forward as learning effects result in decreased costs for 

individual technologies. By 2022, the long term ICMs take effect and costs decrease yet 

again. For vocational vehicles, cost trends are more difficult to discern as diesel engines 

begin adding technology in 2014, gasoline engines begin adding technology in 2016, and 

the trucks themselves begin adding technology in 2014. With learning effects the costs, 

in general, decrease each year except for the heavy-duty gasoline engine changes in 2016. 

Long term ICMs take effect in 2022 to provide more cost reductions. For combination 

tractors, costs generally decrease each year due to learning effects with the exception of 

2017 when the engines placed in sleeper cab tractors add turbo compounding. Following 

that, learning impacts result in cost reductions and the long term ICMs take effect in 2022 

for further cost reductions. By 2030 and later, cost–per-truck estimates remain constant 

for all classes. Regarding the long term ICMs taking effect in 2022, the agencies 
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117 of

consider this the point at which some indirect costs decrease or are no longer considered 

attributable to the program (e.g., warranty costs go down). Costs per truck remain 

essentially constant thereafter. 

Table VIII-1: Estimated Cost per Truck (2009 dollars)

HD Pickups & Vans Vocational Combination

2014 $165 $329 $6,019

2015 $215 $320 $5,871

2016 $422 $397 $5,677

2017 $631 $387 $6,413

2018 $1,048 $378 $6,215

2020 $985 $366 $6,004

2030 $977 $311 $5,075

2040 $977 $305 $5,075

2050 $977 $304 $5,075

These costs would, presumably, have some impact on new truck prices, although 

the agencies make no attempt at determining what the impact of increased costs would be 

on new truck prices. Nonetheless, on a percentage basis, the costs shown in Table VIII-1

for 2018 MY trucks (when all final requirements are fully implemented) would be 

roughly three percent for a typical HD pickup truck or van, less than one percent for a 

typical vocational vehicle, and roughly six percent for a typical combination truck/tractor 

using new truck prices of $40,000, $100,000 and $100,000, respectively. The costs 

would represent lower or higher percentages of new truck prices for new trucks with 

higher or lower prices, respectively. Given the wide range of new truck prices in these 

categories—a Class 4 Vocational work truck might be $40,000 when new while a Class 8 

refuse truck (i.e., a large vocational vehicle) might be as much as $200,000 when new—it 

is very difficult to reflect incremental costs as percentages of new truck prices for all 

trucks. What is presented here is the average cost (Table VIII-1) compared with typical 

new truck prices.

As noted above, the fixed costs were estimated separately from the hardware 

costs for HD diesel engines that are placed in vocational vehicles and combination 

tractors. Those fixed costs are not included in Table VIII-1. The agencies have 

estimated the R&D costs at $6.8 million per manufacturer per year for five years and the 

new test cell costs (to accommodate measurement of N2O emissions) at $63,087 per 

manufacturer. The test cell costs of N2O emissions measurement has been adjusted for 

the final rulemaking to reflect comments which stated approximately 75 percent of 

manufacturers would be required to update existing equipment while the other 25 percent 

would require new equipment. These costs apply individually for LHD, MHD and HHD 

engines. Given the 14 manufacturers impacted by the final standards, 11 of which are 

estimated to sell both MHD and HHD engines and 3 of which are estimated to sell LHD 

engines, we have estimated a five year annual R&D cost of $170.3 million dollars (2 x 11 

x $6.8 million plus 3 x $7.75 million for each year 2012-2016) and a one-time test cell 

cost of $1.6 million dollars (2 x 11 x $63,087 plus 3 x $63,087 in 2013). Estimating 
118 of 

annual sales of HD diesel engines at roughly 600,000 units results in roughly $284 per 

engine per year for five years beginning in 2012 and ending in 2016. Again, these costs 

are not reflected in Table VIII-1, but are included in Table VIII-2 as “Other Engineering 

Costs.” 

The certification and compliance program costs, for all engine and truck types, are 

estimated at $6.5 million in the first year dropping to $2.3 million in each year thereafter 

and continuing indefinitely. These costs are detailed in the “Draft Supporting Statement 

for Information Collection Request” which is contained in the docket for this final 

action.212 The costs are higher in the first year due to capital expenses required to comply

with new reporting burdens (facility upgrade costs are included in engineering costs as 

described above). Estimating annual sales of heavy-duty trucks at roughly 1.5 million 

units would result in just over $4 per engine/truck in the first year and less than $2 per 

engine/truck per year thereafter. These costs are not reflected in Table VIII-1, but are 

included in Table VIII-2 below as “Compliance Program” costs. 

(2) Annual Costs of the HD National Program

The costs presented here represent the incremental costs for newly added 

technology to comply with the program. Together with the projected increases in truck 

sales, the increases in per-truck average costs shown in Table VIII-1, above result in the 

total annual costs presented in Table VIII-2 below. Note that the costs presented in Table 

VIII-2 do not include the savings that will occur as a result of the improvements to fuel 

consumption. Those impacts are presented in Section VIII. E. Note also that the costs 

presented here represent costs estimated to occur presuming that the final standards will 

continue in perpetuity. Any changes to the final standards would be considered as part of 

a future rulemaking. In other words, the final standards do not apply only to 2014-2018 

model year trucks - they do, in fact, apply to all 2014 and later model year trucks. We 

present more detail regarding the 2014-2018 model year trucks in Sections VIII.L and M, 

where we summarize all monetized costs and benefits.

 

212 “Draft Supporting Statement for Information Collection Request,” Control of Greenhouse Gas 

Emissions from New Motor Vehicles: Proposed Heavy-Duty Engine and Vehicle Standards, EPA ICR 

Tracking Number 2394.01.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

119 of

Table VIII-2: Annual Costs Associated with the Program ($Millions of 2009 dollars)

Year HD Pickup 

and Vans

Vocational

Vehicles

Combination

Tractors

Other

Engineering

Costs

Compliance 

Program 

Costs

Annual

Costs

2012 $0 $0 $0 $170 $0 $170

2013 $0 $0 $0 $172 $0 $172

2014 $130 $185 $1,078 $170 $6.5 $1,569

2015 $157 $170 $922 $170 $2.3 $1,422

2016 $300 $202 $820 $170 $2.3 $1,495

2017 $447 $198 $951 $0 $2.3 $1,598

2018 $751 $201 $1,000 $0 $2.3 $1,955

2020 $754 $202 $1,001 $0 $2.3 $1,959

2030 $918 $216 $1,076 $0 $2.3 $2,212

2040 $1,024 $281 $1,372 $0 $2.3 $2,679

2050 $1,156 $354 $1,777 $0 $2.3 $3,290

NPV, 3% $17,070 $4,950 $24,487 $793 $52 $47,352

NPV, 7% $8,467 $2,588 $12,855 $724 $30 $24,665

C. Indirect Cost Multipliers

(1) Markup Factors to Estimate Indirect Costs

For all segments in this analysis, indirect costs are estimated by applying indirect 

cost multipliers (ICM) to direct cost estimates. ICMs were calculated by EPA as a basis 

for estimating the impact on indirect costs of individual vehicle technology changes that 

would result from regulatory actions. Separate ICMs were derived for low, medium, and 

high complexity technologies, thus enabling estimates of indirect costs that reflect the 

variation in research, overhead, and other indirect costs that can occur among different 

technologies. ICMs were also applied in the light-duty rule. 

Prior to developing the ICM methodology, EPA and NHTSA both applied a retail 

price equivalent (RPE) factor to estimate indirect costs. RPEs are estimated by dividing 

the total revenue of a manufacturer by the direct manufacturing costs. As such, it 

includes all forms of indirect costs for a manufacturer and assumes that the ratio applies 

equally for all technologies. ICMs are based on RPE estimates that are then modified to 

reflect only those elements of indirect costs that would be expected to change in response 

to a regulatory-induced technology change. For example, warranty costs would be

reflected in both RPE and ICM estimates, while marketing costs might only be reflected 

in an RPE estimate but not an ICM estimate for a particular technology, if the new 

regulatory-induced technology change is not one expected to be marketed to consumers. 

Because ICMs calculated by EPA are for individual technologies, many of which are 

small in scale, they often reflect a subset of RPE costs; as a result, the RPE is typically 

higher than an ICM. This is not always the case, as ICM estimates for complex 

technologies may reflect higher than average indirect costs, with the resulting ICM larger 

than the averaged RPE for the industry. 
120 of 

There is some level of uncertainty surrounding both the ICM and RPE markup 

factors. The ICM estimates used in this final action group all technologies into three 

broad categories and treat them as if individual technologies within each of the three 

categories (low, medium, and high complexity) will have the same ratio of indirect costs 

to direct costs. This simplification means it is likely that the direct cost for some 

technologies within a category will be higher and some lower than the estimate for the 

category in general. More importantly, the ICM estimates have not been validated 

through a direct accounting of actual indirect costs for individual technologies. Rather, 

the ICM estimates were developed using adjustment factors developed in two separate 

occasions: the first, a consensus process, was reported in the RTI report; the second, a 

modified Delphi method, was conducted separately and reported in an EPA memo.213 

Both these panels were composed of EPA staff members with previous background in the 

automobile industry; the memberships of the two panels overlapped but were not the 

same.214 The panels evaluated each element of the industry’s RPE estimates and 

estimated the degree to which those elements would be expected to change in proportion 

to changes in direct manufacturing costs. The method and estimates in the RTI report 

were peer reviewed by three industry experts and subsequently by reviewers for the 

International Journal of Production Economics.215 RPEs themselves are inherently

difficult to estimate because the accounting statements of manufacturers do not neatly

categorize all cost elements as either direct or indirect costs. Hence, each researcher 

developing an RPE estimate must apply a certain amount of judgment to the allocation of 

the costs. Moreover, RPEs for heavy- and medium-duty trucks and for engine 

manufacturers are not as well studied as they are for the light-duty automobile industry. 

Since empirical estimates of ICMs are ultimately derived from the same data used to 

measure RPEs, this affects both measures. However, the value of RPE has not been 

measured for specific technologies, or for groups of specific technologies. Thus applying 

a single average RPE to any given technology by definition overstates costs for very

simple technologies, or understates them for advanced technologies.

In the proposal, we requested comment on our ICM factors and whether it was 

most appropriate to use ICMs or RPEs. We received no comment on the issue 

specifically, other than basic comments that perhaps our ICM factors were low. In 

response, for this final action, we have adjusted our ICM factors such that they are 

slightly higher and, importantly, we have changed the way in which the factors are 

applied. The first change—increased ICM factors—has been done as a result of further 

thought among the EPA and NHTSA team that the ICM factors presented in the original 

 

213 Helfand, Gloria, and Sherwood, Todd. “Documentation of the Development of Indirect Cost Multipliers 

for Three Automotive Technologies.” Memorandum, Assessment and Standards Division, Office of 

Transportation and Air Quality, U.S. Environmental Protection Agency, August 2009.

214 NHTSA staff participated in the development of the process for the second, modified Delphi panel, and 

reviewed the results as they were developed, but did not serve on the panel.

215 The results of the RTI report were published in Alex Rogozhin, Michael Gallaher, Gloria Helfand, and 

Walter McManus, “Using Indirect Cost Multipliers to Estimate the Total Cost of Adding New Technology 

in the Automobile Industry.” International Journal of Production Economics 124 (2010): 360-368.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

121 of

RTI report216 for low and medium complexity technologies should no longer be used and 

that we should rely solely on the modified-Delphi values for these complexity levels.217 

For that reason, we have eliminated the averaging of original RTI values with modifiedDelphi values and instead are relying solely on the modified-Delphi values for low and 

medium complexity technologies. The second change—the way the factors are applied—

results in the warranty portion of the indirect costs being applied as a multiplicative factor 

(thereby decreasing going forward as direct manufacturing costs decrease due to 

learning), and the remainder of the indirect costs being applied as an additive factor 

(thereby remaining constant year-over-year and not being reduced due to learning). This 

second change has a comparatively large impact on the resultant technology costs and, 

we believe, more appropriately estimates costs over time. In addition to these changes, a 

secondary-level change was also made as part of this ICM recalculation to the light-duty

ICMs and, therefore, to the ICMs used in this analysis for heavy-duty pickups and vans. 

That change was to revise upward the RPE level reported in the original RTI report from 

an original value of 1.46 to 1.5 to reflect the long term average RPE. The original RTI 

study was based on 2008 data. However, an analysis of historical RPE data indicates that, 

although there is year to year variation, the average RPE has remained constant at 

roughly 1.5. ICMs will be applied to future year’s data and therefore NHTSA and EPA 

staff believe that it would be appropriate to base ICMs on the historical average rather 

than a single year’s result. Therefore, ICMs were adjusted to reflect this average level 

since the original value excluded net income. As a result, even the High 1 and High 2 

ICMs used for heavy-duty pickups and vans have also changed. These changes to our 

ICMs and the methodology are described in greater detail in Chapter 2 of the final RIA. 

D. Cost per Ton of Emissions Reductions

The agencies have calculated the cost per ton of GHG reductions associated with 

this program on a CO2eq basis using the above costs and the emissions reductions 

described in Sections VI and VII. These values are presented in Table VIII-3 through 

Table VIII-5 for HD pickups & vans, vocational vehicles and combination 

trucks/tractors, respectively. The cost per metric ton of GHG emissions reductions has 

been calculated in the years 2020, 2030, 2040, and 2050 using the annual vehicle 

compliance costs and emission reductions for each of those years. The value in 2050 

represents the long-term cost per ton of the emissions reduced. The agencies have also 

calculated the cost per metric ton of GHG emission reductions including the savings 

associated with reduced fuel consumption (presented below in Section VIII. E. ). This 

latter calculation does not include the other benefits associated with this program such as 

those associated with energy security benefits as discussed later in Section VIII.I. By

including the fuel savings in the cost estimates, the cost per ton is generally less than $0 

since the estimated value of fuel savings outweighs the program costs. The results for 

 

216

 Rogozhin, Alex, Michael Gallaher, and Walter McManus. “Automobile Industry Retail Price 

Equivalent and Indirect Cost Multipliers.” Report prepared for EPA by RTI International. EPA Report 

EPA-420-R-09-003, February 2009.

217 Helfand, Gloria, and Sherwood, Todd. “Documentation of the Development of Indirect Cost Multipliers 

for Three Automotive Technologies.” Memorandum, Assessment and Standards Division, Office of 

Transportation and Air Quality, U.S. Environmental Protection Agency, August 2009.
122 of 

CO2eq costs per ton under the HD National Program across all regulated categories are 

shown in Table VIII-6.

Table VIII-3: Annual Cost per Metric Ton of CO2eq Reduced – HD Pickup Trucks & Vans (2009

dollars)

Year Program 

Cost

Fuel 

Savings 

(post-tax)

CO2eq 

Reduced

Cost per Ton 

(without Fuel 

Savings)

Cost per Ton 

(with Fuel 

Savings)

2020 $800 $1,000 3 $240 -$60

2030 $900 $3,300 10 $90 -$230

2040 $1,000 $4,700 14 $70 -$270

2050 $1,200 $5,900 16 $80 -$300

Table VIII-4: Annual Cost per Metric Ton of CO2eq Reduced – Vocational Vehicles (2009 dollars)218

Year Program 

Cost

Fuel 

Savings 

(post-tax)

CO2eq 

Reduced

Cost per Ton 

(without Fuel 

Savings)

Cost per Ton 

(with Fuel 

Savings)

2020 $200 $1,200 4 $50 -$240

2030 $200 $2,600 9 $20 -$270

2040 $300 $3,800 12 $30 -$300

2050 $400 $5,000 14 $30 -$330

Table VIII-5: Annual Cost per Metric Ton of CO2eq Reduced – Combination Tractors (2009

dollars)219

Year Program 

Cost

Fuel 

Savings 

(post-tax)

CO2eq 

Reduced

Cost per Ton 

(without Fuel 

Savings)

Cost per Ton 

(with Fuel 

Savings)

2020 $1,000 $8,700 32 $30 -$240

2030 $1,100 $17,000 57 $20 -$280

2040 $1,400 $22,100 68 $20 -$300

2050 $1,800 $28,500 78 $20 -$340

 

218 The program costs, fuel savings, and CO2eq reductions of the engines installed in vocational vehicles are 

embedded in the vehicle standards and analysis.

219 The program costs, fuel savings, and CO2eq reductions of the engines installed in tractors are embedded 

in the tractor standards and analysis.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

123 of

Table VIII-6: Annual Cost per Metric Ton of CO2eq Reduced – Final (2009 dollars)

Year Program 

Cost

Fuel 

Savings 

(post-tax)

CO2eq 

Reduced

Cost per Ton 

(without Fuel 

Savings)

Cost per Ton 

(with Fuel 

Savings)

2020 $2,000 $10,900 39 $50 -$230

2030 $2,200 $23,000 76 $30 -$270

2040 $2,700 $30,600 94 $30 -$300

2050 $3,300 $39,500 108 $30 -$340

E. Impacts of Reduction in Fuel Consumption

(1) What are the Projected Changes in Fuel Consumption

The new CO2 standards will result in significant improvements in the fuel 

efficiency of affected trucks. Drivers of those trucks will see corresponding savings 

associated with reduced fuel expenditures. The agencies have estimated the impacts on 

fuel consumption for the tailpipe CO2 standards. To do this, fuel consumption is 

calculated using both current CO2 emission levels and the new CO2 standards. The 

difference between these estimates represents the net savings from the CO2 standards. 

Note that the total number of miles that vehicles are driven each year is different under 

the control case scenario than in the reference case due to the “rebound effect,” which is 

discussed in Section VIII. E. (5) . EPA also notes that drivers who drive more than our 

average estimates for vehicle miles traveled (VMT) will experience more fuel savings; 

drivers who drive less than our average VMT estimates will experience less fuel savings. 

The expected impacts on fuel consumption are shown in Table VIII-7. The 

gallons shown in the tables reflect impacts from the new fuel consumption and CO2

standards and include increased consumption resulting from the rebound effect.
124 of 

Table VIII-7: Fuel Consumption Reductions of the Program (Million gallons)

Year Gasoline Diesel

2014 1 473

2015 3 846

2016 14 1,171

2017 31 1,643

2018 58 2,123

2020 114 2,986

2030 348 5,670

2040 453 7,046

2050 522 8,158

(2) Potential Impacts on Global Fuel Use and Emissions 

EPA’s quantified reductions in fuel consumption focus on the gains from 

reducing fuel used by heavy-duty vehicles within the United States. However, as 

discussed in Section VIII.I, EPA also recognizes that this regulation will lower the world 

price of oil (the “monopsony” effect). Lowering oil prices could lead to an uptick in oil 

consumption globally, leading to a corresponding increase in GHG emissions in other 

countries. This global increase in emissions could slightly offset some of the emission 

reductions achieved domestically as a result of the regulation. 

(3) What are the Monetized Fuel Savings?

Using the fuel consumption estimates presented in Table VIII-7, the agencies can 

calculate the monetized fuel savings associated with the final standards. To do this, 

reduced fuel consumption is multiplied in each year by the corresponding estimated 

average fuel price in that year, using the reference case taken from the AEO 2011. These 

estimates do not account for the significant uncertainty in future fuel prices; the 

monetized fuel savings will be understated if actual fuel prices are higher (or overstated if 

fuel prices are lower) than estimated. AEO is a standard reference used by NHTSA and 

EPA and many other government agencies to estimate the projected price of fuel. This

has been done using both the pre-tax and post-tax fuel prices. Since the post-tax fuel 

prices are the prices paid at fuel pumps, the fuel savings calculated using these prices 

represent the savings consumers would see. The pre-tax fuel savings are those savings 

that society would see. These results are shown in Table VIII-8. Note that in Sections

VIII.L and M, the overall benefits and costs of the rules are presented and, for that 

reason, only the pre-tax fuel savings are presented there.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

125 of

Table VIII-8: Estimated Monetized Fuel Savings ($Millions of 2009 dollars)

Year Fuel Savings 

(pre-tax)

Fuel Savings 

(post-tax)

2014 $1,200 $1,400

2015 $2,200 $2,600

2016 $3,300 $3,800

2017 $4,800 $5,500

2018 $6,400 $7,400

2020 $9,600 $10,900

2030 $20,600 $23,000

2040 $28,000 $30,600

2050 $36,500 $39,500

NPV, 3% $375,300 $415,300

NPV, 7% $166,500 $185,400

As shown in Table VIII-8, the agencies are projecting that truck consumers would 

realize very large fuel savings as a result of the final standards. As discussed further in 

the introductory paragraphs of Section VIII, it is a conundrum from an economic 

perspective that these large fuel savings have not been provided by manufacturers and 

purchased by consumers of these products. Unlike in the light-duty vehicle market, the 

vast majority of vehicles in the medium- and heavy-duty truck market are purchased and 

operated by businesses; for them, fuel costs may represent substantial operating expenses. 

Even in the presence of uncertainty and imperfect information – conditions that hold to 

some degree in every market – we generally expect firms to be cost-minimizing to 

survive in a competitive marketplace and to make decisions that are therefore in the best 

interest of the company and its owners and/or shareholders.

A number of behavioral and market phenomena may lead to a disconnect between 

how businesses account for fuel savings in their decisions and the way in which we 

account for the full stream of fuel savings for these rules, including imperfect information 

in the original and resale markets, split incentives, uncertainty in future fuel prices, and 

adjustment or transactions costs (see Section VIII.A for a more detailed discussion). As 

discussed below in the context of rebound in Section VIII.E.5, the nature of the 

explanation for this gap may influence the actual magnitude of the fuel savings. 

(4) Payback Period and Lifetime Savings on New Truck Purchases

Another factor of interest is the payback period on the purchase of a new truck 

that complies with the new standards. In other words, how long would it take for the 

expected fuel savings to outweigh the increased cost of a new vehicle? For example, a 

new 2018 MY HD pickup truck and van is estimated to cost $1,473 more, a vocational 

vehicle $419 more, and a combination tractor $6,215 more (all values are on average, and 

relative to the reference case vehicle) due to the addition of new GHG reducing 

technology. This new technology will result in lower fuel consumption and, therefore, 
126 of 

savings in fuel expenditures. But how many months or years would pass before the fuel 

savings exceed the upfront costs? Table VIII-9 shows the payback period analysis for 

HD pickup trucks and vans. The table shows fuel consumed under the reference case and 

fuel consumed by a 2018 model year truck under the program, inclusive of fuel 

consumed due to rebound miles. The decrease in fuel consumed under the program is 

then monetized by multiplying by the fuel price reported by AEO (reference case) for 

2018 and later. This value represents the fuel savings expected under the program for a 

HD pickup or van. These savings are then discounted each year since future savings are 

considered to be of less value than current savings. Shown next are estimated increased 

costs (costs do not necessarily reflect increased prices which may be higher or lower than 

costs) for the new truck (refer to Table VIII-1). The next columns of Table VIII-9 show 

the period required for the fuel savings to exceed the new truck costs. As seen in the 

table, in the second year of ownership, the discounted fuel savings (at both 3% and 7% 

discount rates) have begun to outweigh the increased cost of the truck. As shown in the 

table, the full life savings using 3% discounting would be $6,138 and at 7% discounting 

would be $4,459.

Costs in this section, and summarized in Section VIII.L, are shown from the 

greenhouse gas perspective where fuel savings are treated as negative costs, since the 

primary motivations of this program are U.S. energy security and reductions in GHG 

emissions. From that perspective, the benefits of the program are the external effects, 

and the net effects on truck owners and operators are the costs. EPA prefers to account 

for all costs (positive and negative) directly realized by the end user to accurately present 

the total cost and to differentiate those costs and cost savings from more generally 

realized societal benefits. In Section VIII.M, the agencies also present summary tables 

that show the cost and benefit analysis from the fuel efficiency perspective, where the 

purpose of a program to regulate fuel efficiency is primarily to save fuel. From this 

perspective, fuel savings are counted as benefits that occur over the lifetime of the 

vehicle as it consumes less fuel, rather than as negative costs that would be experienced 

either at the time of purchase or over the lifetime of the vehicle. OMB’s Circular A-4, 

which provides guidance to Federal agencies on the development of regulatory analysis, 

makes clear that either approach is acceptable.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

127 of

Table VIII-9: Payback Period for a 2018 Model Year HD Pickup or Van (2009$)

Year of 

Ownership

Reduced Fuel Use 

(gallons)b

Fuel SavingsaIncreased 

Cost

Cumulative Savings

Gasoline Diesel 3% 

Discount 

7% 

Discount

3% 

Discount 

7% 

Discount

1 67 122 $627 $616 -$1,048 -$421 -$433

2 67 122 $617 $583 $196 $151

3 66 120 $600 $546 $796 $696

4 64 117 $570 $499 $1,366 $1,196

5 62 113 $544 $458 $1,910 $1,654

6 59 108 $507 $411 $2,417 $2,065

7 56 102 $474 $370 $2,890 $2,435

Full Life 894 1,617 $7,187 $5,507 -$1,048 $6,138 $4,459

Notes:

a

Fuel savings calculated using the AEO 2011 reference case fuel prices through 2035. Fuel prices beyond 

2035 were extrapolated from an average growth rate for the years 2017 to 2035. Gasoline and diesel fuel 

prices have been weighted by gasoline and diesel fuel reductions estimated for all 2018 MY heavy-duty 

trucks during their lifetimes.

b Gallons under the control case include gallons consumed during rebound driving.

The story is somewhat different for vocational vehicles and combination tractors. 

These cases are shown in Table VIII-10 and Table VIII-11, respectively. Since these 

trucks travel more miles in a given year, their payback periods are shorter and are 

expected to occur within the second year of ownership under both the 3% and 7% 

discounting cases. As can be seen in Table VIII-10 and Table VIII-11, the lifetime fuel 

savings are estimated to be considerable with savings of $5,494 (3%) and $4,268 (7%) 

for the vocational vehicles and $72,875 (3%) and $58,162 (7%) for the combination 

tractors.
128 of 

Table VIII-10: Payback Period for a 2018 Model Year Vocational Vehicle (2009$)

Year of 

Ownership

Reduced Fuel Use 

(gallons)b

Fuel SavingsaIncreased 

Cost

Cumulative Savings

Gasoline Diesel 3% 

Discount 

7% 

Discount

3% 

Discount 

7% 

Discount

1 51 161 $702 $690 -$378 $325 $312

2 47 146 $637 $602 $962 $914

3 44 134 $576 $524 $1,538 $1,438

4 41 122 $516 $452 $2,054 $1,889

5 38 110 $463 $390 $2,516 $2,279

6 34 98 $404 $328 $2,921 $2,607

7 31 87 $359 $280 $3,279 $2,887

Full Life 550 1,458 $5,872 $4,646 -$378 $5,494 $4,268

Notes:

a

Fuel savings calculated using the AEO 2011 reference case fuel prices through 2035. Fuel prices beyond 

2035 were extrapolated from an average growth rate for the years 2017 to 2035. Gasoline and diesel fuel 

prices have been weighted by gasoline and diesel fuel reductions estimated for all 2018 MY heavy-duty 

trucks during their lifetimes.

b Gallons under the control case include gallons consumed during rebound driving.

Table VIII-11: Payback Period for a 2018 Model Year Combination Tractor (2009$)

Year of 

Ownershi

p

Reduced Fuel Use 

(gallons)b

Fuel SavingsaIncrease

d Cost

Cumulative 

Savings

Gasoline Diesel 3% 

Discoun

t 

7% 

Discoun

t

3% 

Discount 

7% 

Discoun

t

1 0 3,223 $10,736 $10,539 -$6,215 $4,522 $4,324

2 0 2,897 $9,619 $9,089 $14,141 $13,413

3 0 2,619 $8,564 $7,790 $22,705 $21,203

4 0 2,359 $7,532 $6,595 $30,237 $27,797

5 0 2,096 $6,626 $5,585 $36,863 $33,382

6 0 1,842 $5,684 $4,611 $42,546 $37,993

7 0 1,617 $4,951 $3,867 $47,497 $41,860

Full Life 0 26,148 $79,089 $64,376 -$6,215 $72,875 $58,162

Notes:

a

Fuel savings calculated using the AEO 2011 reference case fuel prices through 2035. Fuel prices beyond 

2035 were extrapolated from an average growth rate for the years 2017 to 2035. Gasoline and diesel fuel 

prices have been weighted by gasoline and diesel fuel reductions estimated for all 2018 MY heavy-duty 

trucks during their lifetimes.

b Gallons under the control case include gallons consumed during rebound driving.

All of these payback analyses include fuel consumed during rebound VMT in the 

control case but not in the reference case, consistent with other parts of the analysis. 

Further, this analysis does not include other societal impacts such as reduced time spent 

refueling or noise, congestion and accidents since the focus is meant to be on those 

factors buyers think about most while considering a new truck purchase. Note also that 

operators that drive more miles per year than the average would realize greater fuel 

savings than estimated here, and those that drive fewer miles per year would realize 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

129 of

lesser savings. The same holds true for operators that keep their vehicles longer (i.e., 

more years) than average in that they would realize greater lifetime fuel savings than 

operators that keep their vehicles for fewer years than average. Likewise, should fuel 

prices be higher than the AEO 2011 reference case, operators will realize greater fuel 

savings than estimated here while they would realize lesser fuel savings were fuel prices 

to be lower than the AEO 2011 reference case.

(5) Rebound Effect

The VMT rebound effect refers to the fraction of fuel savings expected to result 

from an increase in fuel efficiency that is offset by additional vehicle use. If truck 

shipping costs decrease as a result of lower fuel costs, an increase in truck VMT may

occur. Unlike the light-duty rebound effect, the heavy-duty (HD) rebound effect has not 

been extensively studied. Because the factors influencing the HD rebound effect are 

generally different from those affecting the light-duty rebound effect, much of the 

research on the light-duty rebound effect is not likely to apply to the HD sectors. One of 

the major differences between the HD rebound effect and the light-duty rebound effect is 

that HD vehicles are used primarily for business purposes. Since these businesses are 

profit driven, decision makers are highly likely to be aware of the costs and benefits of 

different shipping decisions, both in the near term and long term. Therefore, shippers are 

much more likely to take into account changes in the overall operating costs per mile 

when making shipping decisions that affect VMT. 

Another difference from the light-duty case is that, as discussed in the recent NAS 

Report220, when calculating the percentage change in trucking costs to determine the 

rebound effect, all changes in the operating costs should be considered. The cost of labor 

and fuel generally constitute the top two shares of truck operating costs, depending on the 

price of petroleum,221, distance traveled, type of truck, and commodity.222 Finally, the 

equipment costs associated with the purchase or lease of the truck is also a significant 

component of total operating costs. Even though vehicle costs are lump-sum purchases, 

they can be considered operating costs for trucking firms, and these costs are, in many

cases, expected to be passed onto the final consumers of shipping services on a variable 

basis. This shipping cost increase could help temper the rebound effect relative to the 

case of light-duty vehicles, in which vehicle costs are not considered an operating cost by

vehicle owners.

When calculating the net change in operating costs, both the increase in new 

vehicle costs and the decrease in fuel costs per mile should be taken into consideration. 

The higher the net cost savings, the higher the expected rebound effect. Conversely, if 

the upfront vehicle costs outweighed future cost savings and total costs increased, 

 

220 See NAS Report, Note Error! Bookmark not defined.216

221 American Transportation Research Institute, An Analysis of the Operational Costs of Trucking, 

December 2008 (Docket ID: EPA-HQ-OAR-2010-0162-0007). 

222 Transport Canada, Operating Cost of Trucks, 2005. See http://www.tc.gc.ca/eng/policy/report-acgoperatingcost2005-2005-e-2-1727.htm, accessed on July 16, 2010 (Docket ID: EPA-HQ-OAR-2010-0162-

0006). See also ATRI, 2008.
130 of 

shipping costs would rise, which would likely result in a decrease in truck VMT. In 

theory, other changes such as maintenance costs and insurance rates would also be taken 

into account, although information on these potential cost changes is extremely limited. 

In the proposal, we invited comments on the most appropriate methodology for factoring 

new vehicle purchase or leasing costs into the per-mile operating costs. We also invited 

comment or data on how these regulations could affect maintenance, insurance, or other 

operating costs. We did not receive any comments on these assumptions.

The following sections describe the factors affecting the rebound effect, different 

methodologies for estimating the rebound effect, and examples of different estimates of 

the rebound effect to date. According to the NAS study, it is “not possible to provide a 

confident measure of the rebound effect,” yet NAS concluded that a rebound effect likely

exists and that “estimates of fuel savings from regulatory standards will be somewhat 

misestimated if the rebound effect is not considered.” While we believe the HD rebound 

effect needs to be studied in more detail, we have attempted to capture the potential 

impact of the rebound effect in our analysis. In the proposal, we solicited data on the 

rebound effect and input on the most appropriate estimates to use for the rebound effect. 

However, we did not receive any new data or substantive comments. Therefore, for this 

final action, we continue to use a rebound effect for vocational vehicles of 15%, a 

rebound effect for HD pickup trucks and vans of 10%, and a rebound effect for 

combination tractors of 5%. These VMT impacts are reflected in the estimates of total 

GHG and other air pollution reductions presented in Chapter 5 of the RIA. 

(a) Factors Affecting the Magnitude of the Rebound Effect

The HD vehicle rebound effect is driven by the interaction of several different 

factors. In the short-run, decreasing the fuel cost per mile of driving could lead to a 

decrease in end product prices. Lower prices could stimulate additional demand for those 

products, which would then result in an increase in VMT. In the long run, shippers could 

reorganize their logistics and distribution networks to take advantage of lower truck 

shipping costs. For example, shippers may shift away from other modes of shipping such 

as rail, barge, or air. In addition, shippers may also choose to reduce the number of 

warehouses, reduce load rates, and make smaller, more frequent shipments, all of which 

could also lead to an increase in HD VMT. Finally, the benefits of the fuel savings could 

ripple through the economy, which could in turn increase overall demand for goods and 

services shipped by trucks, and therefore increase HD VMT. 

Conversely, if a fuel efficiency regulation leads to net increases in the cost of 

trucking because fuel savings do not fully offset the increase in upfront vehicle costs, 

then the price of trucking services could rise, spurring a decrease in HD VMT and a shift 

to alternative shipping modes. These effects would also ripple through the economy. 

(b) Options for Quantifying the Rebound Effect

As described in the previous section, the fuel efficiency rebound effect for HD 

vehicles has not been studied as extensively as the rebound effect for light-duty vehicles, 

and virtually no research has been conducted on the HD pickup truck and van rebound 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

131 of

effect. In the proposal, we discussed four options for quantifying the rebound effect and 

requested comments. We did not receive any substantive comments on the described 

methodologies. 

(i) Aggregate Estimates

The aggregate approximation approach quantifies the overall change in truck 

VMT as a result of a percentage change in freight rates. It is important to note that most 

of the aggregate estimates measure the change in freight demanded (tons or ton-miles), 

rather than a change in fuel consumption or VMT. The change in tons or ton-miles is 

more accurately characterized as a freight elasticity. Therefore, it may not be entirely 

appropriate to interpret these freight elasticities as measures of the rebound effect, 

although these terms are sometimes used interchangeably in the literature.223 Given these 

caveats, freight elasticity estimates rely on estimates of aggregate price elasticity of 

demand for trucking services, given a percentage change in trucking prices, which is 

generally referred to as an “own-price elasticity.” Estimates of trucking own-price 

elasticities vary widely from positive 1.72 to negative 7.92), and there is no general 

consensus on the most appropriate values to use, though a 2004 literature survey found 

aggregate elasticity estimates generally fall in the range of -0.5 to -1.5.224 In other words, 

given an own-price elasticity of -1.5, a 10% decrease in trucking prices leads to a 15% 

increase in truck shipping demand. 

Another challenge of estimating the rebound effect using freight elasticities is that 

these values appear to vary substantially based on the demand elasticity measure (e.g., 

ton or ton-mile), the model specification (e.g., linear functional form or log linear), the 

length of the trip, and the type of cargo. In general, elasticity estimates of longer trips 

tend to be larger than elasticity estimates for shorter trips. In addition, elasticities tend to 

be larger for lower-value commodities compared to higher-value commodities. Although 

these factors explain some of the differences in estimates, much of the observed variation 

cannot be explained quantitatively. For example, a recent study that controlled for these 

variables only accounted for about half of the observed variation.225 

Another important variable influencing freight elasticity estimates is whether 

potential mode shifting is taken into account. Although the total demand for freight 

transport is generally determined by economic activity, there is often the choice of 

shipping freight on modes other than truck. This is because the United States has 

extensive rail, waterway and air transport networks in addition to an extensive highway

network; these networks closely parallel each other and are often both viable choices for 

freight transport for long-distance routes within the continent. If rates go down for one 

mode, there will be an increase in demand for that mode and some demand will be shifted 

 

223 Memo from Energy and Environmental Research Associates, LLC Regarding HDV Rebound Effect, 

dated June 8, 2011.

224 Graham and Glaister, “Road Traffic Demand Elasticity Estimates: A Review,” Transport Reviews 

Volume 24, 3, pp. 261-274, 2004 (Docket ID: EPA-HQ-OAR-2010-0162-0005). 

225 Li, Z., D.A. Hensher, and J.M. Rose, Identifying sources of systematic variation in direct price 

elasticities from revealed preference studies of inter-city freight demand. Transport Policy, 2011.
132 of 

from other modes. This “cross-price elasticity” is a measure of the percentage change in 

demand for shipping by another mode (e.g., rail) given a percentage change in the price 

of trucking. Aggregate estimates of cross-price elasticities also vary widely, and there is 

no general consensus on the most appropriate value to use for analytical purposes. The 

NAS report cites values ranging from 0.35 to 0.59.226 Other reports provide significantly

different cross-price elasticities, ranging from 0.1227 to 2.0.228 

When considering intermodal shift, the most relevant kinds of shipments are those 

that are competitive between rail and truck modes. These trips generally include longhaul shipments greater than 500 miles, which weigh between 50,000 and 80,000 pounds 

(the legal road limit in many states). Special kinds of cargo like coal and short-haul 

deliveries are of less interest because they are generally not economically transferable 

between truck and rail modes, and they would not be expected to shift modes except 

under an extreme price change. However, the total amount of freight that could 

potentially be subject to mode shifting has also not been studied extensively. 

(ii) Sector-Specific Estimates

Given the limited data available regarding the HD rebound effect, the aggregate 

approach greatly simplifies many of the assumptions associated with calculations of the 

rebound effect. In reality, however, responses to changes in fuel efficiency and new 

vehicle costs will vary significantly based on the commodities affected. A detailed, 

sector-specific approach would be expected to more accurately reflect changes in the 

trucking market in response to the standards in this program. For example, input-output 

tables could be used to determine the trucking cost share of the total delivered price of a 

commodity. Using the change in trucking prices described in the aggregate approach, the 

product-specific demand elasticities could be used to calculate the change in sales and 

shipments for each product. The change in shipment increases could then be weighted by 

the share of the trucking industry total, and then summed to get the total increase in 

trucking output. A simplifying assumption could then be made that the increase in output 

results in an increase in VMT. To the best of our knowledge, this type of data has not yet 

been collected. We did not receive any new information in response to our request for 

comments in the proposal, therefore we were unable to use this methodology for 

estimating the rebound effect for this final action. 

(iii) Econometric Estimates 

Similar to the methodology used to estimate the light-duty rebound effect, the HD 

rebound effect could be modeled econometrically by estimating truck demand as a 

 

226 See 2010 NAS Report, Note Error! Bookmark not defined.216. See also 2009 Cambridge 

Systematics, Inc., Draft Final Paper commissioned by the NAS in support of the medium-duty and heavyduty report. Assessment of Fuel Economy Technologies for Medium and Heavy-duty Vehicles: 

Commissioned Paper on Indirect Costs and Alternative Approaches Docket ID: EPA-HQ-OAR-2010-0162-

0009). 

227 Friedlaender, A. and Spady, R. (1980) A derived demand function for freight transportation, Review of

Economics and Statistics, 62, pp. 432–441 (Docket ID: EPA-HQ-OAR-2010-0162-0004).

228 Christidis and Leduc, “Longer and Heavier Vehicles for freight transport,” European Commission Joint 

Research Center’s Institute for Prospective Technology Studies, 2009 (Docket ID: EPA-HQ-OAR-2010-

0162-0010). 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

133 of

function of economic activity (e.g., GDP) and different input prices (e.g., vehicle prices, 

driver wages, and fuel costs per mile). This type of econometric model could be 

estimated for either truck VMT or ton-miles as a measure of demand. The resulting 

elasticity estimates could then be used to determine the change in trucking demand, given 

the change in fuel cost and truck prices per mile from these standards. One of the 

challenges associated with an econometric analysis is the potential for omitted variable 

bias, which could either overstate or understate the potential rebound effect if the omitted 

variable is correlated with the controlled variables.

(iv) Other Modeling Approaches

Regulation of the heavy-duty industry has been studied in more detail in Europe, 

as the European Commission (EC) has considered allowing longer and heavier trucks for 

freight transport. Part of the analysis considered by the EC relies on country-specific 

modeling of changes in the freight sector that would result from changes in regulations.229 

This approach attempts to explicitly calculate modal shift decisions and impacts on GHG 

emissions. Although similar types of analysis have not been conducted extensively in the 

United States, research is currently underway that explores the potential for intermodal 

shifting in the United States. For example, Winebrake and Corbett have developed the 

Geospatial Intermodal Freight Transportation model, which evaluates the potential for 

GHG emissions reductions based on mode shifting, given existing limitations of 

infrastructure and other route characteristics in the United States. 230 This model 

connects multiple road, rail, and waterway transportation networks and embeds activitybased calculations in the model. Within this intermodal network, the model assigns 

various economic, time-of-delivery, energy, and environmental attributes to real-world 

goods movement routes. The model can then calculate different network optimization 

scenarios, based on changes in prices and policies.231 However, more work is needed in 

this area to determine whether this type of methodology is appropriate for the purposes of 

capturing the rebound effect. Therefore, we have not been able to use this methodology

for estimating the rebound effect for this final action. 

(c) Estimates of the Rebound Effect

The aggregate methodology was used by Cambridge Systematics, Inc. (CSI) to 

show several examples of the magnitude of the rebound effect. 232 In their paper 

commissioned by the NAS in support of the recent HD report, CSI calculated an effective 

 

229 Christidis and Leduc, “Longer and Heavier Vehicles for freight transport,” European Commission Joint 

Research Center’s Institute for Prospective Technology Studies, 2009. 

230 Winebrake, James and Corbett, James J. (2010). “Improving the Energy Efficiency and Environmental 

Performance of Goods Movement,” in Sperling, Daniel and James S. Cannon (2010) Climate and 

Transportation Solutions: Findings from the 2009 Asilomar Conference on Transportation and Energy 

Policy. See http://www.its.ucdavis.edu/events/2009book/Chapter13.pdf (Docket ID: EPA-HQ-OAR2010-0162-0011)

231 Winebrake, J. J.; Corbett, J. J.; Falzarano, A.; Hawker, J. S.; Korfmacher, K.; Ketha, S.; Zilora, S., 

Assessing Energy, Environmental, and Economic Tradeoffs in Intermodal Freight Transportation, Journal 

of the Air & Waste Management Association, 58(8), 2008 (Docket ID: EPA-HQ-OAR-2010-0162-0008).

232 Cambridge Systematics, Inc., 2009. 
134 of 

rebound effect for two different technology cost and fuel savings scenarios associated 

with an example Class 8 truck. Scenario 1 increased average fuel economy from 5.59 

mpg to 6.8 mpg, with an additional cost of $22,930. Scenario 2 increased the average 

fuel economy to 9.1 mpg, at an incremental cost of $71,630 per vehicle. The CSI

examples provided estimates using a range of own-price elasticities (-0.5 to -1.5) and 

cross-price elasticities (0.35 to 0.59) from the literature. Based on these two scenarios 

and a number of simplifying assumptions to aid the calculations, CSI found a rebound 

effect of 11-31% for Scenario 1 and 5-16% for Scenario 2 when the fuel savings from 

reduced rail usage were not taken into account (“First rebound effect”). When the fuel 

savings from reduced rail usage were included in the calculations, the overall rebound 

effect was between 9-13% for Scenario 1 and 3-15% for Scenario 2 (“Second Rebound 

Effect”). See Table VIII-12.

CSI included a number of caveats associated with these calculations. Namely, the 

elasticity estimates derived from the literature are “heavily reliant on factors including the 

type of demand measures analyzed (vehicle-miles of travel, ton-miles, or tons), analysis 

geography, trip lengths, markets served, and commodities transported.” Furthermore, the 

CSI example only focused on Class 8 combination tractors and did not attempt to 

quantify the potential rebound effect for any other truck classes. Finally, these scenarios 

were characterized as “sketches” and were not included in the final NAS report. In fact, 

the NAS report asserted that it is “not possible to provide a confident measure of the 

rebound effect,” yet concluded that a rebound effect likely exists and that “estimates of 

fuel savings from regulatory standards will be somewhat misestimated if the rebound 

effect is not considered.” 

Table VIII-12: Range of Rebound Effect Estimates from Cambridge Systematics Aggregate 

Assessment

Scenario 1 

(6.8 mpg, $22,930)

Scenario 2

(9.1 mpg, $71,630)

“First Rebound Effect” (increase in truck 

VMT resulting from decrease in 

operating costs)

11-31% 5-16%

“Second Rebound Effect” (net fuel 

savings when decreases from rail are 

taken into account)

9-13 % 3-15%

As an alternative, using the econometric approach, NHTSA has estimated the 

rebound effect in the short run and long run for single unit (Class 4-7) and (Class 8) 

combination tractors. As shown in Table VIII-13:, the estimates for the long-run rebound 

effect are larger than the estimates in the short run, which is consistent with the theory

that shippers have more flexibility to change their behavior (e.g., restructure contracts or 

logistics) when they are given more time. In addition, the estimates derived from the 

national data also showed larger rebound effects compared to the state data.233 One 

 

233 NHTSA’s estimates of the rebound effect are derived from econometric analysis of national and state 

VMT data reported in Federal Highway Administration, Highway Statistics, various editions, Tables VM-1 

and VM-4. Specifically, the estimates of the rebound effect reported in Table VIII-10 are ranges of the 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

135 of

possible explanation for the difference in the estimates is that the national rebound 

estimates are capturing some of the impacts of changes in economic activity. 

Historically, large increases in fuel prices are highly correlated with economic 

downturns, and there may not be enough variation in the national data to differentiate the 

impact of fuel price changes from changes in economic activity. In contrast, some states 

may see an increase in output when energy prices increase (e.g., large oil producing states 

such as Texas and Alaska); therefore, the state data may be more accurately isolating the 

individual impact of fuel price changes.

Table VIII-13: Range of Rebound Effect Estimates from NHTSA Econometric Analysis

Truck Type National Data State Data

Short Run Long Run Short Run Long Run

Single Unit 13-22% 28-45% 3-8% 12-21%

Combination N/A 12-14% N/A 4-5%

As discussed throughout this section, there are multiple methodologies for 

quantifying the rebound effect, and these different methodologies produce a large range 

of potential values of the rebound effect. However, for the purposes of quantifying the 

rebound effect for this program, we have used a rebound effect with respect to changes in 

fuel costs per mile on the lower range of the long-run estimates. Given the fact that the 

long-run state estimates are generally more consistent with the aggregate estimates, for 

this program we have chosen a rebound effect for vocational vehicles (single unit trucks) 

of 15% that is within the range of estimates from both methodologies. Similarly, we 

have chosen a rebound effect for combination tractors of 5%. 

To date, no estimates of the HD pickup truck and van rebound effect have been 

cited in the literature. Since these vehicles are used for very different purposes than 

heavy-duty vehicles, it does not necessarily seem appropriate to apply one of the heavyduty estimates to the HD pickup trucks and vans. These vehicles are more similar in use 

to large light-duty vehicles, so for the purposes of our analysis, we have chosen to apply

the light-duty rebound effect of 10% to this class of vehicles. 

For the purposes of this program, we have not taken into account any potential 

fuel savings or GHG emission reductions from the rail sector due to mode shifting. We 

requested comments on this assumption in the proposal, but we did not receive any new 

data or input. 

 

estimated short-run and long-run elasticities of annual VMT by single-unit and combination trucks with 

respect to fuel cost per mile driven. (Fuel cost per mile driven during each year is equal to average fuel 

price per gallon during that year divided by average fuel economy of the truck fleet during that same year.) 

These estimates are derived from time-series regression of annual national aggregate VMT for the period 

1970-2008 on measures of nationwide economic activity, including aggregate GDP, the value of durable 

and nondurable goods production, and the volume of U.S. exports and imports of goods, and variables 

affecting the price of trucking services (driver wage rates, truck purchase prices, and fuel costs), and from 

regression of VMT for each individual state over the period 1994-2008 on similar variables measured at the 

state level.
136 of 

Furthermore, we have made a number of simplifying assumptions in our 

calculations, which are discussed in more detail in the RIA. Specifically, we have not 

attempted to capture how current market failures might impact the rebound effect. The 

direction and magnitude of the rebound effect in the HD market are expected to vary

depending on the existence and types of market failures affecting the fuel efficiency of 

the trucking fleet. If firms are already accurately accounting for the costs and benefits of 

these technologies and fuel savings, then these regulations would increase their net costs, 

because trucks would already include all the cost-effective technologies. As a result, the 

rebound effect would actually be negative and truck VMT would decrease as a result of 

these final regulations. However, if firms are not optimizing their behavior today due to 

factors such as lack of reliable information (see Section VIII.A. for further discussion), it 

is more likely that truck VMT would increase. If firms recognize their lower net costs as 

a result of these regulations and pass those costs along to their customers, then the 

rebound effect would increase truck VMT. This response assumes that trucking rates 

include both truck purchase costs and fuel costs, and that the truck purchase costs 

included in the rates spread those costs over the full expected lifetime of the trucks. If 

those costs are spread over a shorter period, as the expected short payback period implies, 

then those purchase costs will inhibit reduction of freight rates, and the rebound effect 

will be smaller. 

As discussed in more detail in Section VIII.A, if there are market failures such as 

split incentives, estimating the rebound effect may depend on the nature of the failures. 

For example, if the original purchaser cannot fully recoup the higher upfront costs 

through fuel savings before selling the vehicle nor pass those costs onto the resale buyer, 

the firm would be expected to raise shipping rates. A firm purchasing the truck secondhand might lower shipping rates if the firm recognizes the cost savings after operating the 

vehicle, leading to an increase in VMT. Similarly, if there are split incentives and the 

vehicle buyer isn’t the same entity that purchases the fuel, than there would theoretically 

be a positive rebound effect. In this scenario, fuel savings would lower the net costs to 

the fuel purchaser, which would result in a larger increase in truck VMT. 

If all of these scenarios occur in the marketplace, the net effect will depend on the 

extent and magnitude of their relative effects, which are also likely to vary across truck 

classes (for instance, split incentives may be a much larger problem for Class 7 and 8 

tractors than they are for HD pickup trucks). Additional details on the rebound effect are 

included in the RIA. 

F. Class Shifting and Fleet Turnover Impacts

The agencies considered two additional potential indirect costs, benefits, effects, 

and externalities which may lead to unintended consequences of the program to improve

the fuel efficiency and reduce GHG emissions from HD trucks. The next sections cover 

the agencies’ qualitative discussions on potential class shifting and fleet turnover effects.

(1) Class Shifting

Heavy-duty vehicles are typically configured and purchased to perform a 

function. For example, a concrete mixer truck is purchased to transport concrete, a 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

137 of

combination tractor is purchased to move freight with the use of a trailer, and a Class 3 

pickup truck could be purchased by a landscape company to pull a trailer carrying 

lawnmowers. The purchaser makes decisions based on many attributes of the vehicle, 

including the gross vehicle weight rating of the vehicle which in part determines the 

amount of freight or equipment that can be carried. If the final HD National Program 

impacts either the performance of the vehicle or the marginal cost of the vehicle relative 

to the other vehicle classes, then consumers may choose to purchase a different vehicle, 

resulting in the unintended consequence of increased fuel consumption and GHG 

emissions in-use.

The agencies, along with the NAS panel, found that there is little or no literature 

which evaluates class shifting between trucks.234 NHTSA and EPA qualitatively

evaluated the final rules in light of potential class shifting. The agencies looked at four 

potential cases of shifting: - from light-duty pickup trucks to heavy-duty pickup trucks; 

from sleeper cabs to day cabs; from combination tractors to vocational vehicles; and 

within vocational vehicles.

Light-duty pickup trucks, those with a GVWR of less than 8,500 pounds, are 

currently regulated under the existing CAFE program and will meet GHG emissions 

standards beginning in 2012. The increased stringency of the light-duty 2012-2016 MY 

vehicle rule has led some to speculate that vehicle consumers may choose to purchase 

heavy-duty pickup trucks that are currently unregulated if the cost of the light-duty

regulation is high relative to the cost to buy the larger heavy-duty pickup trucks. Since 

fuel consumption and GHG emissions rise significantly with vehicle mass, a shift from 

light-duty trucks to heavy-duty trucks would likely lead to higher fuel consumption and 

GHG emissions, an untended consequence of the regulations. Given the significant price 

premium of a heavy-duty truck (often five to ten thousand dollars more than a light-duty 

pickup), we believe that such a class shift would be unlikely even absent this program. 

With these final regulations, any incentive for such a class shift is significantly

diminished. The final regulations for the HD pickup trucks, and similarly for vans, are 

based on similar technologies and therefore reflect a similar expected increase in cost 

when compared to the light-duty GHG regulation. Hence, the combination of the two 

regulations provides little incentive for a shift from light-duty trucks to HD trucks. To 

the extent that our final regulation of heavy-duty pickups and vans could conceivably 

encourage a class shift towards lighter pickups, this unintended consequence would in 

fact be expected to lead to lower fuel consumption and GHG emissions as the smaller 

light-duty pickups are significantly more efficient than heavy-duty pickup trucks.

The projected cost increases for this final action differ significantly between Class 

8 day cabs and Class 8 sleeper cabs, reflecting our expectation that compliance with the 

final standards will lead truck consumers to specify sleeper cabs equipped with APUs 

while day cab consumers will not. Since Class 8 day cab and sleeper cab trucks perform 

essentially the same function when hauling a trailer, this raises the possibility that the 

higher cost for an APU equipped sleeper cab could lead to a shift from sleeper cab to day

 

234 See 2010 NAS Report, Note Error! Bookmark not defined.216, page 152.
138 of 

cab trucks. We do not believe that such an intended consequence will occur for the 

following reasons. The addition of a sleeper berth to a tractor cab is not a consumerselectable attribute in quite the same way as other vehicle features. The sleeper cab 

provides a utility that long-distance trucking fleets need to conduct their operations -- an 

on-board sleeping berth that lets a driver comply with federally-mandated rest periods, as 

required by the Department of Transportation Federal Motor Carrier Safety 

Administration's hours-of-service regulations. The cost of sleeper trucks is already 

higher than the cost of day cabs, yet the fleets that need this utility purchase them.235 A 

day cab simply cannot provide this utility. The need for this utility would not be changed 

even if the marginal costs to reduce greenhouse gas emissions from sleeper cabs exceed 

the marginal costs to reduce greenhouse gas emissions from day cabs.236 A trucking fleet 

could decide to put its drivers in hotels in lieu of using sleeper berths, and switch to day

cabs. However, this is unlikely to occur in any great number, since the added cost for the 

hotel stays would far overwhelm differences in the marginal cost between day and 

sleeper cabs. Even if some fleets do opt to buy hotel rooms and switch to day cabs, they

would be highly unlikely to purchase a day cab that was aerodynamically worse than the 

sleeper cab they replaced, since the need for features optimized for long-distance hauling 

would not have changed. So in practice, there would likely be little difference to the 

environment for any switching that might occur. Further, while our projected costs 

assume the purchase of an APU for compliance, in fact our regulatory structure would 

allow compliance using a near zero cost software utility that eliminates tractor idling after 

five minutes. Using this compliance approach, the cost difference between a Class 8 

sleeper cab and day cab due to our final regulations is small. We are providing this 

alternative compliance approach reflecting that some sleeper cabs are used in team 

driving situations where one driver sleeps while the other drives. In that situation, an 

APU is unnecessary since the tractor is continually being driven when occupied. When it 

is parked, it will automatically eliminate any additional idling through the shutdown 

software. If trucking companies choose this option, then costs based on purchase of 

APUs may overestimate the costs of this program to this sector.

Class shifting from combination tractors to vocational vehicles may occur if a 

customer deems the additional marginal cost of tractors due to the regulation to be greater 

than the utility provided by the tractor. The agencies initially considered this issue when 

deciding whether to include Class 7 tractors with the Class 8 tractors or regulate them as 

vocational vehicles. The agencies’ evaluation of the combined vehicle weight rating of 

the Class 7 shows that if these vehicles were treated significantly differently from the 

Class 8 tractors, then they could be easily substituted for Class 8 tractors. Therefore, the 

agencies are finalizing to include both classes in the tractor category. The agencies 

believe that a shift from tractors to vocational vehicles would be limited because of the 

ability of tractors to pick up and drop off trailers at locations which cannot be done by

vocational vehicles.

 

235 A baseline tractor price of a new day cab is $89,500 versus $113,000 for a new sleeper cab based on 

information gathered by ICF in the “Investigation of Costs for Strategies to Reduce Greenhouse Gas 

Emissions for Heavy-Duty On-Road Vehicles”, July 2010. Page 3. Docket Identification Number EPAHQ-OAR-2010-0162-0044.

236 The average marginal cost difference between sleeper cabs and day cabs in the proposal is nearly 

$6,000.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

139 of

The agencies do not envision that the final regulatory program will cause class 

shifting within the vocational class. The marginal cost difference due to the regulation of 

vocational vehicles is minimal. The cost of LRR tires on a per tire basis is the same for 

all vocational vehicles so the only difference in marginal cost of the vehicles is due to the 

number of axles. The agencies believe that the utility gained from the additional load 

carrying capability of the additional axle will outweigh the additional cost for heavier 

vehicles.237

In conclusion, NHTSA and EPA believe that the final regulatory structure for HD 

trucks does not significantly change the current competitive and market factors that 

determine purchaser preferences among truck types. Furthermore, even if a small amount 

of shifting does occur, any resulting GHG impacts are likely to be negligible because any 

vehicle class that sees an uptick in sales is also being regulated for fuel efficiency. 

Therefore, the agencies did not include an impact of class shifting on the vehicle 

populations used to assess the benefits of the program. 

(2) Fleet Turnover Effect

A regulation that increases the cost to purchase and/or operate trucks could impact 

whether a consumer decides to purchase a new truck and the timing of that purchase. 

The term pre-buy refers to the idea that truck purchases may occur earlier than otherwise 

planned to avoid the additional costs associated with a new regulatory requirement. 

Slower fleet turnover, or low-buys, may occur when owners opt to keep their existing 

truck rather than purchase a new truck due to the incremental cost of the regulation. 

The NAS panel discusses the topics associated with HD truck fleet turnover. 

NAS noted that there is some empirical evidence of pre-buy behavior in response to the 

2004 and 2007 heavy-duty engine emission standards, with larger impacts occurring in 

response to higher costs.238 However, those regulations increased upfront costs to firms 

without any offsetting future cost savings from reduced fuel purchases. In summary, NAS 

stated that

...during periods of stable or growing demand in the freight sector, prebuy behavior may have significant impact on purchase patterns, especially

for larger fleets with better access to capital and financing. Under these 

same conditions, smaller operators may simply elect to keep their current 

equipment on the road longer, all the more likely given continued 

improvements in diesel engine durability over time. On the other hand, to 

the extent that fuel economy improvements can offset incremental 

purchase costs, these impacts will be lessened. Nevertheless, when it 

 

237 The final rule projects the difference in costs between the HHD and MHD vocational vehicle 

technologies is approximately $30.

238 See NAS Report, Note Error! Bookmark not defined.216, pp. 150-151
140 of 

comes to efficiency investments, most heavy-duty fleet operators require 

relatively quick payback periods, on the order of two to three years.239 

The final regulations are projected to return fuel savings to the truck owners that 

offset the cost of the regulation within a few years for vocational vehicles and Class 7 and 

8 tractors, the categories where the potential for prebuy and delayed fleet turnover are 

concerns. In the case of vocational vehicles, the added cost is small enough that it is 

unlikely to have a substantial effect on purchasing behavior. In the case of Class 7 and 8 

trucks, the effects of the regulation on purchasing behavior will depend on the nature of 

the market failures and the extent to which firms consider the projected future fuel 

savings in their purchasing decisions. 

If trucking firms account for the rapid payback, they are unlikely to strategically 

accelerate or delay their purchase plans at additional cost in capital to avoid a regulation 

that will lower their overall operating costs. As discussed in Section VIII.A, this scenario 

may occur if this final program reduces uncertainty about fuel-saving technologies. More 

reliable information about ways to reduce fuel consumption allows truck purchasers to 

evaluate better the benefits and costs of additional fuel savings, primarily in the original 

vehicle market, but possibly in the resale market as well. 

Other market failures may leave open the possibility of some pre-buy or delayed 

purchasing behavior. Firms may not consider the full value of the future fuel savings for 

several reasons. For instance, truck purchasers may not want to invest in fuel efficiency

because of uncertainty about fuel prices. Another explanation is that the resale market 

may not fully recognize the value of fuel savings, due to lack of trust of new technologies 

or changes in the uses of the vehicles. Lack of coordination (also called split 

incentives—see Section VIII.A) between truck purchasers (who emphasize the up-front 

costs of the trucks) and truck operators, who would like the fuel savings, can also lead to 

pre-buy or delayed purchasing behavior. If these market failures prevent firms from fully

internalizing fuel savings when deciding on vehicle purchases, then pre-buy and delayed 

purchase could occur and could result in a slight decrease in the GHG benefits of the 

regulation. 

Thus, whether pre-buy or delayed purchase is likely to play a significant role in 

the truck market depends on the specific behaviors of purchasers in that market. Without 

additional information about which scenario is more likely to be prevalent, the Agencies 

are not projecting a change in fleet turnover characteristics due to this regulation. 

G. Benefits of Reducing CO2 Emissions

(1) Social Cost of Carbon

EPA has assigned a dollar value to reductions in CO2 emissions using recent 

estimates of the social cost of carbon (SCC). The SCC is an estimate of the monetized 

damages associated with an incremental increase in carbon emissions in a given year. It

is intended to include (but is not limited to) changes in net agricultural productivity, 

 

239 See NAS Report, Note Error! Bookmark not defined.216, page 151.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

141 of

human health, property damages from increased flood risk, and the value of ecosystem 

services due to climate change. The SCC estimates used in this analysis were developed 

through an interagency process that included EPA, DOT/NHTSA, and other executive 

branch entities, and concluded in February 2010. We first used these SCC estimates in 

the benefits analysis for the light-duty 2012-2016 MYvehicle rule; see that rule’s 

preamble for a discussion of application of the SCC.

240

 The SCC Technical Support 

Document (SCC TSD) provides a complete discussion of the methods used to develop 

these SCC estimates.241

The interagency group selected four SCC values for use in regulatory analyses, 

which we have applied in this analysis: $5, $22, $36, and $67 per metric ton of CO2

emissions in 2010, in 2009 dollars.242,243 The first three values are based on the average 

SCC from three integrated assessment models, at discount rates of 5, 3, and 2.5 percent, 

respectively. SCCs at several discount rates are included because the literature shows 

that the SCC is quite sensitive to assumptions about the discount rate, and because no 

consensus exists on the appropriate rate to use in an intergenerational context. The fourth 

value is the 95th percentile of the SCC from all three models at a 3 percent discount rate. 

It is included to represent higher-than-expected impacts from temperature change further 

out in the tails of the SCC distribution. Low probability, high impact events are 

incorporated into all of the SCC values through explicit consideration of their effects in 

two of the three models as well as the use of a probability density function for 

equilibrium climate sensitivity. Treating climate sensitivity probabilistically results in 

more high temperature outcomes, which in turn lead to higher projections of damages.

The SCC increases over time because future emissions are expected to produce 

larger incremental damages as physical and economic systems become more stressed in 

response to greater climatic change. Note that the interagency group estimated the 

growth rate of the SCC directly using the three integrated assessment models rather than 

assuming a constant annual growth rate. This helps to ensure that the estimates are 

internally consistent with other modeling assumptions. Table VIII-14 presents the SCC 

estimates used in this analysis.

 

240 See 2010 Light-DutyFinal Rule, Note 7, docket ID EPA-HQ-OAR-2009-0472-11424.

241 Docket ID EPA-HQ-OAR-2009-0472-114577, Technical Support Document: Social Cost of Carbon for 

Regulatory Impact Analysis Under Executive Order 12866, Interagency Working Group on Social Cost of 

Carbon, with participation by Council of Economic Advisers, Council on Environmental Quality, 

Department of Agriculture, Department of Commerce, Department of Energy, Department of 

Transportation, Environmental Protection Agency, National Economic Council, Office of Energy and 

Climate Change, Office of Management and Budget, Office of Science and Technology Policy, and 

Department of Treasury (February 2010). Also available at http://epa.gov/otaq/climate/regulations.htm

242 The interagency group decided that these estimates apply only to CO2 emissions. Given that warming 

profiles and impacts other than temperature change (e.g., ocean acidification) vary across GHGs, the group 

concluded “transforming gases into CO2-equivalents using GWP, and then multiplying the carbonequivalents by the SCC, would not result in accurate estimates of the social costs of non-CO2 gases” (SCC 

TSD, pg 13).

243 The SCC estimates were converted from 2007 dollars to 2008 dollars using a GDP price deflator (1.021) 

and again to 2009 dollars using a GDP price deflator (1.009) obtained from the Bureau of Economic 

Analysis, National Income and Product Accounts Table 1.1.4, Prices Indexes for Gross Domestic Product.
142 of 

When attempting to assess the incremental economic impacts of carbon dioxide 

emissions, the analyst faces a number of serious challenges. A recent report from the 

National Academies of Science points out that any assessment will suffer from 

uncertainty, speculation, and lack of information about (1) future emissions of 

greenhouse gases, (2) the effects of past and future emissions on the climate system, (3) 

the impact of changes in climate on the physical and biological environment, and (4) the 

translation of these environmental impacts into economic damages.244 As a result, any

effort to quantify and monetize the harms associated with climate change will raise 

serious questions of science, economics, and ethics and should be viewed as provisional. 

The interagency group noted a number of limitations to the SCC analysis, 

including the incomplete way in which the integrated assessment models capture 

catastrophic and non-catastrophic impacts, their incomplete treatment of adaptation and 

technological change, uncertainty in the extrapolation of damages to high temperatures, 

and assumptions regarding risk aversion. The limited amount of research linking climate 

impacts to economic damages makes the interagency modeling exercise even more 

difficult. The interagency group hopes that over time researchers and modelers will work 

to fill these gaps and that the SCC estimates used for regulatory analysis by the Federal 

government will continue to evolve with improvements in modeling. Additional details 

on these limitations are discussed in the SCC TSD.

We received several comments regarding the SCC estimates used to analyze the 

proposed standards. In particular, these commenters discussed the incomplete treatment 

of impacts as well as discount rate selection. EPA has reviewed these comments in detail 

and responded to them in the EPA Response to Comments Document for the Joint 

Rulemaking. As noted in that document, the U.S. government intends to revise these 

estimates, taking into account new research findings that were not included in the first 

round, and has set a preliminary goal of revisiting the SCC values in the next few years or 

at such time as substantially updated models become available, and to continue to support 

research in this area. The EPA Response to Comments Document for the Joint 

Rulemaking discusses ongoing research in greater detail.

Applying the global SCC estimates, shown in Table VIII-14, to the estimated 

domestic reductions in CO2 emissions under this final program, we estimate the dollar 

value of the climate related benefits for each analysis year. For internal consistency, the 

annual benefits are discounted back to net present value terms using the same discount 

rate as each SCC estimate (i.e., 5%, 3%, and 2.5%) rather than 3% and 7%.245 These 

estimates are provided in Table VIII-15.

 

244

 National Research Council (2009). Hidden Costs of Energy: Unpriced Consequences of Energy 

Production and Use. National Academies Press. See docket ID EPA-HQ-OAR-2009-0472-11486.

245 It is possible that other benefits or costs of final regulations unrelated to CO2 emissions will be 

discounted at rates that differ from those used to develop the SCC estimates.
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143 of

Table VIII-14: Social Cost of CO2, 2012 – 2050a(in 2009 dollars per Metric Ton)

Year Discount Rate and Statistic

5% Average 3% Average 2.5% Average 3%

95th Percentile

2012 $5.28 $23.06 $37.53 $70.14 

2015 $5.93 $24.58 $39.57 $75.03 

2020 $7.01 $27.10 $42.98 $83.17 

2025 $8.53 $30.43 $47.28 $93.11 

2030 $10.05 $33.75 $51.58 $103.06 

2035 $11.57 $37.08 $55.88 $113.00 

2040 $13.09 $40.40 $60.19 $122.95 

2045 $14.63 $43.34 $63.59 $131.66 

2050 $16.18 $46.27 $66.99 $140.37 

Note:

a The SCC values are dollar-year and emissions-year specific.

Table VIII-15: Monetized CO2 Benefits of Vehicle Program, CO2 Emissionsa(Million 2009$)

YEAR CO2

EMISSIONS 

REDUCTION 

(MMT)

BENEFITS

Avg SCC at 

5% ($5-$16)a

Avg SCC at 3% 

($23-$46)a

Avg SCC at 

2.5% ($38-$67)a

95th percentile 

SCC at 3% 

($70-$140)a

2020 37.7 $264 $1,021 $1,619 $3,133

2030 73.1 $734 $2,467 $3,770 $7,532

2040 90.3 $1,182 $3,650 $5,437 $11,108

2050 103.9 $1,682 $4,810 $6,963 $14,590

Net Present 

Valueb

$9,045 $46,070 $78,037 $140,432

Notes:

a Except for the last row (net present value), the SCC values are dollar-year and emissions-year specific.

b Net present value of reduced CO2 emissions is calculated differently from other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used 

to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail.

H. Non-GHG Health and Environmental Impacts

This section presents EPA’s analysis of the non-GHG health and environmental 

impacts that can be expected to occur as a result of the HD National Program. GHG 

emissions are predominantly the byproduct of fossil fuel combustion processes that also 

produce criteria and hazardous air pollutants. The vehicles that are subject to the 

standards are also significant sources of mobile source air pollution such as direct PM, 

NOX, VOCs and air toxics. The standards will affect exhaust emissions of these 

pollutants from vehicles. They will also affect emissions from upstream sources related 

to changes in fuel consumption. Changes in ambient ozone, PM2.5, and air toxics that 

will result from the standards are expected to affect human health in the form of 
144 of 

premature deaths and other serious human health effects, as well as other important 

public health and welfare effects. 

As many commenters noted, it is important to quantify the health and 

environmental impacts associated with the final rules because a failure to adequately 

consider these ancillary co-pollutant impacts could lead to an incorrect assessment of 

their net costs and benefits. Moreover, co-pollutant impacts tend to accrue in the near 

term, while any effects from reduced climate change mostly accrue over a time frame of 

several decades or longer. 

This section is organized as follows: the first presents the PM- and ozone-related 

health and environmental impacts associated with final program in calendar year (CY) 

2030; the second discusses the related co-benefits associated with the model year (MY) 

analysis of the program.

246

 

(1) Quantified and Monetized Non-GHG Human Health Benefits of the 2030 

Calendar Year Analysis

This analysis reflects the impact of the HD National Program in 2030 compared 

to a future-year reference scenario without the program in place.247 Overall, we estimate 

that the final rules will lead to a net decrease in PM2.5-related health impacts. See Section 

VII.D of this preamble for more information about the air quality modeling results. 

While the PM-related air quality impacts are relatively small, the decrease in populationweighted national average PM2.5 exposure results in a net decrease in adverse PM-related 

human health impacts (the decrease in national population-weighted annual average 

PM2.5 is 0.005 μg/m3). 

The air quality modeling also projects decreases in ozone concentrations in many 

areas. While the ozone-related impacts are relatively small, the decrease in populationweighted national average ozone exposure results in a net decrease in ozone-related 

health impacts (population-weighted maximum 8-hour average ozone decreases by 0.164

ppb).

 

246 EPA typically analyzes rule impacts (emissions, air quality, costs and benefits) in the year in which they 

occur; for this analysis, we selected 2030 as a representative future year. We refer to this analysis as the 

“Calendar Year” (CY) analysis. EPA also conducted a separate analysis of the impacts over the model year 

lifetimes of the 2012 through 2016 model year vehicles. We refer to this analysis as the “Model Year” 

(MY) analysis. In contrast to the CY analysis, the MY lifetime analysis shows the lifetime impacts of the 

program on each of these MY fleets over the course of its lifetime.

247 The future-year reference scenario to which the program impacts are compared in this section assumes 

no future gains in mpg (a “flat” scenario). For the final rulemaking, the agencies have also conducted a 

sensitivity analysis relative to the baseline assumptions. The alternative baseline assumes annual mpg 

projections, in the absence of the program, which were developed by the U.S. Energy Information 

Administration (EIA) for the Annual Energy Outlook (AEO). A description of the alternative baseline can 

be found in RIA Chapter 6. Due to time and resource constraints, EPA was unable to conduct full-scale 

photochemical air quality modeling to reflect the final rule impacts relative to this alternative baseline.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

145 of

We base our analysis of the program’s impact on human health in 2030 on peerreviewed studies of air quality and human health effects.248,249

 These methods are 

described in more detail in the RIA that accompanies this action. Our benefits methods 

are also consistent with recent rulemaking analyses such as the final Transport Rule,250

the light-duty 2012-2016 MY vehicle rule,251 and the final Portland Cement National 

Emissions Standards for Hazardous Air Pollutants (NESHAP) RIA.252 To model the 

ozone and PM air quality impacts of this final action, we used the Community Multiscale 

Air Quality (CMAQ) model (see Chapter 8.2.2 of the RIA that accompanies this 

preamble). The modeled ambient air quality data serves as an input to the Environmental 

Benefits Mapping and Analysis Program version 4.0 (BenMAP).253 BenMAP is a 

computer program developed by the U.S. EPA that integrates a number of the modeling 

elements used in previous analyses (e.g., interpolation functions, population projections, 

health impact functions, valuation functions, analysis and pooling methods) to translate 

modeled air concentration estimates into health effects incidence estimates and monetized 

benefits estimates.

The range of total monetized ozone- and PM-related health impacts is presented 

in Table VIII-16 . We present total benefits based on the PM- and ozone-related 

premature mortality function used. The benefits ranges therefore reflect the addition of 

each estimate of ozone-related premature mortality (each with its own row in Table 

VIII-16) to estimates of PM-related premature mortality. These estimates represent 

EPA’s preferred approach to characterizing a best estimate of benefits. As is the nature 

of Regulatory Impact Analyses (RIAs), the assumptions and methods used to estimate air 

quality benefits evolve to reflect the agency’s most current interpretation of the scientific 

and economic literature. 

 

248 U.S. Environmental Protection Agency. (2006). Final Regulatory Impact Analysis (RIA) for the 

Proposed National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation. Retrieved March, 26, 2009 at http://www.epa.gov/ttn/ecas/ria.html

249 U.S. Environmental Protection Agency. (2008). Final Ozone NAAQS Regulatory Impact Analysis. 

Prepared by: Office of Air and Radiation, Office of Air Quality Planning and Standards. Retrieved March, 

26, 2009 at http://www.epa.gov/ttn/ecas/ria.html

250 Final Federal Implementation Plans to Reduce Interstate Transport of Fine Particulate Matter and 

Ozone. Signed July 6, 2011. Available at http://epa.gov/airtransport/

251 U.S. Environmental Protection Agency. (2010). Regulatory Impact Analysis: Final Rulemaking to 

Establish Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy 

Standards, EPA-420-R-10-009, April 2010. Available on the internet: 

http://www.epa.gov/otaq/climate/regulations/420r10009.pdf

252 U.S. Environmental Protection Agency (U.S. EPA). 2010. Regulatory Impact Analysis: National 

Emission Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry. 

Office of Air Quality Planning and Standards, Research Triangle Park, NC. Augues. Available on the 

Internet at < http://www.epa.gov/ttn/ecas/regdata/RIAs/portlandcementfinalria.pdf >. EPA-HQ-OAR-2009-

0472-0241

253 Information on BenMAP, including downloads of the software, can be found at 

http://www.epa.gov/ttn/ecas/ benmodels.html.
146 of 

Table VIII-16: Estimated 2030 Monetized PM-and Ozone-Related Health Benefitsa

2030 Total Ozone and PM Benefits – PM Mortality Derived from American Cancer Society Analysis and 

Six-Cities Analysisa

Premature Ozone 

Mortality Function

Reference Total Benefits

(Billions, 2009$, 3% 

Discount Rate)b,c

Total Benefits

(Billions, 2009$, 7% 

Discount Rate) b,c

Multi-city analyses Bell et al., 2004 Total: $1.3 - $2.4

PM: $0.74 - $1.8

Ozone: $0.55

Total: $1.2 - $2.2

PM: $0.67 - $1.6

Ozone: $0.55

Huang et al., 2005 Total: $1.6 - $2.7

PM: $0.74 - $1.8

Ozone: $0.91

Total: $1.6 - $2.5

PM: $0.67 - $1.6

Ozone: $0.91

Schwartz, 2005 Total: $1.6 - $2.6

PM: $0.74 - $1.8

Ozone: $0.83

Total: $1.5 - $2.5

PM: $0.67 - $1.6

Ozone: $0.83

Meta-analyses Bell et al., 2005 Total: $2.4 - $3.5

PM: $0.74 - $1.8

Ozone: $1.7

Total: $2.4 - $3.3

PM: $0.67 - $1.6

Ozone: $1.7

Ito et al., 2005 Total: $3.1 - $4.2

PM: $0.74 - $1.8

Ozone: $2.4

Total: $3.0 - $4.0

PM: $0.67 - $1.6

Ozone: $2.4

Levy et al., 2005 Total: $3.1 - $4.2

PM: $0.74 - $1.8

Ozone: $2.4

Total: $3.1 - $4.0

PM: $0.67 - $1.6

Ozone: $2.4

Notes:

a Total includes premature mortality-related and morbidity-related ozone and PM2.5 benefits. Range was 

developed by adding the estimate from the ozone premature mortality function to the estimate of PM2.5-

related premature mortality derived from either the ACS study (Pope et al., 2002) or the Six-Cities study 

(Laden et al., 2006).

b Note that total benefits presented here do not include a number of unquantified benefits categories. A 

detailed listing of unquantified health and welfare effects is provided in Table VIII-17.

c Results reflect the use of both a 3 and 7 percent discount rate, as recommended by EPA’s Guidelines for 

Preparing Economic Analyses and OMB Circular A-4. Results are rounded to two significant digits for 

ease of presentation and computation.

The benefits in Table VIII-16 include all of the human health impacts we are able 

to quantify and monetize at this time. However, the full complement of human health 

and welfare effects associated with PM and ozone remain unquantified because of current 

limitations in methods or available data. We have not quantified a number of known or 

suspected health effects linked with ozone and PM for which appropriate health impact 

functions are not available or which do not provide easily interpretable outcomes (e.g., 

changes in heart rate variability). Additionally, we are unable to quantify a number of 

known welfare effects, including reduced acid and particulate deposition damage to 

cultural monuments and other materials, and environmental benefits due to reductions of 

impacts of eutrophication in coastal areas. These are listed in Table VIII-17. As a result, 

the health benefits quantified in this section are likely underestimates of the total benefits 

attributable to this final action.

Table VIII-17: Unquantified and Non-Monetized Potential Effects

Pollutant/Effects Effects Not Included in Analysis - Changes in:
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147 of

Pollutant/Effects Effects Not Included in Analysis - Changes in:

Ozone Healtha Chronic respiratory damageb

Premature aging of the lungsb

Non-asthma respiratory emergency room visits

Exposure to UVb (+/-)

e

Ozone Welfare Yields for 

-commercial forests

-some fruits and vegetables

-non-commercial crops

Damage to urban ornamental plants

Impacts on recreational demand from damaged forest aesthetics

Ecosystem functions

Exposure to UVb (+/-)

e

PM HealthcPremature mortality - short term exposuresd

Low birth weight

Pulmonary function

Chronic respiratory diseases other than chronic bronchitis

Non-asthma respiratory emergency room visits

Exposure to UVb (+/-)

e

PM Welfare Residential and recreational visibility in non-Class I areas

Soiling and materials damage

Damage to ecosystem functions

Exposure to UVb (+/-)

e

Nitrogen and Sulfate 

Deposition Welfare

Commercial forests due to acidic sulfate and nitrate deposition 

Commercial freshwater fishing due to acidic deposition 

Recreation in terrestrial ecosystems due to acidic deposition 

Existence values for currently healthy ecosystems 

Commercial fishing, agriculture, and forests due to nitrogen deposition 

Recreation in estuarine ecosystems due to nitrogen deposition

Ecosystem functions

Passive fertilization

CO Health Behavioral effects

HC/Toxics Healthf Cancer (benzene, 1,3-butadiene, formaldehyde, acetaldehyde)

Anemia (benzene)

Disruption of production of blood components (benzene)

Reduction in the number of blood platelets (benzene)

Excessive bone marrow formation (benzene)

Depression of lymphocyte counts (benzene)

Reproductive and developmental effects (1,3-butadiene)

Irritation of eyes and mucus membranes (formaldehyde)

Respiratory irritation (formaldehyde)

Asthma attacks in asthmatics (formaldehyde)

Asthma-like symptoms in non-asthmatics (formaldehyde)

Irritation of the eyes, skin, and respiratory tract (acetaldehyde)

Upper respiratory tract irritation and congestion (acrolein)
148 of 

Pollutant/Effects Effects Not Included in Analysis - Changes in:

HC/Toxics Welfare Direct toxic effects to animals

Bioaccumulation in the food chain

Damage to ecosystem function

Odor

Notes:

a

The public health impact of biological responses such as increased airway responsiveness to stimuli, 

inflammation in the lung, acute inflammation and respiratory cell damage, and increased susceptibility to 

respiratory infection are likely partially represented by our quantified endpoints.

b The public health impact of effects such as chronic respiratory damage and premature aging of the lungs 

may be partially represented by quantified endpoints such as hospital admissions or premature mortality, 

but a number of other related health impacts, such as doctor visits and decreased athletic performance, 

remain unquantified.

c

In addition to primary economic endpoints, there are a number of biological responses that have been 

associated with PM health effects including morphological changes and altered host defense mechanisms. 

The public health impact of these biological responses may be partly represented by our quantified 

endpoints.

d While some of the effects of short-term exposures are likely to be captured in the estimates, there may be 

premature mortality due to short-term exposure to PM not captured in the cohort studies used in this 

analysis. However, the PM mortality results derived from the expert elicitation do take into account 

premature mortality effects of short term exposures.

e May result in benefits or disbenefits.

f Many of the key hydrocarbons related to this action are also hazardous air pollutants listed in the CAA.

While there will be impacts associated with air toxic pollutant emission changes 

that result from this final action, we do not attempt to monetize those impacts. This is 

primarily because currently available tools and methods to assess air toxics risk from 

mobile sources at the national scale are not adequate for extrapolation to incidence 

estimations or benefits assessment. The best suite of tools and methods currently

available for assessment at the national scale are those used in the National-Scale Air 

Toxics Assessment (NATA). The EPA Science Advisory Board specifically commented 

in their review of the 1996 NATA that these tools were not yet ready for use in a 

national-scale benefits analysis, because they did not consider the full distribution of 

exposure and risk, or address sub-chronic health effects.254 While EPA has since

improved these tools, there remain critical limitations for estimating incidence and 

assessing benefits of reducing mobile source air toxics. 

As part of the second prospective analysis of the benefits and costs of the Clean 

Air Act,

255 EPA conducted a case study analysis of the health effects associated with 

reducing exposure to benzene in Houston from implementation of the Clean Air Act. 

While reviewing the draft report, EPA’s Advisory Council on Clean Air Compliance 

Analysis concluded that “the challenges for assessing progress in health improvement as 

a result of reductions in emissions of hazardous air pollutants (HAPs) are daunting...due 

 

254 Science Advisory Board. 2001. NATA – Evaluating the National-Scale Air Toxics Assessment for 

1996 – an SAB Advisory. http://www.epa.gov/ttn/atw/sab/sabrev.html.

255 U.S. Environmental Protection Agency (U.S. EPA). 2011. The Benefits and Costs of the Clean Air Act 

from 1990 to 2020. Office of Air and Radiation, Washington, DC. March. Available on the Internet at 

<http://www.epa.gov/air/sect812/feb11/fullreport.pdf>.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

149 of

to a lack of exposure-response functions, uncertainties in emissions inventories and 

background levels, the difficulty of extrapolating risk estimates to low doses and the 

challenges of tracking health progress for diseases, such as cancer, that have long latency

periods.”256 EPA continues to work to address these limitations; however, we did not 

have the methods and tools available for national-scale application in time for the 

analysis of the final action.

257

 

EPA is also unaware of specific information identifying any effects on listed 

endangered species from the small fluctuations in pollutant concentrations associated

with this program (see Section VII.D). Furthermore, our current modeling tools are not 

designed to trace fluctuations in ambient concentration levels to potential impacts on 

particular endangered species. 

(a) Quantified Human Health Impacts

Table VIII-18 and Table VIII-19 present the annual PM2.5 and ozone health 

impacts, respectively, in the 48 contiguous U.S. states associated with the HD National 

Program for 2030. For each endpoint presented inTable VIII-18 and Table VIII-19, we 

provide both the mean estimate and the 90% confidence interval. 

Using EPA’s preferred estimates, based on the American Cancer Society (ACS)

and Six-Cities studies and no threshold assumption in the model of mortality, we estimate 

that the final rules will result in between 78 and 200 cases of avoided PM2.5-related 

premature mortalities annually in 2030. As a sensitivity analysis, when the range of 

expert opinion is used, we estimate between 26 and 260 fewer premature mortalities in 

2030 (see Table 8-14in the RIA that accompanies this action). For ozone-related 

premature mortality in 2030, we estimate a range of between 54 to 240 fewer premature 

mortalities.

Table VIII-18: Estimated PM2.5-Related Health Impactsa

Health Effect 2030 Annual Reduction 

in Incidence

(5th% - 95th%ile)

 

256 U.S. Environmental Protection Agency—Science Advisory Board (U.S. EPA-SAB). 2008. Benefits of 

Reducing Benzene Emissions in Houston, 1990–2020. EPA-COUNCIL-08-001. July. Available at 

<http://yosemite.epa.gov/sab/sabproduct.nsf/D4D7EC9DAEDA8A548525748600728A83/$File/EPACOUNCIL-08-001-unsigned.pdf>.

257 In April, 2009, EPA hosted a workshop on estimating the benefits or reducing hazardous air pollutants. 

This workshop built upon the work accomplished in the June 2000 Science Advisory Board/EPA 

Workshop on the Benefits of Reductions in Exposure to Hazardous Air Pollutants, which generated 

thoughtful discussion on approaches to estimating human health benefits from reductions in air toxics 

exposure, but no consensus was reached on methods that could be implemented in the near term for a broad 

selection of air toxics. Please visit http://epa.gov/air/toxicair/2009workshop.html for more information 

about the workshop and its associated materials.
150 of 

Health Effect 2030 Annual Reduction 

in Incidence

(5th% - 95th%ile)

Premature Mortality – Derived from epidemiology 

literatureb

 Adult, age 30+, ACS Cohort Study (Pope et al., 2002)

 Adult, age 25+, Six-Cities Study (Laden et al., 2006)

 Infant, age <1 year (Woodruff et al., 1997)

78

(30 – 130)

200

(110 – 290)

0

(0 – 1)

Chronic bronchitis (adult, age 26 and over) 53

(10 – 97)

Non-fatal myocardial infarction (adult, age 18 and over) 150

(54 – 240)

Hospital admissions - respiratory (all ages)c20

(10 – 30)

Hospital admissions - cardiovascular (adults, age >18)d45

(32 – 52)

Emergency room visits for asthma (age 18 years and 

younger) 

81

(48 – 120)

Acute bronchitis, (children, age 8-12) 130

(0 – 270)

Lower respiratory symptoms (children, age 7-14) 1,600

(750 – 2,400)

Upper respiratory symptoms (asthmatic children, age 9-

18)

1,200

(370 – 2,000)

Asthma exacerbation (asthmatic children, age 6-18) 1,400

(160 – 4,000)

Work loss days 9,700

(8,500 – 11,000)

Minor restricted activity days (adults age 18-65) 57,000

(48,000 – 66,000)

Notes:

a

Incidence is rounded to two significant digits. Estimates represent incidence within the 48 

contiguous United States. 

b

PM-related adult mortality based upon the American Cancer Society (ACS) Cohort Study (Pope et 

al., 2002) and the Six-Cities Study (Laden et al., 2006). Note that these are two alternative estimates 

of adult mortality and should not be summed. PM-related infant mortality based upon a study by 

Woodruff, Grillo, and Schoendorf, (1997).258

c Respiratory hospital admissions for PM include admissions for chronic obstructive pulmonary 

disease (COPD), pneumonia and asthma.

d Cardiovascular hospital admissions for PM include total cardiovascular and subcategories for 

ischemic heart disease, dysrhythmias, and heart failure.

 

258 Woodruff, T.J., J. Grillo, and K.C. Schoendorf. 1997. “The Relationship Between Selected Causes of 

Postneonatal Infant Mortality and Particulate Air Pollution in the United States.” Environmental Health 

Perspectives 105(6):608-612.
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151 of

Table VIII-19: Estimated Ozone-Related Health Impactsa

Health Effect 2030 Annual Reduction in 

Incidence

(5th% - 95th%ile)

Premature Mortality, All agesb

Multi-City Analyses 

 Bell et al. (2004) – Non-accidental

 Huang et al. (2005) – Cardiopulmonary

 Schwartz (2005) – Non-accidental

Meta-analyses:

 Bell et al. (2005) – All cause

 Ito et al. (2005) – Non-accidental

 Levy et al. (2005) – All cause

54

(23 – 84)

90

(43 – 140)

82

(34 – 130)

170

(96 – 250)

240

(160 – 320)

240

(180 – 310)

Hospital admissions- respiratory causes (adult, 65 

and older)c

510

(69 – 870)

Hospital admissions -respiratory causes (children, 

under 2)

320

(160 – 470)

Emergency room visit for asthma (all ages) 230

(0 – 630)

Minor restricted activity days (adults, age 18-65) 300,000

(150,000 – 450,000)

School absence days 120,000

(52,000 – 170,000

Notes:

a

Incidence is rounded to two significant digits. Estimates represent incidence within the 48 

contiguous U.S. 

b Estimates of ozone-related premature mortality are based upon incidence estimates derived from 

several alternative studies: Bell et al. (2004); Huang et al. (2005); Schwartz (2005) ; Bell et al. 

(2005); Ito et al. (2005); Levy et al. (2005). The estimates of ozone-related premature mortality 

should therefore not be summed.

c Respiratory hospital admissions for ozone include admissions for all respiratory causes and 

subcategories for COPD and pneumonia. 

(b) Monetized Benefits

Table VIII-20 presents the estimated monetary value of changes in the incidence 

of ozone and PM2.5-related health effects. All monetized estimates are stated in 2009$. 

These estimates account for growth in real gross domestic product (GDP) per capita 

between the present and 2030. Our estimate of total monetized benefits in 2030 for the 

program, using the ACS and Six-Cities PM mortality studies and the range of ozone 
152 of 

mortality assumptions, is between $1.3 and $4.2 billion, assuming a 3 percent discount 

rate, or between $1.2 and $4.0 billion, assuming a 7 percent discount rate.

Table VIII-20: Estimated Monetary Value of Changes in Incidence of Health and Welfare Effects in 

2030 (Millions of 2009$) a,b

PM2.5-Related Health Effect (5th and 95th %ile)

Premature Mortality –

Derived from 

Epidemiology Studiesc,d,

Adult, age 30+ - ACS study 

(Pope et al., 2002)

 3% discount rate

 7% discount rate

$680

($87 - $1,800)

$620

($79 - $1,600)

Adult, age 25+ - Six-Cities 

study (Laden et al., 2006)

 3% discount rate

 7% discount rate

$1,800

($250 - $4,300)

$1,600

($220 - $3,900)

Infant Mortality, <1 year –

(Woodruff et al. 1997)

$2.5

($0 - $9.4)

Chronic bronchitis (adults, 26 and over) $29

($2.4 - $96)

Non-fatal acute myocardial infarctions 

 3% discount rate

 7% discount rate

$16

($3.7 - $38)

$16

($3.4 - $38)

Hospital admissions for respiratory causes $0.31

($0.15 - $0.45)

Hospital admissions for cardiovascular causes $1.3

($0.83 - $1.8)

Emergency room visits for asthma $0.03

($0.02 - $0.05)

Acute bronchitis (children, age 8–12) $0.01

($0 - $0.03)

Lower respiratory symptoms (children, 7–14) $0.03

($0.01 - $0.06)

Upper respiratory symptoms (asthma, 9–11) $0.04

($0.01 - $0.08)

Asthma exacerbations $0.08

($0.009 - $0.23)

Work loss days $1.6

($1.4 - $1.8)

Minor restricted-activity days (MRADs) $3.6

($2.1 - $5.2)
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153 of

Ozone-related Health Effect

Premature Mortality, All ages –

Derived from Multi-city analyses

Bell et al., 2004 $520

($69 - $1,300)

Huang et al., 2005 $880

($120 - $2,200)

Schwartz, 2005 $800

($100 - $2,000)

Premature Mortality, All ages –

Derived from Meta-analyses

Bell et al., 2005 $1,700

($240 - $4,100)

Ito et al., 2005 $2,300

($350 - $5,500)

Levy et al., 2005 $2,400

($350 - $5,500)

Hospital admissions- respiratory causes (adult, 65 and 

older)

$13

($1.7 - $22)

Hospital admissions- respiratory causes (children, under 2) $3.4

($1.8 - $5.0)

Emergency room visit for asthma (all ages) $0.09

($0 - $0.23)

Minor restricted activity days (adults, age 18-65) $19

($8.6 - $32)

School absence days $11

($5.0 - $16)

Notes:

a Monetary benefits are rounded to two significant digits for ease of presentation and computation. 

PM and ozone benefits are nationwide. 

b Monetary benefits adjusted to account for growth in real GDP per capita between 1990 and the 

analysis year (2030).

c Valuation assumes discounting over the SAB recommended 20 year segmented lag structure. 

Results reflect the use of 3 percent and 7 percent discount rates consistent with EPA and OMB 

guidelines for preparing economic analyses.

(c) What Are the Limitations of the Benefits Analysis?

Every benefit-cost analysis examining the potential effects of a change in 

environmental protection requirements is limited to some extent by data gaps, limitations 

in model capabilities (such as geographic coverage), and uncertainties in the underlying 

scientific and economic studies used to configure the benefit and cost models. 

Limitations of the scientific literature often result in the inability to estimate quantitative 

changes in health and environmental effects, such as potential decreases in premature 

mortality associated with decreased exposure to carbon monoxide. Deficiencies in the 

economics literature often result in the inability to assign economic values even to those 

health and environmental outcomes which can be quantified. These general uncertainties 

in the underlying scientific and economics literature, which can lead to valuations that are 

higher or lower, are discussed in detail in the RIA and its supporting references. Key
154 of 

uncertainties that have a bearing on the results of the benefit-cost analysis of the final 

rules include the following:

 The exclusion of potentially significant and unquantified benefit categories (such as 

health, odor, and ecological benefits of reduction in air toxics, ozone, and PM);

 Errors in measurement and projection for variables such as population growth;

 Uncertainties in the estimation of future year emissions inventories and air quality;

 Uncertainty in the estimated relationships of health and welfare effects to changes in 

pollutant concentrations including the shape of the C-R function, the size of the effect 

estimates, and the relative toxicity of the many components of the PM mixture; 

 Uncertainties in exposure estimation; and

 Uncertainties associated with the effect of potential future actions to limit emissions.

As Table VIII-20 indicates, total benefits are driven primarily by the reduction in 

premature mortalities each year. Some key assumptions underlying the premature 

mortality estimates include the following, which may also contribute to uncertainty:

 Inhalation of fine particles is causally associated with premature death at 

concentrations near those experienced by most Americans on a daily basis. Although 

biological mechanisms for this effect have not yet been completely established, the 

weight of the available epidemiological, toxicological, and experimental evidence 

supports an assumption of causality. The impacts of including a probabilistic 

representation of causality were explored in the expert elicitation-based results of the 

PM NAAQS RIA. 

 All fine particles, regardless of their chemical composition, are equally potent in 

causing premature mortality. This is an important assumption, because PM produced 

via transported precursors emitted from heavy-duty engines may differ significantly

from PM precursors released from electric generating units and other industrial 

sources. However, no clear scientific grounds exist for supporting differential effects 

estimates by particle type.

 The C-R function for fine particles is approximately linear within the range of 

ambient concentrations under consideration. Thus, the estimates include health 

benefits from reducing fine particles in areas with varied concentrations of PM, 

including both regions that may be in attainment with PM2.5 standards and those that 

are at risk of not meeting the standards.

 There is uncertainty in the magnitude of the association between ozone and premature 

mortality. The range of ozone benefits associated with the coordinated strategy is 

estimated based on the risk of several sources of ozone-related mortality effect 

estimates. In a report on the estimation of ozone-related premature mortality

published by the National Research Council, a panel of experts and reviewers 

concluded that short-term exposure to ambient ozone is likely to contribute to 

premature deaths and that ozone-related mortality should be included in estimates of 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

155 of

the health benefits of reducing ozone exposure.259 EPA has requested advice from the 

National Academy of Sciences on how best to quantify uncertainty in the relationship 

between ozone exposure and premature mortality in the context of quantifying 

benefits.

Despite the uncertainties described above, we believe this analysis provides a 

conservative estimate of the estimated non-GHG health and environmental benefits of the 

standards in future years because of the exclusion of potentially significant benefit 

categories that are not quantifiable at this time. Acknowledging benefits omissions and 

uncertainties, we present a best estimate of the total benefits based on our interpretation 

of the best available scientific literature and methods supported by EPA’s technical peer 

review panel, the Science Advisory Board’s Health Effects Subcommittee (SAB-HES). 

The National Academies of Science (NRC, 2002) has also reviewed EPA’s methodology 

for analyzing the health benefits of measures taken to reduce air pollution. EPA 

addressed many of these comments in the analysis of the final PM NAAQS.260,261 This 

analysis incorporates this work to the extent possible. 

(2) Non-GHG Human Health Benefits of the Model Year (MY) Analysis

As described in Section VII, the final standards will reduce emissions of several 

criteria and toxic pollutants and precursors. EPA typically analyzes rule impacts 

(emissions, air quality, costs and benefits) in the year in which they occur; for the 

analysis of non-GHG ambient air quality and health impacts, we selected 2030 as a 

representative future year since resource and time constraints precluded EPA from 

considering multiple calendar years. We refer to this analysis as the “Calendar Year” 

(CY) analysis because the benefits of the program reflect impacts across all regulated 

vehicles in a calendar year. 

EPA also conducted a separate analysis of the impacts over the model year 

lifetimes of the 2014 through 2018 model year vehicles. We refer to this analysis as the 

“Model Year” (MY) analysis (see Chapter 6 of the RIA that accompanies this preamble). 

In contrast to the CY analysis, the MY analysis estimates the impacts of the program on 

each MY fleet over the course of its lifetime. Due to analytical and resource limitations, 

however, MY non-GHG emissions (direct PM, VOCs, NO2 and SO2) were not estimated 

for this analysis. Because MY impacts are measured in relation to only the lifetime of a 

particular vehicle model year (2014, 2015, 2016, 2017, and 2018), and assumes no 

additional controls to model year vehicles beyond 2018, the impacts are smaller than if 

the impacts of all regulated vehicles were considered. We therefore expect that the nonGHG health-related benefits associated with the MY analysis will be smaller than those 

 

259 National Research Council (NRC), 2008. Estimating Mortality Risk Reduction and Economic Benefits

from Controlling Ozone Air Pollution. The National Academies Press: Washington, D.C.

260 National Research Council (NRC). 2002. Estimating the Public Health Benefits of Proposed Air 

Pollution Regulations. The National Academies Press: Washington, D.C.

261 U.S. Environmental Protection Agency. October 2006. Final Regulatory Impact Analysis (RIA) for the 

Proposed National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation. Available at http://www.epa.gov/ttn/ecas/ria.html.
156 of 

estimated for the CY analysis, both in a given year (such as 2030) and in present value 

terms across a given time period (such as 2014 – 2050). 

I. Energy Security Impacts

The HD National Program is designed to reduce fuel consumption and GHG 

emissions in medium and heavy-duty (HD) vehicles, which will result in improved fuel 

efficiency and, in turn, help to reduce U.S. petroleum imports. A reduction of U.S. 

petroleum imports reduces both financial and strategic risks caused by potential sudden 

disruptions in the supply of imported petroleum to the U.S. This reduction in risk is a 

measure of improved U.S. energy security. This section summarizes the agencies’ 

estimates of U.S. oil import reductions and energy security benefits of the final HD 

National Program. Additional discussion of this issue can be found in Chapter 9.7 of the 

RIA.

(1) Implications of Reduced Petroleum Use on U.S. Imports

In 2008, U.S. petroleum import expenditures represented 21 percent of total U.S. 

imports of all goods and services.262 In 2008, the United States imported 66 percent of 

the petroleum it consumed, and the transportation sector accounted for 70 percent of total 

U.S. petroleum consumption. This compares to approximately 37 percent of petroleum 

from imports and 55 percent of consumption from petroleum in the transportation sector 

in 1975.263 It is clear that petroleum imports have a significant impact on the U.S. 

economy.

Requiring lower GHG vehicle technology and fuel efficient technology in HD 

vehicles in the U.S. is expected to lower U.S. oil imports. EPA used the MOVES model 

to estimate the fuel savings due to this program. A detailed explanation of the MOVES 

model can be found in Chapter 5 of the RIA.

Based on a detailed analysis of differences in fuel consumption, petroleum 

imports, and imports of refined petroleum products and crude oil using the Reference 

Case presented in the Energy Information Administration’s Annual Energy Outlook 

(AEO) 2011 Early Release, EPA and NHTSA estimate that approximately 50 percent of 

the reduction in fuel consumption resulting from adopting improved GHG emissions 

standards and fuel efficiency standards is likely to be reflected in reduced U.S. imports of 

refined fuel, while the remaining 50 percent is expected to be reflected in reduced 

domestic fuel refining. Of this latter figure, 90 percent is anticipated to reduce U.S. 

imports of crude petroleum for use as a refinery feedstock, while the remaining 10 

percent is expected to reduce U.S. domestic production of crude petroleum. Thus, on 

balance, each gallon of fuel saved as a consequence of the HD GHG and fuel efficiency

standards is anticipated to reduce total U.S. imports of petroleum by 0.95 gallons.264 The 

 

262 Source: U.S. Bureau of Economic Analysis, U.S. International Transactions Accounts Data, as shown on 

June 24, 2009.

263 Source: U.S. Department of Energy, Annual Energy Review 2008, Report No. DOE/EIA-0384(2008), 

Tables 5.1 and 5.13c, June 26, 2009.

264 This figure is calculated as 0.50 + 0.50*0.9 = 0.50 + 0.45 = 0.95.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

157 of

agencies’ estimates of the reduction in U.S. oil imports from this program for selected 

years, in millions of barrels per day, are presented in Table VIII-21 below. These 

estimates assume that the fuel efficiency of HD vehicles remains constant in the baseline. 

Table VIII-21: U.S. Oil Import Reductions from the HD National Program for Selected Years 

(Millions of Barrels per Day, mmbd)

Year mmbd

2020 0.202

2030 0.393

2040 0.489

2050 0.566

(2) Energy Security Implications

In order to understand the energy security implications of reducing U.S. 

petroleum imports, EPA worked with Oak Ridge National Laboratory (ORNL), which 

has developed approaches for evaluating the economic costs and energy security

implications of oil use. The energy security estimates provided below are based upon a 

methodology developed in a peer-reviewed study entitled ”The Energy Security Benefits 

of Reduced Oil Use, 2006-2015,” completed in March 2008. This study is included as 

part of the docket for this final action.

265,266

When conducting this analysis, ORNL considered the full economic cost of 

importing petroleum into the United States. The economic cost of importing petroleum 

into the U.S. is defined to include two components in addition to the purchase price of 

petroleum itself. These are: (1) the higher costs for oil imports resulting from the effect 

of increasing U.S. import demand on the world oil price and on the market power of the 

Organization of the Petroleum Exporting Countries (i.e., the “demand” or “monopsony”

costs); and (2) the risk of reductions in U.S. economic output and disruption of the U.S. 

economy caused by sudden disruptions in the supply of imported petroleum to the U.S. 

(i.e., macroeconomic disruption/adjustment costs). Maintaining a U.S. military presence 

to help secure stable oil supply from potentially vulnerable regions of the world was not 

included in this analysis because its attribution to particular missions or activities is hard 

to quantify.

For this action, ORNL estimated energy security premiums by incorporating the 

most recent available AEO 2011 Early Release oil price forecasts and market trends. 

Energy security premiums for the years 2020, 2030, 2040, and 2050 are presented in

 

265 Leiby, Paul N., "Estimating the Energy Security Benefits of Reduced U.S. Oil Imports" Oak Ridge 

National Laboratory, ORNL/TM-2007/028, Final Report, 2008. (Docket EPA-HQ-OAR-2010-0162)

266 The ORNL study “The Energy Security Benefits of Reduced Oil Use, 2006-2015," completed in March

2008, is an update version of the approach used for estimating the energy security benefits of U.S. oil 

import reductions developed in an ORNL 1997 Report by Leiby, Paul N., Donald W. Jones, T. Randall 

Curlee, and Russell Lee, entitled “Oil Imports: An Assessment of Benefits and Costs." (Docket EPA-HQOAR-2010-0162)
158 of 

Table VIII-22, as well as a breakdown of the components of the energy security

premiums for each of these years.267 The components of the energy security premiums

and their values are discussed in detail in Chapter 9.7 of the RIA.

Table VIII-22: Energy Security Premiums in Selected Years (2009$/Barrel)

Year

(range)

Monopsony Macroeconomic 

Disruption/Adjustment Costs

Total Mid-Point

2020 $11.29

($3.86 - $21.32)

$7.11

($3.50 - $11.40)

$18.41

($9.70 - $28.94)

2030 $11.17

($3.92 - $20.58) 

$8.32

($4.04 - $13.33)

$19.49

($10.49 -$29.63)

2035 $10.56

($3.69 - $19.62)

$8.71

($3.86 - $14.35)

$19.27

($10.32 - $29.13)

The literature on the energy security for the last two decades has routinely 

combined the monopsony and the macroeconomic disruption components when 

calculating the total value of the energy security premium. However, in the context of 

using a global SCC value, the question arises: how should the energy security premium 

be determined when a global perspective is taken? Monopsony benefits represent 

avoided payments by the United States to oil producers in foreign countries that result 

from a decrease in the world oil price as the U.S. decreases its consumption of imported 

oil. 

Several commenters commented on the agencies’ energy security analysis of this 

program. The Conservative Law Foundation, Interfaith Care for Creation, Environmental 

Defense Fund and American Lung Association (EDF/ALA) and R. Desjardin noted that 

the standards in this program will increase our national security by decreasing U.S. 

dependence on foreign oil imports. The Competitive Enterprise Institute (CEI) felt that 

there is no relationship between reduced U.S. oil imports and U.S. energy security; the 

commenter sees no relationship between reduced oil imports and, for example, the 

number of hijackings, bombings, and other terrorist-related activities that have occurred 

through time. CBD commented that the benefit of the reduction of military costs 

associated with maintaining a secure oil supply should be fully accounted for, and EDF 

recommended a more extensive analysis of the external security costs of oil dependence. 

The agencies recognize that potential national and energy security risks exist due 

to the possibility of tension over oil supplies. Much of the world’s oil and gas supplies 

are located in countries facing social, economic, and demographic challenges, thus

making them even more vulnerable to potential local instability. For example, in 2010 

just over 40 percent of world oil supply came from OPEC nations, and this share is not 

expected to decline in the AEO 2011 projections through 2030. Approximately 28

percent of global supply is from Persian Gulf countries alone. As another measure of 

 

267 AEO 2011 forecasts energy market trends and values only to 2035. The energy security premium 

estimates post-2035 were assumed to be the 2035 estimate.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

159 of

concentration, of the 137 countries/principalities that export either crude oil or refined 

petroleum product, the top 12 have recently accounted for over 55 percent of exports.268 

Eight of these countries are members of OPEC, and a 9th is Russia.269 In a market where 

even a 1-2 percent supply loss raises prices noticeably, and where a 10 percent supply

loss could lead to a significant price shock, this regional concentration is of concern.

Historically, the countries of the Middle East have been the source of eight of the ten

major world oil disruptions270 with the 9th originating in Venezuela, an OPEC member. 

Because of U.S. dependence on oil, the military could be called on to protect 

energy resources through such measures as securing shipping lanes from foreign oil 

fields. To maintain such military effectiveness and flexibility, the Department of Defense 

identified in the Quadrennial Defense Review that it is “increasing its use of renewable 

energy supplies and reducing energy demand to improve operational effectiveness, 

reduce greenhouse gas emissions in support of U.S. climate change initiatives, and 

protect the Department from energy price fluctuations.”272 The Department of the Navy 

has also stated that the Navy and Marine Corps rely far too much on petroleum, which 

“degrades the strategic position of our country and the tactical performance of our forces. 

The global supply of oil is finite, it is becoming increasingly difficult to find and exploit, 

and over time cost continues to rise.”273 

In remarks given to the White House Energy Security Summit on April 26, 2011, 

Deputy Security of Defense William J. Lynn, III noted the direct impact of energy

security on military readiness and flexibility. According to Deputy Security Lynn, 

“Today, energy technology remains a critical element of our military superiority. 

Addressing energy needs must be a fundamental part of our military planning.”274 

Thus, to the degree to which the final rules reduce reliance upon imported energy

supplies or promotes the development of technologies that can be deployed by either 

consumers or the nation’s defense forces, the United States could expect benefits related 

to national security, reduced energy costs, and increased energy supply. These benefits

are why President Obama has identified this program as a key component for improving 

 

268 Based on data from the CIA, combining various recent years, 

https://www.cia.gov/library/publications/the-world-factbook/rankorder/2176rank.html.

269 The other three are Norway, Canada, and the EU, an exporter of product.

270 IEA 2011 “IEA Response System for Oil Supply Emergencies

272 U.S. Department of Defense. 2010. Quadrennial Defense Review Report. Secretary of 

Defense: Washington, D.C. 128 pages.

273 The Department of the Navy’s Energy Goals (http://www.navy.mil/features/Navy_EnergySecurity.pdf) 

(Last accessed May 31, 2011).

274 U.S. Department of Defense, Speech: Remarks at the White House Energy Security Summit. Tuesday, 

April 26, 2011. (http://www.defense.gov/speeches/speech.aspx?speechid=1556) (Last accessed May 31, 

2011).
160 of 

energy efficiency and putting America on a path to reducing oil imports in the Blueprint 

for a Secure Energy Future.275

Although the agencies recognize that there clearly is a benefit to the United States 

from reducing dependence on foreign oil, the agencies have been unable to calculate the 

monetary benefit that the United States will receive from the improvements in national 

security expected to result from this program. In contrast, the other portion of the energy

security premium, the U.S. macroeconomic disruption and adjustment cost that arises 

from U.S. petroleum imports, is included in the energy security benefits estimated for this 

program. To summarize, the agencies have included only the macroeconomic disruption 

portion of the energy security benefits to estimate the monetary value of the total energy

security benefits of this program. The agencies have calculated energy security in very

specific terms, as the reduction of both financial and strategic risks caused by potential 

sudden disruptions in the supply of imported petroleum to the U.S. Reducing the amount 

of oil imported reduces those risks, and thus increases the nation’s energy security. 

Another commenter, citing Administration guidelines (OMB Circular A-4) for 

conducting economic analyses, felt that the agency should include the monopsony benefit 

as part of its overall costs and benefits analysis. After reviewing the guidelines cited by

the commenter, the agencies have concluded that excluding the monopsony benefit from 

its overall costs and benefits analysis continues to be appropriate when a global 

perspective is taken. However, the agencies recognize that the monopsony benefit has 

distributional impacts for the U.S., and continue to describe and discuss the monopsony

benefit in this section of the Preamble.

The total annual energy security benefits for the final HD National Program are 

reported in Table VIII-23 for the years 2020, 2030, 2040 and 2050. 

Table VIII-23: Total Annual Energy Security Benefits from the HD National Program

in 2020, 2030, 2040 and 2050 (Millions, 2009$)

Year Benefits

2020 $499

2030 $1,132

2040 $1,477

2050 $1,710

J. Other Impacts

(1) Noise, Congestion and Accidents

Increased vehicle use associated with a positive rebound effect also contributes to 

increased traffic congestion, motor vehicle accidents, and highway noise. Depending on 

 

275 The White House, Blueprint for a Secure Energy Future (March 30, 2011) 

(http://www.whitehouse.gov/sites/default/files/blueprint_secure_energy_future.pdf) (Last accessed May 27, 

2011).
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161 of

how the additional travel is distributed throughout the day and on where it takes place, 

additional vehicle use can contribute to traffic congestion and delays by increasing traffic 

volumes on facilities that are already heavily traveled during peak periods. These added 

delays impose higher costs on drivers and other vehicle occupants in the form of 

increased travel time and operating expenses, increased costs associated with traffic 

accidents, and increased traffic noise. Because drivers do not take these added costs into 

account in deciding when and where to travel, they must be accounted for separately as a 

cost of the added driving associated with the rebound effect.

EPA and NHTSA rely on estimates of congestion, accident, and noise costs 

caused by pickup trucks and vans, single unit trucks, buses, and combination tractors

developed by the Federal Highway Administration to estimate the increased external 

costs caused by added driving due to the rebound effect.276 The Federal Highway

Administration (FHWA) estimates are intended to measure the increases in costs from 

added congestion, property damages and injuries in traffic accidents, and noise levels 

caused by various types of trucks that are borne by persons other than their drivers (or 

“marginal” external costs). EPA and NHTSA employed estimates from this source 

previously in the analysis accompanying the light-Duty 2012-16 MY vehicle rule. The 

agencies continue to find them appropriate for this analysis after reviewing the 

procedures used by FHWA to develop them and considering other available estimates of 

these values. 

FHWA’s congestion cost estimates for trucks, which are weighted averages based 

on the estimated fractions of peak and off-peak freeway travel for each class of trucks, 

already account for the fact that trucks make up a smaller fraction of peak period traffic 

on congested roads because they try to avoid peak periods when possible. FHWA’s 

congestion cost estimates focus on freeways because non-freeway effects are less serious 

due to lower traffic volumes and opportunities to re-route around the congestion. The 

agencies, however, applied the congestion cost to the overall VMT increase, though the 

fraction of VMT on each road type used in MOVES range from 27 to 29 percent of the 

vehicle miles on freeways for vocational vehicles and 53 percent for combination 

tractors. The results of this analysis potentially overestimate the costs and provide a 

conservative estimate. 

The agencies are using FHWA’s “Middle” estimates for marginal congestion, 

accident, and noise costs caused by increased travel from trucks. This approach is 

consistent with the current methodology used in the Light-Duty GHG rulemaking 

analysis. These costs are multiplied by the annual increases in vehicle miles travelled

from the positive rebound effect to yield the estimated cost increases resulting from 

increased congestion, accidents, and noise during each future year. The values the 

agencies used to calculate these increased costs are included in Table VIII-24:.

 

276 These estimates were developed by FHWA for use in its 1997 Federal Highway Cost Allocation Study; 

see http://www.fhwa.dot.gov/policy/hcas/final/index.htm (last accessed July 21, 2010).
162 of 

Table VIII-24: Noise, Accident, and Congestion Costs per Mile (2009$)

External Costs Pickup Trucks and 

Vans ($/VMT)

Vocational Vehicles

($/VMT)

Combination 

Tractors ($/VMT)

Congestion $0.049 $0.111 $0.108

Accidents $0.027 $0.019 $0.022

Noise $0.001 $0.009 $0.020

In aggregate, the increased costs due to noise, accidents, and congestion from the 

additional truck driving are presented in Table VIII-25.

Table VIII-25: Accident, Noise, and Congestion Costs (Millions, 2009$)

Year Pickup Trucks 

and Vans

Vocational

Vehicles

Combination

Tractors

Total Costs

2012 $0 $0 $0 $0

2013 $0 $0 $0 $0

2014 $8 $21 $18 $46

2015 $15 $38 $31 $84

2016 $22 $55 $43 $120

2017 $29 $71 $54 $153

2018 $36 $85 $64 $186

2020 $51 $112 $83 $246

2030 $105 $195 $138 $437

2040 $130 $256 $166 $551

2050 $148 $298 $191 $638

NPV, 3% $1,818 $3,620 $2,492 $7,929

NPV, 7% $832 $1,680 $1,184 $3,695

(2) Savings Due to Reduced Refueling Time

Reducing the fuel consumption of heavy-duty trucks may either increase their 

driving range before they require refueling, or motivate truck purchasers to buy, and 

manufacturers to offer, smaller fuel tanks. Keeping the fuel tank the same size allows 

truck operators to reduce the frequency with which drivers typically refuel their vehicles; 

it thus extends the upper limit of the range they can travel before requiring refueling. 

Alternatively, if purchasers and manufacturers respond to improved fuel efficiency by

reducing the size of fuel tanks to maintain a constant driving range, the smaller tank will 

require less time in actual refueling. 

Because refueling time represents a time cost of truck operation, these time 

savings should be incorporated into truck purchasers’ decisions over how much fuelsaving technology they want in their vehicles. The savings calculated here thus raise the 

same questions discussed in Preamble VIII.A and RIA Section 9.1 does the apparent 

existence of these savings reflect failures in the market for fuel efficiency, or does it 
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163 of

reflect costs not addressed in this analysis? The response to these questions could vary

across truck segment. See those sections for further analysis of this question.

This analysis estimates the reduction in the annual time spent filling the fuel tank; 

this reduced time could come either from fewer refueling events, if the fuel tank stays the 

same size, or less time spent during each refueling event, if the fuel tank is made 

proportionately smaller. The refueling savings are calculated as the savings in the 

amount of time that would have been necessary to pump the fuel. The calculation does 

not include time spent searching for a fuel station or other time spent at the station; it is 

assumed that the time savings occur only during refueling. The value of the time saved is 

estimated at the hourly rate recommended for truck operators ($22.36 in 2009 dollars) in 

DOT guidance for valuing time savings.277

The refueling savings include the increased fuel consumption resulting from 

additional mileage associated with the rebound effect. However, the estimate of the 

rebound effect does not account for any reduction in net operating costs from lower 

refueling time. As discussed earlier, the rebound effect should be a measure of the change 

in VMT with respect to the net change in overall operating costs. Ideally, changes in 

refueling time would factor into this calculation, although the effect is expected to be 

minor because refueling time savings are small relative to the value of reduced fuel 

expenditures.

The details of this calculation are discussed in the RIA Chapter 9.3.2. The 

savings associated with reduced refueling time for a truck of each type throughout its 

lifetime are shown in Table VIII-26. The aggregate savings associated with reduced 

refueling time are shown in Table VIII-27 for vehicles sold in 2014 through 2050. 

 

277 U.S. Department of Transportation, “Revised Departmental Guidance for Valuation of Travel Time in 

Economic Analysis,” February 11, 2003, Table 4 (which shows a value of $18.10 in 2000 dollars); 

available at http://ostpxweb.dot.gov/policy/Data/VOTrevision1_2-11-03.pdf (last accessed September 9, 

2010).
164 of 

Table VIII-26: Lifetime Refueling Savings for a 2018 MY Truck of Each Type (2009$)

Pickup Trucks 

and Vans

Vocational Vehicles Combination 

Tractor

3% Discount Rate $31 $34 $341

7% Discount Rate $19 $22 $223

Table VIII-27: Annual Refueling Savings (Millions, 2009$) 

Year Pickup Trucks 

and Vans

Vocational 

Vehicles

Combination 

Tractor

Total

2012 $0.0 $0.0 $0.0 $0.0

2013 $0.0 $0.0 $0.0 $0.0

2014 $0.2 $1.4 $8.0 $9.6

2015 $0.5 $2.6 $14.3 $17.3

2016 $1.3 $3.8 $19.6 $24.6

2017 $2.7 $6.2 $26.7 $35.6

2018 $5.2 $8.5 $33.8 $47.5

2020 $10.5 $12.7 $46.2 $69.3

2030 $32.6 $25.8 $82.9 $141

2040 $43.4 $35.1 $100.5 $179

2050 $50.1 $41.3 $116.1 $207

NPV, 3% $541 $468 $1,467 $2,476

NPV, 7% $231 $210 $685 $1,126

K. The Effect of Safety Standards and Voluntary Safety Improvements

on Vehicle Weight

Safety standards developed by NHTSA in previous rulemakings may make 

compliance with the fuel efficiency and CO2 emissions standards more difficult or may

reduce the projected benefits of the program. The primary way that safety regulations 

can impact fuel efficiency and CO2 emissions is through increased vehicle weight, which 

reduces the fuel efficiency (and thus increases the CO2 emissions) of the vehicle. Using 

MY 2010 as a baseline, this section discusses the effects of other government regulations 

on MYs 2014-2016 medium and heavy-duty vehicle fuel efficiency and CO2 emissions. 

At this time, no known safety standards will affect new models in MY 2017 or 2018. 

NHTSA’s estimates are based on cost and weight tear-down studies of a few vehicles and 

cannot possibly cover all the variations in the manufacturers’ fleets. NHTSA also 

requested, and various manufacturers provided, confidential estimates of increases in 

weight resulting from safety improvements. Those increases are shown in subsequent 

tables. 

We have broken down our analysis of the impact of safety standards that might 

affect the MYs 2014-2016 fleets into three parts: 1) those NHTSA final rules with 

known effective dates, 2) proposed rules or soon-to-be proposed rules by NHTSA with or 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

165 of

without final effective dates, and 3) currently voluntary safety improvements planned by

the manufacturers. 

(1) Weight Impacts of Required Safety Standards 

NHTSA has undertaken several rulemakings in which several standards would 

become effective for medium- and heavy-duty (MD/HD) vehicles between MY 2014 and 

MY 2016. We will examine the potential impact on MD/HD vehicle weights for MYs

2014-2016 using MY 2010 as a baseline. 

 FMVSS 119, Heavy Truck Tires Endurance and High Speed Tests

 FMVSS 121, Air Brake Systems Stopping Distance 

 FMVSS 214, Motor Coach Lap/Shoulder Belts

 MD/HD Vehicle Electronic Stability Control Systems

(a) FMVSS 119, Heavy Truck Tires Endurance and High Speed Tests

NHTSA tentatively determined that the FMVSS No. 119 performance tests 

developed in 1973 should be updated to reflect the increased operational speeds and 

duration of truck tires in commercial service. A Notice of Proposed Rulemaking (NPRM) 

was issued December 7, 2010 (75 FR 60036). It proposed to increase significantly the 

stringency of the endurance test and to add a new high speed test. The data in the large 

truck crash causation study (LTCCS) that preceded that NPRM found that J and L load 

range tires were having proportionately more problems than the other sizes and the 

agency’s test results indicate that H, J, and L load range tires are more likely to fail the 

proposed requirements among the targeted F, G, H, J and L load range tires.278 To 

address these problems, the H and J load range tires could potentially use improved 

rubber compounds, which would add no weight to the tires, to reduce heat retention and 

improve the durability of the tires. The L load range tires, in contrast, appear to need to 

use high tensile strength steel chords in the tire bead, carcass and belt areas, which would 

enable a weight reduction with no strength penalties. Thus, if the update to FMVSS No. 

119 was finalized, we anticipate no change in weight for H and J load range tires and a 

small reduction in weight for L load range tires. This proposal could become a final rule 

with an effective date of MY 2016.

(b) FMVSS No. 121, Airbrake Systems Stopping Distance

FMVSS No. 121 contains performance and equipment requirements for braking 

systems on vehicles with air brake systems. The most recent major final rule affecting 

FMVSS No. 121 was published on July 27, 2009, and became effective on November 24, 

2009 (MY 2009). The final rule requires the vast majority of new heavy truck tractors 

(approximately 99 percent of the fleet) to achieve a 30 percent reduction in stopping 

distance compared to currently required levels. Three-axle tractors with a gross vehicle 

 

278 “Preliminary Regulatory Impact Analysis, FMVSS No. 119, New Pneumatic Tires for Motor Vehicles

with a GVWR of More Than 4,536 kg (10,000 pounds), June 2010. 
166 of 

weight rating (GVWR) of 59,600 pounds or less must meet the reduced stopping distance 

requirements by August 1, 2011 (MY 2011), while two-axle tractors and tractors with a 

GVWR above 59,600 pounds must meet the reduced stopping distance requirements by 

the later date of August 1, 2013 (MY 2013). NHTSA determined that there are several 

brake systems that can meet the requirements established in the final rule, including

installation of larger S-cam drum brakes or disc brake systems at all positions, or hybrid 

disc and larger rear S-cam drum brake systems. 

According to data provided by a manufacturer (Bendix) in response to the NPRM, 

the heaviest drum brakes weigh more than the lightest disc brakes, while the heaviest disc 

brakes weigh more than the lightest drum brakes. For a three-axle tractor equipped with 

all disc brakes, then, the total weight could increase by 212 pounds or could decrease by

134 pounds compared to an all-drum-braked tractor, depending on which disc or drum 

brakes are used for comparison. The improved brakes may add a small amount of weight 

to the affected vehicles for MYs 2014-2016, resulting in a slight increase in fuel 

consumption. 

(c) FMVSS No. 208, Motor coach Lap/Shoulder Belts

NHTSA is proposing lap/shoulder belts for all motorcoach seats. About 2,000 

motorcoaches are sold per year in the United States. Based on preliminary results from 

the agency’s cost/weight teardown studies of motor coach seats,279 NHTSA estimates that 

the weight added by 3-point lap/shoulder belts ranges from 5.96 to 9.95 pounds per 2-

person seat. This is the weight only of the seat belt assembly itself, and does not include 

changing the design of the seat, reinforcing the floor, walls or other areas of the motor 

coach. Few current production motor coaches have been installed with lap/shoulder belts 

on their seats, and the number of vehicles with these belts already installed could be 

negligible. Assuming a 54 passenger motor coach, the added weight for the 3-point 

lap/shoulder belt assembly would be in the range of 161 to 269 pounds (27 * (5.96 to 

9.95)) per vehicle. This proposal could become a final rule with an effective date of MY

2016. 

(d) Electronic Stability Control Systems (ESC) for Medium- and Heavy-Duty 

(MD/HD) Vehicles

The purpose of an ESC system for MD/HD vehicles is to reduce crashes caused 

by rollover or by directional loss-of-control. ESC monitors a vehicle’s rollover threshold 

and lateral stability using vehicle speed, wheel speed, steering wheel angle, lateral 

acceleration, side slip and yaw rate data and upon sensing an impending rollover or loss 

of directional control situation automatically reduces engine throttle and applies braking 

forces to individual wheels or sets of wheel to slow the vehicle down and regain 

directional control. ESC is not currently required in MD/HD vehicles, but could be 

proposed to be required in these vehicles by NHTSA. FMVSS No. 105, Hydraulic and 

electric brake systems, requires multipurpose passenger vehicles, trucks and buses with a 

 

279 Cost and Weight Analysis of Two Motorcoach Seating Systems: One With and One Without ThreePoint Lap/Shoulder Belt Restraints, Ludtke and Associates, July 2010.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

167 of

GVWR greater than 4,536 kg (10,000 pounds) to be equipped with an antilock brake 

system (ABS). All MD/HD vehicles having a GVWR of more than 10,000 pounds, are 

required to have ABS installed by that standard.

In addition to the existing ABS functionality, ESC requires sensors including a 

yaw rate sensor, lateral acceleration sensor, steering angle sensor and brake pressure 

sensor along with a brake solenoid valve. According to data provided by Meritor 

WABCO, the weight of an ESC system for the model 4S4M tractor is estimated to be 

around 55.5 pounds, and the weight of the ABS only is estimated to be 45.5 pounds. 

Thus, we estimate the added weight for the ESC for the vehicle to be 10 (55.5 – 45.5) 

pounds. 

(2) Summary – Overview of Anticipated Weight Increases

Table VIII-28 summarizes estimates made by NHTSA regarding the weight added 

by the above discussed standards or likely rulemakings. NHTSA estimates that weight 

additions required by final rules and likely NHTSA regulations effective in MY 2016 

compared to the MY 2010 fleet will increase motor coach vehicle weight by 171 to 279 

pounds and will increase other heavy-duty truck weights by 10 pounds.

Table VIII-28: Weight Additions Due to Final Rules or Likely NHTSA Regulations: Comparing MY 

2016 to the MY 2010 Baseline Fleet

Standard Number Added Weight in 

pounds

MD/HD Vehicle

Added Weight in 

kilograms

MD/HD Vehicle

119 0 0

121 0 (?) 0 (?)

208

Motor coaches only

161-269 73-122

MD/HD Vehicle Electronic 

Stability Control Systems

10 4.5

Total

Motor coaches

171- 279 77.5-126.5

Total

All other MD/HD vehicles

10 4.5

(3) Effects of Vehicle Mass Reduction on Safety

NHTSA and EPA have been considering the effect of vehicle weight on vehicle 

safety for the past several years in the context of our joint rulemaking for light-duty 

vehicle CAFE and GHG standards, consistent with NHTSA’s long-standing 

consideration of safety effects in setting CAFE standards. Combining all modes of 

impact, the latest analysis by NHTSA for the light-duty 2012-2016 MY vehicle rule280

 

280 “Final Regulatory Impact Analysis, Corporate Average Fuel Economy for MY 2012 - MY 2016 

Passenger Cars and Light Trucks”, NHTSA, March 2010, (Docket No. NHTSA-2009-0059-0344.1).
168 of 

found that reducing the weight of the heavier light trucks (LT > 3,870) had a positive 

overall effect on safety, reducing societal fatalities. 

In the context of the current rulemaking for HD fuel consumption and GHG 

standards, one would expect that reducing the weight of medium-duty trucks similarly

would, if anything, have a positive impact on safety. However, given the large difference 

in weight between light-duty vehicles and medium-duty trucks, and even larger 

difference between light-duty vehicles and heavy-duty vehicles with loads, the agencies 

believe that the impact of weight reductions of medium- and heavy-duty trucks would not 

have a noticeable impact on safety for any of these classes of vehicles.

However, the agencies recognize that it is important to conduct further study and 

research into the interaction of mass, size and safety to assist future rulemakings, and we 

expect that the collaborative interagency work currently on-going to address this issue for 

the light-duty vehicle context may also be able to inform our evaluation of safety effects 

for the final HD program. We intend to continue monitoring this issue going forward, 

and may take steps in a future rulemaking if it appears that the MD/HD fuel efficiency

and GHG standards have unforeseen safety consequences. The American Chemistry

Council stated in comments to the agencies that plastics and plastic composite materials 

provide a new way to lighten vehicles while maintaining passenger safety. They added 

that properties of plastics including strength to weight ratio, energy absorption, and 

flexible design make these materials well suited for the manufacture of medium- and 

heavy-duty vehicles. They submitted supporting analyses with their comments. The 

National School Transportation Association stated that added structural integrity 

requirements increase weight of school buses, and thus decrease fuel economy. They

asked that if there are safety and fuel economy trade-offs, manufacturers should be able 

to receive a waiver from the regulation’s requirements. Since no weight reduction is 

required for school buses – or any other vocational vehicle – the agencies do not believe 

this is an issue with the current regulation.

L. Summary of Costs and Benefits 

In this section, the agencies present a summary of costs, benefits, and net benefits 

of the HD National program. 

Table VIII-29 shows the estimated annual monetized costs of the final program 

for the indicated calendar years. The table also shows the net present values of those 

costs for the calendar years 2012-2050 using both 3 percent and 7 percent discount 

rates.281 Table VIII-30 shows the estimated annual monetized fuel savings of the final 

program. The table also shows the net present values of those fuel savings for the same 

calendar years using both 3 percent and 7 percent discount rates. In this table, the 

aggregate value of fuel savings is calculated using pre-tax fuel prices since savings in fuel 

taxes do not represent a reduction in the value of economic resources utilized in 

producing and consuming fuel. Note that fuel savings shown here result from reductions 

 

281 For the estimation of the stream of costs and benefits, we assume that after implementation of the final 

MY 2014-2017 standards, the 2017 standards apply to each year out to 2050.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

169 of

in fleet-wide fuel use. Thus, they grow over time as an increasing fraction of the fleet 

meets the 2018 standards. 

Table VIII-29: Estimated Monetized Costs of the Final Program (Millions, 2009$ )

a

2020 2030 2040 2050 NPV, Years

2012-2050, 3% 

Discount Rate

NPV, Years

2012-2050, 7% 

Discount Rate

Technology

Costs

$2,000 $2,200 $2,700 $3,300 $47,400 $24,700

Note:

a Technology costs for separate truck segments can be found in Section VIII.B.1.

Table VIII-30: Estimated Fuel Savings of the Final Program (Millions, 2009$ )

a

2020 2030 2040 2050 NPV, Years

2012-2050, 3% 

Discount Rate

NPV, Years

2012-2050, 7% 

Discount Rate

Fuel 

Savings 

(pre-tax)

$9,600 $20,600 $28,000 $36,500 $375,300 $166,500

Note:

a

Fuel savings for separate truck segments can be found in Section VIII.B.1.

Table VIII-31 presents estimated annual monetized benefits for the indicated 

calendar years. The table also shows the net present values of those benefits for the 

calendar years 2012-2050 using both 3 percent and 7 percent discount rates. The table 

shows the benefits of reduced CO2 emissions—and consequently the annual quantified 

benefits (i.e., total benefits)—for each of four SCC values estimated by the interagency

working group. As discussed in the RIA Section 9.3, there are some limitations to the 

SCC analysis, including the incomplete way in which the integrated assessment models 

capture catastrophic and non-catastrophic impacts, their incomplete treatment of 

adaptation and technological change, uncertainty in the extrapolation of damages to high 

temperatures, and assumptions regarding risk aversion. 

In addition, these monetized GHG benefits exclude the value of net reductions in 

non-CO2 GHG emissions (CH4, N2O, HFC) expected under this action. Although EPA 

has not monetized the benefits of reductions in non-CO2 GHGs, the value of these 

reductions should not be interpreted as zero. Rather, the net reductions in non-CO2

GHGs will contribute to this program’s climate benefits, as explained in Section VI.C. 
170 of 

Table VIII-31: Monetized Benefits Associated with the Final Program (Millions, 2009$)

2020 2030 2040 2050 NPV, Years 

2012-2050, 

3% Discount 

Ratea

NPV, Years 

2012-2050, 

7% Discount 

Ratea

Reduced CO2 Emissions at each assumed SCC value b

5% (avg SCC) $300 $700 $1,200 $1,700 $9,000 $9,000

3% (avg SCC) $1,000 $2,500 $3,600 $4,800 $46,100 $46,100

2.5% (avg SCC) $1,600 $3,800 $5,400 $7,000 $78,000 $78,000

3% (95th 

percentile)

$3,100 $7,500 $11,100 $14,600 $140,400 $140,400

Energy Security 

Impacts (price 

shock)

$500 $1,100 $1,500 $1,700 $19,800 $8,800

Accidents, 

Congestion, Noise

-$200 -$400 -$600 -$600 -$7,900 -$3,700

Refueling Savings $100 $100 $200 $200 $2,500 $1,100

Non-GHG Impacts 

c,d

B $2,800 $2,800 $2,800 $25,300 $9,100

Non-CO2 GHG 

Impactse

n/a n/a n/a n/a n/a n/a

Total Annual Benefits at each assumed SCC value b

5% (avg SCC) $700 $4,300 $5,100 $5,800 $48,700 $24,300

3% (avg SCC) $1,400 $6,100 $7,500 $8,900 $85,800 $61,400

2.5% (avg SCC) $2,000 $7,400 $9,300 $11,100 $117,700 $93,300

3% (95th percentile) $3,500 $11,100 $15,000 $18,700 $180,100 $155,700

Notes:

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used 

to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. See Section VIII.F.

c Note that “B” indicates unquantified criteria pollutant benefits in the year 2020. For the analysis of the 

final program, we only modeled the rule’s PM2.5- and ozone-related impacts in the calendar year 2030. For 

the purposes of estimating a stream of future-year criteria pollutant benefits, we assume that the benefits 

out to 2050 are equal to, and no less than, those modeled in 2030 as reflected by the stream of estimated 

future emission reductions. The NPV of criteria pollutant-related benefits should therefore be considered a 

conservative estimate of the potential benefits associated with the final program.

d Non-GHG-related health and welfare impacts (related to PM2.5 and ozone exposure) range between $1,300

and $4,200 million in 2030, 2040, and 2050. $2,800 was chosen as the mid-point of this range for the 

purposes of estimating total benefits across all monetized categories.

e The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG 

emissions expected under this program (See RIA Chapter 5). Although EPA has not monetized changes in 

non-CO2 GHGs, the value of any increases or reductions should not be interpreted as zero. 

Table VIII-32 presents estimated annual net benefits for the indicated calendar 

years. The table also shows the net present values of those net benefits for the calendar 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

171 of

years 2012-2050 using both 3 percent and 7 percent discount rates. The table includes 

the benefits of reduced CO2 emissions (and consequently the annual net benefits) for each 

of four SCC values considered by EPA. 

Table VIII-32: Monetized Net Benefits Associated with the Final Program (Millions, 2009$)

2020 2030 2040 2050 NPV, 3%a NPV, 7%a

Technology Costs $2,000 $2,200 $2,700 $3,300 $47,400 $24,700

Fuel Savings $9,600 $20,600 $28,000 $36,500 $375,300 $166,500

Total Annual Benefits at each assumed SCC value b

5% (avg SCC) $700 $4,300 $5,100 $5,800 $48,700 $24,300

3% (avg SCC) $1,400 $6,100 $7,500 $8,900 $85,800 $61,400

2.5% (avg SCC) $2,000 $7,400 $9,300 $11,100 $117,700 $93,300

3% (95th 

percentile)

$3,500 $11,100 $15,000 $18,700 $180,100 $155,700

Monetized Net Benefits at each assumed SCC value c

5% (avg SCC) $8,300 $22,700 $30,400 $39,000 $376,600 $166,100

3% (avg SCC) $9,000 $24,500 $32,800 $42,100 $413,700 $203,200

2.5% (avg SCC) $9,600 $25,800 $34,600 $44,300 $445,600 $235,100

3% (95th 

percentile)

$11,100 $29,500 $40,300 $51,900 $508,000 $297,500

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used 

to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail.

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c Net Benefits equal Fuel Savings minus Technology Costs plus Benefits.

EPA also conducted a separate analysis of the total benefits over the model year 

lifetimes of the 2014 through 2018 model year trucks. In contrast to the calendar year 

analysis presented above in Table VIII-29 through Table VIII-32, the model year lifetime 

analysis below shows the impacts of the final program on vehicles produced during each 

of the model years 2014 through 2018 over the course of their expected lifetimes. The 

net societal benefits over the full lifetimes of vehicles produced during each of the five 

model years from 2014 through 2018 are shown in Table VIII-33 and Table VIII-34 at 

both 3 percent and 7 percent discount rates, respectively. 
172 of 

Table VIII-33: Monetized Technology Costs, Fuel Savings, Benefits, and Net Benefits Associated with 

the Lifetimes of 2014-2018 Model Year Trucks (Millions, 2009$; 3% Discount Rate)

2014

MY

2015

MY

2016

MY

2017

MY

2018

MY

Sum

Technology Costs -$1,600 -$1,400 -$1,500 -$1,600 -$2,000 -$8,100

Fuel Savings (pre-tax) $9,300 $8,300 $8,100 $11,500 $12,900 $50,100

Energy Security 

Impacts (price shock)

$500 $400 $400 $600 $700 $2,700

Accidents, 

Congestion, Noise

-$300 -$300 -$300 -$300 -$300 -$1,500

Refueling Savings $60 $60 $60 $80 $100 $400

Non-CO2 GHG 

Impacts and NonGHG Impacts c,d

n/a n/a n/a n/a n/a n/a

Reduced CO2 Emissions at each assumed SCC value a, b

5% (avg SCC) $200 $200 $200 $300 $300 $1,200

3% (avg SCC) $1,100 $900 $900 $1,300 $1,500 $5,700

2.5% (avg SCC) $1,800 $1,600 $1,500 $2,100 $2,400 $9,400

3% (95th percentile) $3,300 $2,900 $2,800 $4,000 $4,500 $17,000

Monetized Net Benefits at each assumed SCC value a, b

5% (avg SCC) $8,200 $7,300 $7,000 $10,600 $11,700 $44,800

3% (avg SCC) $9,100 $8,000 $7,700 $11,600 $12,900 $49,300

2.5% (avg SCC) $9,800 $8,700 $8,300 $12,400 $13,800 $53,000

3% (95th percentile) $11,300 $10,000 $9,600 $14,300 $15,900 $60,600

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used 

to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG 

emissions expected under this action (see RIA Chapter 5). Although EPA has not monetized changes in 

non-CO2 GHGs, the value of any increases or reductions should not be interpreted as zero. 

d Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and SO2) 

were not estimated for this analysis.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

173 of

Table VIII-34: Monetized Technology Costs, Fuel Savings, Benefits, and Net Benefits Associated with 

the Lifetimes of 2014-2018 Model Year Trucks (Millions, 2009$; 7% Discount Rate)

2014 

MY

2015 

MY

2016 

MY

2017 

MY

2018 

MY

Sum

Technology Costs -$1,600 -$1,400 -$1,500 -$1,600 -$2,000 -$8,100

Fuel Savings (pre-tax) $6,900 $5,900 $5,600 $7,600 $8,300 $34,400

Energy Security Impacts 

(price shock)

$400 $300 $300 $400 $400 $1,800

Accidents, Congestion, 

Noise

-$200 -$200 -$200 -$200 -$200 -$1,000

Refueling Savings $50 $40 $40 $60 $60 $200

Non-CO2 GHG Impacts and 

Non-GHG Impacts c,d

n/a n/a n/a n/a n/a n/a

Reduced CO2 Emissions at each assumed SCC value a, b

5% (avg SCC) $200 $200 $200 $300 $300 $1,200

3% (avg SCC) $1,100 $900 $900 $1,300 $1,500 $5,700

2.5% (avg SCC) $1,800 $1,600 $1,500 $2,100 $2,400 $9,400

3% (95th percentile) $3,300 $2,900 $2,800 $4,000 $4,500 $17,000

Monetized Net Benefits at each assumed SCC value a, b

5% (avg SCC) $5,800 $4,800 $4,400 $6,600 $6,900 $28,500

3% (avg SCC) $6,700 $5,500 $5,100 $7,600 $8,100 $33,000

2.5% (avg SCC) $7,400 $6,200 $5,700 $8,400 $9,000 $36,700

3% (95th percentile) $8,900 $7,500 $7,000 $10,300 $11,100 $44,300

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used 

to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG 

emissions expected under this action (see RIA Chapter 5). Although EPA has not monetized changes in 

non-CO2 GHGs, the value of any increases or reductions should not be interpreted as zero. 

d Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and SO2) 

were not estimated for this analysis.

Table VIII-36Table VIII-35 and Table VIII-36 show similar model year estimates 

to those provided above in Table VIII-33 and Table VIII-34 , but reflect specific 

differences in the NHTSA HD program over the 3 mandatory model years of that 

program. These include no HD diesel engine impacts prior to MY 2017, assumption of 

the NHTSA phase-in schedule for HD pickup trucks and vans which achieves 3 year 

phase-in stability (67%-67%-67%-100% in MY 2016-2019 respectively), the inclusion of 

combination tractors from MY 2016 forward, and the exclusion of RVs, which are not 

regulated by NHTSA.
174 of 

Table VIII-35: Monetized Technology Costs, Fuel Savings, Benefits, and Net Benefits Associated with 

the Lifetimes of 2016-2018 Model Year Trucks (Millions, 2009$; 3% Discount Rate)

2016 MY 2017 MY 2018 MY Sum

Technology Costs -$1,500 -$1,600 -$1,700 -$5,200

Fuel Savings (pre-tax) $5,500 $10,900 $11,500 $27,900

Energy Security Impacts (price 

shock)

$300 $600 $600 $1,500

Accidents, Congestion, Noise -$300 -$300 -$300 -$900

Refueling Savings $40 $80 $80 $200

Non-CO2 GHG Impacts and NonGHG Impacts c,dn/a n/a n/a n/a

Reduced CO2 Emissions at each assumed SCC value a, b

5% (avg SCC) $100 $300 $300 $700

3% (avg SCC) $600 $1,200 $1,300 $3,100

2.5% (avg SCC) $1,000 $2,000 $2,200 $5,200

3% (95th percentile) $1,900 $3,800 $4,000 $9,700

Monetized Net Benefits at each assumed SCC value a, b

5% (avg SCC) $4,100 $10,000 $10,500 $24,200

3% (avg SCC) $4,600 $10,900 $11,500 $26,600

2.5% (avg SCC) $5,000 $11,700 $12,400 $28,700

3% (95th percentile) $5,900 $13,500 $14,200 $33,200

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used 

to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG 

emissions expected under this proposal (see RIA Chapter 5). Although EPA has not monetized changes in 

non-CO2 GHGs, the value of any increases or reductions should not be interpreted as zero. 

d Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and SO2) 

were not estimated for this analysis.

Table VIII-36: Monetized Technology Costs, Fuel Savings, Benefits, and Net Benefits Associated with 

the Lifetimes of 2016-2018 Model Year Trucks (Millions, 2009$; 7% Discount Rate)

2016 MY 2017 MY 2018 MY Sum

Technology Costs -$1,500 -$1,600 -$1,700 -$5,200

Fuel Savings (pre-tax) $3,800 $7,200 $7,300 $18,300

Energy Security Impacts (price 

shock)

$200 $400 $400 $1,000

Accidents, Congestion, Noise -$200 -$200 -$200 -$600
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175 of

2016 MY 2017 MY 2018 MY Sum

Refueling Savings $30 $50 $50 $130

Non-CO2 GHG Impacts and NonGHG Impacts c,dn/a n/a n/a n/a

Reduced CO2 Emissions at each assumed SCC value a, b

5% (avg SCC) $100 $300 $300 $700

3% (avg SCC) $600 $1,200 $1,300 $3,100

2.5% (avg SCC) $1,000 $2,000 $2,200 $5,200

3% (95th percentile) $1,900 $3,800 $4,000 $9,700

Monetized Net Benefits at each assumed SCC value a, b

5% (avg SCC) $2,400 $6,200 $6,200 $14,300

3% (avg SCC) $2,900 $7,100 $7,200 $16,700

2.5% (avg SCC) $3,300 $7,900 $8,100 $18,800

3% (95th percentile) $4,200 $9,700 $9,900 $23,300

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 2.5 percent) is used 

to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG 

emissions expected under this proposal (see RIA Chapter 5). Although EPA has not monetized changes in 

non-CO2 GHGs, the value of any increases or reductions should not be interpreted as zero.d Due to 

analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and SO2) were not 

estimated for this analysis.

M. Employment Impacts

(1) Introduction

Although analysis of employment impacts is not part of a cost-benefit analysis 

(except to the extent that labor costs contribute to costs), employment impacts of federal 

rules are of particular concern in the current economic climate of sizeable unemployment. 

The recently issued Executive Order 13563, “Improving Regulation and Regulatory 

Review” (January 18, 2011), states, “Our regulatory system must protect public health, 

welfare, safety, and our environment while promoting economic growth, innovation, 

competitiveness, and job creation” (emphasis added). Although EPA and NHTSA did 

not undertake an employment analysis of the proposed rules, several commenters 

suggested that we undertake an employment analysis for the final rulemaking. Consistent 

with Executive order 13563, we have provided a discussion of the potential employment 

impacts of the Heavy-Duty National Program. 

Our general conclusion is that employment impacts in the regulated sector (truck 

and engine manufacturing) and the parts sectors depend on a combination of factors, 

some of which are positive, and some of which can be positive or negative; effects on 
176 of 

employment in the transport and shipping sectors are ambiguous; the fuel supplying 

sectors may face reduced employment; and there may be increased general employment 

due to reduction in costs that may be passed along to the transport industry and thus to 

the public. Because we did not include employment analysis in the NPRM and provide 

opportunity for public comment on the methods, we here present a qualitative discussion. 

Because the discussion is qualitative, we do not sum the net effects on employment in the 

economy. We also note that the employment effects may be different in the immediate 

implementation phase than in the ongoing compliance phase; this analysis focuses on the 

longer-term effects rather than the immediate effects.

When the economy is at full employment, an environmental regulation is unlikely 

to have much impact on net overall U.S. employment; instead, labor would primarily be 

shifted from one sector to another. These shifts in employment impose an opportunity

cost on society, approximated by the wages of the employees, as regulation diverts 

workers from other activities in the economy.

282

 In this situation, any effects on net 

employment are likely to be transitory as workers change jobs. (For example, some 

workers may need to be retrained or require time to search for new jobs, while shortages 

in some sectors or regions could bid up wages to attract workers).283

It is also true that, if a regulation comes into effect during a period of high 

unemployment, a change in labor demand due to regulation may affect net overall U.S. 

employment because the labor market is not in equilibrium. Either negative or positive 

effects are possible. Schmalansee and Stavins284 point out that net positive employment 

effects are possible in the near term when the economy is at less than full employment 

due to the potential hiring of idle labor resources by the regulated sector to meet new 

requirements (e.g., to install new equipment) and new economic activity in sectors related 

to the regulated sector. In the longer run, the net effect on employment is more difficult to 

predict and will depend on the way in which the related industries respond to the 

regulatory requirements. As Schmalansee and Stavins note, it is possible that the 

magnitude of the effect on employment could vary over time, region, and sector, and 

positive effects on employment in some regions or sectors could be offset by negative 

effects in other regions or sectors. For this reason, they urge caution in reporting partial 

employment effects since it can “paint an inaccurate picture of net employment impacts if 

not placed in the broader economic context.” 

This rulemaking is expected to have a relatively small effect on net employment 

in the United States through the regulated sector – the truck and engine manufacturer 

industry – and several related sectors, specifically, industries that supply the truck and 

 

282 Schmalensee, Richard, and Robert N. Stavins. “A Guide to Economic and Policy Analysis of EPA’s 

Transport Rule.” White paper commissioned by Excelon Corporation, March 2011.

283 Although the employment level would not change substantially, there would be costs to the 

workers associated with shifting from one activity to another. Jacobson, Louis S., Robert J. LaLonde, and 

Daniel G. Sullivan, “Earnings Losses of Displaced Workers.” American Economic Review 83(4) (1993): 

685-709.

284 Ibid.
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177 of

engine manufacturing industry (e.g., truck parts), the trucking industry itself, other 

industries involved in transporting goods (e.g., rail and shipping), the petroleum refining 

sector, and the retail sector. According to the U.S. Bureau of Labor Statistics, about 1.25 

million people were employed in the truck transportation industry and about 675,000 

people were employed in the motor vehicle parts industry between 2010 and 2011.285 

Although heavy-duty vehicles (HD) account for approximately 4% of the vehicles on the 

road, these vehicles consume more than 20% of on-road gasoline and diesel fuel use. As 

discussed in Chapter 5 of this RIA, this rulemaking is predicted to reduce the amount of 

fuel these vehicles use, and thus affect the petroleum refinery industry. The petroleum 

refinery industry employed about 65,000 people in the U.S. in 2009, the most recent year 

that employment estimates are available for this sector.286 As discussed in Chapter 5 of 

this RIA, this rulemaking is predicted to reduce the amount of fuel these vehicles use, and 

thus affect the petroleum refinery industry. The petroleum refinery industry employed 

about 65,000 people in the U.S. in 2009, the most recent year that employment estimates 

are available for this sector.287 Finally, since the net reduction in cost associated with 

these rules is expected to lead to lower transportation and shipping costs, in a competitive 

market a substantial portion of those cost savings will be passed along to consumers, who 

then will have additional discretionary income (how much of the cost is passed along to 

consumers depends on market structure and the relative price elasticities). 

Several commenters suggested that the HD vehicle rules would lead to an increase 

in employment in affected sectors by offering the potential for new employment 

opportunities in the design and production of new vehicle technologies. Also, these 

commenters suggested that since the U.S. manufacturers and suppliers are leaders in 

certain advanced truck technologies, this program has the potential to help them 

consolidate their leadership and thrive in a global market. In this context, several 

commenters referred to an assessment by the Union of Concerned Scientists (UCS) and 

CalStart of the economic and employment benefits of the improved efficiency in HD 

vehicles.288 The study predicts an increase in tens of thousands of jobs between 2020 and 

2030, as result of higher fuel efficiency for HD vehicles. These quantitative estimates 

were derived using a standard input-output model, though the estimates themselves have 

not yet been peer reviewed. Input-output (I/O) models do not account for opportunity

costs of labor – that is, all employment needs due to the regulatory change will be met by

unemployed workers. In addition, I/O models assume no changes in the average use of 

labor per dollar of output in the affected sectors. For these and other reasons, these may

at best be considered an imprecise upper bound on actual employment impacts.289

 

285 U.S. Bureau of Labor Statistics seasonally-adjusted Current Employment Statistics Survey for the Truck 

Transportation Industry (NAICS 484) and the Motor Vehicle Parts Manufacturing Industry (NAICS 3363).

287 U.S. Census Bureau, 2009 Annual Survey of Manufactures, Published December 3, 2010.

287 U.S. Census Bureau, 2009 Annual Survey of Manufactures, Published December 3, 2010.

288 Union of Concerned Scientists and CalStart, Delivering Jobs: The Economic Costs and Benefits of 

Improving Fuel Economy of Heavy Duty Vehicles, July, 2010. http://www.ucsusa.org/deliveringjobs.

289 Berck, Peter, and Sandra Hoffman. “Assessing the Employment Impacts of Environmental and Natural 

Resource Policy.” Environmental and Resource Economics 22 (2002): 133-156.
178 of 

Determining the direction of employment effects even in the regulated industry

may be difficult due to the presence of competing effects that lead to an ambiguous 

adjustment in employment as a result of environmental regulation. Morgenstern, Pizer 

and Shih290 identify three separate ways that employment levels may change in the 

regulated industry in response to a new (or more stringent) regulation. 

 Demand effect: higher production costs due to the regulation will lead to 

higher market prices; higher prices in turn reduce demand for the good, 

reducing the demand for labor to make that good. In the authors’ words, 

the “extent of this effect depends on the cost increase passed on to 

consumers as well as the demand elasticity of industry output”. 

 Cost effect: As costs go up, plants add more capital and labor (holding 

other factors constant), with potentially positive effects on employment; in 

the authors’ words, as “production costs rise, more inputs, including labor, 

are used to produce the same amount of output”.

 Factor-shift effect: post-regulation production technologies may be more 

or less labor-intensive (i.e., more/less labor is required per dollar of 

output) (“factor-shift effect”). In the authors’ words, “environmental 

activities may be more labor intensive than conventional production,” 

meaning that “the amount of labor per dollar of output will rise,” though it 

is also possible that “cleaner operations could involve automation and less 

employment, for example”.

The “demand effect” is expected to have a negative effect on employment, the “cost 

effect” to have a positive effect on employment, and the “factor-shift effect” has an 

ambiguous effect on employment. Without more information with respect to the 

magnitudes of these competing effects, it is not possible to predict the total effect 

environmental regulation will have on employment levels in a regulated sector

Morgenstern et al. estimated the effects on employment of spending on pollution 

abatement for four highly polluting/regulated industries (pulp and paper, plastics, steel, 

and petroleum refining). They conclude that increased abatement expenditures generally 

have not caused a significant change in employment in those sectors. More specifically, 

their results show that, on average across the industries studied, each additional $1 

million spent on pollution abatement results in a (statistically insignificant) net increase 

of 1.5 jobs. While the specific sectors Morgenstern et al. examined are different that the 

sectors considered here, the methodology that Morgenstern et al. developed is still useful 

in this context.

(2) Overview of Affected Sectors

The above discussion focuses on employment changes in the regulated sector, but 

the regulated sector is not the only source of changes in employment. In these rules, the 

 

290 Morgenstern, Richard D., William A. Pizer, and Jhih-Shyang Shih. “Jobs Versus the Environment: An 

Industry-Level Perspective.” Journal of Environmental Economics and Management 43 (2002): 412-436.
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179 of

regulated sectors are truck and engine manufacturers; they are responsible for meeting the 

standards set in these rules. The effects of these rules are also likely to have impacts 

beyond the directly regulated sector. Some of the related sectors which these rules are 

also likely to impact include: motor vehicle parts producers, to the extent that the truck 

and engine industries purchase components rather than manufacture them in-house; 

shipping and transport, because many companies in this sector purchase trucks and their 

operating costs will be affected by both higher truck prices and fuel savings; oil refineries 

due to reduced demand for petroleum-based fuels; and the final retail market, which is 

where any net cost reductions due to fuel savings are ultimately expected to be 

experienced. We acknowledge that there may be impacts in other sectors that are not 

discussed here, but we have sought to include the sectors where we think the impacts are 

most direct. The following discussion describes the direction of impacts on employment 

in these industries. The effects of the HD National Program on net U.S. employment 

depend, not only on their relative magnitudes, but also on employment levels in the 

overall economy. As previously discussed, in a full-employment economy these sectorspecific impacts will be mostly offset by employment changes elsewhere in the economy 

and would not be expected to result in a net change in jobs. However, in an economy 

with significant unemployment these changes may affect net employment in the U.S.

(a) Truck and Engine Manufacturers

The regulated sector consists of truck and engine manufacturers. Employment 

associated with manufacturing trucks and engines may be affected by the demand, cost, 

and factor-shift effects. 

Demand Effect

The demand effect depends on the effects of this rulemaking on HD vehicle sales. 

If vehicle sales increase, then more people will be required to assemble trucks and their 

components. If vehicle sales decrease, employment associated with these activities will 

decrease. The effects of this rulemaking on HD vehicle sales depend on the perceived 

desirability of the new vehicles. Unlike in Morgenstern et al.’s study, where the demand 

effect decreased employment, there are countervailing possibilities in the HD market due 

to the fuel savings resulting from this program. On one hand, this rulemaking will 

increase vehicle costs; by itself, this effect would reduce vehicle sales. On the other 

hand, this rulemaking will reduce the fuel costs of operating the vehicle; by itself, this 

effect would increase vehicle sales, especially if potential buyers have an expectation of 

higher fuel prices. The agencies have not made an estimate of the potential change in 

vehicle sales. However as discussed in Preamble Section VIII.E.5 the agencies have 

estimated an increase in vehicle miles traveled (i.e., VMT rebound) due to the reduced 

operating costs of trucks meeting these new standards. Since increased VMT is most 

likely to be met with more drivers and more trucks, our projection of VMT rebound is 

suggestive of an increase in vehicle sales and truck driver employment (recognizing that 

these increases may be partially offset by a decrease in manufacturing and sales for 

equipment of other modes of transportation such as rail cars or barges). 
180 of 

As discussed above in Section VIII.A, the agencies find that the reduction in fuel 

costs associated with this rulemaking outweigh the increase in vehicle cost. This finding 

is puzzling: market forces should lead truck manufacturers and buyers to install all costeffective fuel-saving technology, but the agencies find that they have not. Section VIII.A 

discusses various hypotheses that have been suggested to explain this phenomenon. 

Some of the explanations suggest that vehicle manufacturers and buyers will benefit from 

the rulemaking, and vehicle sales will increase; others suggest that the opposite might 

occur. The agencies do not have strong evidence supporting one specific explanation 

over another. However, some in the heavy-duty industry indicate the potential for an 

increase in jobs. As stated by Tom Linebarger (President and Chief Operating Officer of 

Cummins) and Fred Krupp (President of the Environmental Defense Fund), “Finally, 

strong environmental standards play a crucial role in getting innovations to market that 

will create economic opportunity for American companies and jobs for American 

workers. . . . It helps that Cummins and other forward-thinking businesses view this as an 

opportunity to innovate and increase international market share.”

291

One commenter raised the issue of whether there could be a loss of recreation 

vehicle (RV) industry jobs due to a reduction in the sales of motor homes and towable 

RVs. As mentioned above, the effects of this rulemaking on HD vehicle sales depend on 

the desirability of the new vehicles. 

Cost Effect

The truck and engine manufacturing sector has great flexibility in how to respond 

to the requirement for reduced greenhouse gases and increasing fuel efficiency, with a 

broad suite of technologies being available to achieve the standards. These technologies 

are described in detail in Chapter 2 of this RIA. Among these technologies, a distinction 

can be made between technologies that can be “added on” to conventional trucks versus 

those that replace features of a conventional truck. “Added on” features, such as 

auxiliary power units, require additional labor to install the technologies on trucks, thus 

clearly increasing labor demand (the “cost effect”). The pure cost effect always increases 

employment, though the net effect on the regulated industry depends on its effects in 

combination with the demand and factor-shift effects.

Factor-Shift Effect

For “replacement” technologies, the predicted impact on labor demand from 

regulation depends on the change in the amount of labor used to build and install one type 

of technology compared to another. In some cases, the new technologies are predicted to 

be more complex than the existing technologies and may therefore require additional 

labor installation inputs. In other cases, the opposite may be true: labor intensity may be 

lower for some replacement technologies.

 

291 Tom Linebarger (President and Chief Operating Officer of Cummins) and Fred Krupp (President of the 

Environmental Defense Fund), "Clear rules can create better engines, clean air," Indianapolis Star, October 

28, 2010, p. 19; included as part of Cummins' comments on the rule, Docket Number EPA-HQ-OAR-2010-

0162-1765.1[1]
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181 of

Most of the technologies that are expected to be used to meet these standards are 

replacement technologies. For example, almost all of the engine improvements involve 

replacement technologies that are not expected to significantly change the labor 

requirements. Similarly, regulations of the chassis on vocational vehicles will only

require the installation of a different type of tire, which is also not expected to have large 

labor intensity impacts. Therefore, the potential magnitude of the factor shift effect is 

expected to be relatively small, though slightly positive due to the additional labor needed 

to install more complex technologies. 

Summary for the Truck and Engine Manufacturing Sector

For the truck and engine manufacturing sector, the demand effect may result in 

either increased or decreased employment; the cost effect is expected to increase 

employment; and the factor-shift effect is expected to have a small, possibly slightly

positive effect on employment in this sector. The net effect on employment in this sector 

depends on the sum of these factors.

(b) Motor Vehicle Parts Manufacturing Sector

Some vehicle parts are made in-house and would be included directly in the 

regulated sector. Others are made by independent suppliers and are not directly

regulated, but they will be affected by the rules as well. The parts manufacturing sector 

will be involved primarily in providing “add-on” parts, or components for replacement 

parts built internally. If demand for these parts increases due to the increased use of these 

parts, employment effects in this sector are expected to be positive. If the demand effect 

in the regulated sectors is significantly negative enough, it is possible that demand for 

other parts may decrease. As noted, the agencies do not predict a direction for the 

demand effect.

(c) Transport and Shipping Sectors

Although not directly regulated by these rules, employment effects in the 

transport and shipping sector are likely to result from these regulations. If the overall 

cost of shipping a ton of freight decreases because of increased fuel efficiency (taking 

into account the increase in upfront purchasing costs), in a perfectly competitive industry

these costs savings will be passed along to customers. With lower prices, demand for 

shipping would lead to an increase in demand for truck shipping services (consistent with 

the VMT rebound effect analysis) and therefore an increase in employment in the truck 

shipping sector. In addition, if the relative cost of shipping freight via trucks becomes 

cheaper than shipping by other modes (e.g., rail or barge), then employment in the truck 

transport industry is likely to increase. If the trucking industry is more labor intensive 

than other modes, we would expect this effect to lead to an overall increase in 

employment in the transport and shipping sectors.292,293 Such a shift would, however, be 

 

292 American Transportation Research Institute, “An Analysis of the Operational Costs of Trucking: 2011 

Update.” See http://www.atrionline.org/research/results/Op_Costs_2011_Update_one_page_summary.pdf.
182 of 

at the expense of employment in the sectors that are losing business to trucking. The first 

effect – a gain due to lower shipping costs – is likely to lead to a net increase in 

employment. The second effect, due to mode-shifting, may increase employment in 

trucking, but decreases in other shipping sectors.

(d) Fuel Suppliers

In addition to the effects on the trucking industry and related truck parts sector, 

these rules will result in reductions in fuel use that lower GHG emissions. Fuel saving, 

principally reductions in liquid fuels such as diesel and gasoline, will affect employment 

in the fuel suppliers industry sectors, principally the Petroleum Refinery sector.294 

Expected fuel consumption reductions by fuel type, and by heavy-duty vehicle 

type, can be found in Table VIII-7. These reductions reflect impacts from the new fuel 

efficiency and GHG standards and include increased consumption from the rebound 

effect. These fuel savings are monetized in Table VIII-8 by multiplying the reduced fuel 

consumption in each year by the corresponding estimated average fuel price in that year, 

using the Reference Case from the AEO 2011. In 2014, the pre-tax fuel savings is $1.2 

billion (2009$). While these figures represent a level of fuel savings for purchasers of 

fuel, it also represents a loss in value of output for the petroleum refinery industry. Since 

50 percent of the fuel would have been refined in the U.S., the loss in output to the U.S. 

Petroleum Refinery sector is $600 million (2009$), which will result in reduced sectoral 

employment.295 Because this sector is very capital-intensive, the employment effect is 

not expected to be large.

(e) Fuel Savings

As a result of this rulemaking, it is anticipated that trucking firms will experience 

fuel savings. Fuel savings lower the costs of transportation goods and services. In a 

competitive market, the fuel savings that initially accrue to trucking firms are likely to be 

passed along as lower transportation costs that, in turn, could result in lower prices for 

final goods and services. Alternatively, the savings could be kept internally in firms for 

investments or for returns to firm owners. In either case, the savings will accrue to some 

segment of consumers: either owners of trucking firms or the general public. In both 

cases, the effect will be increased spending by consumers in other sectors of the 

economy, creating jobs in a diverse set of sectors, including retail and service industries. 

 

293 Association of American Railroads, “All Inclusive Index and Rail Adjustment Factor.” June 3, 2011. 

See http://www.aar.org/~/media/aar/RailCostIndexes/AAR-RCAF-2011-Q3.ashx

294 North American Industry Classification System (NAICS) Code 32411.

295 EPA and NHTSA estimate that approximately 50 percent of the reduction in fuel consumption resulting 

from adopting improved fuel GHG standards and fuel efficiency standards is likely to be reflected in 

reduced U.S. imports of refined fuel, while the remaining 50 percent is expected to be reflected in reduced 

domestic fuel refining. Of this latter figure, 90 percent is anticipated to reduce U.S. imports of crude 

petroleum for use as a refinery feedstock, while the remaining 10 percent is expected to reduce U.S. 

domestic production of crude petroleum. Because we do not expect to see a significant reduction in crude 

oil production in the U.S., we do not expect this rule to have a significant impact on the Oil and Gas 

Extraction industry sector in the U.S. (NAICS 211000). For more information, refer to Section VIII-I on 

the energy security impacts from the program.
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183 of

As mentioned above, the value of fuel savings from this rulemaking is projected 

to be $1.2 billion (2009$) in 2014, according to Table VIII-8. If all those savings are 

spent, the fuel savings will stimulate increased employment in the economy through 

those expenditures. If the fuel savings accrue primarily to firm owners, they may either 

reinvest the money or take it as profit. Reinvesting the money in firm operations would 

increase employment directly. If they take the money as profit, to the extent that these 

owners are wealthier than the general public, they may spend less of the savings, and the 

resulting employment impacts would be smaller than if the savings went to the public. 

Thus, while fuel savings are expected to decrease employment in the refinery sector, they

are expected to increase employment through increased consumer expenditures.

(3) Summary

The net employment effects of this rulemaking are expected to be found 

throughout several key sectors: truck and engine manufacturers, the trucking industry, 

truck parts manufacturing, fuel production, and consumers. For the regulated sector, the 

demand effect may result in either increased or decreased employment, depending on the 

net effect on HD vehicle sales; the cost effect is expected to increase employment in the 

regulated sector; and the factor-shift effect is expected to have a small, possibly slightly 

positive effect on employment, though we cannot definitively say this is the case without 

quantification. The net effect depends on the combination of these effects. Increased 

expenditures by truck and engine parts manufacturers are expected to require increased 

labor to build parts, though this effect also depends on any changes in overall demand 

and on the labor intensity of production of new parts; increased complexity of 

technologies may imply increased labor inputs for some parts, though others might be 

less labor-intensive. It is possible, if access to capital markets is limited, that this rule 

might displace other HD sector investment, which would reduce employment associated 

with those activities. Lower prices for shipping are expected to lead to an increase in 

demand for truck shipping services and, therefore, an increase in employment in that 

sector, though this effect may be offset somewhat by changes in employment in other 

shipping sectors. Reduced fuel production implies less employment in the fuel provision 

sectors. Finally, any net cost savings would be expected to be passed along to some 

segment of consumers: either the general public or the owners of trucking firms, who are 

expected then to increase employment through their expenditures. Given the job creation 

as a result of the $1.2B (2009$) in fuel savings in 2014 and the possible employment 

increases in the manufacturing and parts sectors, we find it highly unlikely that there 

would be significant net job losses related to this policy. Given the current level of 

unemployment, net positive employment effects are possible, especially in the near term, 

due to the potential hiring of idle labor resources by the regulated sector to plan for and 

meet new requirements. In the future, when full employment is expected to return, any

changes in employment levels in the regulated sector due to this program are mostly

expected to be offset by changes in employment in other sectors.
184 of 

IX. Analysis of the Alternatives 

The heavy-duty truck segment is very complex. The sector consists of a diverse 

group of impacted parties, including engine manufacturers, chassis manufacturers, truck 

manufacturers, trailer manufacturers, truck fleet owners and the public. The final 

standards that the agencies have adopted today maximize the environmental and fuel 

savings benefits of the program while taking into consideration the unique and varied 

nature of the regulated industries. In developing this final rulemaking, we considered a 

number of alternatives that could have resulted in potentially fewer or greater GHG and 

fuel consumption reductions than the program we are finalizing. This section 

summarizes the alternatives we considered and presents assessments of technology costs, 

CO2 reductions, and fuel savings associated with each alternative. The agencies reduced 

the number of alternatives analyzed in this final rulemaking compared to the proposal 

because we did not receive any comments supporting standard setting for a smaller subset 

than HD pickup trucks, combination tractors, and vocational vehicles (as well as engines 

used in vocational vehicles and combination tractors). As discussed below, the agencies 

have also refined some of the alternatives analyzed in response to the comments received.

A. What Are the Alternatives that the Agencies Considered?

In developing alternatives, NHTSA must consider EISA's requirement for the 

MD/HD fuel efficiency program noted above. 49 U.S.C. 32902(k)(2) and (3) contain the 

following three requirements specific to the MD/HD vehicle fuel efficiency improvement 

program: (1) The program must be “designed to achieve the maximum feasible 

improvement”; (2) the various required aspects of the program must be appropriate, costeffective, and technologically feasible for MD/HD vehicles; and (3) the standards 

adopted under the program must provide not less than four model years of lead time and 

three model years of regulatory stability. In considering these various requirements, 

NHTSA will also account for relevant environmental and safety considerations.

The alternatives below represent a broad range of approaches for a HD vehicle 

fuel efficiency and GHG emissions program. Details regarding the modeling of each 

alternative are included in RIA Chapter 6. The alternatives in order of increasing fuel 

efficiency and GHG emissions reductions are:

(1) Alternative 1: No Action

A “no action” alternative assumes that the agencies would not issue rules 

regarding a MD/HD fuel efficiency improvement program. This alternative is presented 

in order for NHTSA to comply with the National Environmental Policy Act (NEPA) and 

to provide an analytical baseline against which to compare environmental impacts of the 

other regulatory alternatives.296 The agencies refer to this as the “No Action Alternative” 

 

296 NEPA requires agencies to consider a “no action” alternative in their NEPA analyses and to compare the 

effects of not taking action with the effects of the reasonable action alternatives to demonstrate the different 

environmental effects of the action alternatives. See 40 CFR 1502.2(e), 1502.14(d).CEQ has explained that 

“[T]he regulations require the analysis of the no action alternative even if the agency is under a court order 

or legislative command to act. This analysis provides a benchmark, enabling decision makers to compare 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

185 of

or as a “no increase” or “baseline” alternative. As described in RIA Chapter 5, this noaction alternative is considered the reference case. 

The no action alternative first presented in this final action is based on the 

assumption that the new vehicle fleet continues to perform at the same level as new 2010 

vehicles. In this way, it provides a comparison between today’s new trucks and the 

increased cost and reduced fuel consumption of future compliant vehicles. 

The agencies recognize that there is substantial uncertainty in determining an 

appropriate baseline against which to compare the effects of the proposed action. The 

lack of prior regulation of HD fuel efficiency means that there is a lack of historic data 

regarding trends in this sector. Therefore, in this final action, the agencies have also 

included an analysis using a baseline derived from annual projections developed by the 

U.S. Energy Information Administration (EIA) for the Annual Energy Outlook (AEO). 

For this alternative baseline, the agencies analyzed the new truck fuel economy

projections for the Light Commercial Trucks, along with the Medium- and Heavy-Duty

Freight Vehicles developed in AEO 2011.297 The agencies converted the fuel economy 

improvements into CO2 emissions reductions relative to a 2010 model year (see RIA 

Chapter 6).

The baseline derived from the AEO forecast provides a comparison between the 

impacts of the proposed standards and EIA’s projection of future new truck performance 

absent regulation. This alternative baseline is informative in showing one possible 

projection of future vehicle performance based on other factors beyond the regulation the 

agencies are finalizing today. The AEO forecast makes a number of assumptions that 

should be noted. AEO 2011 assumes improved fuel efficiency for 8,500-10,000 lb. 

GVWR heavy-duty pickups due to the light-duty 2012-2016 MY regulations. We project 

a similar capability for fuel economy improvement as AEO does for this class of 

vehicles; however, the agencies recognize that absent regulation manufacturers may

decline to add the necessary technologies to reach the level of our proposed standards. 

For medium and heavy-duty vocational vehicles, AEO 2011 projects a small reduction in 

fuel efficiency over time (an increase in fuel consumption), similar to that achieved under 

the MY 2010 baseline. For Class 8 combination tractors, the AEO 2011 baseline 

projections an annual improvement of approximately 0.3 percent.

We are not able to make an estimate of the cost of the AEO 2011 alternative 

baseline because we are not able to accurately determine the technology mix used in the 

AEO 2011 analysis to achieve the projected improvements in fuel efficiency. We do 

know they differ significantly from our own analysis as the EIA projections do not 

include the full range of technologies considered by the agencies (e.g. EIA’s analysis 

 

the magnitude of environmental effects of the action alternatives. [See 40 CFR 1502.14(c).] * * * Inclusion 

of such an analysis in the EIS is necessary to inform Congress, the public, and the President as intended by 

NEPA. [See 40 CFR 1500.1(a).]'' Forty Most Asked Questions Concerning CEQ's National Environmental 

Policy Act Regulations, 46 FR 18026 (1981) (emphasis added).

297 U.S. Energy Information Administration. Annual Energy Outlook 2011 Early Release. Last viewed on 

March 29, 2011 at http://www.eia.doe.gov/forecasts/aeo/. See Supplemental Tables 7, 63, and 68.
186 of 

does not consider the use of idle reduction technologies and diesel auxiliary power units 

to reduce fuel consumption associated with vehicle hoteling). If one were to assume that 

the cost of the AEO2011 baseline was proportional to projected improvement relative to 

our preferred alternative, the total AEO2011 baseline cost estimate would be 

approximately equal to the total cost of the preferred case, but vary by category.

(2) Alternative 2: 12 Percent Less Stringent than the Preferred Alternative

Alternative 2 represents an alternative stringency level to the agencies’ preferred 

approach. Alternative 2 represents a stringency level which is approximately 12 percent 

less stringent than the preferred approach. The agencies calculated the Alternative 2 

stringency level in order to meet two goals. First, we sought to create an alternative that 

regulated the same engine and vehicle categories as the preferred alternative, but at lower 

stringency (10-20 percent lower) than the preferred alternative. Second we wanted an 

alternative that reflected removal of the least cost effective technology that we believed 

manufacturers would add last in order to meet the preferred alternative. In other words, 

we wanted an alternative that as closely as possible reflected the last increment in 

stringency prior to reaching our preferred alternative. Please see Table 2-39 in RIA 

Chapter 2 for a list of all of the technologies, as well as their cost and relative 

effectiveness. The resulting Alternative 2 is based on the same technologies used in 

Alternative 3 except as follows for each of the three categories.

The combination tractor standard would be based on the removal of the Advanced 

SmartWay aerodynamic package and weight reduction technologies, which decreases the 

average combination tractor GHG emissions and fuel consumption reduction by

approximately 1 percent. 

The HD pickup truck and van standard would be based on removal of the 5 

percent mass reduction technology, which decreases the average truck reduction of fuel 

consumption and GHG emissions by approximately 1.6 percent. 

The vocational vehicle standard would be based on removal of low rolling 

resistance tires – in essence meaning that there would be no expected improvement in 

performance from vocational vehicles, only from engines used to power them. This 

alternative would also reduce the amount of technologies applied to diesel engines used 

in vocational vehicles such that the engines achieve a 3 percent reduction in 2014 model 

year and a 5 percent reduction in 2017 model year, both compared to a 2010 model year 

baseline, 

The agencies have decided not to finalize Alternative 2, because as shown below,

Alternative 3 is more stringent, is technically feasible, and results in a greater net benefit 

to society. 

(3) Alternative 3: Preferred Alternative and Final Standards

Alternative 3 represents the agencies’ preferred approach. This alternative 

consists of the finalized fuel efficiency and GHG standards for HD engines, HD pickup 

trucks and vans, Class 2b through Class 8 vocational vehicles, and Class 7 and 8 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

187 of

combination tractors. Details regarding modeling of this alternative are included in RIA 

Chapter 5 as the control case. 

The agencies selected Alternative 3 over Alternatives 4 and 5 described below 

because the agencies concluded that alternatives 4 and 5 were not technically feasible to 

achieve given the leadtime provided in these final rules. Hence, we have concluded that 

Alternative 3 represents the maximum feasible improvement. Section 2 of this preamble 

provides an explanation of the consideration that agencies gave to setting more stringent 

standards based on the application of additional technologies and our reasons for 

concluding that the identified technologies for each of the vehicle and engine standards 

that constitute Alternative 3 represented the maximum feasible improvement based on 

technological feasibility. In general, we reached this conclusion for one of two reasons. 

For some technologies such as Rankine Waste Heat Recovery engine technologies, the 

agencies have concluded that the technology is still in the research phase and will not be 

developed fully for new engine production in the time frame of this first regulatory

action. In other cases, the agencies concluded that the manufacturing capacity for 

technologies such as advanced battery systems for heavy-duty hybrid drivetrains could 

not be expanded quickly enough to allow for significant vehicle production volume in the 

time frame of this program. 

(4) Alternative 4: 20 Percent More Stringent than the Preferred Alternative

Alternative 4 represents a modeled alternative which is 20 percent more stringent 

than the preferred approach. The agencies derived the stringency level based on similar 

goals as for Alternative 2. Specifically, we wanted an alternative that would reflect an 

incremental improvement over the preferred alternative based on adding the next most 

cost effective technology in each of the categories. We believed these were the 

technologies most likely to be attempted by manufacturers if a more stringent standard 

were established. As discussed above and in the feasibility discussion in Section III, we 

are not finalizing Alternative 4 because we do not believe that the technologies used in 

this alternative can be developed and introduced in the time frametime frame of this 

rulemaking. We note that the estimated costs for this alternative are denoted as ‘+c.’ The 

+c is intended to make clear that the cost estimates we are showing do not include 

additional costs related to pulling ahead the development and expanding manufacturing 

base for the additional technologies (for example, building new factories in the next few 

years). The resulting Alternative 4 is based on the same technologies used in Alternative 

3 except as follows for each of the three categories.

The combination tractor standard would be based on the addition of Rankine 

waste heat recovery systems and 100 percent application of advanced aerodynamic 

technologies, such as underbody airflow treatment, advanced gap reduction, rearview 

cameras to replace mirrors, and wheel system streamlining, to high roof sleeper cab 

combination tractors. The agencies do not believe that either advanced aerodynamic 

technologies or Rankine waste heat recovery systems should be used to set the standard 

for HD engines in 2017 MY because this technology is still in the research phase. The 

agencies assumed 59 percent of all combination tractors are sleeper cabs and of those, 80 
188 of 

percent are high roof sleeper cabs. The agencies assumed a 12 kWh waste heat recovery

system would reduce CO2 emissions by 6 percent at a cost of $8,400 per truck.298 The 

estimated reduction in CO2 emissions from the engine for this alternative is included in 

RIA Chapter 6. The impact of 100 percent application of the advanced aerodynamic 

technology package would lead to a total 20.7 percent reduction in Cd values for high 

roof sleeper cabs over a 2010 MY baseline tractor. The incremental cost of this 

technology over the preferred case is $1,027 per vehicle. 

The HD pickup truck and van standard would be based on the addition of the 

turbocharged, downsized technology to gasoline engines which would bring the total 

reduction for gasoline HD pickup trucks and vans to 15 percent and match the level of 

reduction for the diesel pickup trucks. The agencies do not consider this to be a 

technology from which the 2017MY gasoline HD pickup truck standards should be 

premised on because we are not yet convinced that turbocharged downsized gasoline 

engines can be applied to heavy-duty truck applications in a durable manner. We are 

aware that manufacturers are testing such engines and that in pickup trucks with a duty

cycle representing a mix of passenger vehicle and work applications the engines can be 

durable. However, we are unable to conclude today that such engines will be durable and 

hence technically feasible when applied in heavy-duty truck applications with an 

expected higher average load factor. The estimated incremental cost increase to HD 

pickup trucks and vans to replace a stoichiometric gasoline direct injected V8 engine with 

coupled cam phasing used in Alternative 3 with a V6 stoichiometric gasoline direct 

injection DOHC with dual cam phasing, discrete valve lift, and twin turbochargers is 

estimated to be $1,743.299

The vocational vehicle standard would be based on the addition hybrid 

powertrains to 6 percent of the vehicles. The agencies assumed a 32 percent per vehicle 

reduction in GHG emissions and fuel consumption due to the hybrid with a cost of 

$26,667 per vehicle based on the average effectiveness and costs developed in the NAS 

report for box trucks, bucket trucks, and refuse haulers.300 

(5) Alternative 5: Trailers Plus Accelerated Hybrid

Alternative 5 builds on Alternative 4 through additional hybrid powertrain 

application rates in the HD sector and by adding a performance standard for fuel 

efficiency and GHG emissions to commercial trailers. This alternative includes all 

elements of Alternative 4 (some of which we already regard as infeasible in the model 

years covered by the final rules), plus the application of additional hybrid powertrains to 

the pickup trucks, vans, vocational vehicles, and tractors. In addition, the agencies 

applied aerodynamic technologies to commercial box trailers, along with tire 

technologies for all commercial trailers. 

The agencies set the hybrid penetration for each category such that it represents 

50 percent of the HD pickup truck and van segment, 50 percent of vocational vehicles, 

 

298 TIAX. 2009. Page 4-20.

299 See RIA Chapter 2, Table 2.35.

300 NAS Report. Page 146.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

189 of

and 5 percent of tractors in 2017 model year. The agencies have concluded that it is not 

feasible to achieve hybrid technology penetration rates at or even near these levels in the 

time frametime frame of this rulemaking. As with Alternative 4, we include a +c in our 

cost estimates for this alternative to reflect additional costs not estimated by the agencies. 

The agencies assumed that a hybrid powertrain would provide a 32 percent reduction in 

CO2 emissions and fuel consumption of a vocational vehicle at a projected cost of 

$26,667 per vehicle, based on the average of the NAS report findings for box trucks, 

bucket trucks, and refuse vehicles.301 The agencies are projecting a cost of $9,000 per 

vehicle for the HD pickup trucks and vans with an effectiveness of 18 percent, again 

based on the NAS report.302 Lastly, the effectiveness of hybrid powertrains installed in 

tractors was assumed to be 10 percent at a cost of $25,000 based on the NAS report.303

The combination tractor technology package for Alternative 5 includes the 

preferred alternative technologies, waste heat recovery and Advanced SmartWay

aerodynamic package used in Alternative 4, and application of hybrid powertrains 

discussed above, in addition to a regulation for commercial trailers pulled by combination 

tractors. The agencies assumed a box trailer program would mirror the SmartWay

program and include tire and aerodynamic requirements. The agencies added low rolling 

resistance tires to all commercial trailers, which are assumed to have 15 percent lower 

rolling resistance than the baseline trailer tire which is equivalent to the target value 

required by SmartWay. The aerodynamics of the box trailers were assumed to improve 

the coefficient of drag for the combination tractor-trailer by 10 percent through the 

application of technologies such as trailer skirts and gap reducers.304 These technologies 

would result in further reductions in drag coefficient and rolling resistance coefficient 

from the MY 2010 baseline. As stated above for hybrids, the agencies do not believe that 

it is possible to achieve technology penetration rates at or even near these levels in the 

time frametime frame of this rulemaking. 

The combination tractor costs for this alternative are equal to the costs in 

Alternative 4, plus $25,000 for hybrid powertrains in ten percent of tractors, plus the 

costs of trailers. The costs for the trailer program of Alternative 5 were derived based on 

the assumption that trailer aerodynamic improvements would cost $2,150 per trailer. 

This cost assumes side fairings and gap reducers and is based on the ICF cost estimate.305 

The agencies applied the aerodynamic improvement to only box trailers, which represent 

approximately 60 percent of the trailer sales. The agencies used $528 per trailer (2014 

MY cost) for low rolling resistance based on the agencies’ estimate of $66 per tire in the 

tractor program. Lastly, the agencies assumed the trailer volume is equal to three times 

the tractor volume based on the 3:1 ratio of trailers to tractors in the market today. 

 

301 NAS Report. Page 146.

302 NAS Report. Page 146.

303 NAS Report. Page 146.

304 The Cd improvement of 10 percent for trailer improvements was derived from the TIAX report, Table 4-

26 on page 4-50.

305 Assumed retail prices of $1,300 for side skirts and $850 for gap reducers based on the ICF Cost Report, 

page 90.
190 of 

B. How Do These Alternatives Compare in Overall GHG Emissions 

Reductions and Fuel Efficiency and Cost?

The agencies analyzed all five alternatives through the MOVES model to evaluate 

the impact of each alternative, as shown in Table IX-1. The table contains the annual CO2

and fuel savings in 2030 and 2050 for each alternative (relative to the reference scenario 

of Alternative 1), presenting both the total savings across all regulatory categories, and 

for each regulatory category. 

Table IX-2 presents the annual technology costs associated with each alternative 

(relative to the reference scenario of Alternative 1) in 2030 and 2050 for each regulatory

category. In addition, the total annual downstream impacts of NOX, CO, PM, and VOC 

emissions in 2030 for each of the alternatives are included in Table IX-3. 

Lastly, the agencies project the monetized net benefits associated with each 

alternative in 2030 and 2050 as shown in Table IX-4 and Table IX-5.

Table IX-1: Annual CO2 and Oil Reductions Relative to Alternative 1 in 2030 and 2050

DOWNSTREAM CO2

REDUCTIONS (MMT)

OIL REDUCTIONS 

(BILLION GALLONS)

2030 2050 2030 2050

Alt. 1 Baseline 0 0 0 0

Alt. 1a AEO 2011 Baseline- Total 39 90 3.9 9.0

Tractors 29 73 2.9 7.1

HD Pickup Trucks 9 16 0.9 1.7

Vocational Vehicles 1 2 0.1 0.2

Alt. 2 Less Stringent- Total 54 78 5.4 7.7

Tractors 42 59 4.2 5.8

HD Pickup Trucks 7 11 0.8 1.2

Vocational Vehicles 5 7 0.4 0.7

Alt. 3 Preferred – Total 61 88 6.0 8.7

Tractors 45 63 4.4 6.2

HD Pickup Trucks 8 13 0.9 1.3

Vocational Vehicles 7 11 0.7 1.1

Alt. 4 More Stringent– Total 74 107 7.4 10.7

Tractors 53 74 5.2 7.3

HD Pickup Trucks 10 15 1.0 1.6

Vocational Vehicles 11 18 1.1 1.8

Alt. 5 Max Technology– Total 99 146 9.8 14.5

Tractors 61 85 6.0 8.3

HD Pickup Trucks 15 24 1.6 2.5

Vocational Vehicles 23 37 2.2 3.6
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

191 of

Table IX-2: Technology Cost Projections Relative to Alternative 1 for Each Alternativea

TECHNOLOGY COSTS (2009$ MILLIONS)

2030 2050

Alt. 1 Baseline $0 $0

Alt. 1a AEO 2011 Baseline –

Total b

-- --

Tractors -- --

HD Pickup Trucks -- --

Vocational Vehicles -- --

Alt. 2 Less Stringent – Total $1,676 $2,440

Tractors $743 $1,227

HD Pickup Trucks $817 $1,029

Vocational Vehicles $117 $185

Alt. 3 Preferred – Total $2,210 $3,287

Tractors $1,076 $1,777

HD Pickup Trucks $918 $1,156

Vocational Vehicles $216 $354

Alt. 4 More Stringent – Total $5,211+c $6,996+c

Tractors $1,953+c $3,225+c

HD Pickup Trucks $1,442+c $1,816+c

Vocational Vehicles $1,816+c $1,954+c

$17,909+c $27,306+c Alt. 5 Max Technology – Total $2,747+c $4,292+c

Tractors $5,669+c $7,142+c

HD Pickup Trucks $9,493+c $15,873+c

Vocational Vehicles $5,211+c $6,996+c

Notes:

a The +c is intended to make clear that the cost estimates we are showing do not include 

additional costs related to pulling ahead the development and expanding manufacturing 

base for these technologies.

b The agencies did not conduct a cost analysis for the AEO2011 baseline.

Table IX-3: Downstream Impacts Relative to Alternative 1 of Key Non-GHGs for Each Alternative 

in 2030

NOX CO PM2.5 VOC

Alt. 1 Baseline 0% 0% 0% 0%

Alt. 1a AEO 2011 

Baseline 8.8% 1.0% -3.8% 7.2%

Alt. 2 Less Stringent -21.9% -2.0% 8.4% -19.0%

Alt. 3 Preferred -22.0% -2.0% 8.5% -19.1%

Alt. 4 More Stringent -22.5% -2.0% 8.7% -19.5%

Alt. 5 Max Technology

-22.9% -2.1% 8.4%

(1) -

20.0%
192 of 

Table IX-4: Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year Vehicles(3% discount rate, Million 2009 dollars)

Alt.1 

Baseline

Alt.2 Less 

Stringent

Alt.3 

Preferred

Alt.4 More 

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$5,900 -$8,100 -$20,700+c -$37,200+c

Fuel Savings (pre-tax) $0 $45,000 $50,100 $63,900 $79,100

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $1,100 $1,200 $1,600 $1,900

3% (avg SCC) $0 $5,100 $5,700 $7,200 $9,000

2.5% (avg SCC) $0 $8,400 $9,400 $12,000 $15,000

3% (95th percentile) $0 $16,000 $17,000 $22,000 $27,000

Energy Security Impacts (price 

shock) $0

$2,400 $2,700 $3,400 $4,200

Accidents, Congestion, Noise $0 -$1,300 -$1,500 -$1,600 -$1,600

Refueling Savings $0 $300 $400 $500 $600

Non-CO2 GHG Impacts and 

Non-GHG Impacts c N/A N/A N/A N/A N/A

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $41,600 $44,800 $47,100+c $47,000+c

3% (avg SCC) $0 $45,600 $49,300 $52,700+c $54,100+c

2.5% (avg SCC) $0 $48,900 $53,000 $57,500+c $60,100+c

3% (95th percentile) $0 $56,500 $60,600 $67,500+c $72,100+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 

percent) is used to calculate net present value of SCC for internal consistency. Refer to the SCC TSD 

for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG 

emissions expected under this rulemaking (see RIA Chapter 5). Although EPA has not monetized 

changes in non-CO2 GHGs, the value of any increases or reductions should not be interpreted as zero. 

d “+c” indicates additional costs not estimated in this rulemaking.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

193 of

Table IX-5 Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year Vehicles(7% discount rate, Million 2009 dollars)

Alt.1

Baseline

Alt.2 Less 

Stringent

Alt.3 

Preferred

Alt.4 More 

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$5,900 -$8,100 -

$20,700+c

-$37,200+c

Fuel Savings (pre-tax) $0 $30,900 $34,400 $43,800 $53,900

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $1,100 $1,200 $1,600 $1,900

3% (avg SCC) $0 $5,100 $5,700 $7,200 $9,000

2.5% (avg SCC) $0 $8,400 $9,400 $12,000 $15,000

3% (95th percentile) $0 $16,000 $17,000 $22,000 $27,000

Energy Security Impacts (price 

shock)

$0 $1,600 $1,800 $2,300 $2,900

Accidents, Congestion, Noise $0 -$900 -$1,000 -$1,100 -$1,100

Refueling Savings $0 $200 $200 $300 $400

Non-CO2 GHG Impacts and 

Non-GHG Impacts c

N/A N/A N/A N/A N/A

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $27,000 $28,500 $26,200+c $20,800+c

3% (avg SCC) $0 $31,000 $33,000 $31,800+c $27,900+c

2.5% (avg SCC) $0 $34,300 $36,700 $36,600+c $33,900+c

3% (95th percentile) $0 $41,900 $44,300 $46,600+c $45,900+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 

percent) is used to calculate net present value of SCC for internal consistency. Refer to the SCC TSD 

for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c The monetized GHG benefits presented in this analysis exclude the value of changes in non-CO2 GHG 

emissions expected under this rulemaking (see RIA Chapter 5). Although EPA has not monetized 

changes in non-CO2 GHGs, the value of any increases or reductions should not be interpreted as zero. 

d “+c” indicates additional costs not estimated in this rulemaking.The agencies also project 

the monetized net benefits associated with each alternative by vehicle class for the 2014 

through 2018 MY vehicles over their lifetimes as shown in Table IX-6 through Table 

IX-8 at a 3 percent discount rate for HD pickup trucks & vans, vocational vehicles and 

combination tractors, respectively, and in Table IX-9 through Table IX-11 at a 7 percent

discount rate for HD pickup trucks & vans, vocational vehicles and combination tractors, 

respectively.
194 of 

Table IX-6 Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year HD Pickup Trucks & Vans (3% discount rate, Million 

2009 dollars)

Alt.1

Baseline

Alt.2 Less 

Stringent

Alt.3

Preferred

Alt.4 More 

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$1,780 -$1,970 -$3,220+c -$9,890+c

Fuel Savings (pre-tax) $0 $3,480 $4,060 $4,910 $7,700

Energy Security Impacts (price 

shock)

$0

$190 $220 $270 $420

Accidents, Congestion, Noise $0 -$330 -$350 -$370 -$350

Refueling Savings $0 $40 $50 $60 $90

Non-CO2 GHG Impacts and 

Non-GHG Impacts c

N/A N/A N/A N/A N/A

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $100 $100 $100 $200

3% (avg SCC) $0 $500 $500 $600 $900

2.5% (avg SCC) $0 $800 $900 $1,100 $1,500

3% (95th percentile) $0 $1,400 $1,600 $1,900 $2,800

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $1,700 $2,110 $1,750+c -$1,830+c

3% (avg SCC) $0 $2,100 $2,510 $2,250+c -$1,130+c

2.5% (avg SCC) $0 $2,400 $2,910 $2,750+c -$530+c

3% (95th percentile) $0 $3,000 $3,610 $3,550+c $770+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 percent) is 

used to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and SO2) 

were not estimated for this analysis. Although EPA has not monetized changes in non-CO2 GHGs, the 

value of any increases or reductions should not be interpreted as zero.

d “+c” indicates additional costs not estimated in this rulemaking.

Table IX-7 Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year Vocational Vehicles (3% discount rate, Million 2009

dollars)
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

195 of

Alt.1

Baseline

Alt.2 Less 

Stringent

Alt.3

Preferred

Alt.4 More 

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$670 -$1,140 -$9,140+c -$15,840+c

Fuel Savings (pre-tax) $0 $3,420 $5,420 $8,930 $14,270

Energy Security Impacts (price 

shock)

$0

$180 $290 $480 $760

Accidents, Congestion, Noise $0 -$540 -$650 -$670 -$500

Refueling Savings $0 $40 $60 $110 $170

Non-CO2 GHG Impacts and 

Non-GHG Impacts c

N/A N/A N/A N/A N/A

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $100 $100 $200 $300

3% (avg SCC) $0 $400 $600 $1,000 $1,500

2.5% (avg SCC) $0 $700 $1,100 $1,700 $2,600

3% (95th percentile) $0 $1,300 $1,900 $3,100 $4,700

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $2,530 $4,080 -$90+c -$840+c

3% (avg SCC) $0 $2,830 $4,580 $710+c $360+c

2.5% (avg SCC) $0 $3,130 $5,080 $1,410+c $1,460+c

3% (95th percentile) $0 $3,730 $5,880 $2,810+c $3,560+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The 

same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 

2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to the 

SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the 

SCC estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-

$46; for Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section 

VIII.G also presents these SCC estimates.

c Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and 

SO2) were not estimated for this analysis. Although EPA has not monetized changes in non-CO2

GHGs, the value of any increases or reductions should not be interpreted as zero.

d “+c” indicates additional costs not estimated in this rulemaking.

Table IX-8 Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year Combination Tractors (3% discount rate, Million 2009

dollars)
196 of 

Alt.1

Baseline

Alt.2 Less 

Stringent

Alt.3

Preferred

Alt.4 More 

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$3,300 -$4,950 -$8,430+c -$11,540+c

Fuel Savings (pre-tax) $0 $38,140 $40,650 $50,030 $57,190

Energy Security Impacts (price 

shock)

$0

$2,030 $2,160 $2,660 $3,040

Accidents, Congestion, Noise $0 -$450 -$480 -$590 -$770

Refueling Savings $0 $230 $250 $300 $350

Non-CO2 GHG Impacts and 

Non-GHG Impacts c

N/A N/A N/A N/A N/A

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $900 $1,000 $1,200 $1,400

3% (avg SCC) $0 $4,200 $4,500 $5,600 $6,500

2.5% (avg SCC) $0 $7,000 $7,500 $9,300 $11,000

3% (95th percentile) $0 $13,000 $14,000 $17,000 $20,000

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $37,550 $38,630 $45,170+c $49,670+c

3% (avg SCC) $0 $40,850 $42,130 $49,570+c $54,770+c

2.5% (avg SCC) $0 $43,650 $45,130 $53,270+c $59,270+c

3% (95th percentile) $0 $49,650 $51,630 $60,970+c $68,270+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The 

same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 

2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to the 

SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the 

SCC estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-

$46; for Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section 

VIII.G also presents these SCC estimates.

c Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and 

SO2) were not estimated for this analysis. Although EPA has not monetized changes in non-CO2

GHGs, the value of any increases or reductions should not be interpreted as zero.

d “+c” indicates additional costs not estimated in this rulemaking.

Table IX-9 Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year HD Pickup Trucks & Vans (7% discount rate, Million 

2009 dollars)
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

197 of

Alt.1

Baseline

Alt.2 Less 

Stringent

Alt.3

Preferred

Alt.4 More 

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$1,780 -$1,970 -$3,220+c -$9,890+c

Fuel Savings (pre-tax) $0 $2,180 $2,550 $3,090 $4,830

Energy Security Impacts (price 

shock)

$0

$120 $140 $170 $260

Accidents, Congestion, Noise $0 -$220 -$230 -$250 -$230

Refueling Savings $0 $30 $30 $40 $60

Non-CO2 GHG Impacts and 

Non-GHG Impacts c

N/A N/A N/A N/A N/A

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $100 $100 $100 $200

3% (avg SCC) $0 $500 $500 $600 $900

2.5% (avg SCC) $0 $800 $900 $1,100 $1,500

3% (95th percentile) $0 $1,400 $1,600 $1,900 $2,800

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $430 $620 -$70+c -$4,770+c

3% (avg SCC) $0 $830 $1,020 $430+c -$4,070+c

2.5% (avg SCC) $0 $1,130 $1,420 $930+c -$3,470+c

3% (95th percentile) $0 $1,730 $2,120 $1,730+c -$2,170+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The 

same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 

2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to the 

SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the 

SCC estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-

$46; for Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section 

VIII.G also presents these SCC estimates.

c Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and 

SO2) were not estimated for this analysis. Although EPA has not monetized changes in non-CO2

GHGs, the value of any increases or reductions should not be interpreted as zero.

d “+c” indicates additional costs not estimated in this rulemaking.

Table IX-10 Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year Vocational Vehicles (7% discount rate, Million 2009

dollars)
198 of 

Alt.1

Baseline

Alt.2 Less 

Stringent

Alt.3

Preferred

Alt.4 More 

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$670 -$1,140 -$9,140+c -$15,840+c

Fuel Savings (pre-tax) $0 $2,280 $3,630 $5,970 $9,410

Energy Security Impacts (price 

shock)

$0

$120 $190 $320 $500

Accidents, Congestion, Noise $0 -$380 -$450 -$460 -$350

Refueling Savings $0 $30 $40 $70 $110

Non-CO2 GHG Impacts and 

Non-GHG Impacts c

N/A N/A N/A N/A N/A

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $100 $100 $200 $300

3% (avg SCC) $0 $400 $600 $1,000 $1,500

2.5% (avg SCC) $0 $700 $1,100 $1,700 $2,600

3% (95th percentile) $0 $1,300 $1,900 $3,100 $4,700

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $1,480 $2,370 -$3,040+c -$5,870+c

3% (avg SCC) $0 $1,780 $2,870 -$2,240+c -$4,670+c

2.5% (avg SCC) $0 $2,080 $3,370 -$1,540+c -$3,570+c

3% (95th percentile) $0 $2,680 $4,170 -$140+c -$1,470+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The 

same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 

2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to the 

SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the 

SCC estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-

$46; for Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section 

VIII.G also presents these SCC estimates.

c Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and 

SO2) were not estimated for this analysis. Although EPA has not monetized changes in non-CO2

GHGs, the value of any increases or reductions should not be interpreted as zero.

d “+c” indicates additional costs not estimated in this rulemaking.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

199 of

Table IX-11 Monetized Net Benefits Associated with Each Alternative Relative to Alternative 1 for 

Lifetime of 2014 through 2018 Model Year Combination Tractors (7% discount rate, Million 2009

dollars)

Alt.1

Baseline

Alt.2 Less 

Stringent

Alt.3

Preferred

Alt.4 More

Stringent

Alt.5 Max 

Technology

Truck Program Costs d$0 -$3,300 -$4,950 -$8,430+c -$11,540+c

Fuel Savings (pre-tax) $0 $26,420 $28,170 $34,710 $39,680

Energy Security Impacts (price 

shock)

$0

$1,410 $1,500 $1,850 $2,110

Accidents, Congestion, Noise $0 -$320 -$340 -$420 -$550

Refueling Savings $0 $160 $170 $210 $240

Non-CO2 GHG Impacts and 

Non-GHG Impacts c

N/A N/A N/A N/A N/A

Reduced CO2 Emissions at Each Assumed SCC Value a,b

5% (avg SCC) $0 $900 $1,000 $1,200 $1,400

3% (avg SCC) $0 $4,200 $4,500 $5,600 $6,500

2.5% (avg SCC) $0 $7,000 $7,500 $9,300 $11,000

3% (95th percentile) $0 $13,000 $14,000 $17,000 $20,000

Monetized Net Benefits at Each Assumed SCC Value a,b

5% (avg SCC) $0 $25,270 $25,550 $29,120+c $31,340+c

3% (avg SCC) $0 $28,570 $29,050 $33,520+c $36,440+c

2.5% (avg SCC) $0 $31,370 $32,050 $37,220+c $40,940+c

3% (95th percentile) $0 $37,370 $38,550 $44,920+c $49,940+c

Notes: 

a Net present value of reduced CO2 emissions is calculated differently than other benefits. The same 

discount rate used to discount the value of damages from future emissions (SCC at 5, 3, and 2.5 percent) is 

used to calculate net present value of SCC for internal consistency. Refer to the SCC TSD for more detail. 

b

Section VIII.G notes that SCC increases over time. Corresponding to the years in this table, the SCC 

estimates range as follows: for Average SCC at 5%: $5-$16; for Average SCC at 3%: $22-$46; for 

Average SCC at 2.5%: $36-$66; and for 95th percentile SCC at 3%: $66-$139. Section VIII.G also 

presents these SCC estimates.

c Due to analytical and resource limitations, MY non-GHG emissions (direct PM, VOCs, NO2 and SO2) 

were not estimated for this analysis. Although EPA has not monetized changes in non-CO2 GHGs, the 

value of any increases or reductions should not be interpreted as zero.

d “+c” indicates additional costs not estimated in this rulemaking.

C. What Is the Agencies’ Decision Regarding Trailer Standards?

A central theme throughout our HD Program is the recognition of the diversity

and complexity of the heavy-duty vehicle segment. Trailers are an important part of this 

segment and are no less diverse in the range of functions and applications they serve. 

They are the primary vehicle for moving freight in the United States. The type of freight 

varies from retail products to be sold in stores, to bulk goods such as stones, to industrial 

liquids such as chemicals, to equipment such as bulldozers. Semi-trailers come in a large 

variety of styles – box, refrigerated box, flatbed, tankers, bulk, dump, grain, and many

others. The most common type of trailer is the box trailer, but even box trailers come in 
200 of 

many different lengths ranging from 28 feet to 53 feet or greater, and in different widths, 

heights, depths, materials (wood, composites, and/or aluminum), construction (curtain 

side or hard side), axle configuration (sliding tandem or fixed tandem), and multiple other 

distinct features. NHTSA and EPA believe trailers impact the fuel consumption and CO2

emissions from combination tractors and the agencies see opportunities for reductions. 

Unlike our experience with trucks and engines, the agencies have very limited experience 

related to regulating trailers for fuel efficiency or emissions. Likewise, the trailer 

manufacturing industry has only the most limited experience complying with regulations 

related to emissions and none with regard to EPA or NHTSA certification and 

compliance procedures.

The agencies broadly solicited comments on controlling fuel efficiency and GHG 

emissions through eventual trailer regulations as we described in the notice of proposed 

rulemaking which could set the foundation of a future rulemaking for trailers. 75 FR at 

74345-351 (although this was a solicitation for comment regarding future action outside 

the present rulemaking). 

The general theme of the comments received was that technologies exist today

that can improve trailer efficiency. We received several comments from stakeholders 

which encouraged the agencies to set fuel efficiency and GHG emissions standards for 

trailers in this rulemaking. The agencies also received comments supporting a delay in 

trailer regulations. Specifically, IPI commented that the agencies should regulate trailers 

at least to some degree, arguing that the agencies’ reasoning for not doing so was 

insufficient and requesting a plan and schedule in the final rule for the future regulation 

of trailers. One commenter recognized that there are well over 100 trailer manufacturers 

in the U.S., with almost all being small businesses. They stressed the need for the 

agencies to reach out to the trailer industry and associations prior to developing a 

regulatory program for this industry. In addition, they stated that time is needed to 

develop sufficient research into the area. None of the commenters that supported trailer 

regulation in this action addressed the complexities of the trailer industry, nor a method 

to measure trailer aerodynamic improvements

In the NPRM, the agencies discussed relatively conceptual approaches to how a 

future trailer regulation could be developed; however, we did not provide a proposed test

procedure or proposed standard. The agencies proposed to delay the regulation of 

trailers, as the inclusion would not be feasible at this time due to the lack of a test 

procedure and the myriad of technical and policy issues not teed up in the NPRM or 

addressed in comments. Additionally, since a number of trailer manufacturing entities 

are small businesses, EPA and NHTSA need to allow sufficient time to convene a 

SBREFA panel to conduct the proper outreach to the potentially impacted stakeholders. 

NHTSA and EPA agree that the regulation of trailers, when appropriate, is likely to 

provide fuel efficiency benefits. We continue to believe that both agencies must perform 

a more comprehensive assessment of the trailer industry, and therefore that their 

inclusion at this time is not feasible. Until that time, the SmartWay Transport Partnership 

Program will continue to encourage the development and use of technologies to reduce 

fuel consumption and CO2 emissions from trailers.
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

201 of

X. Public Participation 

The agencies proposed their respective rules on November 30, 2010 (75 FR 

74152). Two public hearings were held to provide interested parties the opportunity to 

present data, views, or arguments concerning the proposal; the first hearing was held in 

Chicago, IL on November 15, 2010, and the second in Cambridge, MA on November 18, 

2010. The public was invited to submit written comments on the proposal during the 

formal comment period, which ended on January 31, 2011. The agencies received over 

41,000 comments - over 3,000 of them unique - from industry, environmental 

organizations, states, and individuals.

The vast majority of commenters supported the central tenets of the proposed HD 

National Program. That is, there was broad support for a national program which would 

reduce fuel consumption and GHG emissions from the three heavy-duty regulatory

categories – heavy-duty pickup trucks and vans, vocational vehicles, and combination 

tractors. The agencies received specific comments on many aspects of the proposal. 

Throughout this notice, the agencies discuss many of the key issues arising from 

the public comments and the agencies’ responses. In addition, the agencies have 

addressed all of the public comments in the Response to Comments document associated 

with this final action and located in the docket (Docket ID EPA–HQ–OAR–2010–0162, 

or NHTSA-2010-0079). 

XI. NHTSA’s Record of Decision

On May 21, 2010, President Obama issued a memorandum entitled “Improving 

Energy Security, American Competitiveness and Job Creation, and Environmental 

Protection through a Transformation of our Nation’s Fleet of Cars and Trucks” to the 

Secretary of Transportation, the Administrator of NHTSA, the Administrator of EPA, and 

the Secretary of Energy.

306 The memorandum requested that the Administrators of EPA 

and NHTSA begin work on a Joint Rulemaking under EISA and the Clean Air Act and 

establish fuel efficiency and GHG emission standards for commercial medium- and 

heavy-duty vehicles beginning with MY 2014. The President requested that NHTSA

implement fuel efficiency standards and EPA implement GHG emission standards that 

take into account the market structure of the trucking industry and the unique demands of 

heavy-duty vehicle applications; seek harmonization with applicable State standards; 

consider the findings and recommendations published in the National Academy of 

Sciences (NAS) report on medium- and heavy-duty truck regulation; strengthen the 

industry and enhance job creation in the United States; and seek input from all 

stakeholders, while recognizing the continued leadership role of California and other 

States.

 

306 The White House, Office of the Press Secretary, Presidential Memorandum Regarding Fuel Efficiency 

Standards (May 21, 2010); The White House, Office of the Press Secretary, President Obama Directs 

Administration to Create First-Ever National Efficiency and Emissions Standards for Medium- and HeavyDuty Trucks (May 21, 2010). 
202 of 

In accordance with this policy, this Final Rule promulgates fuel efficiency

standards for HD vehicles built in MYs 2014-2018. This Final Rule constitutes the 

Record of Decision (ROD) for NHTSA’s HD vehicle Fuel Efficiency Improvement 

Program, pursuant to the National Environmental Policy Act (NEPA) and the Council on 

Environmental Quality’s (CEQ) implementing regulations.307 See 40 CFR § 1505.2. 

As required by CEQ regulations, this Final Rule and ROD sets forth the 

following: (1) the agency’s decision; (2) alternatives considered by NHTSA in reaching 

its decision, including the environmentally preferable alternative; (3) the factors balanced 

by NHTSA in making its decision, including considerations of national policy; (4) how 

these factors and considerations entered into its decision; and (5) the agency’s 

preferences among alternatives based on relevant factors, including economic and 

technical considerations and agency statutory missions. This Final Rule also briefly

addresses mitigation.

A. The Agency’s Decision

In the Draft Environmental Impact Statement (DEIS) and the Final Environmental 

Impact Statement (FEIS), the agency identified a Preferred Alternative which would set 

overall fuel consumption standards for HD vehicles and engines. The Preferred 

Alternative, identified as Alternative 3 in the FEIS, would include standards for engines 

used in Classes 2b-8 vocational vehicles (except engines in HD pickups and vans, which 

are regulated as complete vehicles), fuel consumption standards for HD pickups and vans 

by work factor, overall vehicle fuel consumption standards for Classes 2b-8 vocational 

vehicles (in gal/1,000 ton-miles), and overall fuel consumption standards for Classes 7 

and 8 tractors. 

The Preferred Alternative identified in the NPRM, DEIS, and FEIS assumed that 

the vocational vehicle standards would lead to a 10 percent reduction in the tire rolling 

resistance levels of the tires installed in vocational vehicles. After carefully reviewing 

and analyzing all of the information in the public record including technical support 

documents, the FEIS, and public and agency comments submitted on the DEIS, the FEIS, 

and the NPRM, NHTSA has decided to finalize a standard that includes slightly more 

stringent requirements for vocational vehicles than those included in the Preferred 

Alternative analyzed in the FEIS. Subsequent to issuing the proposed rule, NHTSA and 

EPA conducted a tire testing program to evaluate the tire rolling resistance of 156 

different tires across a wide range of truck applications. The results of the study indicate 

that the baseline tire rolling resistance of this segment of vehicles was better than the 

level assumed during the proposal. In the final action, therefore, the agencies made the 

vocational truck standards slightly more stringent than those included as part of the 

Preferred Alternative for the FEIS, reflecting the better overall performance of tires in 

this segment. In addition, the agencies have reduced the projected improvement in 

 

307 NEPA is codified at 42 U.S.C. §§ 4321-47. CEQ NEPA implementing regulations are codified at 40 

Code of Federal Regulations (CFR) Parts 1500-08. 
*** E.O. 12866 Review – Draft – Do Not Cite, Quote, or Release During Review ***

203 of

average tire performance from 10 percent to 5 percent, reflecting the better than expected 

baseline performance. NHTSA’s analysis indicates that the Agency’s Decision will 

result in slightly less fuel savings and CO2 emissions reductions than those noted in the 

EIS.308 For environmental impacts associated with the final rule, see Sections VI.C and 

VII of this Final Rule.309

B. Alternatives Considered by NHTSA in Reaching its Decision, 

Including the Environmentally Preferable Alternative

When preparing an EIS, NEPA requires an agency to compare the potential 

environmental impacts of its proposed action and a reasonable range of alternatives. In 

the FEIS, NHTSA identified alternatives that represent the spectrum of potential actions 

the agency could take. The environmental impacts of these alternatives, in turn, represent 

the spectrum of potential environmental impacts that could result from NHTSA’s chosen 

action in setting fuel efficiency standards for HD vehicles. 

The FEIS analyzed the impacts of four “action” alternatives, each of which would 

separately regulate segments of the HD vehicle fleet.310 Three of the action alternatives 

(Alternatives 2, 3 and 4) would regulate the same vehicle categories, but at increasing

levels of stringency, with Alternative 2 being the least stringent alternative and 

Alternative 4 being the most stringent. Alternatives 2 and 4 were constructed by starting 

with the Preferred Alternative (Alternative 3) and either removing the least cost effective 

technology in each of the vehicle categories or adding the next most cost effective 

technology in each of the vehicle categories.311 

Alternative 5 built on the Preferred Alternative by adding a performance standard 

for the commercial trailers pulled by tractors and by specifying more stringent standards 

based on accelerated adoption of hybrid powertrains for HD vehicles. The DEIS and 

FEIS also analyzed the impacts that would be expected if NHTSA adopted no HD vehicle 

standards (the No Action Alternative). For a discussion of the environmental impacts 

associated with each of the alternatives, see Chapters 3 and 4 of the FEIS.

 

308 The agencies’ analysis indicates that the change results in a decrease in total 2014-2050 fuel savings of 

about 1.05% percent compared to the Preferred Alternative modeled in the EIS and a corresponding 

increase in CO2 emissions.

309 The environmental impacts of this decision fall within the spectrum of impacts analyzed in the DEIS 

and the FEIS. There are no “substantial changes to the proposed action” and there are no “significant new 

circumstances or information relevant to environmental concerns and bearing on the proposed action or its 

impacts.” Therefore, consistent with 40 CFR § 1502.9(c), no supplement to the EIS is required.

310 In the DEIS, NHTSA analyzed several alternatives that applied only to specific components and/or 

segments of the HD vehicle fleet. Many commenters urged the agency to consider alternatives that applied 

to the entire HD vehicle fleet, reasoning that such an approach would be more consistent with EISA 

requirements. After careful consideration, NHTSA decided that those alternatives that would set standards 

for the whole fleet—that is, the engine as well as the entire vehicle for pickup trucks and vans, vocational 

vehicles, and tractors—best met the purpose and need for this action. It also allows for the achievement of 

the “maximum feasible improvement” in HD fuel efficiency. Therefore, the FEIS examined impacts 

associated with four of the action alternatives analyzed in the DEIS. 

311 See Section 2.3.2 of the FEIS.
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Along with the FEIS, the agency conducted a national-scale photochemical air 

quality modeling and health risk assessment for a subset of the DEIS alternatives to 

support and confirm the health effects and health-related economic estimates of the EIS. 

The photochemical air quality study is included as Appendix F to the FEIS. The study

used air quality modeling and health benefits analysis tools to quantify the air quality and 

health-related benefits associated with the alternative HD standards. 

NHTSA’s environmental analysis indicates that Alternative 5 (Trailers and 

Accelerated Hybrid) is the overall Environmentally Preferable Alternative because it 

would result in the largest reductions in fuel use and GHG emissions among the 

alternatives considered. Under each action alternative the agency considered, the 

reduction in fuel consumption resulting from higher fuel efficiency causes emissions that 

occur during fuel refining and distribution to decline. For most pollutants, this decline is 

more than sufficient to offset the increase in tailpipe emissions that results from increased 

driving due to the fuel efficiency rebound effect, leading to a net reduction in total 

emissions from fuel production, distribution, and use. Because it leads to the largest 

reductions in fuel refining, distribution, and consumption among the alternatives 

considered, Alternative 5 would also lead to the lowest total emissions of CO2 and other 

GHGs, as well as most criteria air pollutants and mobile source air toxics (MSATs).

312

NHTSA’s environmental analysis indicates that emissions of carbon monoxide 

(CO), acrolein, acetaldehyde, and formaldehyde are slightly (less than one percent)

higher under Alternative 5 than under some other action alternatives and analysis years. 

This occurs when increased tailpipe emissions are forecast to exceed the reductions in 

emissions due to reduced fuel refining and distribution. Thus, while Alternative 5 is the 

environmentally preferable alternative on the basis of CO2 and other GHGs, and on the 

basis of most criteria air pollutants and MSATs, other alternatives are environmentally

preferable from the standpoint of some criteria air pollutants and MSATs in some years. 

Overall, NHTSA considers Alternative 5 to be the Environmentally Preferable 

Alternative.

For additional discussion regarding the alternatives considered by the agency in 

reaching its decision, including the Environmentally Preferable Alternative, see Section 

IX of this Final Rule. For a discussion of the environmental impacts associated with each 

alternative, see Chapters 3 and 4 of the FEIS.

C. Factors Balanced by NHTSA in Making its Decision

For discussion of the factors balanced by NHTSA in making its decision, see 

Sections III, VIII and IX of this Final Rule.

 

312 Emissions of diesel particulate matter (DPM) and fine particulate matter (PM2.5) for Alternative 5 are 

forecast to be lower than under other action alternatives under all analysis years, but slightly higher than 

under the No Action Alternative in analysis years 2030 and 2050. See FEIS Table 3.5.2-5. This anomaly 

results from the agencies’ assumptions regarding the percent of all long-haul tractors that use an APU 

rather than the truck’s engine as a power source during extended idling (discussed further in FEIS Section 

3.2.4.1). 
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205 of

D. How the Factors and Considerations Balanced by NHTSA Entered 

into its Decision

For discussion of how the factors and considerations balanced by the agency 

entered into NHTSA’s Decision, see Sections III, VIII and IX of this Final Rule.

E. The Agency’s Preferences among Alternatives Based on Relevant 

Factors, Including Economic and Technical Considerations and 

Agency Statutory Missions

For discussion of the agency’s preferences among alternatives based on relevant 

factors, including economic and technical considerations, see Section VIII and IX of this 

Final Rule.

F. Mitigation

The CEQ regulations specify that a ROD must “state whether all practicable 

means to avoid or minimize environmental harm from the alternative selected have been 

adopted, and if not, why they were not.” 49 CFR § 1505.2(c). The majority of the 

environmental effects of NHTSA’s action are positive, i.e., beneficial environmental 

impacts, and would not raise issues of mitigation. Emissions of criteria and toxic air 

pollutants are generally projected to decrease under the final standards under all analysis 

years as compared to their levels under the No Action Alternative. Analysis of the 

environmental trends reported in the FEIS indicates that the only exceptions to this 

decline are emissions of PM2.5, DPM, and 1,3-butadiene in some analysis years. See 

Chapter 5 of the FEIS. The agency forecasts these emissions increases because, under all 

the alternatives analyzed in the EIS, increase in vehicle use due to improved fuel 

efficiency is projected to result in growth in total miles traveled by HD vehicles. The 

growth in travel outpaces emissions reductions for some pollutants, resulting in projected 

increases for these pollutants. In addition, NHTSA’s NEPA analysis predicted increases 

in emissions of air toxic and criteria pollutants to occur under certain alternatives based 

on assumptions about the use of Auxiliary Power Units (APUs). For example, NHTSA’s 

NEPA analysis assumes that some manufacturers will install anti-idling technologies 

(including APUs) on some vehicle classes to meet the requirements of the rule and that 

drivers’ subsequent use of those APUs will result in an increase in emissions of some 

criteria and toxic air pollutants.

NHTSA’s authority to promulgate new fuel efficiency standards for HD vehicles 

is limited and does not allow regulation of vehicle emissions or of factors affecting 

vehicle emissions, including driving habits and APU usage. Consequently, under the HD 

Fuel Efficiency Improvement Program, NHTSA must set standards but is unable to take 

steps to mitigate the impacts of these standards. Chapter 5 of the FEIS outlines a number 

of other initiatives across government that could ameliorate the environmental impacts of 

motor vehicle use, including the use of HD vehicles.
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XII. Statutory and Executive Order Reviews

(1) Executive Order 12866: Regulatory Planning and Review

Under section 3(f)(1) of Executive Order 12866 (58 FR 51735, October 4, 1993), 

this action is an “economically significant regulatory action” because it is likely to have 

an annual effect on the economy of $100 million or more. Accordingly, the agencies

submitted this action to the Office of Management and Budget (OMB) for review under 

Executive Order 12866 and any changes made in response to OMB recommendations 

have been documented in the docket for this action.

NHTSA is also subject to Executive Order 13563 (76 FR 3821, January 21, 2011) 

and the Department of Transportation’s Regulatory Policies and Procedures. These final

rules are also significant within the meaning of the DOT Regulatory Policies and 

Procedures. Executive Order 12866 additionally requires NHTSA to submit this action 

to OMB for review and document any changes made in response to OMB 

recommendations.

In addition, the agencies prepared an analysis of the potential costs and benefits 

associated with this action. This analysis is contained in the Regulatory Impact Analysis, 

which is available in the docket for these rules and at the docket internet address listed 

under ADDRESSES above.

(2) National Environmental Policy Act

Under NEPA, a Federal agency must prepare an Environmental Impact Statement 

(EIS) on proposed actions that could significantly impact the quality of the human 

environment. The requirement is designed to serve three major functions: (1) to provide 

the decisionmaker(s) with a detailed description of the potential environmental impacts of 

a proposed action prior to its adoption, (2) to rigorously explore and evaluate all 

reasonable alternatives, and (3) to inform the public of, and allow comment on, such 

efforts. 

In addition, the CEQ regulations emphasize agency cooperation early in the 

NEPA process and allow a lead agency (in this case, NHTSA) to request the assistance of 

other agencies that either have jurisdiction by law or have special expertise regarding 

issues considered in an EIS.313 At NHTSA’s request, both EPA and the Federal Motor 

Carrier Safety Administration (FMCSA) agreed to act as cooperating agencies in the 

preparation of the EIS. EPA has special expertise in climate change and air quality, and 

FMCSA has special expertise regarding HD vehicles. 

NHTSA, in cooperation with EPA and FMCSA, prepared a DEIS, solicited public 

comments in writing and in public hearings, and prepared an FEIS responding to those 

comments. Specifically, in June 2010, NHTSA published a Notice of Intent to prepare an 

 

313 40 CFR § 1501.6.
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EIS for proposed HD fuel efficiency standards.314 See 40 CFR § 1501.7. On October 29, 

2010, EPA issued its Notice of Availability of the DEIS,315 triggering a public comment 

period. See 40 CFR § 1506.10. The public was invited to submit written comments on 

the DEIS until January 3, 2011. NHTSA mailed (both electronically and through regular 

U.S. mail) copies of the DEIS to interested parties, including federal, state, and local 

officials and agencies; elected officials; environmental and public interest groups; Native 

American tribes; and other interested individuals. NHTSA and EPA held two hearings 

on the proposed rules and the EIS, the first on November 15, 2010 in Chicago, Illinois, 

and the second on November 18, 2010 in Cambridge, Massachusetts. 

NHTSA received 3,048 written comments to the DEIS and the NPRM. The 

transcript from the public hearing and written comments submitted to NHTSA are part of 

the administrative record and are available on the Federal Docket, which can be found 

online at http://www.regulations.gov, Reference Docket No. NHTSA-2010-0079. 

NHTSA reviewed and analyzed all comments received during the public comment period 

and revised the FEIS in response to comments on the EIS where appropriate.316 

On June 20, 2011, NHTSA submitted the FEIS to EPA. NHTSA also mailed 

(both electronically and through regular U.S. mail) the FEIS to interested parties and 

posted the FEIS on its website, http://www.nhtsa.gov/fuel-economy. On June 24, 2011, 

EPA published a Notice of Availability of the FEIS in the Federal Register.

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The FEIS analyzes and discloses the potential environmental impacts of the 

proposed HD fuel efficiency standards pursuant to the National Environmental Policy

Act (NEPA), the CEQ regulations implementing NEPA, DOT Order 5610.1C, and 

NHTSA regulations.318 The FEIS compares the potential environmental impacts of 

alternative standards considered by NHTSA for the final rule. It also analyzes direct, 

indirect, and cumulative impacts and analyzes impacts in proportion to their significance. 

See the FEIS and the FEIS Summary for a discussion of the environmental impacts 

analyzed. Docket No. NHTSA-2011-0079.

The standards adopted in this Final Rule have been informed by analyses 

contained in the Medium- and Heavy-Duty Fuel Efficiency Improvement Program, Final 

Environmental Impact Statement, Docket No. NHTSA-2010-0079 (FEIS). For purposes 

of this rulemaking, the agency referred to an extensive compilation of technical and 

policy documents available in NHTSA’s EIS/Rulemaking docket and EPA’s docket. 

 

314 See Notice of Intent to Prepare an Environmental Impact Statement for New Medium- and Heavy-Duty 

Fuel Efficiency Improvement Program, 75 FR 33565 (June 14, 2010).

315 Environmental Impact Statements; Notice of Availability, 75 FR 66756 (Oct. 29, 2010); NHTSA also 

published a separate Notice of Availability describing the program in greater detail, 75 FR 68312 (Nov. 5, 

2010). 

316 The agency also changed the FEIS as a result of updated information that became available after 

issuance of the DEIS. 

317 76 FR 37111 (June 24, 2011).

318 NEPA is codified at 42 U.S.C. 4321-4347. CEQ NEPA implementing regulations are codified at 40 

Code of Federal Regulations (CFR) Parts 1500-1508. NHTSA NEPA implementing regulations are 

codified at 49 CFR Part 520. 
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NHTSA’s EIS and rulemaking docket and EPA’s rulemaking docket can be found online

at http://www.regulations.gov, Reference Docket Nos.: NHTSA-2010-0079 (EIS and 

Rulemaking) and EPA-HQ-OAR-2010-0162 (EPA Rulemaking). 

Based on the foregoing, the agency concludes that the environmental analysis and 

public involvement process complies with NEPA implementing regulations issued by

CEQ, DOT Order 5610.1C, and NHTSA regulations.

(a) Clean Air Act (CAA)

The CAA (42 U.S.C. § 7401) is the primary Federal legislation that addresses air 

quality. Under the authority of the CAA and subsequent amendments, the EPA has 

established National Ambient Air Quality Standards (NAAQS) for six criteria pollutants, 

which are relatively commonplace pollutants that can accumulate in the atmosphere as a 

result of normal levels of human activity. The EPA is required to review the NAAQS 

every five years and to change the levels of the standards if warranted by new scientific 

information.

The air quality of a geographic region is usually assessed by comparing the levels 

of criteria air pollutants found in the atmosphere to the levels established by the NAAQS. 

Concentrations of criteria pollutants within the air mass of a region are measured in parts 

of a pollutant per million parts of air (ppm) or in micrograms of a pollutant per cubic 

meter (μg/m3) of air present in repeated air samples taken at designated monitoring 

locations. These ambient concentrations of each criteria pollutant are compared to the 

permissible levels specified by the NAAQS in order to assess whether the region’s air 

quality is potentially unhealthful.

When the measured concentrations of a criteria pollutant within a geographic 

region are below those permitted by the NAAQS, the region is designated by the EPA as 

an attainment area for that pollutant, while regions where concentrations of criteria 

pollutants exceed Federal standards are called nonattainment areas (NAAs). Former 

NAAs that have attained the NAAQS are designated as maintenance areas. Each NAA is 

required to develop and implement a State Implementation Plan (SIP), which documents 

how the region will reach attainment levels within time periods specified in the CAA. In 

maintenance areas, the SIP documents how the State intends to maintain compliance with 

the NAAQS. When EPA changes a NAAQS, States must revise their SIPs to address 

how they will attain the new standard.

Section 176(c) of the CAA prohibits Federal agencies from taking actions in 

nonattainment or maintenance areas that do not “conform” to the State Implementation 

Plan (SIP). The purpose of this conformity requirement is to ensure that Federal activities 

do not interfere with meeting the emissions targets in the SIPs, do not cause or contribute 

to new violations of the NAAQS, and do not impede the ability to attain or maintain the 

NAAQS. The EPA has issued two sets of regulations to implement CAA Section 176(c):

 The Transportation Conformity Rules (40 CFR Part 93, Subpart A), which 

apply to transportation plans, programs, and projects funded or approved 
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under U.S.C. Title 23 or the Federal Transit Laws (49 U.S.C. Chapter 53). 

Projects funded by the Federal Highway Administration (FHWA) or the 

Federal Transit Administration (FTA) usually are subject to transportation 

conformity. See 40 CFR § 93.102. 

 The General Conformity Rules (40 CFR Part 93, Subpart B) apply to all other 

federal actions not covered under transportation conformity. The General 

Conformity Rule established emissions thresholds, or de minimis levels, for 

use in evaluating the conformity of a project. If the net emissions increases 

attributable to the project are less than these thresholds, then the project is 

presumed to conform and no further conformity evaluation is required. If the 

emissions increases exceed any of these thresholds, then a conformity

determination is required. The conformity determination can entail air quality

modeling studies, consultation with EPA and state air quality agencies, and 

commitments to revise the SIP or to implement measures to mitigate air 

quality impacts.

The final fuel consumption standards and associated program activities are not 

funded or approved under U.S.C. Title 23 or the Federal Transit Act. Further, NHTSA’s 

HD Fuel Efficiency Improvement Program is not a highway or transit project funded or 

approved by FHWA or FTA. Accordingly, the standards and associated rulemakings are 

not subject to transportation conformity.

Under the General Conformity Rule, a conformity determination is required 

where a Federal action would result in total direct and indirect emissions of a criteria 

pollutant or precursor equaling or exceeding the rates specified in 40 CFR § 93.153(b)(1) 

and (2) for nonattainment and maintenance areas. As explained below, NHTSA’s action 

results in neither direct nor indirect emissions as defined in 40 CFR § 93.152. 

The General Conformity Rule defines direct emissions as those of “a criteria 

pollutant or its precursors that are caused or initiated by the Federal action and originate 

in a nonattainment or maintenance area and occur at the same time and place as the action 

and are reasonably foreseeable.” 40 CFR § 93.152. Because NHTSA’s action only sets 

fuel consumption standards for HD vehicles, it causes no direct emissions within the 

meaning of the General Conformity Rule. 

Indirect emissions under the General Conformity Rule include emissions or 

precursors: (1) that are caused or initiated by the Federal action and originate in the same 

nonattainment or maintenance area but occur at a different time or place than the action; 

(2) that are reasonably foreseeable; (3) that the agency can practically control; and (4) for 

which the agency has continuing program responsibility. 40 CFR § 93.152. Each 

element of the definition must be met to qualify as an indirect emission. NHTSA has 

determined that, for the purposes of general conformity, emissions that occur as a result 

of the fuel consumption standards are not caused by NHTSA’s action, but rather occur 

due to subsequent activities that the agency cannot practically control. “[E]ven if a 
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Federal licensing, rulemaking, or other approving action is a required initial step for a 

subsequent activity that causes emissions, such initial steps do not mean that a Federal 

agency can practically control any resulting emissions” (75 FR 17254, 17260; 40 CFR § 

93.152). NHTSA cannot control vehicle manufacturers’ production of HD vehicles and 

consumer purchasing and driving behavior. For the purposes of analyzing the 

environmental impacts of this action under NEPA, NHTSA has made assumptions 

regarding the technologies manufacturers will install and how companies will react to 

increased fuel efficiency standards. Specifically, NHTSA’s NEPA analysis predicted 

increases in air toxic and criteria pollutants to occur in some nonattainment areas under 

certain alternatives based on assumptions about the use of APUs and the rebound effect. 

For example, NHTSA’s NEPA analysis assumes that some manufacturers will install 

anti-idling technologies (including APUs) on some vehicle classes to meet the 

requirements of the program and that drivers’ subsequent use of those APUs will result in 

an increase in some criteria pollutants. However, neither NHTSA’s nor EPA’s rules

mandate this specific manufacturer decision or driver behavior – the program does not 

require that manufacturers install APUs to meet the requirements of the rule, and it does 

not require drivers to use anti-idling technologies instead of, for example, shutting off all 

power when parked. Similarly, NHTSA’s NEPA analysis assumes a rebound effect, 

wherein the standards could create an incentive for additional vehicle use by reducing the 

cost of fuel consumed per mile driven. This rebound effect is an estimate of how 

NHTSA assumes some drivers will react to the rule and is useful for estimating the costs 

and benefits of the rule, but the agency does not have the statutory authority, or the 

program responsibility, to control, among other items discussed above, the actual vehicle 

miles traveled by drivers. Accordingly, changes in any emissions that result from 

NHTSA’s HD vehicle Fuel Efficiency Improvement Program are not changes that the 

agency can practically control; therefore, this action causes no indirect emissions and a 

general conformity determination is not required. 

(b) National Historic Preservation Act (NHPA)

The NHPA (16 U.S.C. § 470) sets forth government policy and procedures 

regarding “historic properties”—that is, districts, sites, buildings, structures, and objects 

included in or eligible for the National Register of Historic Places (NRHP). See also 36 

CFR Part 800. Section 106 of the NHPA requires federal agencies to “take into account” 

the effects of their actions on historic properties. The agency concludes that the NHPA is 

not applicable to NHTSA’s Decision because it does not directly involve historic 

properties. The agency has, however, conducted a qualitative review of the related direct, 

indirect, and cumulative impacts, positive or negative, of the alternatives on potentially

affected resources, including historic and cultural resources. See Section 4.5 of the FEIS.

(c) Executive Order 12898 (Environmental Justice)

Under Executive Order 12898, Federal agencies are required to identify and 

address any disproportionately high and adverse human health or environmental effects 

of its programs, policies, and activities on minority populations and low-income 

populations. NHTSA complied with this order by identifying and addressing the 

potential effects of the alternatives on minority and low-income populations in Sections
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3.6 and 4.6 of the FEIS, where the agency set forth a qualitative analysis of the 

cumulative effects of the alternatives on these populations. 

(d) Fish and Wildlife Conservation Act (FWCA)

The FWCA (16 U.S.C. § 2900) provides financial and technical assistance to 

States for the development, revision, and implementation of conservation plans and 

programs for nongame fish and wildlife. In addition, the Act encourages all Federal 

agencies and departments to utilize their authority to conserve and to promote

conservation of nongame fish and wildlife and their habitats. The agency concludes that 

the FWCA is not applicable to NHTSA’s Decision because it does not directly involve 

fish and wildlife. 

(e) Coastal Zone Management Act (CZMA)

The Coastal Zone Management Act (16 U.S.C. § 1450) provides for the 

preservation, protection, development, and (where possible) restoration and enhancement 

of the nation’s coastal zone resources. Under the statute, States are provided with funds 

and technical assistance in developing coastal zone management programs. Each 

participating State must submit its program to the Secretary of Commerce for approval. 

Once the program has been approved, any activity of a Federal agency, either within or 

outside of the coastal zone, that affects any land or water use or natural resource of the 

coastal zone must be carried out in a manner that is consistent, to the maximum extent 

practicable, with the enforceable policies of the State’s program. 

The agency concludes that the CZMA is not applicable to NHTSA’s Decision 

because it does not involve an activity within, or outside of, the nation’s coastal zones. 

The agency has, however, conducted a qualitative review of the related direct, indirect, 

and cumulative impacts, positive or negative, of the alternatives on potentially affected 

resources, including coastal zones. See Section 4.5 of the FEIS. 

(f) Endangered Species Act (ESA)

Under Section 7(a)(2) of the Endangered Species Act (ESA) federal agencies 

must ensure that actions they authorize, fund, or carry out are “not likely to jeopardize” 

federally listed threatened or endangered species or result in the destruction or adverse 

modification of the designated critical habitat of these species. 16 U.S.C. § 1536(a)(2). 

If a federal agency determines that an agency action may affect a listed species or 

designated critical habitat, it must initiate consultation with the appropriate Service – the 

U.S. Fish and Wildlife Service (FWS) of the Department of the Interior and/ or National 

Oceanic and Atmospheric Administration’s National Marine Fisheries Service (NOAA 

Fisheries Service) of the Department of Commerce, depending on the species involved—

in order to ensure that the action is not likely to jeopardize the species or destroy or 

adversely modify designated critical habitat. See 50 CFR § 402.14. Under this standard, 

the federal agency taking action evaluates the possible effects of its action and determines 

whether to initiate consultation. See 51 FR 19926, 19949 (Jun. 3, 1986). 
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NHTSA received one comment to the Scoping notice for the HD program 

indicating that the agency should engage in consultation under Section 7 of the ESA 

when analyzing the overall impact of GHG emissions and other air pollutants. NHTSA 

has reviewed applicable ESA regulations, case law, guidance, and rulings in assessing the 

potential for impacts to threatened and endangered species from the HD fuel efficiency

standards. Consistent with NHTSA’s determination under the agency’s most recent lightduty fuel economy rule, NHTSA believes that the agency’s action, which will result in 

nationwide fuel savings and, consequently, emissions reductions from what would 

otherwise occur in the absence of the agency’s action, does not require consultation with 

NOAA Fisheries Service or the FWS under Section 7(a)(2) of the ESA. For discussion of 

the agency’s rationale in the context of the CAFE program, see Appendix G of the FEIS

for MYs 2012-2016, available at: http://www.nhtsa.gov/fuel-economy. Accordingly, 

NHTSA has concluded its review of this action under Section 7 of the ESA. 

(g) Floodplain Management (Executive Order 11988 & DOT Order 5650.2)

These Orders require Federal agencies to avoid the long- and short-term adverse 

impacts associated with the occupancy and modification of floodplains, and to restore 

and preserve the natural and beneficial values served by floodplains. Executive Order 

11988 also directs agencies to minimize the impact of floods on human safety, health and 

welfare, and to restore and preserve the natural and beneficial values served by

floodplains through evaluating the potential effects of any actions the agency may take in 

a floodplain and ensuring that its program planning and budget requests reflect 

consideration of flood hazards and floodplain management. DOT Order 5650.2 sets forth 

DOT policies and procedures for implementing Executive Order 11988. The DOT Order 

requires that the agency determine if a proposed action is within the limits of a base 

floodplain, meaning it is encroaching on the floodplain, and whether this encroachment is 

significant. If significant, the agency is required to conduct further analysis of the 

proposed action and any practicable alternatives. If a practicable alternative avoids 

floodplain encroachment, then the agency is required to implement it. 

In this rulemaking, the agency is not occupying, modifying and/or encroaching on 

floodplains. The agency, therefore, concludes that the Orders are not applicable to 

NHTSA’s Decision. The agency has, however, conducted a review of the alternatives on 

potentially affected resources, including floodplains. See Section 4.5 of the FEIS.

(h) Preservation of the Nation’s Wetlands (Executive Order 11990 & DOT Order 

5660.1a)

These Orders require Federal agencies to avoid, to the extent possible, 

undertaking or providing assistance for new construction located in wetlands unless the 

agency head finds that there is no practicable alternative to such construction and that the 

proposed action includes all practicable measures to minimize harms to wetlands that 

may result from such use. Executive Order 11990 also directs agencies to take action to 

minimize the destruction, loss or degradation of wetlands in “conducting Federal 

activities and programs affecting land use, including but not limited to water and related 

land resources planning, regulating, and licensing activities.” DOT Order 5660.1a sets 
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forth DOT policy for interpreting Executive Order 11990 and requires that transportation 

projects “located in or having an impact on wetlands” should be conducted to assure 

protection of the Nation’s wetlands. If a project does have a significant impact on 

wetlands, an EIS must be prepared.

The agency is not undertaking or providing assistance for new construction 

located in wetlands. The agency, therefore, concludes that these Orders do not apply to 

NHTSA’s Decision. The agency has, however, conducted a review of the alternatives on 

potentially affected resources, including wetlands. See Section 4.5 of the FEIS.

(i) Migratory Bird Treaty Act (MBTA), Bald and Golden Eagle Protection Act 

(BGEPA), Executive Order 13186

The MBTA provides for the protection of migratory birds that are native to the 

United States by making it illegal for anyone to pursue, hunt, take, attempt to take, kill, 

capture, collect, possess, buy, sell, trade, ship, import, or export any migratory bird 

covered under the statute. The statute prohibits both intentional and unintentional acts. 

Therefore, the statute is violated if an agency acts in a manner that harms a migratory

bird, whether it was intended or not. See, e.g., United States v. FMC Corp., 572 F.2d 902 

(2nd Cir. 1978).

The BGEPA (16 U.S.C. § 668) prohibits any form of possession or taking of both 

bald and golden eagles. Under the BGEPA, violators are subject to criminal and civil 

sanctions as well as an enhanced penalty provision for subsequent offenses.

Executive Order 13186, “Responsibilities of Federal Agencies to Protect 

Migratory Birds,” helps to further the purposes of the MBTA by requiring a Federal 

agency to develop a Memorandum of Understanding (MOU) with the Fish and Wildlife 

Service when it is taking an action that has (or is likely to have) a measurable negative 

impact on migratory bird populations.

The agency concludes that the MBTA, BGEPA, and Executive Order 13186 do 

not apply to NHTSA’s Decision because there is no disturbance and/or take involved in 

NHTSA’s Decision. 

(j) Department of Transportation Act (Section 4(f))

Section 4(f) of the Department of Transportation Act of 1966 (49 U.S.C. § 303), 

as amended by Pub. Law § 109-59, is designed to preserve publicly owned parklands, 

waterfowl and wildlife refuges, and significant historic sites. Specifically, Section 4(f) of 

the Department of Transportation Act provides that DOT agencies cannot approve a 

transportation program or project that requires the use of any publicly owned land from a 

significant public park, recreation area, or wildlife and waterfowl refuge, or any land 

from a significant historic site, unless a determination is made that: 

 There is no feasible and prudent alternative to the use of land, and 
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 The program or project includes all possible planning to minimize harm to the 

property resulting from use, or

 A transportation use of Section 4(f) property results in a de minimis impact. 

The agency concludes that the Section 4(f) is not applicable to NHTSA’s 

Decision because this rulemaking does not require the use of any publicly owned land. 

For a more detailed discussion, please see Section 3.1 of the FEIS.

(3) Paperwork Reduction Act

The information collection requirements in these rules have been submitted for 

approval to OMB under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The 

information collection requirements are not enforceable until OMB approves them.

The agencies propose to collect information to ensure compliance with the 

provisions in these rules. This includes a variety of testing, reporting and recordkeeping

requirements for vehicle manufacturers. Section 208(a) of the CAA requires that vehicle 

manufacturers provide information the Administrator may reasonably require to 

determine compliance with the regulations; submission of the information is therefore 

mandatory. We will consider confidential all information meeting the requirements of 

section 208(c) of the CAA. 

It is estimated that this collection affects approximately 35 engine and vehicle 

manufacturers. The information that is subject to this collection is collected whenever a 

manufacturer applies for a certificate of conformity. Under section 206 of the CAA (42 

U.S.C. 7521), a manufacturer must have a certificate of conformity before a vehicle or 

engine can be introduced into commerce. 

The burden to the manufacturers affected by these rules has a range based on the 

number of engines and vehicles a manufacturer produces. The total estimated burden 

associated with these rules is 25,052 hours annually (see Table XII-1:). This estimated 

burden for engine and vehicle manufacturers is a total estimate for new reporting 

requirements. Burden is defined at 5 CFR 1320.3(b).

Table XII-1: Burden for Reporting and Recordkeeping Requirements

Number of Affected Vehicle Manufacturers 34

Annual Labor Hours for Each Manufacturer to Prepare and Submit 

Required Information

Varies 

Total Annual Information Collection Burden 35,804 Hours 

An agency may not conduct or sponsor, and a person is not required to respond to 

a collection of information unless it displays a currently valid OMB control number. The 

OMB control numbers for EPA’s regulations are listed in 40 CFR part 9. When this ICR 

is approved by OMB, the agency will publish a technical amendment to 40 CFR part 9 in 

the Federal Register to display the OMB control number for the approved information 

collection requirements contained in this final action.
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(4) Regulatory Flexibility Act

(a) Overview

The Regulatory Flexibility Act generally requires an agency to prepare a 

regulatory flexibility analysis of any rule subject to notice and comment rulemaking 

requirements under the Administrative Procedure Act or any other statute unless the 

agency certifies that the rule will not have a significant economic impact on a substantial 

number of small entities. Small entities include small businesses, small organizations, 

and small governmental jurisdictions.

For purposes of assessing the impacts of these rules on small entities, small entity

is defined as: (1) a small business as defined by SBA regulations at 13 CFR 121.201; (2) 

a small governmental jurisdiction that is a government of a city, county, town, school 

district or special district with a population of less than 50,000; and (3) a small 

organization that is any not-for-profit enterprise which is independently owned and 

operated and is not dominant in its field.

(b) Summary of Potentially Affected Small Entities

The agencies have not conducted an Initial Regulatory Flexibility Analysis for 

this action because we are certifying that these rules would not have a significant 

economic impact on a substantial number of small entities. The agencies are deferring

standards for manufacturers meeting SBA’s definition of small business as described in 

13 CFR 121.201 due to the extremely small fuel savings and emissions contribution of 

these entities, and the short lead time to develop these rules, especially with our 

expectation that the program would need to be structured differently for them (which 

would require more time). The agencies are instead envisioning fuel consumption and 

GHG emissions standards for these entities as part of a future regulatory action. This 

includes small entities in several distinct categories of businesses for heavy-duty engines 

and vehicles: chassis manufacturers, combination tractor manufacturers, and alternative 

fuel engine converters. 

Based on a preliminary assessment, the agencies have identified a total of about 

17 engine manufacturers, 3 complete pickup truck and van manufacturers, 11 

combination tractor manufacturers and 43 heavy-duty chassis manufacturers. Notably, 

several of these manufacturers produce vehicles in more than just one regulatory category

(HD pickup trucks/vans, combination tractors, or vocational vehicles (i.e. heavy-duty 

chassis manufacturers)). Based on the types of vehicles they manufacture, these 

companies, however, would be subject to slightly different testing and reporting 

requirements. Taking this feature of the heavy-duty trucking sector into account, the 

agencies estimate that although there are fewer than 30 manufacturers covered by the 

program, there close to 60 divisions with these companies that will be subject to the final

regulations. Of these, about 15 entities fit the SBA criteria of a small business. There are 

approximately three engine converters, two tractor manufacturers, and ten heavy-duty 

chassis manufacturers in the heavy-duty engine and vehicle market that are small 
216 of 

businesses. (No major heavy-duty engine manufacturers, heavy-duty chassis 

manufacturers, or tractor manufacturers meet the small-entity criteria as defined by

SBA). The agencies estimate that these small entities comprise less than 0.35 percent of 

the total heavy-duty vehicle sales in the United States, and therefore the deferment will 

have a negligible impact on the fuel consumption and GHG emissions reductions from 

the final standards. 

To ensure that the agencies are aware of which companies are being deferred, the 

agencies are requiring that such entities submit a declaration to the agencies containing a 

detailed written description of how that manufacturer qualifies as a small entity under the 

provisions of 13 CFR 121.201. Some small entities, such as heavy-duty tractor and 

chassis manufacturers, are not currently covered under criteria pollutant motor vehicle 

emissions regulations. Small engine entities are currently covered by a number of EPA 

motor vehicle emission regulations, and they routinely submit information and data on an 

annual basis as part of their compliance responsibilities. Because such entities are not 

automatically exempted from other EPA regulations for heavy-duty engines and vehicles, 

absent such a declaration, EPA would assume that the entity was subject to the 

greenhouse gas control requirements in this program. The declaration to the agencies 

will need to be submitted at the time of either engine or vehicle emissions certification 

under the HD highway engine program for criteria pollutants. The agencies expect that 

the additional paperwork burden associated with completing and submitting a small 

entity declaration to gain deferral from the final GHG and fuel consumption standards 

will be negligible and easily done in the context of other routine submittals to the 

agencies. However, the agencies have accounted for this cost with a nominal estimate 

included in the Information Collection Request completed under the Paperwork 

Reduction Act. Additional information can be found in the Paperwork Reduction Act 

discussion in Section XII. (3) Paperwork Reduction Act. Based on this, the agencies are

certifying that the rules will not have a significant economic impact on a substantial 

number of small entities. 

(5) Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub. L. 104-4, 

establishes requirements for Federal agencies to assess the effects of their regulatory

actions on State, local, and tribal governments and the private sector. Under section 202 

of the UMRA, the agencies generally must prepare a written statement, including a costbenefit analysis, for proposed and final rules with “Federal mandates” that may result in 

expenditures to State, local, and tribal governments, in the aggregate, or to the private 

sector, of $134 million or more in any one year. Before promulgating a rule for which a 

written statement is needed, section 205 of the UMRA generally requires the agencies to 

identify and consider a reasonable number of regulatory alternatives and adopt the least 

costly, most cost-effective or least burdensome alternative that achieves the objectives of 

the rule. The provisions of section 205 do not apply when they are inconsistent with 

applicable law. Moreover, section 205 allows the agencies to adopt an alternative other 

than the least costly, most cost-effective or least burdensome alternative if the 

Administrator (of either agency) publishes with the final rule an explanation why that 

alternative was not adopted. 
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Before the agencies establish any regulatory requirements that may significantly

or uniquely affect small governments, including tribal governments, they must have 

developed under section 203 of the UMRA a small government agency plan. The plan 

must provide for notifying potentially affected small governments, enabling officials of 

affected small governments to have meaningful and timely input in the development of 

EPA and NHTSA regulations with significant Federal intergovernmental mandates, and 

informing, educating, and advising small governments on compliance with the regulatory

requirements. 

These rules contain no Federal mandates (under the regulatory provisions of Title 

II of the UMRA) for State, local, or tribal governments. The rules impose no enforceable 

duty on any State, local or tribal governments. The agencies have determined that these 

rules contain no regulatory requirements that might significantly or uniquely affect small 

governments. The agencies have determined that these rules contain a Federal mandate 

that may result in expenditures of $100 or more for the private sector in any one year. 

The agencies believe that the program represents the least costly, most cost-effective 

approach to achieve the statutory requirements of the rules. Section VIII.L, above, 

explains why the agencies believe that the fuel savings that will result from these rules

will lead to lower prices economy-wide, improving U.S. international competitiveness. 

The costs and benefits associated with the program are discussed in more detail above in 

Section VIII and in the Regulatory Impact Analysis, as required by the UMRA.

Table XI-3 presents the rule-related benefits, costs and net benefits in both present 

value terms and in annualized terms. In both cases, the discounted values are based on an 

underlying time varying stream of cost and benefit values that extend into the future 

(2012 through 2050). The distribution of each monetized economic impact over time can 

be viewed in the RIA that accompanies these rules. 

Present values represent the total amount that a stream of monetized 

costs/benefits/net benefits that occur over time are worth now (in year 2009 dollar terms

for this analysis), accounting for the time value of money by discounting future values 

using either a 3 or 7 percent discount rate, per OMB Circular A-4 guidance. An 

annualized value takes the present value and converts it into a constant stream of annual 

values through a given time period (2012 through 2050 in this analysis) and thus averages 

(in present value terms) the annual values. The present value of the constant stream of 

annualized values equals the present value of the underlying time varying stream of 

values. The ratio of benefits to costs is identical whether it is measured with present 

values or annualized values. 

It is important to note that annualized values cannot simply be summed over time 

to reflect total costs/benefits/net benefits; they must be discounted and summed. 

Additionally, the annualized value can vary substantially from the time varying stream of 

cost/benefit/net benefit values that occur in any given year. 
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Table XI-3: Estimated Lifetime and Annualized Discounted Costs, Benefits, and Net Benefits for 

2014-2018 Model Year HD Vehicles assuming the $22/ton SCC Valuea,b (billions 2009 dollars)

Costs Benefits Net Benefits

Lifetime Present Valuec,d– 3% Discount Rate $8.1 $57 $49

Annualized Valuec,e– 3% Discount Rate $0.4 $2.6 $2.2

Lifetime Present Valuec,d– 7% Discount Rate $8.1 $41 $33

Annualized Valuec,e– 7% Discount Rate $0.6 $3.1 $2.5

Notes:

a Although the agencies estimated the benefits associated with four different values of a one ton CO2

reduction (SCC: $5, $22, $36, $66), for the purposes of this overview presentation of estimated 

costs and benefits we are showing the benefits associated with the marginal value deemed to be 

central by the interagency working group on this topic: $22 per ton of CO2, in 2008 dollars and 

2010 emissions and fuel consumption. As noted in Section VIII.G, SCC increases over time.

b Note that net present value of reduced GHG emissions is calculated differently than other benefits. 

The same discount rate used to discount the value of damages from future emissions (SCC at 5, 3, 

and 2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to 

Section VIII.G for more detail.

c Discounted values presented in this table are based on an underlying series of cost and benefit 

values that extend into the future (2012 through 2050). The distribution of each monetized 

economic impact over time can be viewed in the RIA that accompanies this preamble.

d Present value is the total, aggregated amount that a series of monetized costs or benefits that occur 

over time is worth now (in year 2008 dollar terms), discounting future values to the present.

e The annualized value is the constant annual value through a given time period (2012 through 2050 

in this analysis) whose summed present value equals the present value from which it was derived.

(6) Executive Order 13132 (Federalism)

This action does not have federalism implications. It will not have substantial 

direct effects on the States, on the relationship between the national government and the 

States, or on the distribution of power and responsibilities among the various levels of 

government, as specified in Executive Order 13132. These rules will apply to 

manufacturers of motor vehicles and not to state or local governments. Thus, Executive 

Order 13132 does not apply to this action. Although section 6 of Executive Order 13132 

does not apply to this action, the agencies did consult with representatives of state 

governments in developing this action.

NHTSA notes that EPCA contains a provision (49 U.S.C. 32919(a)) that 

expressly preempts any State or local government from adopting or enforcing a law or 

regulation related to fuel economy standards or average fuel economy standards for 

automobiles covered by an average fuel economy standard under 49 U.S.C. Chapter 329. 

However, commercial medium- and heavy-duty on-highway vehicles and work trucks are 

not “automobiles,” as defined in 49 U.S.C. 32901(a)(3). Accordingly, NHTSA has 

tentatively concluded that EPCA’s express preemption provision would not reach the fuel 

efficiency standards to be established in this rulemaking. 

NHTSA also considered the issue of implied or conflict preemption. The 

possibility of such preemption is dependent upon there being an actual conflict between a 

standard established by NHTSA in this rulemaking and a State or local law or regulation. 

See Spriestma v. Mercury Marine, 537 U.S. 51, 64-65 (2002). At present, NHTSA has 
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219 of

no knowledge of any State or local law or regulation that would actually conflict with one 

of the fuel efficiency standards being established in this rulemaking. 

(7) Executive Order 13175 (Consultation and Coordination with Indian Tribal 

Governments)

These final rules do not have tribal implications, as specified in Executive Order 

13175 (65 FR 67249, November 9, 2000). These rules will be implemented at the 

Federal level and impose compliance costs only on vehicle manufacturers. Tribal 

governments would be affected only to the extent they purchase and use regulated 

vehicles. Thus, Executive Order 13175 does not apply to these rules.

(8) Executive Order 13045: “Protection of Children from Environmental 

Health Risks and Safety Risks”

This action is subject to Executive Order 13045 (62 FR 19885, April 23, 1997) 

because it is an economically significant regulatory action as defined by Executive Order

12866, and the agencies believe that the environmental health or safety risk addressed by

this action may have a disproportionate effect on children. A synthesis of the science and 

research regarding how climate change may affect children and other vulnerable 

subpopulations is contained in the Technical Support Document for Endangerment or 

Cause or Contribute Findings for Greenhouse Gases under section 202(a) of the Clean 

Air Act, which can be found in the public docket for these rules.

319

 A summary of the 

analysis is presented below.

With respect to GHG emissions, the effects of climate change observed to date 

and projected to occur in the future include the increased likelihood of more frequent and 

intense heat waves. Specifically, EPA’s analysis of the scientific assessment literature has 

determined that severe heat waves are projected to intensify in magnitude, frequency, and 

duration over the portions of the United States where these events already occur, with 

potential increases in mortality and morbidity, especially among the young, elderly, and 

frail. EPA has estimated reductions in projected global mean surface temperatures as a 

result of reductions in GHG emissions associated with the final standards in this action 

(Section II). Children may receive benefits from reductions in GHG emissions because 

they are included in the segment of the population that is most vulnerable to extreme 

temperatures.

For non-GHG pollutants, EPA has determined that climate change is expected to 

increase regional ozone pollution, with associated risks in respiratory infection, 

aggravation of asthma, and premature death. The directional effect of climate change on 

ambient PM levels remains uncertain. However, disturbances such as wildfires are 

increasing in the United States and are likely to intensify in a warmer future with drier 

soils and longer growing seasons. PM emissions from forest fires can contribute to acute 

and chronic illnesses of the respiratory system, particularly in children, including 

 

319 See Endangerment TSD, Note 10, above.
220 of 

pneumonia, upper respiratory diseases, asthma and chronic obstructive pulmonary

diseases.

(9) Executive Order 13211 (Energy Effects)

This rulemaking is not a “significant energy action” as defined in Executive Order 

13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, 

Distribution, or Use” (66 FR 28355, May 22, 2001) because it is not likely to have a 

significant adverse effect on the supply, distribution, or use of energy. In fact, these rules

have a positive effect on energy supply and use. Because the final GHG emission and 

fuel consumption standards will result in significant fuel savings, these rules encourage 

more efficient use of fuels. Therefore, we have concluded that these rules are not likely

to have any adverse energy effects. Our energy effects analysis is described above in 

Section VIII.H.

(10) National Technology Transfer Advancement Act

Section 12(d) of the National Technology Transfer and Advancement Act of 1995 

(“NTTAA”), Public Law No. 104-113, 12(d) (15 U.S.C. 272 note) directs the agencies to 

use voluntary consensus standards in its regulatory activities unless to do so would be 

inconsistent with applicable law or otherwise impractical. Voluntary consensus standards 

are technical standards (e.g., materials, specifications, test methods, sampling procedures, 

and business practices) that are developed or adopted by voluntary consensus standards 

bodies. NTTAA directs the agencies to provide Congress, through OMB, explanations 

when the agencies decide not to use available and applicable voluntary consensus 

standards.

For CO2, N2O, and CH4 emissions and fuel consumption from heavy-duty 

engines, the agencies will collect data over the same tests that are used for the heavy-duty 

highway engine program for criteria pollutants. This will minimize the amount of testing 

done by manufacturers, since manufacturers are already required to run these tests. 

For CO2, N2O, and CH4 emissions and fuel consumption from complete pickup 

trucks and vans, the agencies will collect data over the same tests that are used for EPA’s

heavy-duty highway engine program for criteria pollutants and for the California Air 

Resources Board. This will minimize the amount of testing done by manufacturers, since 

manufacturers are already required to run these tests.

For CO2 emissions and fuel consumption from heavy-duty combination tractors 

and vocational vehicles, the agencies will collect data through the use of a simulation 

model instead of a full-vehicle chassis dynamometer testing. This will minimize the 

amount of testing done by manufacturers. EPA’s compliance assessment tool is based 

upon well-established engineering and physics principals that are the basis of general 

academic understanding in this area, and the foundation of any dynamic vehicle 

simulation model, including the models cited by ICCT in its study.

320

 Therefore, the 

EPA’s compliance assessment tool satisfies the description of a consensus. For the 

 

320 ICCT. ICCT Evaluation of Vehicle Simulation Tools. 2009. 
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221 of

evaluation of tire rolling resistance input to the model, EPA is finalizing to use the ISO 

28580 test, a voluntary consensus methodology. EPA is adopting several alternatives for 

the evaluation of aerodynamics which allows the industry to continue to use their own 

evaluation tools because EPA does not know of a single consensus standard available for 

heavy-duty truck aerodynamic evaluation.

For air conditioning standards, EPA is finalizing a consensus methodology

developed by the Society of Automotive Engineers (SAE). 

(11) Executive Order 12898: Federal Actions to Address Environmental 

Justice in Minority Populations and Low-Income Populations

Executive Order 12898 (59 FR 7629, February 16, 1994) establishes federal 

executive policy on environmental justice. Its main provision directs federal agencies, to 

the greatest extent practicable and permitted by law, to make environmental justice part 

of their mission by identifying and addressing, as appropriate, disproportionately high 

and adverse human health or environmental effects of their programs, policies, and 

activities on minority populations and low-income populations in the United States. 

With respect to GHG emissions, EPA has determined that these final rules will 

not have disproportionately high and adverse human health or environmental effects on 

minority or low-income populations because they increase the level of environmental 

protection for all affected populations without having any disproportionately high and 

adverse human health or environmental effects on any population, including any minority 

or low-income population. The reductions in CO2 and other GHGs associated with the 

standards will affect climate change projections, and EPA has estimated reductions in 

projected global mean surface temperatures (Section VI). Within communities 

experiencing climate change, certain parts of the population may be especially

vulnerable; these include the poor, the elderly, those already in poor health, the disabled, 

those living alone, and/or indigenous populations dependent on one or a few resources.321 

In addition, the U.S. Climate Change Science Program stated as one of its conclusions: 

“The United States is certainly capable of adapting to the collective impacts of climate 

change. However, there will still be certain individuals and locations where the adaptive 

capacity is less and these individuals and their communities will be disproportionally

impacted by climate change.” 322 Therefore, these specific sub-populations may receive 

benefits from reductions in GHGs. 

For non-GHG co-pollutants such as ozone, PM2.5, and toxics, EPA has concluded 

that it is not practicable to determine whether there would be disproportionately high and 

adverse human health or environmental effects on minority and/or low income 

populations from these rules. 

 

321 See Endangerment TSD, Note 10, above.

322 CCSP (2008) Analyses of the effects of global change on human health and welfare and human systems. 

A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. 

[Gamble, J.L. (ed.), K.L. Ebi, F.G. Sussman, T.J. Wilbanks, (Authors)]. U.S. Environmental Protection 

Agency, Washington, DC, USA.
222 of 

(12) Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small 

Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a 

rule may take effect, the agency promulgating the rule must submit a rule report, which 

includes a copy of the rule, to each House of the Congress and to the Comptroller 

General of the United States. The agencies will submit a report containing these rules

and other required information to the U.S. Senate, the U.S. House of Representatives, and 

the Comptroller General of the United States prior to publication of the rules in the 

Federal Register. A Major rule cannot take effect until 60 days after it is published in the 

Federal Register. This action is a “major rule” as defined by 5 U.S.C. 804(2). These rules

will be effective [Insert date 60 days after publication in the Federal Register], sixty

days after date of publication in the Federal Register.

(13) Privacy Act

Anyone is able to search the electronic form of all comments received into any of 

our dockets by the name of the individual submitting the comment (or signing the 

comment, if submitted on behalf of an organization, business, labor union, etc.). You may

review DOT’s complete Privacy Act statement in the Federal Register (65 FR 19477–78, 

April 11, 2000) or you may visit http://www.dot.gov/privacy.html.

XIII. Statutory Provisions and Legal Authority

A. EPA

Statutory authority for the vehicle controls in these rules is found in CAA section 

202(a) (which authorizes standards for emissions of pollutants from new motor vehicles 

which emissions cause or contribute to air pollution which may reasonably be anticipated 

to endanger public health or welfare), sections 202(d), 203-209, 216, and 301 of the 

CAA, 42 U.S.C. 7521 (a), 7521 (d), 7522, 7523, 7524, 7525, 7541, 7542, 7543, 7550, 

and 7601.

B. NHTSA

Statutory authority for the fuel consumption standards in these rules is found in

EISA section 103 (which authorizes a fuel efficiency improvement program, designed to 

achieve the maximum feasible improvement to be created for commercial medium- and 

heavy-duty on-highway vehicles and work trucks, to include appropriate test methods, 

measurement metrics, standards, and compliance and enforcement protocols that are 

appropriate, cost-effective and technologically feasible) of the Energy Independence and 

Security Act of 2007, 49 U.S.C. 32902(k).

List of Subjects

40 CFR Part 85

Confidential business information, Imports, Labeling, Motor vehicle pollution, Reporting 

and recordkeeping requirements, Research, Warranties.
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40 CFR Part 86

Administrative practice and procedure, Confidential business information, Incorporation 

by reference, Labeling, Motor vehicle pollution, Reporting and recordkeeping 

requirements.

40 CFR Part 600

Administrative practice and procedure, Electric power, Fuel economy, Incorporation by

reference, Labeling, Reporting and recordkeeping requirements.

40 CFR Parts 1033

Administrative practice and procedure, Air pollution control.

40 CFR Parts 1036 and 1037

Administrative practice and procedure, Air pollution control, Confidential business 

information, Environmental protection, Incorporation by reference, Labeling, Motor 

vehicle pollution, Reporting and recordkeeping requirements, Warranties.

40 CFR Part 1039

Environmental protection, Administrative practice and procedure, Air pollution control, 

Confidential business information, Imports, Labeling, Penalties, Reporting and 

recordkeeping requirements, Warranties.

40 CFR Parts 1065 and 1066

Administrative practice and procedure, Air pollution control, Reporting and 

recordkeeping requirements, Research.

40 CFR Part 1068

Environmental protection, Administrative practice and procedure, Confidential business 

information, Imports, Incorporation by reference, Motor vehicle pollution, Penalties, 

Reporting and recordkeeping requirements, Warranties.

49 CFR Parts 523, 534, and 535

Fuel Efficiency