STAFF REPORT: 

INITIAL STATEMENT OF REASONS FOR

PROPOSED RULEMAKING

PUBLIC HEARING TO CONSIDER ADOPTION OF THE 

REGULATION TO REDUCE GREENHOUSE GAS EMISSIONS 

FROM HEAVY-DUTY VEHICLES

Mobile Source Control Division 

Emission Research and 

Regulatory Development Branch 

October 2008 
State of California 

AIR RESOURCES BOARD 

Initial Statement of Reasons: 

Proposed Regulation to Reduce Greenhouse Gas Emissions from 

Heavy-Duty Vehicles 

Public Hearing to Consider 

ADOPTION OF PROPOSED REGULATION TO REDUCE GREENHOUSE GAS 

EMISSIONS FROM HEAVY-DUTY VEHICLES 

To be considered by the Air Resources Board on December 11, 2008, at: 

California Environmental Protection Agency 

Air Resources Board 

Byron Sher Auditorium, Second Floor 

1001 I Street 

Sacramento, California 95814 

Mobile Source Control Division

Robert Cross, Chief 

Steven Albu, Assistant Chief 

Emission Research and Regulatory Development Branch

Michael Carter, Chief 

On-Road Heavy Duty Diesel Section 

Stephan Lemieux, Manager 

This report has been prepared by the staff of the Air Resources Board. Publication 

does not signify that the contents reflect the views and policies of the Air Resources 

Board, nor does mention of trade names or commercial products constitute 

endorsement or recommendation for use. 
State of California 

AIR RESOURCES BOARD 

PROPOSED REGULATION TO REDUCDE GREENHOUSE GAS EMISSIONS FROM 

HEAVY-DUTY VEHICLES 

Primary Authors

Stephan Lemieux 

Daniel Hawelti 

David Chen 

Susan O’Connor 

Dassi Pintar 

Alex Santos 

Contributing Authors 

Keith Macias 

Lei Zhou 

Andrew Spencer 

Ryman Simangan 

Krista Fregoso 

Legal Counsel

Stephen Adams, Office of Legal Affairs 

Supporting Divisions

Planning and Technical Support Division 

Enforcement Division 

Acknowledgements

This report was prepared with the assistance and support from the other divisions and 

offices of the Air Resources Board. In addition, we would like to acknowledge the 

assistance and cooperation that we have received from many individuals and 

organizations. 

 
- i - 

TABLE OF CONTENTS

EXECUTIVE SUMMARY ........................................................................................... ES1

I. Introduction and Overview ................................................................................ 1

A. INTRODUCTION ....................................................................................................... 1

B. OVERVIEW.............................................................................................................. 1

II. Regulatory Authority.......................................................................................... 2

A. SUMMARY OF REGULATORY AUTHORITY ................................................................... 2

III. Public Outreach and Environmental Justice.................................................... 3

A. PUBLIC OUTREACH EFFORTS ................................................................................... 3

B. ENVIRONMENTAL JUSTICE........................................................................................ 8

IV. Need for Greenhouse Gas Emission Reductions............................................ 8

V. On-road Vehicle Descriptions ........................................................................... 8

A. OVERVIEW.............................................................................................................. 8

B. HEAVY-DUTY TRACTORS.......................................................................................... 9

C. BOX-TYPE TRAILERS ............................................................................................. 10

VI. Population and GHG Contribution from Heavy-Duty Vehicles..................... 11

A. POPULATION......................................................................................................... 11

B. GHG CONTRIBUTION ............................................................................................ 15

VII. U.S. EPA SmartWay Transport Partnership ................................................... 17

A. DESCRIPTION OF PROGRAM ................................................................................... 17

B. SMARTWAY TRACTORS ......................................................................................... 19

C. SMARTWAY TRAILERS........................................................................................... 20

VIII. Proposed Regulation ....................................................................................... 20

A. PROPOSED REGULATION OVERVIEW....................................................................... 20

B. PURPOSE ............................................................................................................. 21

C. APPLICABILITY ...................................................................................................... 21

D. DEFINITIONS......................................................................................................... 21

E. REQUIREMENTS AND COMPLIANCE DEADLINES........................................................ 22

F. MAINTENANCE REQUIREMENTS .............................................................................. 27
- ii - 

G. EXEMPTIONS ........................................................................................................ 27

H. REPORTING REQUIREMENTS.................................................................................. 28

I. ENFORCEMENT AND FINES..................................................................................... 28

IX. Technological Feasibility of Control Measure ............................................... 29

A. SMARTWAY CERTIFIED TRACTORS......................................................................... 29

B. TRAILER AERODYNAMIC TECHNOLOGIES ................................................................. 33

C. TRACTOR AND TRAILER LOW-ROLLING RESISTANCE TIRES ....................................... 42

X. Alternatives Considered .................................................................................. 46

A. NO ACTION........................................................................................................... 48

B. EXPAND APPLICABILITY ......................................................................................... 50

XI. Environmental Impact ...................................................................................... 51

A. LEGAL REQUIREMENTS.......................................................................................... 51

B. REASONABLY FORESEEABLE ENVIRONMENTAL IMPACTS .......................................... 52

C. REASONABLY FORESEEABLE MITIGATION MEASURES .............................................. 57

D. ALTERNATIVE MEANS OF COMPLIANCE WITH THE PROPOSED REGULATION ................ 57

XII. Cost and Economic Impact.............................................................................. 57

A. SUMMARY ............................................................................................................ 57

B. LEGAL REQUIREMENTS.......................................................................................... 58

C. METHODOLOGY FOR ESTIMATING COST AND ECONOMIC IMPACT............................... 59

D. ESTIMATED COSTS OF THE PROPOSED REGULATION ............................................... 59

E. POTENTIAL IMPACT ON A SMALL BUSINESS.............................................................. 63

F. POTENTIAL IMPACT ON EMPLOYMENT, BUSINESS CREATION, ELIMINATION, OR 

EXPANSION .......................................................................................................... 64

G. ESTIMATED COSTS TO LOCAL, STATE, AND FEDERAL AGENCIES ............................... 65

H. COST-EFFECTIVENESS OF THE PROPOSED REGULATION.......................................... 66

I. SUMMARY OF CURRENT FINANCIAL ASSISTANCE AND GRANT PROGRAMS.................. 67

XIII. Requirements of AB 32 .................................................................................... 69

XIV. Issues ................................................................................................................ 75

A. MEXICAN BORDER ISSUES ..................................................................................... 75

B. OTHER RULEMAKINGS ........................................................................................... 76
- iii - 

XV. Recommendation ............................................................................................. 79

XVI. References ........................................................................................................ 80

Appendix A: Proposed Regulation to Reduce Greenhouse Gas Emissions from HeavyDuty Vehicles 

Appendix B: Workshop Notice Flyers 

Appendix C: Emission Inventory Analysis and Results 

Appendix D: U.S. EPA SmartWay Documents 

Appendix E: Fleet Summaries 

Appendix F: Optional Trailer Fleet Compliance Schedules 

Appendix G: Implementation and Enforcement 
- iv - 

Table of Contents (cont.)

List of Tables Page

Table III-1: Public Workshop Dates, Locations and Times............................................. 3

Table III-2: Presentations ............................................................................................... 5

Table III-3: Associations, Companies and Other Organizations Contacted.................... 5

Table VI-1: 2010 and 2020 Tractor Population and Annual VMT in California ............. 12

Table VI-2: Percentage of Tractors with Primary Range of Operation Greater than 100 

Miles................................................................................................... 12

Table VI-3: Percentage of 53-Foot Box Type Trailers .................................................. 13

Table VI-4: 2010 and 2020 Impacted Tractor Population and the Corresponding Annual 

VMT.................................................................................................... 14

Table VI-5: 2010 and 2020 Impacted 53-Foot Box-Type Trailers................................. 15

Table VI-6: 1990, 2002-2004 Average, and 2020 Projected Transportation Sector GHG 

Emissions (MMT CO2e) (ARB, 2008b) ............................................... 16

Table VIII-1: Proposed Tractor Requirements.............................................................. 23

Table VIII-2: Proposed 2011 and Later Model Year Trailer Compliance Options, 

Beginning January 1, 2010................................................................. 24

Table VIII-3: Proposed Optional Large Fleet (21+) Compliance Schedule for 2010 and 

Earlier Model Year 53-foot or Longer Box-Type Trailers, Except 

Refrigerated-Van Trailers with Transport Refrigeration Units using 

2003 to 2009 Model Year Engines ..................................................... 25

Table VIII-4: Proposed Optional Compliance Schedule for Small Trailer Fleets of 2010 

and Earlier Model Year 53-foot or Longer Box-Type Trailers ............. 25

Table VIII-5: Refrigerated Fleet Compliance Deadlines ............................................... 26

Table IX-1: U.S. EPA Certified SmartWay Tractors....................................................... 33

Table IX-2: Fuel Savings Ranges for Trailer Aerodynamic Devices (Freight Wing, 

2007; Laydon, 2007; Surcel, 2007a; Surcel, 2007b) .......................... 38

Table IX-3: Comparison of Tire Rolling Resistance Coefficients.................................. 43

Table X-1: Alternative Regulatory Structures Considered............................................. 47

Table XI-1: Fuel Efficiency Improvements – Based on Proposed Requirements ......... 54

Table XI-2: 2010, 2015, and 2020 GHG Emission Benefits - Statewide and Nationwide 

(MMT CO2e) ....................................................................................... 55

Table XII-1: Tractor and Trailer Costs ........................................................................... 60

Table XII-2: Annual Maintenance Costs/Fees.............................................................. 61
- v - 

Table XII-3: Annual Operating Cost Savings................................................................ 62

Table XII-4: Owner-Operator Compliance Costs.......................................................... 64

Table XII-5: Fiscal Year Costs for State Agencies ....................................................... 65

Table XII-6: Average Annualized Cost Savings............................................................ 66
- vi - 

Table of Contents (cont.)

List of Figures Page

Figure V-1: Box-Type Trailers ...................................................................................... 10

Figure VI-1: California GHG Emissions by Sector – 2002-2004 Average (ARB, 2008b)16

Figure VI-2: Transportation Sector GHG Emissions – 2002-2004 Average 

(179 MMTCO2e) (ARB, 2008b)........................................................... 17

Figure IX-1: SmartWay Tractors................................................................................... 31

Figure IX-2: Trailer Side Skirts ..................................................................................... 35

Figure IX-3: Adamworks Aeromax Retractable Fairing ................................................ 36

Figure IX-4: Front Trailer Gap Fairings......................................................................... 37

Figure IX-5: Rear Trailer Fairings................................................................................. 38

Figure IX-6: Contributors to Rolling Resistance (Michelin, 2002)................................. 44

Figure XI-1: Statewide GHG Emissions With and Without the Regulation ................... 55
ES1

EXECUTIVE SUMMARY 

The State of California has traditionally been a pioneer in efforts to reduce air 

pollution, dating back to 1963 when the California New Motor Vehicle Pollution 

Control Board adopted the nation’s first motor vehicle emission standards. In 2004, 

ARB continued its tradition of leadership with the adoption of the first greenhouse gas 

(GHG) emission reduction measure in the nation, applicable to light-duty vehicles. The 

staff proposal presented in this Initial Statement of Reasons reduces GHG emissions 

from another category of motor vehicles that substantially contributes to human GHG 

emissions: heavy-duty vehicles (HDVs). 

Climate Change Overview 

While the Earth’s natural climate is dynamic and constantly changing, the climate 

change observed over the last one-and-one-half centuries seems to differ in both its 

rate and its magnitude. Many sources of data indicate that the Earth is warming faster 

than at any time in the last millennium. For example, 11 of the last 12 years from 1995 

to 2006 rank among the 12 warmest years in instrumental record of global surface 

temperatures (IPCC, 2007). As the global mean surface temperature increases, 

significant adverse effects may be observed: decreased water supply, higher sea 

levels, changed agricultural patterns, altered ecosystems, and worse air quality. 

Global temperatures have been linked to the GHG effect, where certain gases in the 

lower atmosphere absorb radiation released by the Earth’s surface that was heated by 

solar radiation. While the GHG effect is important in maintaining the temperature of the 

Earth’s lower atmosphere, the addition of more GHG emissions into the atmosphere 

due to human activities may be causing the increase in the average global ambient 

temperature. Burning of fossil fuels, agriculture, use of refrigeration systems, and other 

human activities release GHG emissions. 

The transportation sector is the largest contributor of human GHG emissions in 

California: 38 percent of total carbon dioxide equivalent (CO2e) emissions in 2004. Of 

this sector, the largest contributing category was that of passenger vehicles at 74 

percent of the total transportation CO2e emissions. The second largest contributing 

category was that of HDVs, responsible for 20 percent of the total transportation 

emissions. 

Regulatory Authority 

The California Global Warming Solutions Act of 2006 (AB 32) established requirements 

for a comprehensive program of regulatory and market mechanisms to achieve real, 

quantifiable, and cost-effective reductions of GHG emissions. AB 32 gave ARB 

responsibility for monitoring and reducing GHG emissions. It requires ARB and other 

state agencies to adopt regulations and other requirements that would reduce, by 2020, 

statewide GHG emission levels to the equivalent of 1990 levels. This represents a 
ES2

reduction of about 25 percent. Further, by Executive Order the Governor has directed 

that GHG emission levels be reduced to 80 percent below 1990 levels by 2050. The 

2020 goal establishes an aggressive, but achievable, mid-term target, and the 2050 

goal represents the level scientists believe is necessary to reach in order to stabilize the 

climate. 

To swiftly address GHG reductions in the near-term, AB 32 also directs ARB to identify 

a list of early action measures to be adopted by the Board and made enforceable by 

January 1, 2010. In 2007, the Board identified 44 early action measures, consisting of 

potential regulations affecting motor vehicles, fuels, refrigerant in cars, and many other 

sources. Included were nine discrete early action measures for which the Board would 

adopt regulations by the end of 2009. The proposed Heavy-Duty Vehicle Greenhouse 

Gas Emission Reduction Regulation is one of the nine discrete early action measures. 

Federal SmartWay Partnership Program 

The proposed regulation references a federal voluntary program called the United 

States Environmental Protection Agency (U.S. EPA) SmartWay Partnership Program. 

The U.S. EPA SmartWay Partnership Program aims to improve energy efficiency, 

reduce GHG and air pollutant emissions, and improve energy security of the ground 

freight movement system. Under the SmartWay program, U.S. EPA certifies tractors 

and trailers that have been demonstrated to be more fuel efficient than their traditional 

counterparts. At this time, there are SmartWay specifications for tractors with sleeper 

cabs and for 53-foot or longer dry-van trailers, and therefore, only these products can 

be certified by original equipment manufacturers under the SmartWay program. The 

SmartWay program also approves individual aerodynamic equipment for trailers and 

efficient (low-rolling resistance) tires for tractors and trailers. 

Regulatory Proposal 

The proposed regulation reduces GHG emissions by improving long-haul HDV fuel 

efficiency. A more efficient HDV uses less fuel, and as a result, emits less GHG 

emissions. A HDV consists of a heavy-duty tractor (tractor), and a trailer. The 

proposed regulation requires new and existing long-haul on-road tractors pulling 53-foot 

or longer box-type trailers and 53-foot and longer box-type trailers pulled by tractors, 

which operate on California highways, to be equipped with SmartWay approved 

aerodynamic technologies and low-rolling resistance tires. For purposes of the 

proposed regulation, a box-type trailer is a dry-van trailer or a refrigerated-van trailer. 

The proposed regulation does not apply to tractors pulling other types of trailers, e.g., 

box-type trailers of lengths shorter than 53 feet, or to tractors pulling flatbeds, or logging 

trailers, drop-frame trailers, curtain-side trailers, or chassis trailers hauling shipping 

containers. Also exempt from the requirements of the regulation are authorized 

emergency vehicles and military tactical support vehicles, as well as short-haul and 

drayage tractors, as defined in the proposal. 

 Proposed Requirements for Tractors 
ES3

Beginning January 1, 2010, a 2011 and subsequent model year tractor with a sleeper 

berth that pulls a 53-foot or longer box-type trailer on a California highway would be 

required to be a U.S. EPA certified SmartWay tractor. As noted previously, SmartWay 

does not currently certify a tractor without a sleeper berth, i.e., day cab, and thus, these 

tractors would not be required to be SmartWay certified. In addition, low-rolling 

resistance tires that meet U.S. EPA SmartWay specifications would be required 

beginning January 1, 2010, for a 2011 and subsequent model year tractor regardless of 

whether it has a sleeper berth or not. 

Beginning January 1, 2012, a 2010 and earlier model year tractor with or without a 

sleeper berth that pulls a 53-foot or longer box-type trailer on a California highway 

would be required to be equipped with low-rolling resistance tires. This would be the 

only retrofit requirement for these tractors, and allows most 2010 or earlier model year 

tractors to use their existing tires for the remainder of their useful life before replacing 

them with low-rolling resistance tires. 

 Proposed Requirements for Trailers 

Beginning on January 1, 2010, a 2011 and newer 53-foot or longer box-type trailer 

pulled by a tractor on a California highway would be required to be either (1) a U.S. EPA 

certified SmartWay trailer or (2) retrofitted with SmartWay approved technologies. The 

first option, to use a U.S. EPA certified SmartWay trailer, is currently only available for 

dry-van trailer applications. U.S. EPA has defined specifications for this type of trailer, 

and several manufacturers have already certified models. For refrigerated-van trailers, 

the second option, to retrofit with SmartWay approved technologies, would be the 

available compliance approach. In the future, the SmartWay program may expand to 

cover refrigerated trailers, as well as other types of trailers, potentially making the first 

option (above) available for refrigerated trailers. 

2010 and earlier model year 53-foot or longer box-type trailers that will be pulled by 

tractors on California highways would be required to be retrofitted with SmartWay 

approved technologies by January 1, 2013. The retrofit requirements would be identical 

to the second option for 2011 and subsequent model year trailers, described above. In 

lieu of meeting the January 1, 2013 compliance date, the trailer owner could choose to 

comply with an optional trailer fleet compliance schedule only if it meets the following 

conditions: (1) submits a compliance plan by the due date, (2) meets its annual 

commitments for retrofitting trailers, and (3) allows ARB to audit records periodically. 

There are two proposed optional trailer fleet compliance schedules that would be based 

on trailer fleet size: the large fleet compliance schedule and the small fleet compliance 

schedule. The large fleet compliance schedule would apply to fleets with 21 and 

greater trailers. A six year phase-in is proposed for large fleets, with the first 

compliance year starting in 2010 and the last compliance year ending in 2015. For 

added flexibility, a trailer owner could participate in an early compliance option, in which 

credit is given for 2010 and earlier model year box-type trailer that are compliant by 

December 31, 2009. The early compliance credit could be used to delay the retrofit of 

some affected trailers until 2016. 
ES4

The small fleet compliance schedule would apply to trailer fleets with 1 to 20 trailers. 

Compliance would be delayed, beginning in 2013 and completed in 2016. 

Also proposed is a delayed compliance provision for refrigerated-van fleets. This 

provision would apply to 2003 to 2008 model year refrigerated-van trailers equipped 

with diesel-fueled transport refrigeration units (TRUs). The flexibility proposed for TRUs 

is because owners of these vehicles will be subjected to another ARB regulation, called 

the Airborne Toxic Control Measure for In-Use Diesel-Fueled Transport Refrigeration 

Units and TRU Generator Sets, and Facilities Where TRUs Operate (TRU Rule), which 

will require replacement or retrofit of the TRU concurrent with the proposed optional 

compliance schedules. A three year compliance schedule is proposed for these trailers 

with the first compliance year starting in 2017 and the last compliance year ending in 

2019. 

Requirements for the Owners, Drivers, Motor Carriers, California-based 

Brokers, and California-based Shippers 

The proposed regulation would establish the following requirements for each of the 

parties listed below. A notice of violation would be issued to each of the parties listed 

below if a tractor or trailer subject to the proposed regulation is found to be 

noncompliant. 

• Owners of tractors pulling 53-foot or longer box-type trailers on California highways: 

Tractor owners would be responsible to ensure that the tractors subject to the 

proposed regulation comply with the proposed requirements within the proposed 

compliance schedule. Owners would also need to ensure that aerodynamic devices, 

if applicable, and low-rolling resistance tires are used and maintained in good 

operating condition. This would ensure that the SmartWay components are 

operating as designed. 

• Owners of 53-foot or longer box-type trailers pulled by tractors on California 

highways: Like owners of tractors subject to the proposed regulation, trailer owners 

would be responsible for ensuring that the applicable trailers comply with the 

proposed requirements within the proposed compliance schedule, as well as 

ensuring that the equipment is maintained in good operating condition. Owners of 

affected trailers would also be required to submit information to ARB if they choose 

to participate in an optional compliance schedule. 

• Drivers of tractors pulling 53-foot or longer box-type trailers on California highways: 

Drivers would be responsible for ensuring that tractors and trailers to be driven are in 

compliance with the proposed regulation and meet the proposed good operating 

condition criteria. 

• Motor carriers and California-based brokers that dispatch tractors pulling 53-foot or 

longer box-type trailers on California highways: Motor carriers and California-based 

brokers would be responsible for ensuring that the tractors and trailers they dispatch 

to pick up freight comply with the proposed regulatory requirements. 
ES5

• California-based shippers that ship freight in 53-foot or longer box-type trailers pulled 

by tractors on California highways: Shippers would be responsible for ensuring that 

any freight being picked up at their facility is done so only by compliant tractors and 

trailers. 

Enforcement 

ARB enforcement staff would enforce the requirements of the proposed regulation as 

follows: 

• Drivers, owners of tractors and trailers, and motor carriers could receive penalties 

upon issuance of a notice of violation (NOV) as determined at roadside inspection 

locations, facility inspections, and audits. 

• California-based brokers and California-based shippers would be notified of motor 

carriers and tractor trailer owners that they have contracted with, that have failed to 

settle previously issued NOVs. The purpose of this notification would be to give them 

the opportunity to take the necessary actions to prevent future violations. If, 

however, ARB enforcement staff finds that the California-based broker or shipper 

continues to use delinquent motor carriers, tractor owners, or trailer owners, the 

California-based broker or shipper could be subject to penalties. 

Environmental Impact 

The statewide GHG emission benefits of the proposed regulation are projected to be 1.0 

million metric tons (MMT) of CO2-equivalent (CO2e) emissions in 2020. Reductions of 

GHG emissions would extend beyond the California state borders as California 

interstate trucks that travel outside California and out-of-state trucks that travel onto 

California highways are subjected to the proposed regulation. Nationwide benefits of 

the proposed regulation are projected to be 6.7 MMT of CO2e emissions in 2020. From 

2010 to 2020, the cumulative GHG emission benefits are estimated to be approximately 

7.8 MMT CO2e statewide and 52.1 MMT CO2e nationwide. 

In addition to GHG benefits, reducing aerodynamic drag and rolling resistance will also 

reduce NOx emissions. Statewide NOx emission reductions are projected to be 4.3 and 

1.4 tons per day in 2014 and 2020, respectively. 

Economic Impact 

The proposed regulation would impact trucking businesses that own tractors and 53-

foot or longer box-type trailers subject to the proposed regulation. While compliance 

with the proposed regulation would require an initial capital cost, it is expected that a 

cost savings would ultimately result due to the increase in HDV fuel efficiency and the 

resultant usage of less fuel. The average estimated cost increase for the purchase of a 

SmartWay certified tractor equipped with aerodynamic devices and low-rolling 

resistance tires is $2,100 per tractor. The estimated average cost of trailer compliance 
ES6

for the initial purchase and installation of aerodynamic technologies and low-rolling 

resistance tires is approximately $2,900 per trailer. In addition, annual maintenance 

costs for inspection and repair of installed aerodynamic technologies, and replacement 

and retread costs for low-rolling resistance tires, is estimated to be about $143 for the 

tractor and $120 for the trailer. Therefore, the initial capital cost for a tractor-trailer 

combination would average about $5,000, with an annual increased maintenance cost 

of $263. However, the industry average trailer-to-tractor ratio is estimated to be 2.5-to-1 

per owner. This translates into an average cost of $9,200 per owner. 

Operating cost savings resulting from the fuel efficiency improvement of compliant 

tractors and trailers are anticipated to be substantial. A tractor-trailer combination that 

complies with the proposed regulation is expected to realize a 7 to 10 percent fuel 

economy gain, depending on the types of tractor and trailer improvements. Assuming 

this range, the fuel savings would be approximately $4,000 to $5,700 per year for a 

tractor-trailer combination.1 The fuel savings due to the proposed requirements would 

allow the owner to recover the initial capital and maintenance costs for both the tractor 

and trailer in less than 1.5 years. If an owner had more trailers than tractors, i.e., a 

trailer-to-tractor ratio of more than one, it would require additional time for the payback 

of the initial capital costs. Businesses that are required to equip trailers with 

aerodynamic technologies and low-rolling resistance tires but do not own or operate 

tractors (including owners of trailer fleets and certain shippers) may not directly recoup 

initial costs if they do not directly pay for fuel. However, staff anticipates that at least 

some of the fuel savings from trailers equipped with SmartWay devices and tires will be 

indirectly shared by trailer owners through price structures that reflect fuel savings 

associated with these trailers. 

The total estimated lifetime equipment cost of complying with the proposed regulation is 

about $10.4 billion. However, over the same period of time, the total estimated cost 

(fuel) savings are about $14.7 billion. Therefore, a net savings of approximately $4.3 

billion in 2008 dollar values is expected. The total estimated statewide lifetime cost of 

complying for California based tractors and trailers is about $0.5 billion and the cost 

savings over the same period of time are $1.1 billion. This yields a net statewide cost 

savings of almost $0.6 billion. This net cost savings would be realized by fleet 

operators and owner-operators of compliant tractors and trailers and are directly 

attributed to operating cost savings associated with improved fuel economy. 

Some financial assistance and grant programs are available to aid tractor and trailer 

owners in complying with the proposed requirements. These programs are available 

through the federal, state, and local governments; they provide technical assistance, 

loans for the purchase of fuel savings and emissions reducing vehicles and 

technologies, and grants to assist eligible partners to adopt diesel emissions reduction 

 

1

 The assumptions for this calculation are as follows: a baseline fuel economy of 5.8 miles per 

gallon, an average long-haul mileage accrual rate of 125,000 miles per year, 84 percent of 

the vehicle miles traveled at highway speed benefit fully from the aerodynamic devices, and 

a projected diesel fuel cost of $3.14 per gallon. If the cost per gallon in diesel fuel is higher 

than $3.14, the fuel savings due to the proposed regulation would be proportionately greater. 
ES7

strategies. In particular, in California, $48 million has been appropriated to fund a 

heavy-duty vehicle air quality loan guarantee program (anticipated loan values of $300 

million) to encourage early compliance by on-road fleets affected by this proposed 

regulation and the proposed In-Use Truck and Bus Regulation (particulate matter and 

NOx reduction). In developing this air quality loan program, ARB staff is currently 

coordinating with the State Treasurer’s Office and private sector banks to tailor a 

program to meet the specific needs of the heavy-duty vehicle sector. 

Staff Recommendation 

ARB staff recommends that the Board adopt the regulation as proposed in the Initial 

Statement of Reasons. The proposed regulation is intended to achieve feasible and 

cost-effective GHG emissions from HDVs. 
1

I. INTRODUCTION AND OVERVIEW 

A. Introduction 

The mission of the California Air Resources Board (ARB or Board) is to protect public 

health, welfare, and ecological resources through the effective and efficient reduction of 

air pollutants, while recognizing and considering the effects on the economy of the State 

(ARB, 2002). ARB’s vision is that all individuals in California, especially children and 

the elderly, can live in a healthful environment – free from harmful exposure and the 

effects of air pollution. To this end, staff is proposing a regulation to reduce greenhouse 

gas (GHG) emissions from long-haul heavy-duty vehicles (HDVs). These HDVs are 

commonly used for freight transport and consist of a heavy-duty tractor (tractor), and a 

trailer. The proposed regulation affects 53-foot or longer box-type trailers and the 

tractors that pull them, when operating on California highways. 

B. Overview 

The proposed regulation would reduce GHG emissions by requiring new and existing 

on-road tractors and trailers to be equipped with technologies that improve fuel 

efficiency and reduce GHG and oxides of nitrogen (NOx) emissions, when operating on 

California highways. The proposed regulation references a federal voluntary program, 

called the United States Environmental Protection Agency (U.S. EPA) SmartWay 

Transport Partnership, which is designed to improve the environmental performance 

associated with the overall ground freight delivery system in the United States. In 

particular, the program “certifies” or approves technologies, such as aerodynamic 

equipment and low-rolling resistance tires that reduce GHG emissions and improve fuel 

efficiency of HDVs. Currently, the federal program is limited to HDVs equipped with 

sleeping berths pulling 53-foot and longer box-type trailers. 

The proposal would require the use of aerodynamic equipment and low-rolling 

resistance tires beginning January 1, 2010. Certain types of HDVs will be exempted 

from the proposed regulatory requirements, including short-haul trucks and drayage 

trucks. 

Compliance with these requirements would be mandatory for those parties that use the 

applicable tractor and trailer to transport freight, including the owner, driver, motor 

carrier, California-based broker, and California-based shipper. These requirements 

would pertain to all applicable tractors and trailers that operate on California highways 

regardless of where the vehicles are domiciled. 

The statewide GHG emission benefits of the proposed regulation are projected to be 1.0 

million metric tons of carbon dioxide equivalent (MMT CO2e)2

 emissions in 2020. In 

 

2

 Carbon dioxide equivalent (CO2e) is a metric measure used to compare the emissions from 

various GHGs based upon their global warming potential. Global warming potential (GWP) 

is the index used to translate the level of emissions of various gases into a common measure 

in order to compare the relative radiative forcing of different gases without directly calculating 

the changes in atmospheric concentrations. GWPs are calculated as the ratio of the 

radiative forcing that would result from the emissions of one kilogram of a GHG to that from 
2

addition to GHG benefits, reducing aerodynamic drag and rolling resistance will also 

reduce NOx emissions. Statewide NOx emission reductions are projected to be 4.3 and 

1.4 tons per day in 2014 and 2020, respectively. 

The proposed regulation would impact trucking businesses that own tractors and 53-

foot or longer box-type trailers subject to the proposed regulation. While compliance 

with the proposed regulation would require an initial up-front capital cost, fuel savings 

will more than offset the initial cost. The initial capital cost for a tractor-trailer 

combination would average about $5,000 with an annual increased maintenance cost of 

$263. 

Operating cost savings resulting from the fuel efficiency improvement of compliant 

tractors and trailers is anticipated to be substantial. Fuel savings for a compliant tractortrailer combination are expected to be 7 to 10 percent. Thus, fuel savings would be 

approximately $4,000 to $5,700 per year.3 The fuel savings due to the proposed 

requirements would allow the owner to recover the initial capital and maintenance costs 

for both the tractor and trailer in less than 1.5 years. If an owner had more trailers than 

tractors, i.e., a trailer to tractor ratio of more than one, it would require additional time for 

the payback of the initial capital costs. Owners of only trailers would not benefit directly 

from fuel savings. 

The total estimated statewide lifetime cost of complying with the proposed regulation is 

about $10.4 billion. However, over the same period of time, the total estimated fuel cost 

savings is about $14.7 billion. Therefore, a net savings of approximately $4.3 billion in 

2008 dollar values is expected. 

II. REGULATORY AUTHORITY

A. Summary of Regulatory Authority 

California first addressed climate change in 1988 with the passage of AB 4420 directing 

the California Energy Commission, in consultation with ARB and other agencies, to 

study global warming impacts to the state and develop an inventory of GHG emission 

sources. Since then, many other pieces of legislation have been passed to continue to 

research global warming impacts, to establish and update GHG emission inventories, 

and to develop mitigation efforts. In particular, AB 1493, signed on July 22, 2002, 

required ARB to develop and adopt regulations that achieve the maximum feasible and 

cost-effective reduction of GHGs from light-duty vehicles. This resulted in the first 

 

emission of one kilogram of CO2 over a period of time (usually 100 years). For example, the 

GWP of CO2, methane, and nitrous oxide is 1, 21, and 310, respectively. CO2 equivalents 

are commonly expressed as "million metric tons of carbon dioxide equivalents (MMT CO2e)". 

3

 The assumptions for this calculation are as follows: a baseline fuel economy of 5.8 miles per 

gallon, an average long-haul mileage accrual rate of 125,000 miles per year, 84 percent of 

the vehicle miles traveled at highway speed benefit fully from the aerodynamic devices, and 

a projected diesel fuel cost of $3.14 per gallon. If the cost per gallon of diesel fuel is higher 

than $3.14, the fuel savings due to the proposed regulation would be proportionately greater. 
3

regulation in the nation, adopted by ARB in September 2004, to control GHG emissions 

from motor vehicles. 

In 2006, the California Global Warming Solutions Act of 2006 (AB 32) was signed into 

law, creating a comprehensive, multi-year program to reduce GHG emissions in 

California (Nunez, 2002). It calls for the reduction of GHG emissions to 1990 levels by 

the year 2020, a reduction of about 25 percent. In addition, the Governor issued an 

Executive Order directing state agencies to reduce GHG emissions to 80 percent below 

1990 levels by 2050. The 2020 goal establishes an aggressive, but achievable, midterm target, while the 2050 goal represents the level scientists believe must be reached 

in order to stabilize the climate. 

To swiftly address GHG reductions in the near-term, one requirement of AB 32 directed 

ARB to identify a list of early action measures that could be adopted by the Board by 

January 1, 2011. In 2007, the Board identified 44 such early action measures including 

potential regulations affecting motor vehicles, fuels, refrigerant in cars, and many other 

sources, including nine “discrete” early action measures, which would be adopted and 

enforceable by January 1, 2010 (ARB, 2007). The proposed Heavy-Duty Vehicle 

Greenhouse Gas Emission Reduction Measure is one of these discrete early action 

measures. 

 

III. PUBLIC OUTREACH AND ENVIRONMENTAL JUSTICE

A. Public Outreach Efforts 

During the development of the regulatory proposal, ARB staff conducted numerous 

outreach efforts to inform affected parties of the proposal and to obtain stakeholder 

comments. Outreach efforts included public workshops, individual meetings, and email 

and telephone contacts. 

1. Public Workshops 

Three separate series of workshops were conducted jointly with another regulatory 

proposal, the In-use On-road Heavy-duty Diesel-fueled Vehicle Regulation (Truck and 

Bus Rule). The first series, held in January and February 2008, consisted of ten 

workshops in eight locations throughout California. The second series, held in May and 

June 2008, included twelve workshops in eight California locations. The third series, 

held in July and August 2008, included eleven workshops in eight locations throughout 

California. In addition, staff conducted two series of independent workshops focused 

exclusively on the proposed regulation, one in June 2008 and the other in July and 

August 2008. Table III-1 provides a listing of the dates, times and locations of the 

workshops. 

Table III-1: Public Workshop Dates, Locations and Times 

Date Location Time 

January 28, 2008 Sacramento Day 
4

January 30, 2008 Fresno Day 

January 31, 2008 El Monte Day 

January 31, 2008 Riverside Evening 

February 4, 2008 San Diego Day 

February 4, 2008 El Centro Evening 

February 6, 2008 Redding Day 

February 6, 2008 Redding Evening 

February 11, 2008 Berkeley Day 

February 11, 2008 Berkeley Evening 

May 21, 2008 El Monte Day 

May 27, 2008 San Diego Day 

May 27, 2008 El Centro Evening 

May 29, 2008 Riverside Evening 

May 30, 2008 San Jose Day 

May 30, 2008 San Jose Evening 

June 2, 2008 Redding Day 

June 2, 2008 Redding Evening 

June 4, 2008 Sacramento Day 

June 4, 2008 Sacramento Evening 

June 10, 2008 Fresno Day 

June 10, 2008 Fresno Evening 

July 22, 2008 San Diego Day 

July 22, 2008 El Centro Evening 

July 24, 2008 El Monte Day 

July 28, 2008 Redding Day 

July 28, 2008 Redding Evening 

July 30, 2008 San Jose Day 

July 30, 2008 San Jose Evening 

July 31, 2008 Sacramento Day 

August 4, 2008 Riverside Evening 

August 5, 2008 Fresno Day 

August 5, 2008 Arvin Evening 

June 6, 2008 Sacramento Day 

June 12, 2008 El Monte Day 

June 13, 2008 San Diego Day 

July 28, 2008 Sacramento Day 

July 29, 2008 San Diego/Otay Mesa Day 

August 5, 2008 El Monte Day 

In order to ensure that Spanish-speaking stakeholders, particularly those involved in 

commerce at the U.S.-Mexican border, were able to understand the proposal and 

provide their comments, the draft regulation and presentation documents were 

translated into Spanish. In addition, the public workshop held in San Diego/Otay Mesa 

on July 29, 2008, was conducted with Spanish interpreters. Efforts to reach the 
5

attendees to inform them about the upcoming workshop included distributing flyers 

translated into Spanish at a California Highway Patrol border-crossing facility and 

through the Otay Mesa Chamber of Commerce (See Appendix B). 

2. Individual Meetings 

ARB staff conducted several presentations and off-site meetings targeted at specific 

stakeholder groups to inform them about the proposed regulation and obtain their 

participation and feedback in the process. These presentations were given at the 

following locations or events: 

Table III-2: Presentations 

Date Organization/Event 

June 9, 2008 Greening the Supply Chain Conference 

July 17, 2008 Distribution Management Association -

Inland Empire Chapter 

August 6, 2008 International Warehouse Logistics 

Association 

July 30, 2008 Otay Mesa Chamber of Commerce 

September 12, 2008 Ralphs Grocery Distribution Center 

September 18, 2008 Los Angeles area logistics facilities tour 

3. Other Outreach 

Staff contacted more than 60 industry associations, representing the trucking, logistics, 

manufacturing, wholesale, and retail industries, as well as individual industry members, 

to inform them of the proposal and invite them to provide comments. Staff also met with 

various stakeholders individually to gather information, to discuss the proposed 

requirements, and to discuss issues of concern. These stakeholders included motor 

carriers, the trucking industry, warehouse and logistics companies, and equipment 

manufacturers. Staff met with manufacturers of trailer aerodynamic technologies and 

manufacturers of low-rolling resistance tires to understand their product offerings, as 

well as with managers of fleets in the U.S. and Canada that currently use the types of 

aerodynamic devices required by this regulation, to gain first-hand knowledge of their 

experiences with the equipment. Summaries of fleet meetings can be found in 

Appendix E. Table III-3 provides a list of the various associations, companies, and other 

organizations contacted. 

Table III-3: Associations, Companies and Other Organizations Contacted 

ACT Research AdamWorks Inc. 

ADS Logistics LLC Advance Auto Parts 

Advanced Logistics & Distribution Systems Affiliated Warehouse Companies 

American Chain of Warehouses Inc American Home Furnishings Alliance 

American Logistics Association American Supply Association 
6

American Trucking Association (ATA) American Wholesale Marketers 

Association 

Appliance Parts Distributors Association 

(APDA) 

Association of Home Appliance 

Manufacturers 

AT Dynamics B& B Trucking 

Bakersfield Quality Distribution Center Business Environmental Resource Center 

(BERC) 

Best Buy Co. Inc. Best Logistics Inc 

Brent Redmond Transportation Brockway Smith 

Brookvale International Corp Budway Trucking & Warehouse 

Bureau of Home Furnishings CA Manufacturers Technology Association

CA Retailers Association CA Wholesale Marketers Assoc 

Cal Chamber of Commerce California Distribution Centers 

California Furniture Manufacturers 

Association 

California Grocers Association 

California Trucking Association (CTA) California Warehouse Association 

Carry Transit Cascade Drayage & Warehouse 

Cascades Coalition for Responsible Transportation 

Containerization & Intermodal Institute 

(CII) 

Cooperative Grocers' Information Network 

(CGIN) 

Costco Wholesale Council of Supply Chain Management

Professionals 

CVS Caremark Daimler/Freightliner 

Dependable Logistics Services Distribution & LTL Carriers Association 

Distribution Management Association Environment Canada, Environmental 

Stewardship Branch 

Falcon Transport Food Industry Association Executives 

(FIAE) 

Food Ingredient Distributors Association 

(FIDA) 

Freight Wing 

Global Cold Chain Alliance/International 

Assoc. of Refrigerated Warehouses 

Great Dane 

Hiner Transport Home Depot 

Hy-Vee foods IKEA North America 

Inland Cold Storage Inland Empire Economic Partnership 

Intermodal Association of North America International 

International Foodservice Distributors 

Association 

International Society of Logistics 

International Warehouse Logistics 

Association (IWLA) 

JBHunt 

J-Line Transport Kenworth 

Laydon Composites Longs Drug 

Los Angeles Cold Storage Co Lowes 

Mexican American Grocers Association National Association of WholesalerDistributors 
7

National Association of Chain Drug Stores National Association of Manufacturers 

National Electronic Distributors 

Association 

National Grocers Association 

National Home Furnishings Association 

(NHFA) 

National Motor Freight Traffic Association 

National Private Truck Council National Retail Federation 

National Transportation & Logistics 

Association 

New Century 

Normandin Transport North American Transportation Council 

Nose Cone OOIDA (Owner Operator Independent 

Drivers Assoc) 

Otay Mesa Chamber of Commerce PAFCO (Pacific American Fish Co, Inc) 

Performance Warehouse Association 

(PWA) 

Peterbilt/Paccar 

Private Label Manufacturers Association Quest Global 

Ralphs/Food 4 Less (Kroger) Retail Industry Leaders Association (RILA)

Rite Aid RL Jones Customhouse Brokers 

Safeway Inc Sandag 

Schneider National, Inc Sears Holdings 

Secretaria del Medio Ambiente y Recursos 

Naturales (SEMARNAT) 

Sherwin Williams 

Silver Eagle Manufacturing Co. Stater Bros Holdings Inc 

Stockton Chamber of Commerce Supervalu Inc (Albertsons) 

Supply Chain & Logistics Association of 

Canada 

Swift 

Target Corp Textile Rental Services Association 

The National Customs Brokers & 

Forwarders Association of America 

The National Industrial Transportation 

League 

Toy Industry Association (TIA) Toys R Us 

Trailmobile Trailwood Transport 

Trans Am Transload Distribution Association 

Transportation Intermediaries Association Transtex Composite 

Truckload Carriers Association Twin City 

Unicold Corporation US Customs border inspection facility Otay 

Mesa 

US Growers Cold Storage Inc US WTO, National Institute of Standards & 

Technology (NIST) 

Utility Trailer Van Eerden Trucking 

Ventura Transfer Company Volvo 

Walgreens Walmart 

Warehouse Specialists Inc Warehousing Education & Research 

Council 

West Coast Warehousing Western Home Furnishings Association, 

Whole Foods Market Inc. World Food Logistics Organization 

Yandell Truckaway, Inc Hendrickson Trucking 
8

Tire Retread Information Bureau Marangoni Retreading Systems 

Bridgestone Bandag Tire Solutions 

B. Environmental Justice 

As a matter of policy, ARB is committed to integrating environmental justice in all of its 

activities. On December 13, 2001, the Board approved Environmental Justice Policies 

and Actions (Policies), which formally established a framework for incorporating 

environmental justice into the ARB’s programs, consistent with the directives of state 

law. Environmental justice is defined as the fair treatment of people of all races, 

cultures, and incomes with respect to the development, adoption, implementation, and 

enforcement of environmental laws, regulations, and policies (ARB, 2001). ARB 

recognizes its obligation to work closely with all stakeholders – communities, 

environmental and public health organizations, industry, business owners, other 

agencies and all other interested parties – to successfully implement these Policies. 

These Policies apply to all communities in California, but recognize that environmental 

justice issues have been raised more in the context of low-income and minority 

communities. 

The proposed regulation would benefit the people of California by reducing fuel 

consumption of tractors pulling 53-foot or longer box-type trailers throughout the state, 

and reducing emissions of GHGs and criteria pollutants in all communities throughout 

California, including those with environmental justice concerns. 

IV. NEED FOR GREENHOUSE GAS EMISSION REDUCTIONS

Human, or anthropogenic, activities have altered the chemical composition of the 

atmosphere through the buildup of GHG emissions. Over the past century the Earth’s 

northern hemisphere has warmed at a faster rate than at any other time over the last 

millennium. The potential impacts of a warming of the planet include: a rise in sea level, 

spread of certain diseases out of their usual geographic ranges, loss of agricultural 

production, decreased water supply, altering of ecosystems, increased strength and 

frequency of storms, extreme heat events, air pollution episodes, and the consequences 

of these effects on the economy. As a result, there is an urgent need to curtail GHG 

emissions from all anthropogenic sources where technologically feasible and 

economically practicable. (IPPC, 2007; ARB, 2004) 

V. ON-ROAD VEHICLE DESCRIPTIONS 

A. Overview 

This chapter provides general background information on tractors and trailers, and 

describes the vehicles that will be subjected to the proposed regulation. 
9

B. Heavy-duty Tractors 

1. Background 

An on-road tractor can pull any one of a myriad of trailers to pick up and deliver freight. 

A long-haul tractor typically has three axles: a front, or steer, axle that uses two wheels, 

and two rear, or drive, axles that have double wheels on each side of the axle. Thus, a 

three-axle tractor may have ten wheels. A tractor may also have only two axles (a steer 

axle and drive axle), which is easier to maneuver in tight areas, but has less loadcarrying capacity. Although dual wheels for the drive axles are the most common 

configuration, there is also limited use of single wide-base tires (also known as “super 

singles”) on each end of an axle, due to their fuel economy benefits. A tractor is also 

equipped with a coupling known as a fifth wheel, which is used to join it with the trailer. 

Some tractors have a moveable fifth wheel, also called a slider, which can move 

forward or backward on the tractor frame. The slider helps distribute the weight of a 

loaded trailer more evenly between the tractor and trailer axles, in order to stay within 

federal axle weight limits and bridge laws. 

Typically, a tractor that pulls a trailer for a long haul has a cab that is designed for driver 

comfort and will contain a roomy sleeping berth, or sleeper. A long-haul tractor that is 

pulling trailers will typically operate at highway speeds during the majority of its trip. 

Another type of tractor may be used for in-city deliveries and day trips where it may 

return daily to the location where it is garaged. These tractors are termed local or short 

haul. A short-haul tractor typically operates at city speeds, with some highway driving. 

While HDV exhaust emissions have been regulated since 1973 in the United States, 

GHG emissions from HDVs are currently unregulated. However, recent voluntary 

efforts to increase fuel efficiency have reduced GHG emissions. For example, tractors 

have recently been designed with more aerodynamic features such as rounded rather 

than flat edges on the cab in order to reduce wind resistance. Some tractors have 

aerodynamic designs on the fuel tank, exhaust stack, and other protruding parts. These 

designs reduce aerodynamic drag, which, in turn, reduces needed engine power to 

propel the vehicle forward. Since there are, as yet, no regulatory requirements 

established to mandate aerodynamic features on tractors, the degree of aerodynamic 

improvement varies from manufacturer to manufacturer and within a manufacturer’s 

own line of trucks. 

2. Tractor Manufacturers 

There are many manufacturers of tractors subject to the proposed regulation. They 

include Freightliner, Navistar International, Kenworth, Mack, Peterbilt, and Volvo Trucks. 

Some tractor manufacturers also manufacture engines for their tractors, but most 

manufacturers design vehicles to accept engines manufactured by other companies. 

3. Commercial Truck Classifications 

Commercial truck classifications are based on the vehicle’s gross vehicle weight rating. 

The gross vehicle weight rating is the value specified by the manufacturer as the 

maximum design loaded weight of a single vehicle, which means the total weight of the 
10

tractor and the trailer with freight. The proposed regulation applies only to Class 7 and 

8 tractors. A Class 7 tractor has a gross vehicle weight rating of 26,001 to 33,000 

pounds, and a Class 8 tractor is over 33,000 pounds gross vehicle weight rating. Most 

of the affected vehicles are Class 8 tractors. 

C. Box-type Trailers 

1. Background 

There are many different types of trailers used on the road to carry freight. Most trailers 

have two axles, with dual wheels on each side of the axle, and thus have eight wheels. 

A trailer may be equipped with a moveable tandem axle, also called a slider, which 

mates with the fifth wheel of the tractor. Like the tractor’s fifth wheel, the tandem axle 

can be moved forward or backward to more evenly distribute the weight of the loaded 

trailer between the tractor and trailer’s axles and to meet bridge laws. 

The most common type of trailer on the road is the box-type trailer, also called a van 

trailer. Types of box-type trailers include dry-van trailers and refrigerated-van trailers, 

also called reefers (see Figure V-1). A dry-van trailer, which hauls dry freight such as 

appliances, clothing, and furniture, does not require a temperature-controlled 

environment. A refrigerated-van trailer has a refrigeration or heating unit built into the 

trailer to maintain precise temperatures and is used to haul frozen food, fresh produce, 

hot or warm food, and other perishable items. 

Figure V-1: Box-Type Trailers 

Other common types of trailer designs include the curtain-side trailer, chassis trailer, 

drop-frame trailer, tanker, and flatbed trailer. The proposed regulation does not apply to 

these types of trailers. As with tractors, current trailer designs incorporate some 

aerodynamic features, such as rounded or tapered front corners and smooth, rather 

than ribbed sides, but the use of these features is inconsistent from manufacturer to 

manufacturer and from model to model. 
11

2. Trailer Manufacturers 

Manufacturers of 53-foot box-type trailers will be affected by the proposed regulation. 

These manufacturers include Utility Trailer Manufacturing Company, Wabash National 

Corporation, Great Dane Trailers, Trailmobile Corporation, Hyundai Translead, and 

other box-type trailer manufacturers. 

VI. POPULATION AND GHG CONTRIBUTION FROM HEAVY-DUTY VEHICLES 

A. Population 

Assessing the number of tractors and trailers impacted by the rule was a challenge 

because the impacted tractors are a subset of the overall fleet and no complete 

database exists for trailers. Thus, as an example, for the tractors, staff had to take into 

account the percentage of total tractors that are long-haul, and of those, the number 

that pull 53-foot or longer box-type trailers. Staff’s methodology and the assumptions 

used to determine the tractor and trailer population impacted by the proposal are 

discussed below. A variety of data sources were used to establish the tractor and trailer 

population impacted by the proposed rule. These include the following: ARB Motor 

Vehicle Emissions Inventory (ARB Inventory), U.S. Bureau of Census 2002 Vehicle 

Inventory and Use Survey (VIUS), Americas Commercial Transportation Research 

Company (ACT Research), U.S. Bureau of Census Current Industrial Reports (CIR), 

and Commercial Carrier Journal (CCJ). (See Appendix C for a more detailed 

description of these data sources.) 

1. Tractors 

Tractors impacted by the proposed regulation include Class 7 and 8 California-based 

intrastate and interstate tractors, and out-of-state-based tractors that operate in 

California. Staff used ARB’s updated inventory (ARB, 2008a) as the basis for 

developing the tractor inventory affected by the proposed regulation. For purposes of 

this analysis, out-of-state-based Class 7 and 8 trucks operating in California and all 

California-based Class 7 and 8 interstate trucks are assumed to be tractors, since they 

are involved in interstate long-haul freight operation and as such generally use tractortrailer combination trucks. Table VI-1 shows the projected total tractor population, both 

short-haul and long-haul, operating in California in 2010 and 2020 and the 

corresponding annual vehicle miles traveled (VMT). 
12

Table VI-1: 2010 and 2020 Tractor Population and Annual VMT in California 

Class 7 & 8 

Tractors 

Annual VMT 

(106

 miles) Fleet 

2010 2020 2010 2020 

CA Intrastate 72,310 96,621 3,360 4,540

CA Interstate 62,292 83,927 2,673 3,611

Neighboring Out-of-State 43,278 58,275 1,274 1,721

Non-neighboring Out-of-State 469,323 626,853 3,935 5,316

Total 647,203 865,677 11,241 15,187

The population numbers shown in Table VI-1 were adjusted to differentiate long-haul 

from short-haul tractors that pull any size box-type trailer. Staff used the 2002 VIUS 

data to determine the long-haul fraction for California intrastate, interstate, and 

neighboring out-of-state fleets (Census, 2002). Specifically, the VIUS data provided 

staff with information on (1) the primary range of operation (to determine the percentage 

of vehicles with a primary range of operation greater than 100 miles), and (2) jurisdiction 

in which the vehicle was most driven (to determine whether fleets operate interstate or 

exclusively intrastate). As shown in Table VI-2, this information was used by staff to 

conclude that 23 percent of California’s intrastate tractors and 71 percent of California’s 

interstate tractors operate long-haul. For out-of-state registered tractors, 69 percent of 

tractors registered in neighboring states are affected. For the purpose of this proposal, 

a range of more than 100 miles from their home base would classify these tractors as 

long-haul. It is assumed that all tractors from non-neighboring states travel more than 

100 miles, resulting in the long-haul population percentage for this category equal to 

100 percent. 

Table VI-2: Percentage of Tractors with Primary Range of Operation Greater than 

100 Miles 

Fleet 

Percentage of Tractors 

with Primary Range of 

Operation > 100 Miles 

CA Intrastate 23% 

CA Interstate 71% 

Neighboring 

Out-of-State 69% 

Non-neighboring 

Out-of-State 100% 
13

Table VI-2 gives the fraction of the tractor population with a primary range of operation 

greater than 100 miles. These percentages include all long-haul tractors that pull all 

types of trailers. However, because the proposed regulation applies only to long-haul 

tractors that pull 53-foot or longer box-type trailers, the percentages in Table VI-2 were 

further adjusted, as explained below. 

To determine the percentage of box-type trailers that are 53-foot or longer, it was 

necessary to first assess what percentage of trailers sold each year are box-type. Staff 

analyzed trailer production data from the CIR report (Census, 2000), which showed that 

the percentage of box-type trailers sold each year from 1988 to 2000 varied from 70 to 

77 percent with an overall average of 73 percent. As shown in Table VI-3, staff 

assumed that this average was appropriate for California intrastate, interstate, and 

neighboring out-of-state fleets operating in California. It was also assumed that since 

essentially all non-neighboring out-of-state tractors pull loads for greater distances, it 

would be appropriate to assume that more than 73 percent are box-type. Staff 

assumed that 90 percent of these tractors pull box-type trailers. 

The next step, to determine the percentage of box-type trailers that are 53-foot or 

longer, staff consulted several trailer manufacturers and ACT Research.4 Two of the 

major trailer manufacturers indicated that approximately 90 percent or more of box-type 

trailers produced are 53-foot or longer trailers. Based on correspondence with ACT 

Research, 85 to 90 percent of refrigerated-van and dry-van trailers are 53-foot or longer 

(Vieth, 2008). Therefore, as shown in Table VI-3, staff assumes that 85 percent of the 

box-type trailers pulled by California intrastate, interstate, and neighboring out-of-state 

tractors, and 90 percent of those pulled by non-neighboring out-of-state tractors are 53-

foot or longer. 

Table VI-3: Percentage of 53-Foot Box Type Trailers 

Fleet Percent Box-Type 

Trailers 

Percent that are 53-foot 

or Longer 

CA Intrastate 73 85 

CA Interstate 73 85 

Neighboring Out-of-State 73 85 

Non-neighboring Out-of-State 90 90 

Based on the total tractor population shown in Table VI-1 and the factors shown in 

Tables VI-2 and VI-3, staff estimated the tractor population impacted by the proposed 

regulation and the corresponding annual VMT, which is reflected in Table VI-4 for years 

2010 and 2020. 

 

4

 ACT Research is a subscriber-funded research company that collects and analyzes 

commercial vehicle data from manufacturers. 
14

Table VI-4: 2010 and 2020 Impacted Tractor Population and the Corresponding 

Annual VMT 

Impacted Tractor 

Population 

Annual VMT 

(106

 miles) Fleet 

2010 2020 2010 2020 

CA Intrastate 9,547 12,910 705 952

CA Interstate 27,462 37,005 1,320 1,783

Neighboring Out-of-State 18,525 24,962 663 896

Non-neighboring Out-of-State 380,152 507,751 3,187 4,306

Total 435,686 582,628 5,875 7,937

2. Trailers 

Available data were used to estimate the number of tractors that would be impacted by 

the proposed rule, as discussed above. For trailers, no database exists that provides a 

complete inventory on the total number of box-type trailers that would be impacted by 

the proposed rule. The ratio of trailers-to-tractors in many fleets is often not one-to-one 

(in which case the same numbers provided in Table VI-4 for tractors could have been 

used to estimate trailer inventory). The ratio varies considerably from fleet to fleet. 

Many fleets typically own more trailers than tractors in order to maximize efficiency and 

reduce downtime for the tractor while waiting for the trailer to be unloaded and loaded. 

The ratio varies from zero for some owner-operators that own only tractors and pull 

trailers owned by other businesses, to “infinity” for some shippers that own only trailers 

and use the services of carriers to pull their trailers. Since data describing the tractortrailer composition of all fleets that operate in California were not available, staff 

determined an approximate trailer-to-tractor ratio using data from annual CCJ 

publications (Vise, 2007; Vise, 2008). The published data included the number of 

trailers and tractors owned by the top 250 carriers in the country in calendar years 2006 

and 2007. Analysis of the two annual datasets provided an estimated ratio of 2.5-to-1 

trailers to tractors for both years. 

The number of box-type trailers impacted by the proposed rule was then estimated by 

multiplying the trailer-to-tractor ratio of 2.5 by the number of tractors impacted by the 

proposed rule shown in Table VI-4. Table VI-5 shows the resulting 53-foot box-type 

trailer population impacted by staff’s proposal for calendar years 2010 and 2020. 
15

Table VI-5: 2010 and 2020 Impacted 53-Foot Box-Type Trailers 

Fleet 2010 2020

CA Intrastate 23,868 32,275

CA Interstate 68,655 92,513

Neighboring Out-of-State 46,313 62,405

Non-neighboring Out-of-State 950,380 1,269,378

Total 1,089,215 1,456,570

B. GHG Contribution 

1. Overview, HDV Fleet 

Figure VI-1 shows 2002 to 2004 average GHG emissions inventory broken down by 

sector (ARB, 2008b). As shown in the figure, the transportation sector, which includes 

on-road vehicles, aviation, rail, and ships, is the largest contributor to the total statewide 

GHG emissions inventory, producing approximately 38 percent of the state’s total 

GHGs, or 179 MMT CO2e. In 2020, GHG emissions from this sector are projected to 

increase by 25 percent (46 MMT CO2e) relative to the 2002 to 2004 average and by 50 

percent (75 MMT CO2e) relative to 1990 levels, as shown in Table VI-6. Thus, 

emissions from the transportation sector must be significantly reduced in order to 

achieve the AB 32 requirement that State GHG emission levels be reduced to 1990 

levels by the year 2020. Furthermore, as shown in Figure VI-2, on-road vehicle 

emissions account for more than 90 percent of the transportation emissions, with 74 

percent from light-duty vehicles and 20 percent from on-road HDVs. This implies that 

most of the needed emission reductions from the transportation sector must come from 

on-road vehicles. The proposed regulation would therefore contribute towards 

achieving AB 32 goals by reducing emissions from on-road HDVs, and specifically from 

tractors that pull box-type trailers. 
16

Transportation

38%

Industrial

20%

Electricity

23%

Agriculture

6%

Recycling and 

Waste

1%

High GWP

3%

Commercial and 

Residential

9%

Figure VI-1: California GHG Emissions by Sector – 2002-2004 Average 

(ARB, 2008b) 

Table VI-6: 1990, 2002-2004 Average, and 2020 Projected Transportation Sector 

GHG Emissions (MMT CO2e) (ARB, 2008b) 

Fleet Calendar Year 

 1990 2002-2004 

Average Emissions 

Projected 2020 

Emissions (BAU) 

Passenger Vehicles 108.9 133.9 160.8 

Heavy-duty Trucks 29.0 34.7 48.3 

Ships & Commercial 

Boats 2.2 3.3 6.3 

Aviation (Intrastate) 5.1 3.2 4.9 

Rail 2.3 3.0 3.8 

Unspecified 3.0 1.2 1.4 

Emissions Total 150.7 179.3 225.4 
17

Passenger Vehicles

74%

Heavy Duty Trucks

20%

Aviation

(Intrastate Only)

Ships 2%

2%

Rail

2%

Figure VI-2: Transportation Sector GHG Emissions – 2002-2004 Average 

(179 MMTCO2e) (ARB, 2008b) 

2. Emissions Contribution of Impacted Tractor-trailers 

Baseline GHG emissions for fleets impacted by the proposed regulation were estimated 

using the adjusted VMT shown in Table VI-4, an assumed fleet average fuel economy 

of 5.8 miles per gallon, and a GHG emission factor of 10.4 kilograms CO2e per gallon of 

diesel fuel (ARB, 2008c). The baseline GHG emissions in California from long-haul 

tractors pulling box-type trailers are 8.5 MMT CO2e in 2010 and 11 MMT CO2e in 2020. 

VII. U.S. EPA SMARTWAY TRANSPORT PARTNERSHIP

A. Description of Program 

The SmartWay Transport Partnership (SmartWay) is a voluntary program developed by 

the United States Environmental Protection Agency (U.S. EPA) to reduce fuel 

consumption and emissions (criteria pollutant and GHG) resulting from the 

transportation of freight. The information presented in this chapter regarding the 

SmartWay program was acquired from a collection of references obtained from the U.S. 

EPA (see Appendix D). Through this program, freight industry companies enter into a 

partnership with U.S. EPA to implement strategies that improve their transportation 

efficiency. In return for their collaboration, U.S. EPA rewards these companies with 

certain market-based incentives, such as the privilege to advertise their SmartWay 

participation, business preference by other SmartWay partners, and for top-performers, 

the right to display the official SmartWay logo. U.S. EPA also continually promotes 

these partnerships in the public forum, which helps partners establish and maintain a 
18

“green” image. Currently, the SmartWay program has more than 850 partners and aims 

to reduce oil consumption by as much as 150 million barrels per year, carbon dioxide 

emissions by as much as 66 million metric tons per year, and oxides of nitrogen 

emissions by as much as 200,000 tons per year by 2012.5 

U.S. EPA developed SmartWay primarily for carriers (truck and rail), shippers, and 

logistics companies because of their influence on freight movement in the United 

States. By implementing strategies that improve transportation efficiency, these 

companies can earn performance points, the accumulation of which makes up their 

SmartWay score. This score serves three main purposes: it allows companies to 

monitor their environmental performance; it can be used as a marketing tool; and it can 

improve business opportunities, since contracting with other SmartWay partners 

increases the SmartWay scores of member businesses. 

SmartWay carriers and trailer-operating shippers may use the following strategies to 

earn points: 

• Reduce idle time 

• Improve vehicle aerodynamics 

• Improve freight logistics 

• Use automatic tire inflation systems 

• Use low-rolling resistance tires 

• Implement driver training 

• Use low-viscosity lubricants 

• Reduce vehicle weight 

• Reduce speed 

• Use intermodal shipping 

• Use hybrid powertrain technology 

• Contract with other SmartWay partners 

SmartWay shippers may also use the strategies listed below: 

• Use intermodal shipping 

• Provide preferential docking for SmartWay carriers

• Provide driver comfort stations 

• Use electric forklifts 

• Implement anti-idling policies 

• Implement pickup/delivery scheduling 

• Improve freight management to ensure full truckloads 

• Improve efficiency of light fleet vehicles 

• Improve warehouse efficiency 

• Contract with other SmartWay partners 

 

5

http://www.epa.gov/smartway/swplan.htm (July 10, 2008) 
19

For logistics companies, scores are based solely on the SmartWay participation and 

scores of the carriers and shippers with whom they contract. 

The option to earn points through the use of SmartWay partners encourages the 

industry as a whole to improve its environmental performance. Not only does a partner 

earn points for employing the services of another SmartWay partner, but more points 

are awarded for using partners with higher scores. Therefore, doing more in terms of 

improving efficiency, even if it requires additional investment, can actually serve as a 

business advantage. 

Although some strategies listed in this section require upfront capital investment, 

SmartWay is expected to ultimately reduce the monetary cost of transportation as well 

as transportation’s impact on the environment and public health. 

B. SmartWay Tractors 

Under the SmartWay program, U.S. EPA certifies tractors that have been demonstrated 

to use less fuel and produce lower emissions than their traditional counterparts. These 

tractors, which are designed to reduce aerodynamic drag, rolling resistance, and idle 

times, may be used to improve a partner’s efficiency and SmartWay score. U.S. EPA 

developed the SmartWay tractor specifications in collaboration with the truck 

manufacturing industry and continues to update these specifications as technology 

advances. Several truck manufacturers currently offer U.S. EPA certified SmartWay 

tractors, including Freightliner, International, Kenworth, Mack, Peterbilt, and Volvo. 

1. Technical Specifications and Requirements for SmartWay Tractors 

To certify a tractor under the SmartWay program, a truck manufacturer must 

demonstrate to U.S. EPA that the tractor is equipped with the following: 

• A 2007 or subsequent model year primary engine 

• An integrated cab-high roof fairing 

• Tractor-mounted side-fairing gap reducers 

• Tractor fuel-tank side fairings 

• Aerodynamic bumpers and mirrors 

• An option for reducing extended idling 

• Low-rolling resistance tires 

Since tractors are typically designed from the ground up, retrofitting in-use tractors to 

meet SmartWay specifications is not practical. Therefore, in-use tractors are not 

considered for SmartWay certification. This is not the case for trailers, which will be 

explained in the following section. At this time, U.S. EPA only certifies tractors 

equipped with an integrated sleeper berth. However, they are currently developing 

specifications for day cab tractors as well. 
20

C. SmartWay Trailers 

Under the SmartWay program, carriers and shippers may use U.S. EPA certified 

SmartWay trailers to earn points. SmartWay trailers incorporate a number of the 

strategies listed in Section VII.A above, and are designed to meet specifications that 

emphasize improved fuel efficiency and reduced emissions. These specifications were 

developed collaboratively by U.S. EPA and the trailer manufacturing industry. At this 

time, U.S. EPA has only developed specifications for dry-van trailers, and therefore, 

only these trailers can be certified under the SmartWay program. Several trailer 

manufacturers currently offer U.S. EPA certified SmartWay trailers, including Great 

Dane, Hyundai Translead, Manac, Stoughton, Strick, Utility, and Wabash National. 

To designate a trailer as a U.S. EPA certified SmartWay trailer, the trailer must either be 

equipped with the necessary SmartWay approved devices to meet U.S. EPA’s design 

specifications, or be track tested for fuel consumption against a base trailer. This can 

be done by the original equipment manufacturers during manufacture, or it can be done 

on existing used trailers in the fleet. 

The design specifications for a U.S. EPA certified SmartWay trailer currently require the 

following equipment: 

• SmartWay approved side skirt fairings 

• Either a SmartWay approved front-mounted trailer gap fairing or a SmartWay 

approved rear-mounted trailer fairing 

• SmartWay approved low-rolling resistance tires 

In order to demonstrate a trailer as a U.S. EPA certified SmartWay trailer through track 

testing, the testing must show that the trailer consumes at least 6.5% less fuel than a 

base trailer under similar drive and duty conditions. For this testing, the “SAE J1321, 

Type II” protocol6

 must be used to measure fuel consumption. 

VIII. PROPOSED REGULATION

A. Proposed Regulation Overview 

The proposed regulation would reduce GHG emissions by requiring new and existing 

53-foot or longer box-type trailers, and the tractors that pull them, to be equipped with 

SmartWay technologies when operating on California highways. The proposed 

regulatory language is contained in the new sections 95300 through 95312 of title 17, 

California Code of Regulations (see Appendix A of this report). The proposed 

requirements for both the tractors and trailers begin January 1, 2010. These 

requirements pertain to all applicable tractors and box-type trailers that operate on 

California highways regardless of where the vehicles are domiciled. 

 

6

The SAE J1321, Type II test procedure does not specify any test parameters, such as environmental conditions, 

test design, load requirements, drive cycles, etc. Therefore, U.S. EPA reviews all test parameters before each test 

to ensure that testing is performed in a consistent manner. 
21

B. Purpose 

The purpose of the proposed regulation is to reduce GHG emissions from tractors that 

pull 53-foot or longer box-type trailers on California highways. GHG emissions would 

be reduced from these vehicles through the use of aerodynamic technologies and lowrolling resistance tires, which reduce aerodynamic drag and rolling resistance, 

respectively. This will result in the tractor requiring less energy to propel the vehicle 

forward, resulting in reduced fuel usage and GHG and NOx emissions. 

C. Applicability 

The proposed regulation applies to 53-foot or longer box-type trailers and the tractors 

that pull them when driven on California highways. The proposed tractor and trailer 

requirements apply to the owner, driver, motor carrier, California-based broker, and 

California-based shipper. The proposed regulation does not apply to tractors pulling 

other types of trailers, e.g., box-type trailers of lengths shorter than 53 feet, or to tractors 

pulling flatbeds, or logging trailers, drop-frame trailers, curtain-side trailers, or chassis 

trailers hauling shipping containers. Also exempt from the requirements of the 

regulation are authorized emergency vehicles and military tactical support vehicles, as 

well as short-haul and drayage tractors, as defined in the proposal. 

D. Definitions 

The proposed regulation contains many definitions to define and clarify the 

requirements. Only the key definitions are highlighted in this section. The full list of 

definitions can be found in the text of the proposed regulation, provided in Appendix A. 

1. Aerodynamic Technologies 

Aerodynamic technologies are devices designed to reduce wind resistance on the 

tractor or trailer that will improve overall vehicle fuel efficiency and reduce exhaust GHG 

emissions. Examples of such technologies for the tractor are fuel tank fairings, 

integrated cab roof fairings, and side extender fairings. Examples of trailer technologies 

are side skirts, front fairings, and rear (or boat tail) fairings. 

2. Parties Responsible for Compliance 

The parties responsible for compliance with the proposed regulation include the owner, 

driver, motor carrier, California-based broker, and California-based shipper. Each of 

these parties is defined here. The owner of a tractor or trailer is the person who legally 

holds the title of the vehicle or the lessee that has legal responsibility for registration and 

maintenance of the vehicle. The driver of a tractor is the operator of the tractor on a 

California highway. The motor carrier and the broker are the business intermediaries 

that contract with a person for pick-up and delivery of commercial freight, and either 

contract with tractor owners or, if a motor carrier, employs drivers of its own vehicles to 

pick-up or deliver freight. The shipper is the person or commercial operation that has 

possession of freight prior to its transportation, including, but not limited to, the owner of 

the freight, a distribution center, or a temporary freight storage facility. Only shippers 
22

that are located in California are subject to the proposed requirements. When freight is 

shipped in a 53-foot or longer box-type trailer, each of the aforementioned parties would 

be responsible to ensure that both the tractor and the trailer are in compliance with the 

proposed requirements. 

3. U.S. EPA SmartWay Partnership Program 

The U.S. EPA SmartWay partnership program is a federal voluntary program aimed at 

improving energy efficiency, reducing GHG and air pollutant emissions, and improving 

energy security of the ground freight movement system. The SmartWay program 

certifies tractors and trailers that have the cleanest, most fuel-efficient equipment 

available. U.S. EPA certified SmartWay tractors and SmartWay trailers may be 

identified by the special certification mark on the inside of the tractor cab or trailer. U.S. 

EPA approved SmartWay aerodynamic devices for retrofitting non-SmartWay trailers 

are also identified through the SmartWay program. These devices meet the SmartWay 

technical specifications and requirements for improved fuel efficiency. 

E. Requirements and Compliance Deadlines 

1. Heavy-Duty Tractors 

Different requirements would apply for tractors with sleeper berths and those without 

sleeper berths that pull 53-foot or longer box-type trailers on California highways (Table 

VIII-1). Beginning January 1, 2010, a 2011 and subsequent model year tractor with a 

sleeper berth would be required to be a U.S. EPA certified SmartWay tractor. A U.S. 

EPA certified SmartWay tractor typically has a high roof sleeper cab equipped with an 

integrated sleeper cab roof fairing, aerodynamic mirrors, an aerodynamic bumper, cab 

side extenders, fuel tank fairings, and low-rolling resistance tires. A description of 

tractor aerodynamic devices can be found in chapter IX, section A.2. SmartWay does 

not currently certify a tractor without a sleeper berth, i.e., day cab, and thus, these 

tractors are not included in the proposed regulation. 

Low-rolling resistance tires that meet U.S. EPA SmartWay specifications would be 

required beginning January 1, 2010, for a 2011 and subsequent model year tractor 

regardless of whether it has a sleeper berth or not. 2010 and earlier model year tractors 

with or without sleeper berths would have additional time to comply with the low-rolling 

resistance tire requirements; it is proposed that they comply with these tire requirements 

by January 1, 2012. This flexibility minimizes waste and tire disposal issues by allowing 

most existing tires on the vehicle to be used for their normal useful life, and replaced 

with low-rolling resistance tires only when new tires are needed. Thus, by January 1, 

2012, all tractors that pull 53-foot or longer trailers would have low-rolling resistance 

tires. 
23

Table VIII-1: Proposed Tractor Requirements 

Requirement 

Model Year 2011 & 

Later Tractors with 

Sleeper Berths 

Model Year 2011 & 

Later Tractors 

without Sleeper 

Berths 

All Model Year 2010 

and Earlier Tractors 

SmartWay Certified 

Tractor 1/1/2010 Not Applicable Not Applicable 

SmartWay 

Approved low-rolling 

resistance tires 

1/1/2010 1/1/2010 1/1/2012 

2. Trailers 

a) Requirements for 2011 and Subsequent Model Year Trailers 

Beginning on January 1, 2010, a 2011 and subsequent model year 53-foot or longer 

box-type trailer pulled by a tractor on a California highway would be required to be 

either a U.S. EPA certified SmartWay trailer or retrofitted with SmartWay approved 

technologies (See Table VIII-2). 

The first option, to use a U.S. EPA certified SmartWay trailer, is currently only available 

for dry-van trailer applications. The U.S. EPA has defined specifications for this type of 

trailer, and several manufacturers have already certified models. Certified dry-van 

trailers are equipped with side skirts, front trailer fairings, and low-rolling resistance 

tires. For refrigerated-van trailers, retrofitting with SmartWay approved technologies 

would be the only option for compliance. In the future, the SmartWay program may 

expand to certify refrigerated trailers, as well as other types of trailers, making this 

alternative available. 

The second option, compliance by retrofitting with SmartWay approved aerodynamic 

and low-rolling resistance tire technologies, is available to both dry-van and refrigeratedvan trailers. The proposed regulation would require dry-van trailers to use low-rolling 

resistance tires and either be retrofitted with (1) aerodynamic equipment that collectively 

meets or exceeds a 5 percent fuel savings in accordance with test requirements defined 

by the U.S. EPA SmartWay Partnership Program, or (2) side skirts plus a front fairing or 

rear trailer fairing that are SmartWay approved. This latter combination of aerodynamic 

devices has been certified by SmartWay to meet the five percent fuel savings criteria. 

Refrigerated-van trailers would be required to be retrofitted with low-rolling resistance 

tires and either (1) any combination of aerodynamic equipment that collectively meets or 

exceeds 4 percent fuel savings in accordance with test requirements defined by the 

SmartWay program, or (2) side skirts that are SmartWay approved. The lower percent 

fuel savings criteria for refrigerated-van trailers reflects the lack of a requirement for a 

front or rear fairing on these types of trailers. A front trailer fairing is not feasible on a 

refrigerated-van trailer because the transport refrigeration unit (TRU) is typically 

installed where the front trailer fairing would be mounted. Requiring a rear-fairing on all 

refrigerated-van trailers is too restrictive, since current SmartWay approved rear fairing 

technologies are not compatible with roll-up door trailers. 
24

Table VIII-2: Proposed 2011 and Later Model Year Trailer Compliance Options, 

Beginning January 1, 2010 

Option 2: Retrofit Existing Trailer 

Trailer Type 

Option 1: 

Purchase Certified 

SmartWay Trailer 

Retrofitted with SmartWay 

approved low rolling 

resistance tires and 

SmartWay approved 

aerodynamic devices 

Retrofitted with SmartWay 

approved low rolling 

resistance tires and 

aerodynamic devices 

demonstrated to meet min. 

fuel savings per SmartWay 

Program 

Dry-Van Available Aero=side skirts + rear or 

front fairing 

Aero must meet 5% fuel 

savings 

RefrigeratedVan Not Available* Aero= side skirts Aero must meet 4% fuel 

savings 

* At time of publishing, U.S. EPA had not yet established SmartWay certification specifications for refrigerated-van 

trailers

b) Requirements for 2010 and Earlier Model Year Trailers 

The 2010 and earlier model year 53-foot or longer box-type trailers that are pulled by 

tractors on California highways would be required to be retrofitted with SmartWay 

approved technologies by January 1, 2013. The retrofit requirements would be identical 

to the second option for 2011 and subsequent model year trailers described above. In 

lieu of meeting the January 1, 2013, compliance date, the trailer owner could choose to 

comply with an optional trailer fleet compliance schedule. 

There are two proposed optional trailer fleet compliance schedules that would be based 

on trailer fleet size: the large fleet compliance schedule and the small fleet compliance 

schedule. A large fleet is defined as a fleet of 21 or more trailers. A small fleet is 

defined as a fleet of 20 or less trailers. In order to participate, a trailer owner that owns 

the requisite number of trailers would be required to meet the following criteria: (1) 

submit a compliance plan by July 1, 2010 for the large fleet optional compliance 

schedule or by July 1, 2012 for the small fleet compliance schedule, (2) meet the annual 

commitments for retrofitting trailers, and (3) allow ARB to audit records periodically. 

The compliance plan would include a statement of intent, information on each trailer, 

and details as to which affected trailers would be retrofitted to comply with each year of 

the optional phase-in schedule requirements. If the owner fails to comply with any of 

the three conditions for optional compliance participation, it may result in termination of 

the optional compliance schedule(s). If the fleet’s participation in the optional 

compliance schedule is terminated, all trailers in the fleet have to be in compliance 

within 90 days or by December 31, 2012, whichever is later. 

The large fleet compliance schedule is shown in Table VIII-3. A six year phase-in is 

proposed for large fleets beginning in 2010 and ending in 2015. For added flexibility, a 
25

trailer owner could participate in an early compliance option. For every 2010 and earlier 

model year box-type trailer that is compliant with the proposed regulation by December 

31, 2009, the owner could delay the retrofit of 1.5 noncompliant trailers until 2016. If a 

trailer owner participates in the early compliance option, the submitted compliance plan 

would need to contain information on the list of trailers that are brought into compliance 

by December 31, 2009, and the list of trailers that are delayed for compliance until 

2016. The early compliance option is discussed in more detail in Appendix F, Optional 

Trailer Fleet Compliance Schedules. 

Table VIII-3: Proposed Optional Large Fleet (21+) Compliance Schedule for 2010 

and Earlier Model Year 53-foot or Longer Box-Type Trailers, Except RefrigeratedVan Trailers with Transport Refrigeration Units using 2003 to 2009 Model Year 

Engines 

 12/31/10 12/31/11 12/31/12 12/31/13 12/31/14 12/31/15 

Required 

Percent 

Compliance 

5% 15% 30% 50% 75% 100% 

The small fleet compliance schedule is shown in Table VIII-4. The phase-in for small 

fleets begins in 2013 and ends in 2016. 

Table VIII-4: Proposed Optional Compliance Schedule for Small Trailer Fleets of 

2010 and Earlier Model Year 53-foot or Longer Box-Type Trailers

12/31/13 12/31/14 12/31/15 12/31/16 

Required 

Percent 

Compliance 

25% 50% 75% 100% 

3. Refrigerated Fleet Compliance Provision 

Since refrigerated trailers would be concurrently impacted by the proposed regulation 

and the previously adopted Airborne Toxic Control Measure for In-Use Diesel-Fueled 

Transport Refrigeration Units (TRU) and TRU Generator Sets, and Facilities Where 

TRUs Operate (TRU Rule), staff developed a special provision that would allow the 

delay of retrofits and retirements of certain in-use refrigerated trailers. Specifically, the 

refrigerated fleet compliance provision would apply to 2003 through 2008 model year 

refrigerated-van trailers equipped with 2003 and subsequent model year TRUs. 

Because allowing the delay of all refrigerated trailers would significantly reduce the 

cumulative GHG benefits expected from the proposed regulation, the refrigerated fleet 

compliance provision would not apply to the following trailers: 

• 2009 and 2010 model year trailers: The greatest GHG and fuel economy benefits 

would likely be achieved by bringing these trailers into compliance first. This is 
26

because these trailers would be newer, so they would see more road miles and 

have more time to realize returns on investment. 

• 2002 and previous model year trailers: These trailers would likely reach the 

natural end of their long-haul service before the phase-in of the refrigerated fleet 

compliance provision would begin. 

In addition, because the provision would only apply to in-use trailers, 2011 and 

subsequent model year trailers would not be eligible. 

A trailer owner participating under this provision would be required to bring trailers of the 

model years listed in Table VIII-5 into compliance by December 31 of the applicable 

year. 

Table VIII-5: Refrigerated Fleet Compliance Deadlines 

Year 2017 2018 2019 

Trailer Model 

Year 2003-2004 2005-2006 2007-2008 

4. Requirements for the Owner, Driver, Motor Carrier, Broker and Shipper 

As mentioned previously, the responsibility for compliance rests primarily with the owner 

of the tractor and trailer, but the driver, motor carrier, California-based broker, and 

California-based shipper also share responsibilities. Noncompliance with the proposed 

tractor or trailer requirements may result in a notice of violation to each aforementioned 

party. The responsibility of the owner would be to ensure the applicable tractors and 

trailers comply with the proposed requirements within the proposed compliance 

schedule. The owner of affected trailers would also be required to report information to 

ARB on its trailers and its compliance plan, if applicable. 

The driver would be responsible to ensure that the tractor-trailer to be driven is in 

compliance with this proposed regulation, i.e., SmartWay certified, and meets the good 

operating condition criteria. If the tractor-trailer is not in compliance, the driver should 

refuse to operate the tractor-trailer. Failure to do so may result in a notice of violation. 

The driver should also ensure that the following information is available to be presented 

to authorized enforcement personnel: driver’s license, tractor registration, origin of 

freight being transported, destination of freight being transported, and motor carrier 

information, if applicable. 

Motor carriers would be responsible to ensure that a tractor-trailer they dispatch to pick 

up and deliver freight complies with the proposed regulatory requirements. To facilitate 

compliance, motor carriers would be required to provide the following information to the 

dispatched driver: the motor carrier business name, street address, contact person, 

and contact person’s business phone number. 

The requirements for California-based brokers are similar to those discussed in the 

previous paragraph for motor carriers. In addition, ARB would also have the authority to 
27

restrict California-based brokers from using the services and vehicles of particular motor 

carriers, tractor owners and trailer owners that have failed to settle a previously issued 

notice of violation. This approach to enforcement is discussed in detail in Appendix G, 

Implementation and Enforcement. 

The California-based shipper would be responsible to ensure that the tractors and boxtype trailers used to transport freight from its facility are in compliance with the proposed 

regulation. ARB would have the authority to restrict California-based shippers from 

using the services and equipment of particular motor carriers, California-based brokers, 

tractor owners and trailer owners that have failed to settle a previously issued notice of 

violation. This approach to enforcement is discussed in detail in Appendix G, 

Implementation and Enforcement. 

Motor carriers, California-based brokers, and California-based shippers may choose to 

discharge the obligation to pay fines through contractual language. For example, once 

a fine has been assessed to a shipper, the shipper could have a contract with the 

noncomplying motor carrier that requires the motor carrier to pay all fines associated 

with the use of noncompliant tractor-trailers. Similarly, a motor carrier could also have a 

contract with a tractor or trailer owner requiring the tractor or trailer owner to pay all 

fines associated with the use of a noncompliant tractor or trailer, respectively. 

 

F. Maintenance Requirements 

Owners and drivers of the applicable tractors and trailers would be responsible to 

ensure that the applicable tractor and trailer are equipped with appropriate equipment 

and that the equipment is in good operating condition. The aerodynamic technology 

would need to be installed according to manufacturer’s specifications, be securely 

fastened to the tractor or trailer, not be missing any panels or sections, and not be 

damaged to the extent that its aerodynamic effectiveness is compromised. In addition, 

a rear trailer fairing must be designed such that, when not in-use, it can be folded back 

against the trailer or otherwise be readily compacted to allow normal functioning of the 

doors. 

G. Exemptions 

The proposed regulation would exempt certain types of tractors and trailers, as 

discussed previously in Section C of this chapter. For a short-haul tractor exemption, 

the trailer would need to be registered with ARB and approved as short-haul, requiring 

annual renewal. A short-haul trailer is defined as only operating within a 100 mile radius 

from the registered location where the trailer is garaged and maintained. A drayage 

truck would also be exempted from the proposed requirements. A drayage truck is 

defined as a truck that only operates within 100 miles of a port or intermodal rail yard 

property of origin or destination. 
28

H. Reporting Requirements 

For tractors, reporting would not be required for the owner of Class 7 or Class 8 tractors 

used exclusively for long-haul purposes. In order for a tractor or trailer to be classified 

as short-haul, and thus exempted from the proposed regulation, it would need to be 

registered with ARB. The owner would need to submit an application with specific 

information on the vehicle, vehicle owner, and vehicle’s local haul base. For tractors, 

the owner would designate, in the application, whether the exemption will be based on a 

limit of 50,000 miles annually or a limit of operation within a 100-mile radius from its 

local base. Once approved, the tractor or trailer would be considered short-haul and not 

subjected to the requirements of the proposed regulation. The short-haul exemption 

would be effective for one year and would require renewal on an annual basis. 

A trailer owner who does not choose to participate in any of the optional compliance 

schedules would not be required to provide reporting of trailers. However, if the owner 

chooses to participate in the optional compliance schedules, a compliance plan would 

be required to be submitted by July 1, 2010. The compliance plan would include a 

statement of intent, information on each affected trailer, and details as to which affected 

trailers would be retrofitted to comply with each year of the optional phase-in schedule 

requirements. 

There are no recordkeeping requirements for shippers specified in the proposed 

regulation. However, ARB staff reserves the right to audit existing shipping records, if 

the shipper or broker continues to use noncompliant tractor-trailer owners and motor 

carriers after being notified of their noncompliance. 

I. Enforcement and Fines 

Enforcement of the proposed requirements may be carried out by authorized 

representatives of ARB, peace officers, and authorized representatives of an air 

pollution control district. A violation of the proposed requirements may result in civil or 

criminal penalties. A violation may be issued for failure to comply with the proposed 

tractor and or trailer requirements, failure to submit the appropriate information, or 

providing false information. The extent of the penalty would depend on the willfulness 

of the violation, the length of time of the noncompliance, the magnitude of the 

noncompliance, and other pertinent factors. Authorized enforcement personnel may 

stop trucks on the highway or at alternative locations, such as on the roadside, at weigh 

stations, or at loading docks, to ensure that the appropriate aerodynamic equipment and 

low-rolling resistance tires are properly installed and in good operating condition. 

If the tractor or trailer does not have the appropriate aerodynamic equipment or lowrolling resistance tires, or if such equipment is damaged or not properly functioning, the 

enforcement personnel would write a notice of violation to the parties involved in the 

movement of freight in the noncompliant vehicle. These may include the owner, driver, 

motor carrier, California-based broker, and California-based shipper of the transported 

freight. While the owner of the tractor and trailer is solely responsible for purchasing 

SmartWay certified tractors and trailers, or retrofitting tractors and trailers with approved 

SmartWay devices, it would also be the responsibility of brokers and California-based 
29

shippers to ensure that only compliant tractors and trailers are used to transport freight 

on California highways. 

If the tractor and/or trailer has been approved for short-haul exemption, the enforcement 

personnel would crosscheck its exemption status with the ARB database and confirm 

that the short-haul tractor and/or trailer is operating within the 100 mile radius from its 

local base or is within its annual miles limit, whichever is applicable. Similarly, an 

enforcement officer may check a drayage truck to ensure that it is operating within 100 

miles of the port or intermodal rail yard property. See Appendix F for a further 

discussion of implementation and enforcement issues. 

IX. TECHNOLOGICAL FEASIBILITY OF CONTROL MEASURE

The proposed regulation would require heavy-duty tractors and box-type trailers to be 

SmartWay certified or use SmartWay approved equipment and tires. The vehicles and 

equipment necessary to comply with the proposed regulation are already commercially 

available and in use today. In addition, new technologies continue to emerge. 

Therefore, staff firmly believes that the technological feasibility of the proposed 

regulation is sound. 

The following sections describe the availability of SmartWay certified tractors, 

SmartWay certified trailers, retrofit equipment for in-use trailers, and low-rolling 

resistance tires. In addition, because there have been concerns expressed about the 

reliability and safety of trailer side skirts, fleet experience with these technologies is 

discussed. 

A. SmartWay Certified Tractors 

The proposed regulation would require all 2011 and subsequent model year long-haul 

tractors that pull 53-foot or longer box-type trailers to be SmartWay certified. Most 

major truck manufacturers currently offer SmartWay tractors and have indicated that 

they are in a position to manufacture more if demand increases. 

Since tractor models are designed as a single unit, retrofitting a tractor with SmartWay 

aerodynamic equipment after its initial build would not be practical. Therefore, for inuse tractors, the proposed regulation would only require the use of low-rolling resistance 

tires, and not aerodynamic technologies. 

1. Base Tractor 

For every SmartWay tractor, a manufacturer must first identify a “base tractor,” upon 

which SmartWay features can be incorporated. To qualify as a base tractor, a tractor 

must have an overall aerodynamic profile and a high roof sleeper cab.7

 Most major 

tractor manufacturers offer at least one base tractor that is eligible for the SmartWay 

program. Some examples are: 

 

7

 As defined by SmartWay Logo Use Guidelines – Language – Tractor Requirements 

27Mar07.doc 
30

• Freightliner Columbia, Century Class S/T, and Cascadia 

• International Prostar and Lonestar 

• Mack Pinnacle 

• Kenworth T2000 and T660 

• Peterbilt 387 and 386 

• Volvo VN Series 

Examples of SmartWay tractors are shown in Figure IX-1.. 

2. Aerodynamic Features 

A base tractor must be equipped with all of the following aerodynamic features to be 

considered for SmartWay certification.8 These features have been defined for the 

purposes of this regulation as follows: 

• Integrated sleeper cab roof fairing – a fairing located on the roof of a sleepercab-equipped tractor that extends from the front windshield of the tractor cab 

to the rear edge of the sleeper cab, with enclosed sides that line up with the 

sides of the sleeper cab. 

• Aerodynamic mirrors – side mirrors designed to minimize air resistance 

• Aerodynamic bumper – a front bumper designed to minimize air resistance 

• Cab side extenders – vertical additions to the rear side of the tractor that fan 

out slightly and reduce the space between the tractor and trailer. 

• Fuel tank fairings or chassis skirt – the fairing located at the base of the cab 

between the front wheel of the tractor and the forward-most rear wheel, 

covering the open space and streamlining the fuel tank. 

 

8

 As defined in SmartWay Logo Use Guidelines – Language – Tractor Requirements 

27Mar07.doc 
31

Figure IX-1: SmartWay Tractors 

3. Experience with SmartWay Certified Tractors 

Based on meetings with various fleets, experiences with SmartWay tractors have been 

favorable. The only concerns raised, that fuel tank fairings can get easily damaged, 

appear to be highly driver-specific. Therefore, staff anticipates that the damage can be 

minimized by providing additional guidance to drivers on how to prevent or minimize 

damage to the fairings. 

4. Incremental Cost of SmartWay Certified Tractors 

The aerodynamic tractor package cost, which includes low-rolling resistance tires, was 

determined from current available retail prices, fleet price quotes, and manufacturer 

price estimates for new SmartWay approved tractors. The average incremental cost of 

the equipment is about $2,100, based on the purchase price of tractors equipped with 

the aerodynamic package. Specifically, this incremental cost assumes that the tractor is 
32

equipped with an aerodynamic equipment package featuring fuel tank fairings or 

chassis skirts, cab side extenders, an integrated sleeper cab roof fairing, aerodynamic 

bumpers and mirrors, and low-rolling resistance tires. 

5. Lifetime Costs of SmartWay Certified Tractors to Owners 

The measure is expected to provide cost savings to tractor owners over the useful life of 

the tractor by reducing operational costs (i.e., fuel consumption). A SmartWay certified 

tractor is expected to reduce fuel consumption by about 3.5 percent compared to a 

regular tractor, resulting in an annual fuel savings of approximately $1,800. Looking at 

the equipment operating costs only, about $22,000 savings is expected over a typical 

equipment life of 11 years. Equipment life was estimated from discussions with fleets 

which stated that a tractor will be typically used in the long-haul application for about 11 

years. Accounting for capital cost, maintenance cost, and fuel savings to the tractor 

owner, the proposed requirement is expected to have a net cost savings of about 

$6,000 (in 2008 dollars). Staff believes this is a conservative estimate of the savings 

since current California retail prices for diesel fuel are higher than the projected fuel cost 

used in this analysis. The cost of the SmartWay package for a tractor can, therefore, be 

recovered from fuel savings in 1 to 1.5 years. For further details on staff’s cost analysis, 

see Chapter XII. 

6. Production Availability 

The proposed regulation would require that, beginning January 1, 2010, all applicable 

tractors be SmartWay certified. This section discusses two important issues associated 

with this requirement: 1) the anticipated demand for these types of tractors; and 2) the 

procedure that a tractor manufacturer would need to undergo to certify a SmartWay 

tractor model. 

For model years 2011, 2015, and 2020, ARB staff estimates that 107,000, 129,000, and 

143,000 new Class 8 SmartWay tractors, respectively, will be sold to comply with the 

proposed rule. These numbers represent about 70 percent of the total number of new 

Class 8 tractors sold nationwide in each of those years that will, at some point in their 

useful life, travel in California. Staff believes that tractor manufacturers will be able to 

meet the increased demand for SmartWay tractors resulting from this proposal. 

Currently, there are six tractor manufacturers that sell a SmartWay base model tractor. 

Table IX-1 lists the manufacturers and the base tractor models that, when properly 

outfitted with aerodynamic equipment and low-rolling resistance tires, currently meet the 

SmartWay specifications. The decision-making process to develop a SmartWay tractor 

is normally preceded by a series of discussions between the U.S. EPA and the 

manufacturer to ensure mutual understanding of the technical specifications and 

requirements of the SmartWay program. Each manufacturer that is approved by the 

U.S. EPA to sell a SmartWay tractor must abide by a licensing agreement, included in 

Appendix D. 
33

Table IX-1: U.S. EPA Certified SmartWay Tractors 

Manufacturer Base Tractor Model 

Navistar International Prostar 

9200i* 

Mack Pinnacle 

Daimler (Freightliner) 

Cascadia 

Century Class 

Columbia 

Kenworth T660 

T2000 

Volvo VN 780 

VN 730 

Peterbilt 387 

386 

* will be replaced with the LoneStar model 

B. Trailer Aerodynamic Technologies 

1. Aerodynamic Technologies 

Aerodynamic technologies are defined in the regulation as components that are 

designed to reduce wind resistance on the tractor or trailer, resulting in improved overall 

tractor fuel economy and reduced carbon dioxide emissions. These technologies are 

currently available commercially through several U.S. and Canadian companies; 

additional companies are in the process of developing new or improved aerodynamic 

products. The types of equipment they currently offer include: trailer side skirts 

(sometimes called belly fairings), front fairings, rear fairings, strakes, traps, and others. 

These aerodynamic products and the companies that manufacture them are briefly 

described below. Some of the identified technologies are SmartWay approved at the 

present time, while others are not. It should be noted that this summary does not imply 

an endorsement of any of the companies or products identified below, nor does it claim 

to reflect a comprehensive list of all aerodynamic technologies currently available or 

under development for box-type trailers. 

a) Trailer Side Skirts 

Trailer side skirts are fairings that extend down from the bottom of the trailer to cover 

part of the open space between the tractor and the rear trailer wheels. They can be 

used on dry-vans as well as on refrigerated-vans. The range of fuel savings 

demonstrated by side skirt manufacturers is between 4 percent and 7 percent. 

Currently available side skirts are made of aluminum, thermoplastics, or composite 

materials. Some are constructed of individual panels that can be replaced separately in 

the event they are damaged, while others are constructed as a single unit extending the 

length of the skirt. One design consists of dual, parallel side panels. A set of side 

skirts, on average, may weigh between 150 and 350 pounds, depending on the 

material, length, and configuration of the skirt. The amount of ground clearance 
34

provided by the various side skirts varies somewhat across the different models; 

generally they average between 10 and 20 inches from the ground in order to strike a 

balance between maximizing fuel savings and avoiding potential damage due to road 

hazards or steeply sloping ramps. According to the manufacturers, installation times 

per trailer range between three and six hours, although some anticipate shorter times 

when installed by fully trained installers. 

The retail costs to purchase a single set of trailer side skirts range between $1000 and 

$2600, excluding installation. Fleet volume pricing would be lower. It is anticipated that 

as demand for these technologies increases, costs will likely drop. The cost to replace 

a panel varies considerably depending on the design of the skirts, from $80 to $500. 

Five different companies manufacture trailer side skirts; four of them offer skirts that are 

commercially available at the time of this writing, while the fifth company is still in the 

prototype phase. 

Currently Available Trailer Side Skirts: 

Figure IX-2 contains photographs of side skirts offered by the four companies discussed 

below. 

• Freight Wing Incorporated offers a selection of side skirts, which they market as 

Belly Fairings, adapted for different types of trailers. Three of these configurations 

are currently SmartWay approved, including the Standard Belly Fairing shown in 

Figure IX-2. Earlier models of the Belly Fairings were constructed of aluminum, 

while their newest version is made from high density polyethylene. 

• Laydon Composites Ltd. offers the TrailerSkirt, a full-length injection molded side 

skirt. It is made of ABS plastic with a rubber strip along the bottom. This product is 

constructed of separate panels; the number of panels used will depend upon the 

length of the trailer (typically between 6 and 8 per side). The Laydon TrailerSkirt is 

SmartWay approved. 

• Silver Eagle Manufacturing offers Mini-Skirts (see two photographs in Figure IX-2). 

The Mini-Skirts are made of aluminum and designed with dual parallel side panels 

that are constructed in four-foot modules. As of this writing they are not yet 

SmartWay approved. 

• Transtex Composite manufactures the MFS Skirt out of a fiberglass/thermoplastic 

composite material. It is constructed of a single panel on each side. The MFS Skirt 

is SmartWay approved. 
35

Figure IX-2: Trailer Side Skirts

Still In Development: 

• Adamworks has developed the AeroMax Retractable Fairing System, which is 

currently in the prototype phase. It is designed to be pneumatically controlled and 

speed sensitive; it deploys at 35 miles per hour (and retracts when speeds fall below 

35 miles per hour). When deployed, it reaches within a few inches of the ground, 

and when retracted, it stays at about 20 inches above ground (see Figure IX-3). The 

potential advantages of this type of design are that it reduces the chance of damage 

at low speeds or at loading docks (when retracted), and yet offers potential 

additional efficiency improvements when deployed closer to the ground, thereby 

reducing air flow under the trailer. As of this writing, this device is not yet SmartWay 

approved. 
36

Figure IX-3: Adamworks Aeromax Retractable Fairing

b) Front Trailer Fairings 

Front trailer fairings are defined in the regulation as curved structures that attach to the 

front facing surface of a trailer that covers all or part of the trailer’s front facing surface. 

These devices serve to reduce the wind resistance caused by the gap between the 

tractor and the trailer and allow for smooth, uninterrupted air flow, regardless of the 

angle of approaching wind. They are most effective when installed on tractor-trailers 

with a gap greater than 36 inches. They are designed to be used on dry-vans and not 

on refrigerated-vans. The average fuel savings associated with front trailer fairings is 

between 1 percent and 2 percent. Currently available front trailer fairings are 

constructed of aluminum, fiberglass or plastic. They typically weigh between 75 and 

140 pounds. 

The approximate retail costs for current front trailer fairings range between $800 and 

$1000. 

The following three companies manufacture some type of front trailer fairing, as shown 

in Figure IX-4: 

• Freight Wing Incorporated produces a few different front trailer fairings. One model, 

the Gap Fairing, is SmartWay approved. It consists of three curved aluminum 

panels that extend forward and inward from the top and sides of the trailer front. 

• Laydon Composites Ltd. produces the Nose Fairing, which is currently made of 

fiberglass. It is SmartWay approved. It consists of three elongated hemispheric 

structures that extend along the top and sides of the trailer front. 
37

• Nose Cone manufactures the Nose Cone/Gap Reducer. It is a rounded air deflector 

that is installed on the upper front portion of a trailer. The Nose Cone is most 

effective on trailers pulled by tractors that do not have the extended roof fairings. 

Previously constructed of aluminum, a newer, plastic version of the Nose Cone has 

received SmartWay approval, and will soon be commercially available. 

Figure IX-4: Front Trailer Gap Fairings 

c) Rear Trailer Fairings 

Rear trailer fairings are structures that attach to the outer edges of the trailer’s rearfacing surface to provide a continuous surface for the air passing over the side and top 

surfaces of the trailer. Some models also have a base plate on the lower surface. 

These fairings reduce turbulence and resistance by reducing “suction” on the rear of the 

trailer. They can be used on both dry-vans and refrigerated-vans. The fuel savings 

associated with rear trailer fairings ranges between 1 percent and 5.1 percent. 

The following three manufacturers offer some type of rear trailer fairing, as shown in 

Figure IX-5. 

• Advanced Transit Dynamics (ATDynamics) manufactures a rear trailer fairing called 

the TrailerTail. The TrailerTail is a rigid structure that extends four feet out from the 

perimeter of the rear of the trailer when deployed. It collapses when the rear doors 

of the trailer are opened, and it expands into its aerodynamic configuration when the 

doors are closed. This device is SmartWay approved. 

• Nose Cone manufactures the Tail Cone. This device is installed on trailers that do 

not open at the rear. As of this writing, this device is not SmartWay approved. 

• Transtex Composite manufactures the BoatTail rear air deflector. It automatically 

folds away when the rear doors are opened, and folds flat against the sides of the 

trailer so as not to interfere with loading or unloading. As of this writing, this device 

is not SmartWay approved. 
38

Figure IX-5: Rear Trailer Fairings 

The ranges of fuel savings offered by each of the three types of aerodynamic devices 

discussed previously are shown in Table IX-2 below. In general, staff expects the 

benefits of using more than one type of device to be additive, although there may be 

synergistic effects or interactions that may limit those additive benefits. 

Table IX-2: Fuel Savings Ranges for Trailer Aerodynamic Devices (Freight Wing, 

2007; Laydon, 2007; Surcel, 2007a; Surcel, 2007b) 

Trailer Aerodynamic 

Devices Fuel Savings Range 

Side skirts 4% - 7% 

Front gap fairings 1% - 2% 

Rear fairings 1% - 5.1% 

d) Other Technologies 

Several manufacturers have developed additional technologies to improve trailer 

aerodynamics, including other types of fairings and a variety of flow control devices 

(vortex strakes, vortex traps, air talons). As of this writing, these devices are not 

SmartWay approved but, if approved, may potentially play a role in meeting California’s 

proposed requirements. 

2. Experience with Aerodynamic Technologies 

ARB staff spoke with representatives of several fleets that have been using some of the 

aerodynamic technologies identified above in order to ascertain what their “real world” 

experiences have been with the technologies. Details of these discussions can be 

found in Appendix E: Fleet Summaries. For the most part, as described below, these 

companies have used some type of trailer side skirt and, in a few cases, some other 

type of technology. It should be noted that the majority of fleets with whom staff spoke 
39

were customers of the manufacturers identified in the previous section of this report. 

Staff also spoke with representatives of two large nationwide fleets that do not currently 

use trailer aerodynamic technologies; these fleets had some previous negative 

experiences with them. Their comments, one of which is detailed in Appendix E (the 

other fleet refused to allow its inclusion in this report), are also summarized below in the 

Previous Users of Aerodynamic Technologies section. 

a) Current Users of Aerodynamic Technologies 

Fleet Descriptions 

The companies with whom staff spoke are located in different parts of the United States, 

including the East, Midwest, South, and West, as well as eastern Canada. Fleet sizes 

ranged from fewer than 50 trailers to over 20,000 trailers. Some operated dry-vans 

exclusively or refrigerated-vans exclusively, while others operated a variety of different 

types of trailers. The majority operated mostly 53-foot trailers, although one used 

smaller trailers (48-foot) exclusively. 

Types of Aerodynamic Technologies 

All of the fleets indicated that they have been using at least one type of side skirt over a 

period of between nine months and more than two years. The numbers of skirts they 

currently use vary considerably, from 2 to 200 skirts, depending primarily on the size of 

their fleet. Some fleets reported that they are planning to install skirts on all of their 

trailers, while others have not yet decided or do not have the capital to invest in them at 

the present time. The majority have continued using the same brand of device; only a 

minority reported trying more than one brand. Also, only a minority have tried devices 

other than side skirts. Of those fleets, a few have tried some type of gap reducing 

fairing, and fewer have tried a rear trailer fairing. 

Fuel Economy and Other Benefits 

In the real world it is difficult to isolate the benefits achieved using one particular 

aerodynamic technology from all other fuel-saving strategies and technologies that may 

be used. Many of the fleets reported that besides side skirts, they also employ the 

following fuel-conserving practices or technologies: speed governing, extensive driver 

education and incentives, low-rolling resistance tires, more fuel efficient (SmartWay) 

tractors, auxiliary power units, etc. For that reason, several fleets were not able to 

isolate the fuel savings achieved from individual components. For those fleets that 

could isolate the benefits, they attributed an estimated three to six percent improvement 

in fuel economy with the skirts – a significant improvement according to these fleet 

representatives. 

In addition to fuel economy, the fleets reported additional benefits when using trailer 

side skirts, including a smoother and more stable ride, particularly in a crosswind; less 

side spray in the rain; and an overall improvement in the ability of the trailer to follow 

straighter. Most fleets were convinced that trailer skirting improves overall safety. 
40

Damage and Repair Issues 

The vast majority of the fleets reported having very few incidents of damage to the side 

skirts. Of those who reported any damage, all were minor. Many were caused by driver 

error, while some were caused by unavoidable accidents. In all cases, none resulted in 

any serious damage to their equipment or anyone else’s property. None reported any 

pieces of the skirts becoming disconnected and flying off the trailers. A few reported 

that when damage did occur, the driver was able to take action to secure the situation 

before driving on the road. 

When damage occurred to aluminum skirts, fleets reported they were often able to 

repair minor damage themselves, by hammering the skirt back into shape. When that 

was not possible, fleets reported that either they had extra replacement panels (where 

applicable) or that the manufacturers quickly sent them replacement panels so that 

repairs were made within a few days. 

Based on anecdotal information, staff became aware that side skirts might accumulate 

excessive amounts of snow and ice in colder climates. However, several fleets 

specifically indicated that they do operate in colder climates and severe weather, and 

have not experienced any problems with snow or ice build-up. Nevertheless, the skirt 

manufacturers have become aware of these potential concerns and are taking steps to 

avoid any future problems. 

Although the majority of fleets have not used rear fairings, a few expressed skepticism 

about the safety and ease of using them. They reported concerns that drivers or 

individuals who load or unload the trailers but are unfamiliar with the equipment could 

easily damage the rear fairings. Staff anticipates that as drivers and warehouse 

personnel become more familiar with the technologies, these concerns will disappear. 

In addition, aerodynamic equipment manufacturers are taking steps to further develop 

and improve their products to eliminate these potential problems. 

Costs and Return on Investment 

The majority of fleets reported paying between $1000 and $2600 for their skirts. 

Several of those who purchased their skirts about two years ago were able to take 

advantage of a grant that paid for one-half of the cost, up to a certain number of skirts. 

The return on investment achieved by some of the fleets (excluding those who received 

grant funding), averaged about 18 months, and ranged from a few months to 3 years 

(most of the fleets reported a trailer-to-tractor ratio of 2-to-1 or 2.5-to-1). 

b) Previous Users of Aerodynamic Technologies 

Staff spoke with representatives of two companies with large fleets who had used trailer 

side skirts in the past, but either stopped using them or were in the process of phasing 

out their use. The following paragraphs identify the main reasons why these companies 

are not current proponents of side skirt use, and discuss how these concerns are being 

addressed. 
41

• Side skirts installed on trailers were damaged by scraping the ground when 

encountering elevated railroad track crossings and steep loading dock ramps. Side 

skirt manufacturers are well aware of this concern and have developed workable 

solutions that are incorporated in many of the side skirt models available today. 

These solutions include using more pliable and durable materials, adjusting the 

height of the skirts to provide more clearance where necessary to prevent damage, 

and designing the skirt to retract when traveling at slow speeds. 

• Side skirts were damaged when encountering objects such as snow banks or fire 

hydrants. As noted in the previous section on Damage and Repair Issues, fleets 

that are currently using side skirts have not encountered significant damage to their 

side skirts. When damage did occur, it was usually minor and often caused by driver 

error. 

• Side skirts were pulled away from their mounting brackets by the wind force 

encountered while traveling on the highway. Most fleets contacted did not 

experience this issue. 

• Side skirts and their support structure collect snow and ice in inclement weather, 

adding weight to the trailer and posing a safety hazard as the ice breaks away when 

the trailer is traveling on the highway. As discussed previously, current side skirt 

users, including those who operate in extreme weather conditions, have not 

encountered these problems. Moreover, the manufacturers have indicated that the 

materials from which their skirts are constructed tend to repel snow and ice. Staff 

therefore anticipates that these issues will continue to be addressed by skirt 

manufacturers. 

• Rain flowing off the side skirts caused a “blinding” spray on vehicles directly behind 

and near the trailer. Fleets that currently use side skirts did not raise this comment; 

in fact, some commented that the skirts provide enhanced visibility for the truck 

driver. 

• Side skirts caused additional delays when crossing the U.S.-Mexico border. Staff 

anticipates that as border inspection personnel become more familiar with such 

aerodynamic devices as side skirts, they will become more efficient at inspecting 

trailers equipped with them, and will no longer delay those vehicles. 

• High trailer-to-tractor ratio makes outfitting an entire large fleet with skirts costprohibitive. Staff recognizes that the return on investment for such fleets will be 

longer than for the average fleet, but anticipates that these fleets will eventually 

realize the cost savings during the trailer’s life.

3. Incremental Cost of Aerodynamic Technologies 

Staff estimated the cost of aerodynamic devices based on currently available retail 

prices, fleet price quotes, and equipment manufacturer prices for new SmartWay 

trailers. The amount of time to install the aerodynamic equipment varied, depending on 

the experience of the person(s) doing the installation. Staff used a typical or average 

time for installation of four hours and a labor rate of $50 per hour. Thus, the average 

incremental cost of the aerodynamic equipment for the trailer (which would include side 
42

skirts and front fairings) would be about $2,900. For further details on staff’s cost 

analysis, please see Chapter XII. 

4. Lifetime Costs of Aerodynamic Technologies to Owners 

The proposed requirements are expected to provide cost savings to owners of trucking 

businesses over the useful life of the trailer by reducing operational costs (i.e., fuel 

consumption). The cost of the add-on devices for a trailer can be recovered from fuel 

savings in 18 months. Looking at the equipment operating costs only, about $35,000 

savings is expected over a typical equipment life of 11 years. Staff used 11 years to be 

consistent with the equipment life of a long-haul trailer. However, it is recognized that a 

trailer may be used for many years in a long-haul application beyond the assumed 

equipment life of 11 years. Accounting for capital cost, maintenance cost, and fuel 

savings, the proposed requirements are expected to result in a net cost savings of 

about $13,000 per trailer (in 2008 dollars). Staff expects that aerodynamic equipment 

prices may be lower for future purchases because of increased production and 

additional manufacturers of approved equipment entering into the market. Again, for 

further details on the staff’s cost analysis, please see Chapter XII. 

5. Product Availability 

Although recent increases in the cost of fuel have made aerodynamic technologies for 

trailers more attractive, demand for them has been extremely limited up to this point. 

Some of the manufacturers identified earlier in this chapter have been producing 

aerodynamic technologies for only a few years. Nevertheless, some of them have 

indicated that they will have the capability to meet upcoming demand for their devices in 

their existing facilities by increasing the number of shifts they operate or by purchasing 

additional equipment to increase the number of production lines. Others indicated that 

they have licensed their technology to other larger and more nationally distributed 

companies, or that they can subcontract production of their products to other 

manufacturers. It is anticipated that the phase-in period provided by this proposal will 

give manufacturers time to expand production volumes and help stabilize the cost of the 

technologies. 

C. Tractor and Trailer Low-rolling Resistance Tires

1. SmartWay Approved Low-rolling Resistance Tires 

Under the SmartWay program, the assumption is that for every 5 percent reduction in 

tire rolling resistance, a 1 percent reduction in fuel savings is attained (U.S. EPA, 2008). 

The goal of requiring low-rolling resistance tires is to achieve a fuel consumption 

savings of at least 3 percent. In order for tires to be SmartWay approved, U.S. EPA 

requires manufacturers to provide test data that demonstrate their tires meet the 

SmartWay performance requirements, using one of the following test methods: 

• Using the SAE J1321 Type II fuel consumption test, demonstrate a 3 percent (or 

greater) fuel savings with low-rolling resistance tires. This test must be performed 

on a test track, rather than “in service”, or 
43

• Using the SAE J1269 tire rolling resistance test, demonstrate that the tire’s rolling 

resistance coefficient complies with the SmartWay “target values.” These values 

(see Table IX-3) are axle-specific. 

Table IX-3: Comparison of Tire Rolling Resistance Coefficients 

Tire 

Position

Standard Tire 

(kg/metric ton) 

SmartWay Tire 

(kg/metric ton) 

Steer Axle 6.8 5.8 

Drive Axle 8.6 7.3 

Trailer Axle 6.1 5.2 

After analyzing tire rolling resistance data, U.S. EPA set the SmartWay target values at 

15 percent below the midrange coefficient levels of the most commonly used long-haul 

tires. A 15 percent reduction in tire rolling resistance results in a 3 percent reduction in 

fuel consumption. The SmartWay target values for tire rolling resistance are expressed 

in kilograms (kg) per metric ton. This measurement takes the amount of resistance 

forces within a tire and divides it by the load mass supported by that tire. For example, 

a tire with a rolling resistance coefficient of “6” (when tested under SAE J1269) has 6 

kilograms of resistive tire forces for each metric ton of downward force on that tire. 

Thus, about 60 newtons of constant force would be required to overcome the rolling 

resistance of such a tire. 

2. Experience with Low-rolling Resistance Tires 

As stated in SAE J1269, rolling resistance is defined as the scalar sum of all contact 

forces tangent to the test surface and parallel to the wheel plane of the tire. The rolling 

resistance coefficient is the ratio of the rolling resistance to the load on the tire (SAE 

J1269). Simply put, the more rolling resistance a tire has, the more energy is required 

to move a vehicle. The three main physical causes of rolling resistance are: hysteretic 

losses, aerodynamic drag, and friction losses (tire/ground and tire/rim). 

Hysteresis is the phenomenon whereby the tire material’s internal molecules slip 

against one another. The energy that should be converted to do the mechanical work of 

moving the vehicle forward ends up getting released in the form of heat. Hysteresis 

occurs as the tires go through their continuous deformation and recovery cycles (Bajer, 

2008); i.e., deforming when in contact with the road (and bearing the weight) and 

recovering when not in contact with the road). By using more resilient rubber 

compounds in the manufacturing process, hysteretic losses can be reduced. 

Aerodynamic drag stems from the wind drag caused by a tire’s tread design. Although 

it can provide additional traction, an aggressive, zigzag tread pattern with deep lugs has 

significantly more wind drag (especially at high speeds) than does a rib tread design tire 

with straight grooves. By designing tread patterns that are more aerodynamic, wind 

drag is reduced; resulting in lower rolling resistance. 
44

Figure IX-6: Contributors to Rolling Resistance (Michelin, 2002) 

Friction losses between the tire and road and between the tire and rim are particularly 

prevalent when tires are new. Forces on drive tires due to acceleration, and upon all 

wheels due to turning and heavy loads, can cause flexing and scuffing to the tire tread 

and sidewalls that result in extra friction. Rough road surfaces further exacerbate this 

problem. The taller, deeper treads of a new tire are more susceptible to this condition 

(lack of lateral stiffness) because there is more tire material available to flex. As a tire 

wears down, lateral stiffness increases and rolling resistance decreases; resulting in 

fuel economy benefits that increase as the tires’ tread depth decreases. Therefore, to 

provide lower rolling resistance, SmartWay tires are designed with tread depths that are 

slightly shallower than most standard long-haul tires. Improvements to the tire casings 

have also been made to reduce sidewall flexing and casing growth (i.e., stretching out 

of shape), as well as strengthening of tire beads to better stabilize tire-to-rim contact. 

The development of low-rolling resistance tires began largely in response to the 1975 

Energy Policy Conservation Act, which established Corporate Average Fuel Economy 

standards for passenger cars and light trucks. Since 1980, the tire and rubber industry 

has responded by reducing the rolling resistance of tires by more than 50 percent. One 

of the greatest factors that reduced rolling resistance was the shift from bias-ply tires to 

radial tires. Although still manufactured (largely due to lower cost), bias-ply tires 

produce higher friction and heat than radials, which results in higher rolling resistance 

and fuel consumption. 

There are several other factors that affect a tire’s rolling resistance, including tire mass, 

rubber formulations, tread design, inflation pressure, speed, ambient/tire temperature, 

applied drive torque, surface roughness, and the vehicle’s wheel alignment (front/steer 

tires). Improvements to the factors over which tire manufacturers have control (i.e., tire 

Tire/Ground 

and Tire/Rim 

Friction Losses (< 5%) 

Hysteretic Losses

80 to 95 % 

Aerodynamic

Drag 

0 to 15% 
45

mass, rubber formulations, and tread design) are the focus of the SmartWay 

performance requirements. 

3. Incremental Costs of Low-rolling Resistance Tires 

According to a tire industry trade publication, in 2005 almost 70 percent of original 

equipment tires and over 60 percent of replacement tires sold for HDV use were radials 

(MTD, 2006). With the advent of the SmartWay program, combined with the recent 

increase in fuel costs, staff believes these percentages are considerably higher today. 

In the staff’s analysis, the cost of SmartWay approved tires over standard HDV radial 

tires ranged from about $0.00 to $50.00 per tire, with an incremental cost of $0.00 to 

$900.00 to replace the tires on a tractor and trailer. The average incremental cost for 

those upgrading to SmartWay tires from bias-ply tires would be slightly higher, but their 

fuel economy benefit will be significantly greater than those who are already using radial 

tires. The estimated tire prices were determined from price quotes obtained from fleets, 

tire manufacturers, and tire retailers. For this analysis, staff assumed that the typical 

HDV has 18 tires: two steer tires, eight drive tires, and eight trailer tires. Although 

SmartWay approved tires typically have slightly shallower tread depths, improvements 

to both the tire casing and tread design have shown that some low-rolling resistance 

tires may last as long as their conventional counterparts. Moreover, many fleets are 

already equipping their tractors and trailers with SmartWay approved tires, so their 

capital expenses for tires have been made already. 

4. Lifetime Costs of Low-rolling Resistance Tires 

With respect to tires, there are notable differences between tractor-trailers and 

passenger cars. Most notably, when the tires wear out on passenger cars, they are 

discarded for new ones. However, when tractor-trailer tires wear out, the tire casings 

are usually retreaded and put back into service again. Therefore, it is not uncommon 

for a tire to start off “new” as a steer tire, get retreaded and used as a drive tire, and 

then retreaded once or twice more and used as a trailer tire before being discarded. 

Some fleets may retread the trailer tires even more often, if the casing remains 

serviceable. Taking this practice into account, staff estimates that tractor-trailers 

equipped with SmartWay approved tires will realize an annual fuel cost savings ranging 

from $500 to $1,000 (greater fuel savings for those replacing bias-ply tires with 

SmartWay tires). 

Another benefit from the use of low-rolling resistance tires is that, because the tires run 

cooler, the tire casings are subject to less heat and fatigue, thereby, improving the 

likelihood that the casings of SmartWay tires will be candidates for multiple retreadings. 

Besides the cost savings associated with retreads (about one-half the cost of new tires), 

retreads result in a reduction in the demand for petroleum. Tires are petrochemical 

products. On average, it takes about 22 gallons of oil to produce a new tire. However, 

it only takes about 7 gallons to produce a retread (TRIB, 2008). Thus, retreading is not 

only a cost-effective alternative, but it also reduces the demand on petroleum 

resources. 
46

5. Product Availability 

In discussions with tire manufacturers, the added demand for SmartWay tires does not 

pose a product availability problem. In years past, tire longevity and traction were the 

important considerations when selecting tires. Now, following the recent increase in fuel 

costs, the demand for fuel-efficient tires has come to the fore. Manufacturers are 

already working towards making their tires more fuel efficient. Although staff anticipates 

that additional tire manufacturers will produce low-rolling resistance tires that meet the 

performance requirements of SmartWay, there are currently four manufacturers with 

SmartWay approved tires: Bridgestone, Continental, Goodyear, and Michelin. 

According to a recent trade publication (MTD, 2008), these four companies comprise 

over 79 percent of the truck tire market share. Moreover, each one of these 

manufacturers produces SmartWay approved tires (listed below) in both the 22.5-inch 

and 24.5-inch HDV rim sizes, and in tread designs optimized for the steer, drive, and 

trailer axle positions. 

Bridgestone Goodyear 

Steer R287, R280 Steer G395 LHS Fuel Max 

Drive M720, Greatec Drive G305 LHD Fuel Max 

Trailer R195, Greatec Trailer G316 LHT Fuel Max 

Continental Michelin 

Steer HSL Steer XZA3, XZA2 

Drive HDL Eco Plus Drive XDA Energy, XDA3, X-One XDA 

Trailer HTL Trailer XTA Energy, XT1, X-One XTA

Another option for the drive and trailer axle positions is the use of SmartWay approved 

wide base tires, or “super singles.” Unless originally equipped, this alternative requires 

replacing the dual-wheel configuration on the drive and/or trailer axles with a single, 

wide tire and rim. The super single tires provide excellent low-rolling resistance and fuel 

economy; and because they weigh less, they allow for greater carrying freight capacity. 

X. ALTERNATIVES CONSIDERED

Staff developed the proposed regulation in an open public process, initially presenting 

draft regulatory concepts that evolved into the proposed regulation. During the 

regulatory development process, the scope, structure, and requirements of the 

regulation changed based on information staff gained through its own research and 

through information exchanged at public workshops and separate meetings with 

interested stakeholders. Ideas that were formulated during the development process 

and incorporated in the final proposed draft regulation included: adding California-based 

shippers to the list of regulated entities; removing receivers and non-California-based 

brokers from the list of regulated entities; exempting short-haul tractors and trailers, 
47

defining an optional compliance schedule that extends over several years, exempting 

curtain-side trailers, and providing credit for early actions. 

When determining whether a suggested change should be incorporated into the 

proposed regulation, staff considered the impact the proposed change would have on 

reaching the following goals: 

• Achieve maximum reductions in GHG emissions as expeditiously as possible by 

improving the efficiency of long-haul tractors and trailers; 

• Base the regulation’s requirements on the U.S. EPA’s SmartWay technology 

specifications and requirements for improved tractor and trailer aerodynamics and 

reduced rolling resistance; 

• Delay the cost to fleet owners that are also retrofitting or replacing equipment to 

comply with title 13, California Code of Regulations, section 2477, Airborne Toxic 

Control Measure for In-Use Diesel-Fueled Transport Refrigeration Units (TRU) and 

TRU Generator Sets, and Facilities Where TRUs Operate; 

• Ensure that the regulation is enforceable on both California-based and out-of-statebased tractors and trailers; 

• Achieve a positive cost-benefit ratio resulting from substantial fuel savings; 

• Achieve cost-effective emission reductions on a dollar per ton basis; and 

• Achieve these goals while keeping in mind the U.S. EPA SmartWay approved 

technologies available today and likely to become available over the next few years. 

 

The alternative regulatory structures considered and reasons they were rejected in favor 

of the proposed regulation are summarized in Table X-1 below. 

Table X-1: Alternative Regulatory Structures Considered 

Approach Why Rejected 

No action – Tractor and trailer owners 

would install SmartWay technology on a 

voluntary basis in accordance with the 

U.S. EPA SmartWay program 

requirements. 

SmartWay technologies have been 

available for several years and most truck 

and trailer owners have not installed them 

despite available fuel savings. Would 

prevent ARB from meeting GHG emission 

reduction goals required by AB 32. 
48

Don’t limit applicability of regulation to 

heavy-duty tractors pulling 53-foot or 

longer box-type trailers

• Expand applicability of aerodynamic 

technology requirements – Require 

aerodynamic technologies to be 

installed on box-type trailers of any 

length and on straight trucks 

• Expand applicability of low-rolling 

resistance tire requirements - 

Require low-rolling resistance tires 

on all heavy-duty tractors, trailers, 

and heavy-duty straight trucks. 

• Beyond scope of current U.S. EPA 

SmartWay Program 

o No SmartWay approved 

aerodynamic technologies exist for 

straight trucks. 

o SmartWay approved technologies 

only exist for 53-foot or longer boxtype trailers 

o SmartWay certified trailers are all 53-

foot or longer. 

• Extending regulation to straight trucks 

results in only modest increase in GHG 

reductions. 

• Heavy-duty tractors pulling 53-foot or 

longer box-type trailers comprise the 

majority of long-range mileage from 

heavy-duty tractors. Those vehicles will 

see the greatest fuel economy benefits 

from the use of aerodynamic 

technologies and low-rolling resistance 

tires. 

• Information to quantify the emission 

benefits of low-rolling resistance tires on 

other heavy-duty truck applications is 

lacking. Thus, it is difficult to assess at 

this time whether the benefits would 

outweigh the costs. 

The sections below provide further quantification and detail on the two alternative 

regulatory structures identified in Table X-1. 

A. No Action 

During the course of the regulatory development process, tractor and trailer owners, as 

well as representatives of trucking industry associations, suggested that the best 

approach is to continue with the voluntary U.S. EPA SmartWay Program. They argued 

that at this time there are insufficient data available to demonstrate how the various 

aerodynamic technologies and low-rolling resistance tires perform in real world 

operations to support a regulation that mandates their use. 

Staff agrees that the use of aerodynamic technologies and low-rolling resistance tires by 

current long-haul transport fleets is not widespread. However, staff believes that there 

are sufficient laboratory test data (generated by U.S. EPA’s SmartWay program, 

Chapter VII) as well as real-world data (information gathered by staff, Chapter IX) to 

support requiring their use in accordance with the proposed regulation. 
49

The reported negative experiences with aerodynamic devices include increased weight 

with little or no fuel efficiency gain, extent and frequency of fairing damage, and 

additional weight added due to snow and ice build-up. The negative experience with 

low-rolling resistance tires includes little or no fuel economy savings and loss of traction 

in off-road applications. The negative concerns about adding weight without fuel 

efficiency gains is being addressed in the proposed regulation by limiting the 

requirement to add aerodynamic devices to only long-haul applications, where most 

vehicle miles traveled are done at highway speeds. Further, by limiting the low-rolling 

resistance tire requirement to tractor-trailer rigs comprised of tractors pulling 53-foot or 

longer box-type trailers on California highways, concerns about loss of traction are 

largely mitigated, since typical off-road applications (e.g., logging, construction 

equipment transport) are not impacted by the proposed regulation. Other negative 

experiences like fairing damage and snow/ice buildup have largely been addressed by 

aerodynamic device manufacturers. In summary, staff believes the negative 

experiences associated with aerodynamic and low-rolling resistance tire technologies 

required by the proposed regulation are being addressed by the manufacturers of those 

products and are further lessened by limiting the applicability of the proposed regulation 

to long-haul tractor-trailer rigs. 

Although the SmartWay program has been in place since 2004, a relatively small 

number of tractors and trailers have been retrofitted with aerodynamic technologies in 

response to this program. This is especially true for trailers, where staff estimates that 

less than 0.3 percent of the total 53-foot or longer box-type trailer inventory incorporates 

aerodynamic technologies. Part of the reason for this lack of use of aerodynamic 

technologies is that SmartWay partners are choosing other options to reduce the GHG 

footprint of their businesses. Strategies chosen include reduction in idling time, 

increasing intermodal transport, reducing trailer weight, and using cleaner diesel engine 

technologies. But the question still remains, why don’t they choose to retrofit trailers 

instead of some of these other options when meeting their SmartWay goals? Staff 

believes the decision not to retrofit is rooted in the conservative nature of the long-haul 

transport business and the magnitude of the up-front capital costs to retrofit an entire 

fleet of trailers. 

Staff estimates that the average capital cost to comply with the proposed regulation is 

approximately $5,000 per tractor and trailer affected. About $2,900 is needed to retrofit 

a box-type trailer with aerodynamic technologies and low-rolling resistance tires. 

However, the operating cost savings resulting from the fuel efficiency improvement 

associated with compliant tractors and trailers is substantial. Staff estimates a 

compliant tractor-trailer combination will save between $4,000 and $5,700 in fuel costs 

every year. To some extent, the transportation industry has recognized the benefits 

associated with improved aerodynamics. Most long-haul tractors have some 

aerodynamic features – roof fairings and fuel tank fairings are two examples. However, 

trailer aerodynamics has lagged woefully behind. Box-trailer design has not evolved 

much over the last 30 years. The trailers are designed to carry the largest possible load 

within federal and state size and weight limits. As a result, trailers are rectangular in 

shape, designed to take advantage of every inch allowed by the size limits, with little 

consideration given to aerodynamics. Staff believes the incorporation of aerodynamic 
50

technologies on box-type trailers will not happen in a timely manner without regulatory 

impetus. Real and quantifiable near-term GHG reduction benefits will be lost if the 

proposed regulation is not implemented. As a result, staff has rejected the “No Action” 

option. 

B. Expand Applicability 

The proposed regulation was identified by staff in October 2007 as a discrete early 

action measure required to be adopted by the Board and made enforceable by January 

1, 2010 (ARB, 2007). Key to its inclusion in the list of discrete early actions was the 

existence of the SmartWay program, which establishes technical specifications and 

requirements for compliant tractors and trailers. The applicability of the proposed 

regulation is inline with the applicability of the SmartWay program’s technical 

specifications and requirements. 

Throughout the regulatory development process environmental groups have suggested 

that the applicability of the proposed regulation should be expanded beyond the 

traditional long-haul configuration of tractor and trailer (i.e., a sleeper cab tractor pulling 

a 53-foot or longer box-type trailer) to include box-type trailers of various lengths and 

types, and straight trucks. Their analysis indicates that requiring aerodynamic device 

retrofits and low-rolling resistance tires on all tractor-trailers pulling box-type trailers and 

straight trucks could get an additional 46 percent reduction in cumulative GHG 

emissions by 2020 (Schubert, 2008). 

Staff agrees that additional GHG emission reductions can be gained by expanding the 

applicability of the proposed regulation beyond the proposed long-haul configuration 

tractors and trailers. But expanding the applicability of the proposed regulation in these 

areas would mean that it would be broader in scope than the applicability of the current 

SmartWay program. Expanding the applicability of the rule would require staff to 

develop an ARB tractor and trailer, tire rolling resistance, and aerodynamic technology 

approval and certification program. A certification testing protocol and certification 

procedure would need to be developed. This could not be accomplished in the 

timeframe allotted to develop the proposed regulation. As a result, staff did not expand 

the applicability of the proposed regulation. However, staff is committed to work with 

U.S. EPA SmartWay program staff and evaluate the feasibility of expanding the 

program in the near future 

Below are listed some of the specific data needs associated with expanding the 

applicability of the proposed regulation that could not be addressed by staff within the 

regulatory development timeframe of the proposed regulation. These issues will be 

addressed by staff in the development of future regulations. 

• Obtain additional test data to verify fuel economy improvements from 

aerodynamic technologies and low-rolling resistance tires on straight trucks, and 

other box-type trailers. For the proposed regulation, staff has relied on the U.S. 

EPA’s published fuel economy benefits based on a Class 8 tractor pulling a 53-

foot box-type trailer loaded to 65 percent of its gross vehicle weight rating 
51

(52,000 lbs.) operated over three drive cycles representative of line-haul tractortrailer operations (Bachman, 2005.) For different trailer sizes and tractor classes 

and vocations, the fuel economy benefits may be different and would need to be 

verified through testing. 

• Obtain additional data on low-rolling resistance tire availability, off-road 

capability, and production capacity. Expanding the applicability of the low-rolling 

resistance tire requirement will increase the demand for these tires and result in 

them being used on tractors and trailers that travel off-road regularly, i.e. log 

hauling. 

• Obtain additional data on the synergistic effects of combining aerodynamic 

technologies on tractors and trailers. Staff relied on the fuel economy benefits 

established by the SmartWay program for combinations of aerodynamic devices. 

Requiring all available aerodynamic technologies on all trailers goes beyond the 

requirements of the SmartWay program. Staff needs to verify the fuel economy 

benefits of such an approach through additional testing. 

 

XI. ENVIRONMENTAL IMPACT

The proposed regulation is driven by the need to reduce GHG emissions from the 

transportation sector and specifically from on-road HDVs. The reductions are expected 

to be achieved through the accelerated introduction of new aerodynamically styled fuel 

efficient tractors and trailers and the retrofit of existing tractors and box-type trailers with 

fuel efficient aerodynamic and tire technologies. 

Staff expects implementation of the regulation to result in significant GHG emission 

reductions and to a lesser extent oxides of nitrogen emission reductions, and does not 

anticipate any significant adverse public health or environmental impacts associated 

with the proposed regulation. The following sections discuss the environmental impacts 

associated with the proposed regulation. 

A. Legal Requirements 

The California Environmental Quality Act (CEQA) and ARB policy require an analysis to 

identify the potential environmental impacts of proposed regulations and to mitigate 

significant effects whenever it is feasible to do so. Since ARB’s program involving 

adoption of regulations has been certified by the Secretary of Resources as meeting 

certain environmental standards set forth in CEQA, the CEQA environmental analysis 

requirements may be included in the Initial Statement of Reasons (ISOR or Staff 

Report) for this rulemaking in lieu of following the CEQA format of an Initial Study and 

Negative Declaration, and Environmental Impact Report (see Public Resources Code, 

section 21080.5). In addition, ARB staff will respond, in the Final Statement of Reasons 

for the regulation, to all significant environmental issues raised by the public during the 

public review period or at the Board public hearing. 
52

Public Resources Code section 21159 requires that the ARB’s environmental impact 

analysis include the following: 

• An analysis of the reasonably foreseeable environmental impacts of the methods 

of compliance; 

• An analysis of reasonably foreseeable mitigation measures; and 

• An analysis of reasonably foreseeable alternative means of compliance with the 

regulation. 

The proposed regulation is designed to reduce GHG emissions from long-haul 

combination trucks. The reductions are needed to reduce global warming which poses 

a threat to the public health, natural resources, economic well being, and the 

environment of California as required by AB 32. 

Alternatives to the proposed regulation are discussed in Chapter X of this report. ARB 

staff has concluded that there are no alternative means of compliance that would 

achieve similar GHG emission reductions at a lower cost. 

B. Reasonably Foreseeable Environmental Impacts 

Staff has identified air quality benefits and minimal negative environmental impacts of 

compliance with the proposed regulation. 

1. Estimated GHG Benefits 

The GHGs associated with diesel exhaust are CO2, methane, and nitrous oxide, with 

CO2 being the major component of the three. Since CO2 is emitted in direct proportion 

to the fuel combusted, any reduction in CO2 emissions requires reduction in the fuel 

burned to propel the vehicle. The proposed regulation would reduce GHG emissions by 

reducing the fuel consumption of HDVs achieved through improvements in aerodynamic 

drag and tire rolling resistance. The GHG reductions would contribute towards attaining 

AB 32 goals for the year 2020. 

Equation XI-1 was used to calculate the GHG reductions from the proposed regulation. 

CO2e Reduced = Fuel Savings*EF/1000 (Equation XI-1) 

Where: CO2e Reduced = average annual reduction in GHGs in metric tons CO2e 

 Fuel Savings = Annual fuel savings in gallons per year 

 EF = GHG emission factor from diesel fuel combustion (10.4 kilograms CO2e 

per gallon of diesel fuel (ARB, 2008c)) 

1000 = Conversion factor from kilograms (kg) to metric tons (1000 kg = 1 MT) 

Annual Fuel Savings: The annual fuel savings is determined from the percent fuel 

efficiency improvement, annual VMT, and the baseline fuel economy. 

Percent Fuel Efficiency Improvements: The percent fuel efficiency improvements 

used to quantify the GHG benefits are shown in Table XI-1. These were determined 

based on the minimum aerodynamic and tire rolling resistance performance 
53

requirements specified in the proposed regulation. For example, the proposed 

regulation would require a minimum fuel efficiency improvement of 3 percent from lowrolling resistance tires on the combined tractor and the trailer, a minimum of 4 percent 

from trailer side skirts, and a minimum of 1 percent from front or rear gap fairings on 

dry-van trailers. Thus, for this example, an in-use pre-2011 model year tractor pulling a 

dry-van trailer would achieve an overall fuel efficiency improvement of 8 percent, as 

shown in Table XI-1. 

The fuel efficiency improvements of currently certified aerodynamic devices are 

determined from track tests conducted at speeds of 60 to 62 miles per hour according to 

“SAE J1321 Type II” test procedures. These aerodynamic devices also reduce drag at 

lower speeds, though to a lesser extent, since aerodynamic drag varies with the square 

of the vehicle speed. 

Annual VMT: The annual VMT applicable to tractors pulling 53-foot or longer box-type 

trailers was determined using the methodology described in Chapter VI. However, the 

resulting total VMT cannot be directly applied to the fuel efficiency improvements shown 

in Table XI-1, since the VMT is accrued at various speeds, while the fuel efficiency 

improvements are determined at speeds of approximately 60 miles per hour. Thus, the 

speed-VMT distribution of the impacted tractors and fuel efficiency improvements at 

different speeds are needed in order to accurately quantify the GHG emission benefits. 

However, such data were not available and therefore staff estimated the GHG benefits 

using only the VMT accrued at highway speeds, without taking into account benefits 

that occur at lower speeds. Accordingly, for non-neighboring out-of-state tractors, staff 

assumed 85 percent of the VMT to be at highway speeds, since these tractors travel 

long distances, spending the majority of their VMT at highway speeds. For neighboring 

out-of-state, California interstate, and California intrastate tractors, staff assumed 75 

percent of the VMT to be at highway speeds, benefiting fully for 75 percent of the VMT 

from the aerodynamic devices.9

 

 

9

 This assumption is consistent with assumptions made by other studies. For example, a report 

by Rocky Mountain Institute indicates 75 percent of the VMT is at highway speeds. (Ogburn, 

2007). 
54

Table XI-1: Fuel Efficiency Improvements – Based on Proposed Requirements 

 Tractor Improvements Trailer Improvements10 Fuel 

Savings 

1 

2011+ model year 

SmartWay certified sleeper 

cab tractor (3.5%) 

Dry-van trailer – 

SmartWay certified or 

retrofitted with side skirts and 

front gap fairings (6.5%) 

10.0% 

2 

2011+ model year 

SmartWay certified sleeper 

cab tractor (3.5%) 

Refrigerated-van trailer – 

SmartWay certified or 

retrofitted with side skirt 

(5.5%) 

9.0% 

3 

2011+ model year day cab 

tractors and all pre-2011 

model year in-use tractors - 

Tire Improvements (1.5%) 

Dry-van trailer – 

SmartWay certified or 

retrofitted with side skirts and 

front gap fairings (6.5%) 

8.0% 

4 

2011+ model year day cab 

tractors and all pre-2011 

model year in-use tractors - 

Tire Improvements (1.5%) 

Refrigerated-van trailer – 

SmartWay certified or 

retrofitted with a side skirt 

(5.5%) 

7.0% 

Baseline Fuel Economy: Staff also used model year specific baseline fuel economy 

values to estimate the fuel savings from the proposed regulation. The fuel economy 

values used are developed by ARB staff and are applicable for on-road HDVs operating 

in California (See Appendix C for a discussion of the development of fuel economy 

values for HDVs). 

For the purposes of quantifying the emission reductions, staff also assumed that all 

fleets will adopt the large fleet trailer compliance plan which provides a compliance 

option for in-use pre-2011 trailers based on a phase-in schedule specified in Appendix F 

of this report. Staff also assumed that in the absence of the proposed regulation, 20 

percent of the tractors sold each year from 2010 to 2020 would be SmartWay certified 

and 25 percent of the in-use pre-2011 model year tractors would use fuel efficient tires. 

The GHG emission benefits were calculated for the years 2010 to 2020 based on VMT 

accrued within California and nationwide. Table XI-2 summarizes the 2010, 2015, and 

2020 statewide and nationwide GHG emission benefits of the proposed regulation. 

Staff estimates that from 2010 to 2020, as new fuel efficient tractors and trailers are 

introduced and in-use ones retrofitted with fuel efficient technologies, GHG emissions 

will be reduced by a cumulative total of approximately 8 MMT CO2e statewide and 

approximately 52 MMT CO2e nationwide. The 2020 benefits are approximately 1 MMT 

CO2e statewide and 6 MMT CO2e nationwide. Figure XI-1 shows the statewide 

 

10 The trailer aerodynamic technologies specified in the table are meant for illustration 

purposes. Fleets can meet the requirements using other aerodynamic technologies that 

meet or exceed the minimum performance requirements. 
55

baseline and controlled GHG emissions for calendar years 2010 to 2020. As seen in 

Figure XI-1, GHG emissions from long-haul tractors continue to increase even with 

implementation of the proposed regulation because the trucking industry will grow 

substantially between now and 2020 (ARB, 2008a). 

Table XI-2: 2010, 2015, and 2020 GHG Emission Benefits - Statewide and 

Nationwide (MMT CO2e) 

 California Nationwide 

Calendar Year Baseline Reductions Baseline Reductions

2010 8.5 0.2 55.6 0.9 

2015 10.1 0.8 65.7 5.5 

2020 11.4 1.0 74.6 6.7 

7.0

7.5

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

2009 2011 2013 2015 2017 2019 2021

Calendar Year

GHG Tailpipe Emissions 

(MMTCO2e)

Baseline

With Regulation

Figure XI-1: Statewide GHG Emissions With and Without the Regulation 
56

2. Estimated Oxides of Nitrogen (NOx) Emission Benefits 

In addition to GHG benefits, reducing aerodynamic drag and rolling resistance also 

reduces NOx emissions (Bachman, 2005; Bachman, 2006). Thus, the proposed 

regulation is expected to provide NOx emission reduction benefits that would contribute 

towards attainment of ambient air quality standards for ozone. Staff used the 

methodology specified in the U.S. EPA SmartWay State Implementation Plan (SIP) and 

Transportation Conformity guidance document (U.S. EPA, 2007) to quantify the NOx 

emission benefits from the proposed regulation. 

Because the effects of the SmartWay technologies on NOx emissions of trucks with 

particulate matter and NOx aftertreatment controls is not yet determined, the U.S. EPA 

recommends that, for SIP and conformity determinations, the NOx reductions not be 

applied to trucks of model years newer than 2006. Furthermore, the NOx emission 

reductions associated with SmartWay retrofit applications vary by speed, requiring the 

VMT to be distributed by speed. Since speed distribution data for the fleet that is 

impacted by the proposed regulation were not available, staff made the following 

assumptions on VMT-speed distribution of long-haul tractors. That is, for nonneighboring out-of-state tractors, staff assumed 85 percent of the VMT to be at highway 

speeds and a corresponding NOx reduction of 9.5 percent. For the remaining 15 

percent of the VMT staff assumed an average speed of 35 miles per hour and a NOx 

reduction of 4.6 percent. For California intrastate, California interstate, and neighboring 

out-of-state tractors, staff assumed 75 percent of the VMT to be at highway speeds and 

a corresponding NOx reduction of 9.5 percent. For the remaining 25 percent of the 

VMT, staff assumed an average speed of 35 miles per hour and a corresponding NOx 

reduction of 4.6 percent. Based on these assumptions and U.S. EPA guidelines, 

California specific NOx reductions were estimated to be 4.3 and 1.4 tons per day in 

2014 and 2020 respectively. These reductions assume a “business as usual” scenario, 

where they do not take into account the impact of other proposed regulations that would 

impact NOx emissions. 

3. Potential Negative Impacts 

Staff has identified one potential negative impact resulting from the proposed 

requirement to use fuel efficient tires. Waste tires may increase during the phase-in 

periods because fleet owners, in order to comply with the proposed requirements, may 

be forced to replace usable tires before the end of their useful life. If not managed 

properly, waste tires can cause serious public health risks and environmental problems, 

such as fires, air and groundwater contamination resulting from burning tires, providing 

habitats for vector breeding, and reduction of landfill capacity. 

Staff believes the proposed requirement would result in minimal or no increase in tire 

waste for the following reasons. The proposed regulation requires that in-use 2010 and 

older model year tractors use fuel efficient tires by January 1, 2012, giving fleet owners 

2 years to comply with the requirements. It also provides in-use 2010 and older model 

year trailers the option to meet the proposed requirements during a 6-year phase-in 

period by January 1, 2016. For long-haul operations, fleets normally replace old steer 

tires with new tires once every year. Thus, replacing steer tires with new fuel efficient 
57

tires during the two-year phase-in period will not result in increased tire waste since the 

replacement can be done at the end of the tire’s normal life. Drive tires, depending on 

the fleet’s tire maintenance program, may be replaced with new tires once every one to 

two years, or recapped once or twice during their lifetime and reused as drive or trailer 

tires. Thus, similar to the steer tires, the drive tires replaced with new fuel efficient tires 

during the two-year compliance period would not result in increased tire waste since 

replacement can occur at the end of the tire’s normal life. Retreaded drive tires that 

would have been reused as drive tires, but because of the proposed requirements are 

now replaced with new fuel efficient tires, could also be used as trailer tires or sold to 

out-of-state fleets or for use on tractors and trailers not affected by the proposed 

regulation, resulting in no increase or minimal increase in tire waste. Trailer tires are 

normally retreaded and reused multiple times. However, the proposed regulation 

provides a phase-in period of six years for fleets to comply with the trailer retrofit 

requirements, providing enough time to retread and reuse trailer tires before they are 

forced to replace them with fuel efficient tires. Trailer tires that cannot be reused in 

California but have remaining life for retread could also be sold to out-of-state fleets, 

thus minimizing tire waste. 

C. Reasonably Foreseeable Mitigation Measures 

ARB staff has concluded that no significant adverse environmental impacts should 

occur from adoption of and compliance with the proposed regulation. Therefore, no 

mitigation measures would be necessary. 

D. Alternative Means of Compliance with the Proposed Regulation 

Alternatives to the proposed regulation are discussed in Chapter IX of this report. ARB 

staff has concluded that the proposed regulation provides the most effective and least 

burdensome approach to reducing GHGs from on-road HDVs. 

XII. COST AND ECONOMIC IMPACT

A. Summary 

AB 32 requires that climate change regulations must consider the impacts on the 

economy of the state. The consideration should include, but not be limited to, the 

impacts of the regulations on jobs and businesses, and California business 

competitiveness. The regulations must take into account the impacts on local 

communities with minority/low-income populations, and affiliated businesses. This

section discusses the economic methodology and cost impacts staff anticipates from 

implementation of the proposed climate change regulation on the California economy. 

The results are intended to provide an overall picture of the economic impacts on the 

economy although an individual business or consumer may experience different 

impacts than anticipated. 

The cost analysis was computed based upon an 11-year equipment lifespan, from 2010 

to 2020. Over that time span, staff expects a net savings of approximately $4.3 billion 

to the affected stakeholders in 2008 dollar values. During the first six years of 
58

implementation from 2010 to 2015, an estimated net savings of $3.5 billion is expected. 

The net savings will be realized by truck operators because of improved fuel economy. 

Businesses that own only trailers and no tractors may not be able to recover the cost of 

retrofitting their trailers through fuel savings, and therefore, they may need to recover 

their investment by paying less to haulers or by passing it on to customers by increasing 

the cost of their merchandise. Ultimately, the substantial operating cost savings seen 

by the truck haulers should result in lower costs to ship goods and result in lower cost 

for consumers. Staff calculated the savings based upon the projected retail price per 

gallon of ultra low sulfur diesel fuel of $3.14 in 2010 to $3.69 in 2020.11 However, staff 

believes this may be a conservative estimate of the savings since recently the California 

average retail price for diesel fuel was about $4.00 per gallon.12 At $4.00 per gallon, the 

lifetime savings of the regulation (over the 11-year lifespan of the equipment) would be 

about $8.5 billion. 

The GHG emission reductions from the proposed rule for all affected vehicles traveling 

in and out of California are estimated at 6.7 MMT CO2e in 2020. An emission benefit of 

approximately 1 MMT CO2e or 15 percent would occur within California. The proposed 

rule is also expected to achieve NOx reductions. The U.S. EPA State Implementation 

Plan (SIP) guidelines for implementation of aerodynamic devices on heavy-duty trucks 

and trailers approved through the SmartWay program estimates NOx reductions 

ranging from 2 to 10 percent per vehicle, depending on speed. Based on the 

guidelines, in addition to the GHG benefits, the proposed measure would result in a 

statewide NOx emission reduction of about 4.3 tons per day (tpd) in 201413 and 1.4 tpd 

in 2020. 

B. Legal Requirements 

The legal requirements for an economic analysis are included in the Government Code 

sections 11346.3 and 11346.5 and the Health and Safety Code section 57005. These 

statutes require all State agencies do an assessment of the potential adverse economic 

impacts on California business enterprises and individuals when any regulation is 

proposed, adopted, or amended. The assessment must include at a minimum, 

consideration of the impact of the proposed regulation on California jobs, business 

expansion, elimination or creation, and the ability of California businesses to compete 

with businesses in other states. State agencies also are required to estimate the cost or 

savings to any State or local agency and school district, in accordance with instructions 

adopted by the Department of Finance. The estimate shall include any nondiscretionary cost or savings to local agencies and the cost or savings in federal funding 

to the State. The ARB must also perform an economic impact analysis of submitted 

alternatives to a proposed regulation before adopting any major regulation. A major 

 

11 Integrated Energy Policy Report, California Energy Commission developed in 2007 and 

projected to 2020 (CEC, 2007). 

12 The United States Energy Information Administration tracks California retail diesel fuel price; 

on September 15, 2008, ultra low sulfur diesel was at $4.05 per gallon (EIA, 2008). 

13 2014 is one of the target years for reducing emissions in the California SIP. 
59

regulation is defined as a regulation that will have a potential cost to California business 

enterprises in an amount exceeding ten million dollars in any single year. 

C. Methodology for Estimating Cost and Economic Impact 

The cost-effectiveness analysis is based on estimates of expected emissions reductions 

and costs for implementation of the proposed regulation. The annual discounted capital 

costs and operating cost savings were calculated to determine the total annual costs or 

net savings. The incremental cost to purchase SmartWay certified aerodynamic 

devices and approved tires begins with the 2011 model year (2010 calendar year) and 

is incurred as a lump sum. Since the equipment may last for many years, the lump sum 

expenditure can be “spread-out” over the expected life of the equipment. Staff used the 

capital recovery method, also known as the amortization method, to spread the costs of 

the equipment and tires over their useful life at a specified interest rate. 

The following formula (Linsley, 1977) is used to calculate the annualized cost of new 

and in-use equipment replacement: 

AC = (ICE)(CRF) 

Where: 

AC = Annualized cost of equipment 

ICE = Incremental consumer expenditure for equipment 

CRF = Capital recovery factor = [ i (1 + i) ^n ] / [ (1 + i) ^(n – 1) ] 

Note that “i” in the CRF formula represents the interest rate (or “opportunity cost”) for 

the incremental consumer expenditure, while “n” represents the equipment life. By 

using the capital recovery factor method, the equipment’s annual depreciation and the 

opportunity cost is accounted for. 

Annual capital cost values of the affected population of tractors and trailers were 

calculated by multiplying the projected population for each year by the incremental cost 

of the required aerodynamic equipment and tires in that year. The affected population 

represents the projected number of tractors sold in that year generated from the ARB’s 

inventory. The trailer population was determined by using a trailer-to-tractor ratio of 2.5 

to 1. Annualized costs are estimated using a real interest rate of 5 percent. All these 

costs are predictions of future prices, which could vary noticeably depending on 

demand, competition, and economic conditions, among other factors. 

D. Estimated Costs of the Proposed Regulation 

Staff estimated aerodynamic device and tire costs from currently available retail prices, 

fleet price quotes, and equipment manufacturer prices for new and in-use SmartWay 

trucks and trailers. The low, average and high cost estimates for the required 

equipment/tires are shown in Table XII-1. Staff assumed in absence of the regulation, 

20 percent of the new tractors sold would be SmartWay certified and 25 percent of new 

day cabs and in-use sleepers would use fuel efficient tires. In staff’s analysis, it was 

assumed that without the regulation, affected trailer owners would not purchase 
60

SmartWay certified trailers nor retrofit their existing trailers. This is based on 

conversations with manufacturers of SmartWay aerodynamic equipment who stated that 

very few fleets had SmartWay equipped trailers. In addition, fleets that had purchased 

aerodynamic trailer equipment mostly did so because they were awarded grant funding. 

Staff assumed that the tractor would be equipped with fuel tank fairings, cab side 

extenders, an integrated sleeper cab roof fairing, aerodynamic bumpers and mirrors, 

and low-rolling resistance tires. The lower price estimate for new sleeper cab 

equipment was based on selecting lower cost SmartWay aerodynamic component 

options, some of which now come standard on new sleeper tractors. Also, depending 

on the manufacturer, the aerodynamic package for new sleepers may include 

components that may not necessarily be needed to meet the minimum requirements for 

the proposed regulation, thereby providing even more benefits than estimated. 

The trailer would be equipped with side skirts and front or rear fairings. Both the tractor 

and trailer are assumed to have SmartWay approved tires. Staff did not include any 

incentive or grant funds that may be available to offset the purchase of the proposed 

technologies, although these programs can provide a significant reduction in capital 

outlay and are discussed in section I.1 of this chapter – Summary of Current Financial 

Assistance and Grant Programs. 

Table XII-1: Tractor and Trailer Costs 

Category Low Average High 

New Sleeper $1,100 $2,100 $3,000 

Trailer $1,900 $2,900 $4,200 

Tractor & Trailer $3,000 $5,000 $7,200 

The estimated tire cost differentials for a conventional heavy-duty tire versus a 

SmartWay approved tire ranged from $0 to $50. For the tire cost analysis, staff 

assumed that the typical long-haul tractor has two steer tires and eight drive tires. Staff 

assumed the trailer has eight tires. 

As noted in the technology discussion, SmartWay approved tire technology has made 

improvements to both the casing and tread design over the years, and may now last as 

long as conventional tires. Based on this, staff assumed that the steer tires will last one 

year, the drive tires will be replaced every two years, and the trailer tires would last four 

years and then be retreaded. One retread was assumed for the tractor drive tires and 

two retreads for the trailer tires. Some fleets may retread the tires as long as the casing 

lasts. Staff also spoke with retreaders that stated that there was no cost difference 

between retreads for a low-rolling resistance tire versus a conventional tire. The 

retreader also stated that the retread cost was based on the amount of rubber used and 

that a low-rolling resistance tire could be less expensive to retread since this tire 

typically does not have a tread depth as thick as a conventional tire. Also, some fleets 

noted that they will continue to use tires with tread left and then switch these tires from 

the steer position to drive position to trailer tire positions to reduce tire purchasing costs; 
61

staff did not account for these additional savings in the cost analysis. From meetings 

with various fleets, it was noted that fleets have a variety of tire replacement practices. 

Staff included maintenance costs and administrative fees, as shown in Table XII-2. No 

incremental maintenance cost for tires was included since it is assumed that a fuel 

efficient low-rolling resistance tire would be maintained in the same manner as a 

conventional tire. 

Many fleets noted that, in general, neither the tractor nor trailer aerodynamic devices 

required any additional annual maintenance. However, to be conservative, staff 

included an annual maintenance and inspection cost of $143.00 based on the repair 

and replacement of a fiberglass panel for one out of every ten tractors. Most of the 

fleets indicated that the maintenance needed for tractor fairings was minimal. Damage 

to trailer side skirts was more common because of loading, environmental conditions, 

and driver errors. For trailer maintenance and repair, staff included a cost of $120.00 

per year. This is an average of $170 per year (about 10 percent of the cost of a side 

skirt) reported by one fleet that used trailer skirts in a very harsh environment of snow 

and ice; and $75 per year from a 2.5 year maintenance study of 20 trailers (Freight 

Wing, Inc., 2008). 

The proposed regulation specifies reporting requirements for short-haul tractors and 

trailers, and in-use trailer compliance schedules. Included in the overall cost is an 

estimated annual $500 per fleet for trailer reporting cost during the first five years of the 

proposed regulation. The fees are meant to account for the record keeping, tracking of 

California compliant tractors/trailers, updating of contract/legal fees, inspection costs for 

freight companies and shippers, and administrative costs during implementation. 

Table XII-2: Annual Maintenance Costs/Fees 

Item Low Average High 

Tractor $30 $143 $233 

Trailers $75 $120 $166 

Contract Administration Fees 0 $3.50/Tractor 

$5/Trailer $5 

Using the above costs, staff estimates that for the industry as a whole, the lifetime 

capital cost of complying with the proposed regulation would be about $10.4 billion and 

the cost savings over the same period of time would be $14.7 billion. This yields a net 

cost savings of almost $4.3 billion. On an annualized basis, the average cost savings 

over the lifetime of the proposed regulation would be about $0.4 billion per year from 

2010 to 2020 (2008 dollars). However, at a retail diesel fuel price of $4.00 per gallon, 

net cost savings would increase to about $8.5 billion or $0.8 billion per year from 2010 

to 2020. 

Approximately 9 percent of the affected tractor and trailer population are based in 

California. The total estimated statewide lifetime cost for California based tractors and 

trailers to comply is about $0.5 billion, and the cost savings over the same period of 
62

time are $1.1 billion. This yields a net statewide cost savings of almost $0.6 billion. 

This net cost savings would be realized by California fleet operators and owner 

operators of compliant tractors and trailers and are directly attributed to operating cost 

savings associated with improved fuel economy. 

On a per vehicle/equipment basis, the total operating cost savings per year ranges from 

approximately $5,400 to $3,700 as shown in Table XII-3. The cost of add-on devices 

would, on average, be $5,000 (Table XII-1), making the cost recovery period less than 

1.5 years. 

Table XII-3: Annual Operating Cost Savings 

Vehicle/Equipment Fuel Savings 

(gallons/year)

Fuel Cost 

Savings1

($/year) 

Maintenance 

Cost 

($/year) 

Total 

Savings14

($/year) 

Fuel 

Savings 

New Sleeper Cab & 

Trailer Combination -1,819 -$5,704 $263 -$5,441 10.0% 

New Sleeper Cab & 

Refrigerated Trailer 

Combination 

-1,737 -$5,133 $263 -$4,870 9.0% 

In-Use Sleeper 

Cab/New Day Cab & 

Trailer Combination 

-1,455 -$4,563 $263 -$4,300 8.0% 

In-Use Sleeper 

Cab/New Day Cab & 

Refrigerated Trailer 

Combination 

-1,273 -$3,993 $263 -$3,729 7.0% 

1

 The estimated fuel cost is $3.14 per gallon in 2010, sourced from the Integrated Energy Policy Report

of the California Energy Commission in 2007 (CEC, 2007).

 

Staff expects that the increased production of the aerodynamic equipment needed to 

meet the proposed regulation would help to lower future purchase costs as economies 

of scale are realized. Also, staff expects additional manufacturers of approved 

aerodynamic equipment to enter the marketplace, providing more competitive pricing. 

As mentioned previously, businesses that own only trailers and no tractors may not be 

able to directly recover the cost of retrofitting their trailers through fuel savings, and 

therefore, they may need to recover their investment either by paying less to haulers 

who receive the direct fuel economy benefit or by passing it on to customers by 

temporarily increasing the cost of their merchandise. 

 

14 The assumptions for this calculation are as follows: a baseline fuel economy of 5.8 miles per 

gallon, an average long-haul mileage accrual rate of 125,000 miles per year, 84 percent of 

the vehicle miles traveled at highway speed that benefit fully from the aerodynamic devices, 

and a projected diesel fuel cost of $3.14 per gallon. If the cost per gallon in diesel fuel is 

higher that $3.14, the fuel savings due to the proposed regulation would be proportionately 

greater. 
63

For instance, due to high fuel prices, some motor carriers are charging a fuel surcharge 

per truckload; however, a company with a dry-van meeting the rule’s requirements 

should incur a lower fuel surcharge. A retrofitted dry-van will increase the fuel economy 

of the tractor pulling it on average by 6.5%. Therefore, it would be reasonable for a 

company that hires a motor carrier to haul their retrofitted or SmartWay certified trailer 

to negotiate a proportional reduction in the freight rate. 

E. Potential Impact on a Small Business 

Most businesses that operate long-haul tractors and trailers are not considered small 

businesses because they generate revenues where the transportation and warehousing 

annual gross receipts exceed $1.5 million (Government Code 11342.610) particularly 

when they own multiple tractors and operate multiple shifts. Similarly, logistics 

companies are typically not considered small businesses. These organizations, 

however, may contract with small fleets and truck owner-operators that could be 

classified as small businesses. 

Based upon transportation revenue estimates, staff developed a “small fleet” definition 

(see Appendix F). A small fleet could own up to 8 tractors and 20 trailers using the 

“small fleet” definition. The typical fuel savings projected for one year for one tractortrailer combination is $3,700 to $5,400, so the payback for an expensive option of 

purchasing a new SmartWay tractor (versus not SmartWay), and retrofitting a trailer is 

less than 1.5 years. 

The notice of public hearing issued in conjunction with this staff report included a 

statement on page 7 that staff assumed that a small business owner did not own any 

trailers. This statement in the notice was in error; as noted in this section of the staff 

report, ARB’s analysis considers that companies owning as many as 20 trailers may be 

small businesses, and the regulation specifically provides that those owning up to this 

number of trailers may utilize a “small fleet compliance schedule.” This misstatement 

had no effect on staff’s economic analysis or on ARB’s determination as stated in the 

notice that the proposed regulatory action would affect small business. 

Staff assumed that most owner-operators will fall under the small business definition. 

The Owner Operator Independent Drivers Association (OOIDA) has a California 

membership of about 5,600 (OOIDA, 2004). According to OOIDA, about 50 percent of 

their members are involved with long-haul, and of these 28 percent operate dry-vans 

and refrigerated-vans that could be affected by the regulations. According to the 

OOIDA survey,15 members own, on average, 1.5 tractors; 82 percent own only one 

tractor. About 40 percent of owner-operators purchase their tractors new and 60 

percent purchase their tractors used. About 53 percent own trailers and those that do 

own trailers have, on average, two trailers. Based on these statistics, the cost of 

compliance will vary as shown in Table XII-4 below:

 

15 Not all owner-operator truck drivers are members of OOIDA. Therefore, the survey results 

discussed may not apply to all owner-operators. 
64

Table XII-4: Owner-Operator Compliance Costs 

Owner-Operator 

Equipment 

Configuration 

Equipment 

Needs 

Cost per One 

Tractor-Trailer 

Combination 

Cost per OwnerOperator with 1.5 

Tractors and 2 Trailers 

Owns used tractor Upgraded tractor 

tires $0 to $500 $0 to $750 

Owns used tractor 

and trailer 

Upgraded tractor 

tires, retrofit trailer $2,900 to $3,400 $5,800 to $6,500 

Purchases new 

SmartWay tractor, 

owns trailer 

SmartWay tractor, 

retrofit trailers $5,000 $9,000 

Outside of California, based on the OOIDA market survey, there are approximately 

160,000 owner-operator businesses (OOIDA, 2004). Of these, staff estimated that 

there are about 18,000 long-haul owner-operator businesses that operate dry-vans and 

refrigerated-vans that may be subject to the proposed rule. 

F. Potential Impact on Employment, Business Creation, Elimination, or 

Expansion 

There are modest up-front costs associated with the proposed regulation before fuel 

efficiency gains occur. It is possible that some very marginal trucking companies would 

not be able to finance the required upgrades. Financial assistance and grant programs 

will be available to assist these businesses. Fuel costs have been shown to have a 

direct correlation to the survivability of many long-haul transport businesses, and this 

proposed regulation is expected to provide a net fuel savings once the required 

equipment is installed. 

The regulation should result in an increased demand for aerodynamic devices and lowrolling resistance tires. This in turn may result in the creation or expansion of some 

businesses as a result of manufacturing, distributing, and marketing of these devices. 

The increased demand in approved aerodynamic devices may also result in the creation 

of some new jobs related to research and development for further improvement of these 

devices. 
65

Most of these types of jobs are expected to be located near chassis or trailer 

manufacturing facilities located outside of California, although some will be created in 

California dealerships and maintenance facilities. New jobs for maintaining/replacing 

aerodynamic devices may also be created. 

The regulation is not expected to affect the ability of California businesses to compete 

with other states by making it more costly to produce goods or services because the 

proposal affects both interstate and intrastate long-haul freight distribution. In addition, 

most of the tractors and trailers affected by the proposed regulation are owned by 

businesses located outside of California. 

G. Estimated Costs to Local, State, and Federal Agencies 

The proposed regulation is not expected to have any impact on local public agencies. 

However, there would be a cost to the State for additional staff to provide the ongoing 

regulatory development, implementation, and enforcement of the regulation. The costs 

for the additional staff would be approximately $3,613,223 in fiscal year 2009-2010 (this 

includes one-time contract and equipment costs). In fiscal year 2010-2011 and going 

forward, the cost to the State would be $6,494,463 annually (in 2008 dollars). The total 

costs for fiscal years 2009-2010 and 2010-2011 are shown in Table XII-5. 

Table XII-5: Fiscal Year Costs for State Agencies 

Fiscal Year State Cost (2008 $) 

FY: 2009 – 2010 $3,613,223 

FY: 2010 – 2011 $6,494,463 

The cost is based on 20 new staff to conduct ongoing regulatory development and 

program implementation and 11 staff for enforcement of the regulation. The need for 20 

new positions was estimated based on the number of staff it has taken to develop and 

implement similar rules.16 It is envisioned that there would be a significant amount of 

coordination and program development work with U.S. EPA SmartWay staff. The 

proposed program would be dynamic in nature, meaning that regulatory amendments 

are expected to be routinely brought before the Board for approval as the program is 

expanded to include new aerodynamic components, trucks, and trailers. Given that the 

heavy-duty truck fleet accounts for 20 percent of the GHG emissions from the 

transportation sector (or 36 MMT CO2e), expansion of the program is not only expected, 

but vitally needed. 

Because ARB’s enforcement staff already has major commitments to other diesel 

regulations, it is expected that existing staffing levels will not be adequate to meet the 

increased demand for inspections and other enforcement activities. Staff anticipates 

additional inspectors will be required to conduct an enforcement program involving field 

 

16 Airborne Toxic Control Measure to Limit Diesel-Fueled Commercial Motor Vehicle Idling, Title 

13, Section 2485; Regulation for In-Use Off-Road Diesel Vehicles, Title 13, Sections 2449, 

2449.1, 2449.2 and 2449.3 
66

inspections, office investigations, and case development for the affected population of 

over 400,000 tractors and over 1 million trailers. A robust enforcement program is 

necessary to assure a level playing field for those that comply, and to assure the GHG 

emission reductions are achieved. 

Staff does not expect any costs to federal agencies as these agencies typically contract 

out for long-haul freight services. 

H. Cost-Effectiveness of the Proposed Regulation 

The basic methodology ARB staff uses to determine cost-effectiveness of a regulation is 

to determine what costs are involved to comply with the proposed regulation and to 

compare those costs to the emission reduction benefits to the public. Since the 

proposed regulation would result in an overall savings to the affected industry, it would 

be cost effective. 

This regulation would result in an estimated CO2 benefit of approximately 1 MMT CO2e 

in California and 6.7 MMT CO2e nationwide in 2020. In addition, the regulation is 

estimated to provide NOx emission reductions of about 4.3 tons per day (tpd) in 2014 

and 1.4 tpd in 2020.17

The regulation would provide a cost savings of $4.3 billion. The annualized net savings 

are the cost savings for the tractors and trailers subject to the regulation from 2010 to 

2020, as shown in Table XII-6. On an average annualized basis, this is equivalent to an 

operating cost savings of about $0.4 billion per year over the 11 years. 

Table XII-6: Average Annualized Cost Savings 

Model Year Cumulative Annual 

Capital Costs 

Annual Operating 

Cost Savings 

Net Savings Total 

2010 $71,994,512 -$586,464,631 -$514,470,120

2011 $233,058,924 -$809,739,777 -$576,680,853

2012 $411,434,088 -$1,176,648,403 -$765,214,315

2013 $613,503,052 -$1,292,353,131 -$678,850,079

2014 $822,210,899 -$1,361,253,981 -$539,043,082

2015 $1,040,505,088 -$1,423,881,061 -$383,375,973

2016 $1,169,863,202 -$1,477,348,117 -$307,484,915

2017 $1,300,497,855 -$1,538,439,022 -$237,941,167

2018 $1,435,448,768 -$1,585,812,457 -$150,363,689

2019 $1,572,800,765 -$1,666,974,913 -$94,174,148

2020 $1,727,329,806 -$1,755,052,155 -$27,722,349

Total 

Savings $10,398,646,958 -$14,673,967,648 -$4,275,320,691

 

17 U.S. EPA methodology entitled, “SmartWay SIP and Transportation Conformity Guidance: 

Accounting for NOx Reductions from Trailer Aerodynamic Kits and Low-rolling Resistance 

Tires” 
67

Total Savings over 6 year implementation -$3,457,634,422

Total Savings over 11 years to 2020 per AB 32 -$4,275,320,691

I. Summary of Current Financial Assistance and Grant Programs 

1. Federal grants and state incentive programs 

a) U.S. EPA: EPA's National Clean Diesel Campaign 

Under the Energy Policy Act of 2005, the Diesel Emissions Reduction Act 

(DERA) authorized $200 million per year for 5 years for implementation of diesel 

emissions reduction projects. The U.S. EPA National Clean Diesel Campaign 

Program (NCDC) consists of the NCDC Grants and Funding Program and the 

State Clean Diesel Grant Program, with the first appropriation of $49.2 million 

authorized by Congress in 2007. The NCDC includes the SmartWay Clean 

Diesel Finance Program. The programs provide technical assistance and grants 

to assist eligible partners to adopt diesel emissions reduction strategies. Grant 

opportunities are announced at the national level or via regional agreements 

such as Region 9 and 10 via the West Coast Collaborative (Federal Register & 

NCDC website). 

b) U.S. EPA SmartWay Partnership Financing Program 

The U.S. EPA SmartWay Finance Center provides a website to assist the 

trucking industry with the purchase of fuel savings and emissions reducing 

vehicles and technologies. This website works by bringing interested buyers and 

lenders together in one place. The interested tractor or tractor equipment buyer 

submits an application for an approved vehicle or technology, and interested 

lenders submit loan or lease offers to the applicant. The applicant decides which 

lenders he/she wants to work with, and both applicant and lender discuss the 

specific terms and conditions of each loan or lease. 

In September 2008, U.S. EPA was awarded $3.4 million in grants to provide 

financial assistance for truckers under the SmartWay Clean Diesel Finance 

Program. These loans will help small trucking firms lower their fuel costs and 

their carbon footprint by purchasing newer used trucks and idling and emissions 

reduction technologies. However, the loans and leases on this web site are 

limited to SmartWay certified vehicles and/or approved technologies and not 

available to the general public. 

Information on financial institutions that provide loans for purchase of new or preowned tractors can be found at the following website 

www.SmartwayFinanceCenter.com. The following provides SmartWay Program 

details from the U.S. EPA website: 

• Interest rates: 5.5 to 8.5 percent, depending on, among other things, each 

applicant’s business history, available collateral, cash flow, and credit score 
68

• Loan payback period: 3 to 6 years, depending on, among other things, 

business history, available collateral, and cash flow 

• Geographic location: Nationwide 

• Eligible activities: Purchase used trucks that are already upgraded, or 

upgrade them with SmartWay or CARB verified idle reduction and/or emission 

reduction technology. 

• Program Goal: Establish a revolving loan fund for the purchase of used 

trucks that have SmartWay upgrades or will receive SmartWay upgrades. 

• Service fee: 2 to 3 percent 

2. California incentive programs 

While ARB’s existing incentive grant programs, such as the Carl Moyer Program, 

have a proven success record in accelerating fleet turnover to newer, cleaner 

vehicles, funding opportunities for regulatory compliance are limited by statutory 

requirements to achieve surplus emission reductions, i.e., reductions that occur 

early and/or are in excess to what is required by regulation. As such, staff is 

currently developing an air quality loan program comprised of various financing 

options to provide an additional, more flexible financial assistance tool to 

regulated fleets. 

The 2008-2009 fiscal year State budget contains a $48 million appropriation to 

fund a heavy-duty vehicle air quality loan program to assist on-road fleets 

affected by staff’s proposal and the proposed Truck and Bus Rule. In developing 

this air quality loan program, ARB staff is coordinating with the State Treasurer’s 

Office (STO) to tailor a program to meet the specific needs of the heavy-duty 

vehicle sector. 

One option being developed by ARB staff is a program with loan guarantees as 

the core component. Loan guarantees are advantageous for two primary 

reasons: 1) by reducing the financial risk to lenders, they create opportunities for 

borrowers that fall slightly below normal lending criteria and may not otherwise 

qualify for loans to obtain affordable financing packages; and 2) they provide an 

inherent benefit of fund leveraging to significantly increase the amount of funds 

available for direct loans to fleet owners. For example, the $48 million budget 

appropriation could result in nearly $340 million in competitive-rate loans to 

heavy-duty vehicle fleet owners, based on a seven-to-one leveraging ratio found 

in similar financing programs within the STO. In conjunction with loan 

guarantees, staff is evaluating other economic assistance tools to extend 

repayment periods and further reduce interest rates, as well as evaluating 

financial mechanisms that maximize State funds to create a large-scale, 

sustainable air quality loan program. 

Because this loan program specifically supports the ARB’s two proposed 

regulations for on-road heavy-duty vehicle fleets, ARB staff will update the Board 
69

on the program at the same time the regulatory proposals are presented for 

Board consideration; funds should be available to assist fleets in early 2009. 

a) Assembly Bill 118 

Assembly Bill 118 (Nunez, 2007) created the Alternative and Renewable Fuels 

and Advanced Technology Program to be administered by the California Energy 

Commission, and the Air Quality Improvement Program to be administered by 

ARB. The Energy Commission program will have about $120 million annually 

beginning in fiscal year 2008-2009, and is geared toward transforming 

California’s fuel and vehicle types to help attain California’s climate change 

goals. ARB will receive $50 million annually to support clean air programs, and 

the first year appropriation is the source of the loan program funds described 

above. AB 118 provides the Energy Commission with over seven years in 

program funding. AB 118 requires that grants received pursuant to this program 

must achieve emission reductions that are early or go beyond what is required by 

regulation. ARB and the Energy Commission are currently developing guidelines 

and eligible project categories for their respective programs, with initial year 

project solicitations expected in mid-2009. 

b) Local Agency Programs 

Most Federal and State programs are administered by local agencies. In most 

cases, equipment operators should check with their local air district for funding 

opportunities, apply to, and be funded through them. Many local programs 

administered in conjunction with Carl Moyer funds operate under the title of 

“Heavy-duty Incentives” or similar. In the same manner, federal funding may be 

distributed through special programs like Sacramento Air Quality Management 

District’s Emergency Clean Air and Transportation Program, supplemented by 

CMAQ (Congestion Mitigation and Air Quality) and state funds. 

In addition, certain vehicle types and uses of trucks may have their own specially 

funded programs. The Ports of Long Beach and Los Angeles fund the Gateway 

Cities Clean Air Action Program fleet modernization plan via a combination of 

use fees (concession and container), Goods Movement and other matching 

sources. This program operates in conjunction with the San Pedro Bay Ports 

Clean Air Action Plan and Local Area Council of Governments, and anticipates 

replacing 16,000 trucks with newer used trucks over the next five years. Other 

agencies and jurisdictions may also have settlement and mitigation funds 

available for air quality improvement programs. 

XIII. REQUIREMENTS OF AB 32 

AB 32, at Health and Safety Code section 38560.5, requires that ARB adopt regulations 

by January 1, 2010 to implement discrete early action GHG emission reduction 

measures. These measures must “achieve the maximum technologically feasible and 

cost-effective reductions in greenhouse gas emissions” from the sources identified for 

early action measures. AB 32 contains additional standards in Health and Safety Code 
70

section 38562 that apply to regulations that will be adopted for general emissions 

reductions consistent with ARB’s scoping plan. Among other things, this section 

requires that reductions must be real, permanent, quantifiable, verifiable, and 

enforceable. ARB is also required to adopt rules and regulations in an open, public 

process. While section 38562 does not directly apply to early action items enacted 

under section 38560.5, ARB is interested in ensuring that its early action measures for 

GHG reductions such as those contained in this proposed regulation meet the broader 

criteria for the GHG reduction regulations that will follow. For that reason, these criteria 

are summarized here, with staff’s assessment as to why the proposed regulatory action 

meets them or is not specifically applicable to them.

 The proposed regulation would reduce GHG emissions by improving long-haul heavyduty vehicle fuel efficiency. This improvement in fuel efficiency would be accomplished 

through the required use of aerodynamic technologies and low-rolling resistance tires. 

Below is a discussion of why staff believes the proposed regulation meets the 

requirements of State law. 

1. The State Board shall adopt rules and regulations in an open public 

process to achieve the maximum technologically feasible and costeffective greenhouse gas emission reduction from sources or categories 

of sources. 

The proposed regulation was developed in consultation with affected parties in an open, 

public process. ARB staff conducted numerous outreach efforts to inform affected 

parties of the proposal and to obtain stakeholder comments. Outreach efforts included 

public workshops, individual meetings, and email and telephone contacts. See Chapter 

III, Public Outreach and Environmental Justice, for a description of the public process. 

2. Design the regulations, including distribution of emissions allowances 

where appropriate, in a manner that is equitable, seeks to minimize costs 

and maximize the total benefits to California, and encourages early action 

to reduce greenhouse gas emissions. 

The proposed regulation requires the use of U.S. EPA SmartWay approved 

aerodynamic technologies and low-rolling resistance tires on long-haul heavy-duty 

vehicles. Long-haul heavy-duty vehicles are the focus of the proposed regulation 

because GHG emission benefits resulting from the use of aerodynamic improvements 

are maximized when vehicles travel a majority of their miles at highway speeds. Heavyduty vehicles that travel a majority of their miles at slower speeds, e.g., short-haul 

delivery vehicles, are exempted from the regulatory requirements. 

The proposed regulation would apply equally to California-registered and out-of-state 

registered long-haul heavy-duty vehicles. All long-haul vehicles (heavy-duty tractors 

pulling 53-foot or longer box-type trailers) subject to the requirements would need to 

comply, regardless of state or country of registration. The proposed regulation would 

also establish requirements for drivers and owners of heavy-duty tractors and 53-foot or 

longer box-type trailers, motor carriers, California-based brokers, and California-based 

shippers. Drivers, motor carriers, tractor owners, and trailer owners would be directly 
71

responsible for ensuring that noncompliant tractors and trailers do not operate on 

California’s highways. Although California-based shippers and brokers would not 

initially be held responsible for noncompliant tractors and trailers, they could be held 

responsible, under certain circumstances, if a motor carrier, tractor owner, or trailer 

owner with whom they did business failed to settle a previously issued notice of 

violation. Under this strategy, staff expects that motor carriers, tractor owners, and 

trailer owners, including those domiciled out of state, would have an incentive to settle 

outstanding violations in order to avoid any potential detriment to their relationships with 

California-based shippers and brokers. Ensuring that out-of-state fleets are treated the 

same as California-registered fleets with respect to enforcement, would provide an 

equitable playing field for doing business in California. See Appendix G, 

Implementation and Enforcement for further information. 

Owners of long-haul vehicles affected by the proposed regulation may have up-front 

costs associated with acquisition of aerodynamic technologies and low-rolling 

resistance tires. These initial costs are expected to be recouped through savings from 

reduced fuel use, and the proposed regulation is expected to result in a substantial net 

savings for the businesses that operate long-haul vehicles in California. See Chapter 

XII, Cost and Economic Impacts, for a more detailed discussion. 

The proposed regulation would provide an incentive for owners of trailers to retrofit their 

trailers early. For every 2010 and earlier model year 53-foot or longer box-type trailer 

that is compliant with the proposed regulation by December 31, 2009, the owner could 

delay the retrofit of 1.5 nonconforming trailers until 2016. This provision encourages 

early compliance and is structured such that GHG emissions would not be lost. The 

early compliance option is discussed in more detail in Appendix F, Optional Trailer Fleet 

Compliance Schedules. 

3. Ensure that activities undertaken to comply with the regulations do not 

disproportionately impact low-income communities. 

Long-haul heavy-duty vehicles operate throughout California; no disproportionate 

localized impacts are expected. Greater GHG and NOx reductions would occur in 

populations located near interstate highways, typically where low-income communities 

are located. 

4. Ensure that entities that have voluntarily reduced their greenhouse gas 

emissions prior to the implementation of this section receive appropriate 

credit for early voluntary reductions. 

The U.S. EPA SmartWay Partnership program is a voluntary program that encourages 

the use of approved aerodynamic technologies and low-rolling resistance tires. In 

response to this program, some long-haul vehicle owners have voluntarily installed 

aerodynamic technologies and low-rolling resistance tires that meet the requirements of 

the proposed regulation. The proposed regulation would allow extra flexibility to fleets 

that have complied early with the requirements by providing additional time to meet the 

requirements. See Appendix F, Optional Trailer Fleet Compliance Schedules. 

 
72

5. Ensure that activities undertaken pursuant to the regulations 

complement, and do not interfere with, efforts to achieve and maintain 

federal and state ambient air quality standards and to reduce toxic air 

contaminant emissions. 

The proposed regulation requiring the use of aerodynamic technologies and low-rolling 

resistance tires on long-haul heavy-duty vehicles would aid in efforts to achieve federal 

and state standards by reducing NOx emissions. Long-haul heavy-duty vehicles 

equipped with aerodynamic devices and low-rolling resistance tires are able to transport 

freight more efficiently, reducing the required load on the engine. Engines operating at 

lower loads have lower peak combustion temperatures and thus lower NOx emission 

rates. The magnitude of the reduction in NOx emissions resulting from improvement in 

tractor-trailer efficiency is dependent on the NOx emission rate of the tractor’s engine. 

Older engines produce more NOx emissions, and thus will realize a greater NOx 

reduction benefit from efficiency improvements. See Chapter XI, Environmental 

Impacts, for a more detailed description. 

6. Consider cost-effectiveness of these regulations. 

The proposed regulation is expected to result in a substantial net savings for the 

businesses that operate long-haul heavy-duty vehicles in California. See Chapter XII, 

Cost and Economic Impacts, for a more detailed discussion. 

7. Consider overall societal benefits, including reductions in other air 

pollutants, diversification of energy sources, and other benefits to the 

economy, environment, and public health. 

The proposed requirements for long-haul heavy-duty vehicles are not expected to cause 

any adverse impacts to society or the environment. California would benefit from the 

reduction of GHG emissions. As discussed in the response to criterion five above, the 

proposal would not cause an increase in volatile organic compound or toxic air 

contaminant emissions, and would result in NOx emission reductions. See Chapter XI, 

Environmental Impacts, for a more detailed description. 

8. Minimize the administrative burden of implementing and complying with 

these regulations. 

For those long-haul heavy-duty vehicle owners that comply with the requirements by the 

established compliance dates, the administrative burden would be minimal. The 

proposed regulation requires no recordkeeping or reporting for these parties. 

Only those tractor or trailer owners that wish to be classified as short-haul, and 

exempted from the requirements of the proposed regulation, or those that choose to 

participate in an optional compliance schedule or the refrigerated fleet compliance 

provision, would be subject to reporting requirements. 

To apply for the short-haul exemption, owners would need to submit an application with 

specific information on the vehicle, vehicle owner, and vehicle’s local haul base. Once 

approved, the tractor or trailer would be considered short-haul and not subject to the 
73

requirements of the proposed regulation. The short-haul exemption would be effective 

for one year and would require renewal on an annual basis. 

To participate in an optional compliance plan, owners would need to submit a 

compliance plan that would include a statement of intent, information on each affected 

trailer, and details as to which affected trailers would be retrofitted each year to comply 

with the optional phase-in schedule requirements. 

To participate in the refrigerated fleet compliance provision, owners would need to 

submit information on each affected refrigerated-van trailer, and details as to which 

affected trailers would be retrofitted each year to comply with the phase-in schedule 

requirements. 

There would be no recordkeeping requirements for motor carriers, California-based 

shippers, or California-based brokers. 

9. Minimize leakage. 

Leakage is not expected as a result of the proposed regulation. Leakage occurs when 

an emission limit or regulatory requirement set by the State causes business activities 

to be displaced outside of California. If leakage were to occur, emissions, jobs and 

other economic benefits to California would be lost. The proposed regulation requires 

that long-haul vehicles traveling on California highways be equipped with aerodynamic 

devices and low-rolling resistance tires, regardless of state or country of registration. 

Therefore, there would not be a situation where a long-haul heavy-duty vehicle 

registered inside the State would be at a competitive disadvantage compared to 

vehicles registered outside of the State. Similarly, both California and out-of-state motor 

carriers would be subject to the same requirements; both would be required to dispatch 

compliant vehicles. 

The proposed regulation does, however, establish additional requirements for 

California-based brokers and California-based shippers. These California-based 

businesses would be required to use compliant long-haul vehicles when dispatching 

vehicles and loading freight for transport, respectively. The primary intent of this 

strategy is to provide an incentive for out-of-state motor carriers, tractor owners, and 

trailer owners to comply with the proposed regulation. Historically, it has been very time 

consuming and costly to collect penalties from unresponsive out-of-state fleets. This is 

because the State has no authority to hold the registrations of out-of-state registered 

vehicles and limited authority to hold the vehicles themselves. Therefore, if an 

out-of-state registered fleet currently refuses to settle a violation, it is necessary, in 

many cases, for the State of California to file a lawsuit against that fleet in their state of 

residence to collect any penalties. However, under the strategy of the proposed 

regulation, staff expects that most motor carriers, tractor owners, and trailer owners, 

including those domiciled out-of-state, would choose to settle their violations in order to 

avoid any potential detriment to their relationships with California-based shippers and 

brokers. Ensuring that out-of-state fleets are treated the same as California-registered 

fleets with respect to enforcement, would provide an equitable playing field for those 

doing business in California. 
74

10. Consider the significance of the contribution of each source or category 

of sources to statewide emissions of greenhouse gases. 

The transportation sector, which includes on-road vehicles, aviation, rail, and ships, is 

the largest contributor to the total statewide GHG emissions inventory, producing 

approximately 38 percent of the state’s total GHGs, or 179 MMT CO2e. This is 

projected to increase to 225 MMT CO2e by 2020 if no actions are taken to reduce 

emissions. Thus, emissions from the transportation sector must be significantly reduced 

in order to achieve the AB 32 requirement that State GHG emission levels be reduced 

to 1990 levels by the year 2020. See Appendix C, Emission Inventory Analysis and 

Results for more details. 

The statewide GHG emission benefits of the proposed regulation are projected to be 1.0 

MMT CO2e emissions in 2020. From 2010 to 2020, the cumulative GHG emission 

benefits are estimated to be approximately 7.8 MMT CO2e statewide. While this 

reduction may appear somewhat modest, when the reduction is considered in 

conjunction with anticipated future GHG reductions from current and future reductions 

from other categories, the total reductions are significant. Key to ARB’s overall strategy 

to meet AB 32’s aggressive GHG emission reduction goals is to achieve relatively small 

reductions from a large number of categories, and thus achieve a significant overall 

reduction in GHG emissions by 2020. 

11. The greenhouse gas emission reductions achieved are real, permanent, 

quantifiable, verifiable, and enforceable by the state board. 

The proposed regulation would require compliant tractors and trailers to be either: 1) 

retrofitted with aerodynamic technologies and low-rolling resistance tires that are U.S. 

EPA SmartWay approved technologies, or 2) a U.S. EPA certified SmartWay tractor or 

trailer. The technical requirements and specifications that compliant tractors and trailers 

would be required to meet are defined by the U.S EPA SmartWay Partnership Program. 

The proposed regulation defines the dates when specified requirements would become 

effective and provides ARB, CHP, and District personnel the authority to inspect heavyduty vehicles and audit records for enforcement. The proposed regulation defines 

recordkeeping and reporting requirements that would provide enforcement personnel 

with information necessary to enforce the requirements of the proposed regulation in the 

field. Once the proposed regulation is approved by the Office of Administrative Law, the 

proposed emission limit would become State law. Based on the above, upon the 

effective date of the proposed emission limit, the reductions would become real, 

permanent, quantifiable, verifiable, and enforceable. 

12. For regulations.... ....the reduction is in addition to any greenhouse gas 

emission reduction otherwise required by law or regulation, and any other 

greenhouse gas emission reduction that otherwise would occur. 

The proposed regulation is the first GHG emission limitation affecting the long-haul 

heavy-duty vehicle industry. No other existing State, federal or other requirements 
75

would affect emissions of GHGs from long-haul heavy-duty vehicles. The proposed 

regulation requirements are based on the requirements of the U.S. EPA’s SmartWay 

Partnership program, which is a voluntary program. Although the SmartWay program 

has been in place since 2004, a relatively small number of tractors and trailers have 

been retrofitted with aerodynamic technologies in response to this program. This is 

especially true for trailers, where staff estimates that less than 0.3 percent of the total 

53-foot or longer box-type trailer inventory incorporates aerodynamic technologies. 

13. If applicable, the greenhouse gas emission reduction occurs over the 

same time period and is equivalent in amount to any direct emission 

reduction required pursuant to this division. 

This requirement is not applicable to the proposed regulation. 

14. The state board shall rely upon the best available economic and scientific 

information and its assessment of existing and projected technological 

capabilities when adopting the regulations required by the law. 

ARB staff used the best available economic and scientific information available to 

develop the proposed regulation. The description in this section documents that the 

proposal was developed in accordance with AB 32 requirements. Chapter XII, Cost and 

Economic Impacts, contains a detailed description of the economic impact of the 

proposed regulation. In addition, a technological assessment of the feasibility of the 

required aerodynamic technologies and low-rolling resistance tire technologies required 

by the proposed regulation is presented in Chapter IX, Technological Feasibility of 

Control Measure. 

XIV. ISSUES

A. Mexican Border Issues 

During the regulatory development process, staff heard comments from a U.S. motor 

carrier regarding concerns associated with complying with the trailer aerodynamic 

technology requirements while routinely driving across the U.S.-Mexico border. 

According to the U.S. motor carrier, the maintenance costs associated with repairing or 

replacing side skirt technology installed on trailers that traveled throughout Mexico 

outweighed the cost savings associated with improved fuel economy. Reportedly, a 

number of the skirts became damaged when traveling on Mexican roads that were in a 

state of disrepair. Also, many of the installed skirts were stolen from trailers that were 

parked overnight in unsecured parking facilities and alongside roadways. 

Mexican motor carriers also had concerns about complying with the rule. At a public 

workshop, a Mexican-based motor carrier stated that a number of the tractor-trailers 

that cross the U.S. border on a daily basis travel 20 miles or less to distribution centers 

in California. They “drop and hook” trailers at these facilities and return back to Mexico. 

“Drop and hook” refers to the activity of dropping-off a trailer at a warehouse or 

distribution center and hooking up to pull a different trailer to another location. Typically, 
76

tractors engaged in drop and hook activities make several trips into the U.S. every 

week. The Mexican-based motor carrier, like the U.S. motor carrier, was concerned 

that the required aerodynamic technologies would be frequently damaged when 

traveling throughout Mexico. Also, there were concerns raised about the capital costs 

associated with these technologies and whether the smaller owner-operators that 

currently own one or two older tractors and trailers would be able to absorb these costs 

and continue doing business. 

In response to the above issues, staff believes the provisions in the proposed regulation 

for exempting short-haul tractors and trailers can be used by many motor carriers that 

traverse the U.S-Mexico border. As discussed in Chapter VIII, Proposed Regulation, 

owners of tractors and trailers may register them as short-haul tractors and trailers as 

long as they only operate within 100 miles of their local base. Tractors have the option 

of limiting their annual vehicle miles traveled to 50,000 miles per year, rather than 

limiting their area of operation. Tractors and trailers that meet the short-haul criteria and 

that are registered with the ARB as short-haul tractors and trailers would be exempted 

from the proposed requirements. This would address issues associated with equipment 

damage and capital costs, but it would require the owners of these tractors and trailers 

to register them with the ARB. Motor carriers that wish to use this option may be 

required to alter their current method of operation, since the area of operation of these 

tractors and trailers would be limited. 

B. Other Rulemakings 

Staff evaluated the impact of having to concurrently comply with the proposed rule and 

two other rulemakings, the proposed Truck and Bus Rule and the previously-adopted 

TRU Rule. The details of this evaluation are presented below. 

1. Impact with Truck and Bus Rule 

Staff’s proposal will be considered for adoption together with the Truck and Bus Rule, 

which would also have a regulatory impact on businesses operating heavy-duty 

vehicles. From 2010 through 2020, the Truck and Bus Rule would require the retrofit, 

repower, or replacement of vehicles equipped with model-year 2006 and older heavyduty diesel-fueled engines. These requirements would phase in concurrently with 

requirements of staff’s proposal. 

Although certain fleets could end up having to bear the burden of concurrently 

complying with both staff’s proposal and the Truck and Bus Rule, staff believes that the 

number of these fleets would likely be small. This is because staff’s proposal would 

only apply to long-haul vehicles, which, according to vehicle population data, are 

typically newer. Therefore, staff does not expect long-haul fleets to have many vehicles 

within the scope of the Truck and Bus Rule’s requirements during the period of 

regulatory overlap. 

Nevertheless, staff realizes that certain businesses could still be significantly impacted 

by both regulations, and therefore, has included the impact analysis below. 
77

a) New Tractor Requirements 

Staff’s proposal would require all 2011 and subsequent model year tractors with sleeper 

berths to be SmartWay certified. Staff does not believe this requirement would 

significantly impact businesses, including ones affected by the Truck and Bus Rule, 

because the incremental cost of a SmartWay certified tractor is relatively small. For 

example, staff estimates that a new SmartWay certified tractor is $2,100 more than a 

typical sleeper berth tractor. Assuming that the average price of a sleeper berth tractor 

is $121,000,18 the incremental cost would be less than 2 percent of the total price of the 

vehicle. In addition, the regulation does not force the turnover of existing vehicles. 

b) In-Use Tractor Requirements 

Staff’s proposal would require all 2010 and previous model year tractors to use 

SmartWay approved low-rolling resistance tires. Staff believes this requirement would 

place very little burden on businesses, primarily because the price difference between a 

SmartWay approved tire and a standard tire is little to none. Based on staff’s verbal 

communication with various fleets, the incremental cost of a SmartWay approved tire 

ranges from $0 to $50. In addition, tires are consumables that are replaced anyway, 

and the tire requirement would allow adequate time for vehicles to wear down their 

existing tires treads before requiring them to change. Moreover, although those 

affected would not be allowed to recap their noncompliant casings, they could still sell 

these casings in the secondary market to short-haul fleets, fleets that do not service 

California, and rubber recyclers. Therefore, staff does not believe that this requirement 

would add to the impact of the proposed regulation. 

c) New Trailer Requirements 

Staff’s proposal would require all 2011 and subsequent model year box-type trailers to 

be SmartWay certified or equipped with a required number of SmartWay approved 

devices. Because natural turnover rates of trailers are low, staff does not believe that 

this requirement by itself would have a significant impact on businesses. However, staff 

expects that many fleets would choose to purchase new SmartWay certified trailers 

instead of retrofitting older trailers with SmartWay approved devices to comply with the 

proposal’s in-use trailer requirements. Therefore, the primary impact of this requirement 

will be considered as part of the impact of the in-use trailer requirements, discussed 

below. 

d) In-Use Trailer Requirements 

The proposed regulation would require all in-use box-type trailers that operate in 

California to be SmartWay certified or equipped with a required number of SmartWay 

approved devices by December 31, 2012. Staff expects the largest impact of this 

proposal to come from these requirements due to the large number of trailers that 

operate in California. 

 

18 “Truck Paper,” October 7, 2008, <http://www.truckpaper.com> 
78

Therefore, to alleviate some of the burden that a business could potentially face when 

trying to comply with both the current proposal and the Truck and Bus Rule, staff’s 

regulatory proposal includes the option for a trailer fleet to participate in a compliance 

schedule that would allow the fleet to delay full compliance of in-use trailers beyond the 

December 31, 2012 compliance deadline. Two compliance schedules were developed 

for this purpose--one for large fleets of trailers (21 or more trailers) and one for small 

fleets of trailers (20 or less trailers). In addition, certain refrigerated trailers concurrently 

affected by the TRU Rule and staff’s proposal could receive an additional delay as 

described in section 2 below. 

Under the large fleet compliance schedule, trailer fleets would be required to begin 

bringing trailers into compliance in 2010, but would be given until the end of 2015 to 

complete their fleet transition. Additional flexibility would be available to fleets that bring 

trailers into compliance before December 31, 2009. Fleets that do so would be given 

one additional year to bring their remaining trailers into compliance. Furthermore, the 

large fleet compliance schedule also begins with a conservative phase-in, which would 

only require 15 percent of a fleet’s trailers to comply by the end of the second 

compliance year (December 31, 2011). This would provide even more flexibility by 

giving fleets the opportunity to get ahead of early percentage requirements in order to 

reduce obligations in later years. Staff believes that the built-in flexibility would allow 

fleets to better manage their capital expenditures for complying with the current 

proposal and the Truck and Bus Rule. Moreover, because long-haul fleets typically 

operate newer vehicles, it would be even less likely for a long-haul fleet to be 

significantly impacted by the Truck and Bus Rule after December 31, 2011. Based on 

the reasons above, staff believes this compliance schedule would provide adequate 

time for large fleets to comply with the requirements of the current proposal, even if they 

are also concurrently subject to the Truck and Bus Rule. 

To further reduce regulatory impacts on smaller fleets, they would not be required to 

begin bringing trailers into compliance until 2013, and would be given until the end of 

2016 to complete their fleet transition. 

2. Impact with TRU Rule 

The TRU Rule requires the retrofit, repower, or replacement of trailers equipped with 

2009 and older model year diesel-fueled TRUs from 2010 through 2016. These 

requirements would phase in concurrently with the large fleet and small fleet compliance 

schedules of staff’s proposal. In addition, since both the TRU Rule and staff’s proposal 

would affect trailers, trailer owners could face a significant burden should they be 

subjected to both regulations. Therefore, staff developed a special provision that would 

delay this proposed regulation’s phase-in requirements for most 2003 through 2008 

model year refrigerated trailers until after 2016. As currently proposed, the refrigerated 

fleet provision would provide three years (2017-2019) to phase in affected refrigerated 

trailers. Staff feels that this would allow fleets to better distribute the regulatory impact 

of complying with the two regulations. 

 
79

XV. RECOMMENDATION

Staff recommends the Board adopt new sections 95300 through 95312 entitled “HeavyDuty Vehicle Greenhouse Gas Emission Reduction Measure” in its entirety in chapter 

16 of the California Code of Regulations, title 17. The regulatory language is set forth in 

the proposed regulation order in Appendix A. 
80

XVI. REFERENCES

ARB, 2001. California Air Resources Board. Policies and Actions for Environmental 

Justice. Sacramento: December 13, 2001. 

http://www.arb.ca.gov/ch/programs/ej/ej.htm

ARB, 2002. California Air Resources Board. California Air Resources Board Strategic 

Plan. Sacramento: January 2002. 

http://www.arb.ca.gov/planning/plan01/plan01.htm

ARB, 2004. California Air Resources Board. Staff Report: Initial Statement of Reasons 

for Proposed Rulemaking, Public Hearing to Consider Adoption of Regulations to 

Control Greenhouse Gas Emissions from Motor Vehicles. Sacramento: August 6, 

2004. http://www.arb.ca.gov/regact/grnhsgas/grnhsgas.htm

ARB, 2007. California Air Resources Board. “Expanded List of Early Action Measures 

to Reduce Greenhouse Gas Emissions in California Recommended for Board 

Consideration.” Sacramento: October 2007. 

http://www.arb.ca.gov/cc/ccea/reports/reports.htm

ARB, 2008a. California Air Resources Board. Staff Report: Initial Statement Of 

Reasons For Proposed Rulemaking. Proposed Regulation For In-Use On-Road 

Diesel Vehicles. Appendix G – Emissions Inventory Methodology and Results. 

Sacramento: To be released October 2008. 

ARB, 2008b. California Air Resources Board. Greenhouse Gas Inventory Data - Draft 

2020 Forecast. Last Reviewed July 29, 2008. Last Accessed September 20, 2008. 

http://www.arb.ca.gov/cc/inventory/data/forecast.htm

ARB, 2008c. California Air Resources Board. Climate Change Proposed Scoping Plan. 

Appendices Volume II: Analysis and Documentation. (Appendix I, p.I-6). 

Sacramento: October 2008. 

http://www.arb.ca.gov/cc/scopingplan/document/scopingplandocument.htm

Bachman, 2005. Bachman, Leon J., Anthony Erb, Cheryl Bynum. Effect of Single Wide 

Tires and Trailer Aerodynamics on Fuel Economy and NOx Emissions of Class 8 

Line-Haul Tractor-Trailers. Society of Automotive Engineer 2005-01-3551 

http://www.epa.gov/smartway/transport/documents/tech/effects-on-fuel-economy.pdf

Bachman, 2006. Bachman , L J., A. Erb, C. Bynum, B. Shoffner, H. De La Fuente, C. 

Ensfield. Fuel Economy Improvements and NOx Reduction by Reduction of 

Parasitic Losses: Effect of Engine Design. Society of Automotive Engineer, 2006-

01-3474. http://www.epa.gov/smartway/transport/documents/tech/fuel-economyimprovements.pdf
81

Bajer, 2008. Bajer, Jacques. Tire Rolling Resistance. Modern Tire Dealer. Uniontown, 

OH: August 2008. 

http://www.moderntiredealer.com/t_inside.cfm?action=art_det&storyID=1524 

CEC 2007. California Energy Commission. Transportation Energy Forecasts for the 

2007 Integrated Energy Policy Report. CEC-600-2007-009-SF. September 2007 

http://www.energy.ca.gov/2007publications/CEC-600-2007-009/CEC-600-2007-009-

SF.PDF

Census, 2000. United States Bureau of Census. Current Industrial Reports, M336L - 

Truck Trailers. http://www.census.gov/cir/www/336/m336l.html

Census, 2002. United States Bureau of Census. 2002 Vehicle Inventory and Use 

Survey Microdata. http://www.census.gov/svsd/www/vius/products.html

EIA, 2008. Energy Information Administration. Diesel Historical Data (.xls) 

http://tonto.eia.doe.gov/oog/info/wohdp/diesel.asp

Freight Wing, 2007. Freight Wing, Inc. Technology, Test Results and Benefits 

Summary. 2007. 

Freight Wing, 2008. Freight Wing, Inc. Maintenance Summary and Cost Analysis: 

10/11/05 thru 4/24/08. Seattle: 2008. 

IPCC, 2007. 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. 

http://www.ipcc.ch/ipccreports/ar4-wg1.htm

Laydon, 2007. Laydon Composites, Ltd. Trailer Skirt. Presentation: Cascade Sierra 

Solutions. 2007. https://secure.cascadesierrasolutions.org/CSS_library/ (Last 

accessed October 20, 2008). 

Linsley, 1977. Linsley, Ray K. Water Resources Engineering. Third Edition. 1977. 

Harper & Row. 

Michelin, 2002. LaClair, Tim J. Tire Rolling Resistance, Its Impact on Fuel Economy, 

and Measurement Standards. Sacramento: September 19, 2002. 

http://www.energy.ca.gov/transportation/tire_efficiency/former_proceeding/2002-09-

19_workshop/TIM_LACLAIR_MICHELIN.PPT

MTD 2006. Modern Tire Dealer. Commercial. Uniontown, OH: January 2006. 

http://www.moderntiredealer.com/t_pop_pdf.cfm?link=research/commercial1.pdf 
82

MTD 2008. Modern Tire Dealer. Truck tire market share. Uniontown, OH: June 2008. 

http://www.moderntiredealer.com/t_pop_pdf.cfm?link=research/JUN_31.pdf 

Nunez, 2002. Assembly Bill No. 32. September 27, 2006. 

http://www.leginfo.ca.gov/pub/05-06/bill/asm/ab_0001-

0050/ab_32_bill_20060927_chaptered.pdf

Ogburn, 2007. Ogburn, Michael J., Laurie A. Ramrot. Truck Efficiency and GHG 

Reduction Opportunities in the Canadian Truck Fleet. 2007.

OOIDA, 2004. OOIDA Foundation Inc. The 2004 Owner-Operator Member Profile 

Survey. 2004. 

SAE J1269. SAE J1269 Rolling Resistance Measurement Procedure for Passenger 

Car, Light Truck, and Highway Truck and Bus Tires. Sep 1, 2006 

SAE J1321. Joint Tmc/SAE Fuel Consumption Test Procedure-Type II. October 1986 

Schubert, 2008. Schubert, R., Matt Kromer. Heavy-Duty Truck Retrofit Technology: 

Assessment and Regulatory Approach Final Report. Report to: Union of Concerned 

Scientists. September 12, 2008 

Surcel, 2007. Surcel, Marius-Dorin. Energostet:2007, Fuel Consumption Test for 

Evaluating Freight Wing Trailer Side Skirts. Internal Report IR-2007-11-28D. 

Pointe-Claire: November 2007. 

Surcel, 2007. Surcel, Marius-Dorin. Energostet:2007, Fuel Consumption Test for 

Evaluating Advanced Transit Dynamics TrailerTailsTM

. Internal Report IR-2007-11-

28A. Pointe-Claire: November 2007. 

TRIB, 2008. Tire Retread & Repair Information Bureau. Retread facts. Pacific Grove, 

CA: 2008. http://www.retread.org/Facts/index.cfm/ID/225.htm 

U.S. EPA, 2007. U.S. Environmental Protection Agency. SmartWay SIP and 

Transportation Conformity Guidance: Accounting for NOx Reductions from Trailer 

Aerodynamic Kits and Low Rolling Resistance Tires. EPA420-B-07-004. 

June 2007. www.epa.gov/otaq/stateresources/transconf/policy/420b07004.pdf

U.S. EPA, 2008. Bynum, Cheryl L. Email Communication with Ms. Cheryl L. Bynum 

(U.S. EPA SmartWay Program). March 25, 2008. 

Vieth, 2008. Vieth, Ken. Telephone Communication with Mr. Ken Vieth, Senior Partner 

and General Manager of Americas Commercial Transportation Research co., LLC 

(ACT Research). July 2, 2008 
83

Vise, 2007. Vise, Avery. The CCJ Top 250: Mediocre at Best. Commercial Carrier 

Journal. August 2007. pp. 61-110. 

http://www.rrpub.com/etrucker/ccj/ccj0807_250.pdf

Vise, 2008. Vise, Avery. The CCJ Top 250: Slower But Solid. Commercial Carrier 

Journal. August 2008. pp. 52-103. http://www.rrpub.com/ccj/pdfs/top250_07.pdf