Examining the Underlying Science and Impacts of Glider Truck Regulations

Examining the Underlying Science and Impacts of Glider Truck Regulations

Statement of
Linda Tsang
Legislative Attorney
Before
Committee on Science, Space, and Technology
Subcommittees on Oversight & Environment
U.S. House of Representatives
Hearing on
“Examining the Underlying Science and
Impacts of Glider Truck Regulations”
September 13, 2018
Congressional Research Service
https://crsreports.congress.gov
TE10028

Congressional Research Service
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Chairman Abraham, Chairman Biggs, Ranking Member Beyer, Ranking Member Bonamici, and
Members of the Subcommittees:
My name is Linda Tsang. I am a Legislative Attorney in the American Law Division of the Congressional
Research Service (CRS). Thank you for inviting me to testify regarding the U.S. Environmental
Protection Agency’s (EPA’s) emission requirements for glider vehicles, glider engines, and glider kits.
My testimony will address the rulemaking process EPA used to adopt emission standards for gliders
pursuant to its rule, Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-
Duty Engines and Vehicles—Phase 2 (Phase 2 Rule) and to propose to repeal them (Proposed Repeal).
My testimony will address the specific procedural requirements for rulemaking under the Clean Air Act
(CAA). It will not address the substantive requirements, legal arguments, policy considerations, or
scientific data relating to the Phase 2 Rule or the Proposed Repeal.
As discussed in more detail below, Congress established procedures in Section 307(d) of the CAA that
govern EPA’s promulgation or revision of new motor vehicle or engine emission regulations. In addition
to the CAA requirements, EPA must also comply with various rulemaking requirements imposed by
statutes and executive orders.
Recent Clean Air Act Rulemakings Related to Glider Kits, Engines, and
Vehicles
Section 202(a) of the CAA directs EPA to establish standards for air pollutant emissions from new motor
vehicles and engines that “cause, or contribute to, air pollution which may reasonably be anticipated to
endanger public health or welfare.”1 On October 25, 2016, EPA and the National Highway Traffic Safety
Administration (NHTSA) jointly published the second phase of greenhouse gas (GHG) emissions and
fuel efficiency standards for medium- and heavy-duty vehicles and engines.2 The Phase 2 Rule set
emission standards for most commercial long-haul tractor-trailers, vocational vehicles, and heavy-duty
pickup trucks and vans, and provided for their phase-in between model year (MY) 2018 and MY 2027.3
As part of the Phase 2 Rule, EPA regulated glider kit, glider engine, and glider vehicle emissions.4 EPA
defined a glider kit as a chassis for a tractor-trailer with a frame, front axle, interior and exterior cab, and
brakes. It becomes a glider vehicle when an engine, transmission, and rear axle are added.5 The final
manufacturer of the glider vehicle (i.e., the entity that assembles the parts) is typically not the original
manufacturer of the glider kit.6 NHTSA did not include glider vehicles under its Phase 2 fuel efficiency
standards.7

1 42 U.S.C. § 7521(a)(1).
2 Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles—Phase 2; Final
Rule, 81 Fed. Reg. 73,478 (Oct. 25, 2016) [hereinafter Phase 2 Rule]. For additional information on the Phase 2 Rules, see CRS
In Focus IF10927, Phase 2 Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and
Vehicles, by Richard K. Lattanzio. The Phase 2 Rule expands on the Phase 1 Rule issued in 2011 for model year 2014 through
2018 motor vehicles. Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines
and Vehicles; Final Rule, 76 Fed. Reg. 57,106 (Sept. 15, 2011).
3 Phase 2 Rule, 81 Fed. Reg. 73,478 (Oct. 25, 2016)
4 81 Fed. Reg. at 73,941-46.
5 Id. at 73,512-13.
6 Id.
7 Id. at 73,526 n.130.
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Petitions for Reconsideration of the Glider Provisions
After EPA issued the Phase 2 Rule, representatives of the glider vehicle assembler industry submitted a
joint petition pursuant to CAA Section 307(d)(7)(B) requesting that EPA reconsider the glider vehicle,
glider engine, and glider kit regulations.8 The petitioners argued, among other things, that CAA Section
202(a) does not authorize EPA to regulate glider kits, vehicles, or engines because glider vehicles are not
“new motor vehicles,” glider engines are not “new motor vehicle engines,” and glider kits are not self-
propelled “motor vehicles” under the CAA.9 The petitioners also argued that the Phase 2 Rule glider
regulations relied on “unsupported assumptions” regarding glider vehicle emissions.10
EPA responded to the glider industry joint petition, stating that it “raises significant questions regarding
the EPA’s authority under the CAA to regulate gliders as well as the soundness of the EPA’s technical
analysis used to support the requirements.”11 Based on the petition, EPA decided to revisit the Phase 2
Rule glider regulations.12
Proposed Repeal of the Glider Provisions
On November 16, 2017, EPA proposed to repeal the Phase 2 Rule emission standards and regulations for
heavy-duty glider vehicles, engines, and kits.13 In the Proposed Repeal, EPA determined that its previous
statutory interpretation of its authority over glider engines, vehicles, and kits was “incorrect” and “not the
best reading” of the CAA.14 EPA proposed to interpret the CAA definitions of “new motor vehicles” and
“new motor vehicle engines” to exclude glider vehicles and engines, respectively. Consistent with this
interpretation of the scope of “new motor vehicle,’’ EPA further proposed that it has no authority to treat
glider kits as ‘‘incomplete’’ motor vehicles under CAA Section 202(a).
Rulemaking Procedures Under the Clean Air Act
While the Administrative Procedure Act (APA) generally governs agency rulemaking procedures,15
Congress established procedures under CAA Section 307(d) to govern EPA’s promulgation of specific
CAA regulations, including regulations for new motor vehicles or engines under Section 202(a).16 These

8 See, e.g., Petition from Tommy C. Fitzgerald, President, Fitzgerald Glider Kits, LLC et al. to E. Scott Pruitt, Admin., EPA (July
10, 2017), https://www.epa.gov/sites/production/files/2017-07/documents/hd-ghg-frfitzgerald-recons-petition-2017-07-10.pdf
[hereinafter Petition]. Other petitions for reconsideration and EPA’s responses to the petitions are available at
https://www.epa.gov/regulations-emissions-vehicles-and-engines/petitions-reconsideration-phase-2-ghg-emissions-and-fuel.
Under Section 307(d)(7)(B), EPA must convene a reconsideration proceeding if the objection could not have been raised during
the public comment period for the proposed rule, and the EPA Administrator concludes that the objection is centrally relevant to
the rule. Id. EPA must “provide the same procedural rights as would have been afforded had the information been available at the
time the rule was proposed.” Id.
9 Petition at 3–4.
10 Id. at 4.
11 Letter from E. Scott Pruitt, Admin., EPA, to Tommy C. Fitzgerald, President, Fitzgerald Glider Kits, LLC (Aug. 17, 2017),
https://www.epa.gov/sites/production/files/2017-08/documents/hd-ghg-phase2-fitzgerald-gliders-ltr-2017-08-17.pdf.
12 Id.
13 Repeal of Emission Requirements for Glider Vehicles, Glider Engines, and Glider Kits; Proposed Rule, 82 Fed. Reg. 53,442
(Nov. 16, 2017) [hereinafter Proposed Repeal].
14 Id. at 53,444-45.
15 5 U.S.C. § 551(1). The APA broadly defines agency as “each of authority of the Government of the United states . . . ,” but
specifically exempts certain entities including “Congress” and the “courts of the United States.” Id. The APA also governs
agency adjudications. See id. §§ 555-57.
16 42 U.S.C. § 7607(d)(1)(K). In addition to new motor vehicle regulations, Section 307(d) procedures apply to the promulgation
or revision of specific CAA standards and requirements listed in Section 307(d)(1). Id. § 7607(d)(1). Section 307 permits judicial
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procedures require EPA, among other things, to establish a public rulemaking docket, publish a notice of
the proposed rulemaking (NOPR) in the Federal Register, allow at least 30 days for public comment, and
provide an opportunity for a public hearing.17 In the Federal Register NOPR, EPA must provide a
statement (known as the preamble) that describes the basis and purpose of the proposed rule, factual data
supporting it, methodology used to obtain and analyze the data, legal interpretations and policy
considerations, and other supporting information.18 During the rulemaking, EPA must also consider all
public comments it receives and other relevant information.19 After considering public comments on the
proposed rule, EPA must publish the final rule in the Federal Register with a new preamble responding to
“significant” comments and identifying any changes to the rule since its proposal.20
CAA Section 307(d) rulemaking procedures governed EPA’s promulgation of the Phase 2 Rule glider
provisions.21 For the Phase 2 Rule, EPA took the following rulemaking actions:22
 EPA and NHTSA established dockets, Docket ID No. EPA–HQ–OAR–2014–0827 and
NHTSA–2014–0132, respectively, which are accessible at http://www.regulations.gov.23
 EPA and NHTSA published a joint proposed Phase 2 Rule in the Federal Register on July
13, 2015.24
 EPA and NHTSA provided a public comment period from July 13, 2015 to October 1,
201525 and held two public hearings on the proposed Phase 2 Rule.26
 EPA provided a statement of basis and purpose for the proposed Phase 2 Rule, including
data, legal interpretations, policy considerations, and other information supporting,
among other things, the proposed requirements for glider kits, engines, and vehicles.27
Because EPA issued the glider provisions pursuant to its authority under the CAA,
NHSTA did not participate in promulgating those provisions.28

review of procedures used to promulgate a final rule if the procedural objections were raised during the public comment period.
Id. § 7607(d)(7)(B). If the procedural objection was impracticable to raise during the public comment (but within the time
specified for judicial review) and centrally relevant to the outcome of the rule, EPA must convene a proceeding for
reconsideration of the rule and provide the same procedural rights as would have been afforded had the information been
available at the time the rule was proposed. Id.
17 Id. at § 7607(d)(2)-(5)
18 Id. at § 7607(d)(3).
19 Id. at § 7607(d)(4).
20 Id. at § 7607(d)(3), (6)(B).
21 42 U.S.C. § 7607(d)(1)(K). EPA procedures used for the Phase 2 Rule were not judicially challenged. Other substantive
provisions related to tractor-trailers were challenged in court. Truck Trailer Mfr. Ass’n v. EPA, Nos. 16-1430 (D.C. Cir. Dec. 22,
2016).
22 This list of rulemaking actions is not a complete list of all rulemaking actions associated with the Phase 2 Rule. Documents
related to the Phase 2 Rule rulemaking are provided in the two dockets, Docket ID No. EPA–HQ–OAR–2014–0827 and
NHTSA–2014–0132, which can accessed at http://www.regulations.gov.
23 Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles—Phase 2;
Proposed Rule, 80 Fed. Reg. 40,138 (July 13, 2015) [hereinafter Proposed Phase 2 Rule].
24 Id.
25 See Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles—Phase 2;
Extension of Comment Period, 80 Fed. Reg. 53,756 (Sept. 8, 2015) (extending the comment period for the proposed rule from
September 17, 2015 to October 1, 2015).
26 See Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles—Phase 2;
Public Hearings, 80 Fed. Reg. 44,863 (July 28, 2015) (scheduling public hearings on August 2 and 18, 2015).
27 Proposed Phase 2 Rule, 80 Fed. Reg. 40,138, 40,329, 40,527-30 (July 13, 2015).
28 Phase 2 Rule, 81 Fed. Reg. 73,478, 73,526 n.130 (Oct. 25, 2016).
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 EPA posted supporting documents and public comments relating to its proposed glider
provisions to the docket.29
 EPA and NHTSA published the final Phase 2 Rule, which included a statement of basis
and responses to significant comments, in the Federal Register on October 25, 2016.30 In
the statement of basis, EPA responded to comments related to the glider provisions.31
CAA Section 307(d) requires EPA to follow the same procedures that it uses to promulgate rules to revise
them.32 Consequently, to remove the glider provisions from the Phase 2 Rule,33 EPA had to comply with
CAA Section 307(d) rulemaking procedures. For the Proposed Repeal, EPA took the following
rulemaking actions:34
 EPA used the existing Phase 2 Rule docket, Docket ID No. EPA–HQ–OAR–2014–0827,
which is accessible at www. regulations.gov, for the Proposed Repeal.35
 EPA published the Proposed Repeal in the Federal Register on November 16, 2017.36
 EPA provided a public comment period from November 16, 2017 to January 5, 2018 and
held a public hearing on the Proposed Repeal on December 4, 2017.37
 EPA provided a statement of basis and purpose of the Proposed Repeal, including legal
interpretations and other supporting information.38
 EPA posted public comments and supporting documents related to the Proposed Repeal
to the docket.39
 Among the public comments and supporting documents on the docket, EPA posted a
report issued by the EPA National Vehicle & Fuel Emissions Laboratory, entitled
“Chassis Dynamometer Testing of Two Recent Model Year Heavy-Duty On-Highway
Diesel Glider Vehicles,” dated November 20, 2017, which reported the results of
“emissions testing of a 2016 model year (MY) Peterbilt 389 sleeper cab tractor and a
2017 MY Peterbilt 579 sleeper cab tractor that were produced as glider vehicles.”40

29 See, e.g., Memorandum from David Choi, Office of Transp. & Air Quality, EPA, Emissions Modeling Files for Glider Analysis
(July 28, 2016), https://www.regulations.gov/document?D=EPA-HQ-OAR-2014-0827-2232 (posting emission modeling files
used to estimate impacts of gliders for the Phase 2 Rule).
30 Phase 2 Rule, 81 Fed. Reg. 73,478 (Oct. 25, 2016).
31 Id. at 73,526.
32 42 U.S.C. § 7607(d)(1)(K).
33 82 Fed. Reg. at 53,448-49. Because EPA issued the glider provisions pursuant to its authority under the CAA, NHSTA did not
participate in the rulemaking repealing those provisions.
34 This list of rulemaking actions is not a complete list of all rulemaking actions associated with the Proposed Repeal. Documents
related to the Proposed Repeal rulemaking are provided in Docket ID No. EPA–HQ–OAR–2014–0827, which can accessed at
http://www.regulations.gov.
35 Proposed Repeal, 82 Fed. Reg. 53,442 (Nov. 16, 2017).
36 Id.
37 Id.
38 Id. at 53,442-48.
39 See Public Submission folder in Docket ID No. EPA–HQ–OAR–2014–0827,
https://www.regulations.gov/docketBrowser?rpp=25&so=DESC&sb=commentDueDate&po=0&dct=PS&D=EPA-HQ-OAR-
2014-0827.
40 EPA NATIONAL VEHICLE & FUEL EMISSIONS LABORATORY, CHASSIS DYNAMOMETER TESTING OF TWO RECENT MODEL YEAR
HEAVY-DUTY ON-HIGHWAY DIESEL GLIDER VEHICLES (Nov. 20, 2017), https://www.regulations.gov/document?D=EPA-HQ-
OAR-2014-0827-2417.
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As of the date of this testimony, EPA has not issued a final rule on the Proposed Repeal.
Statutory and Executive Order Requirements for Rulemakings
Beyond the CAA Section 307(d) rulemaking requirements, EPA must comply with various statutes and
executive orders on rulemaking. This section highlights several rulemaking requirements that may apply
to the Phase 2 Rule and the Proposed Repeal, and identifies some of the actions that EPA took pursuant to
these requirements.41
Executive Order 12866
Executive Order (E.O.) 12866 provides the White House with an opportunity to review and clear
proposed regulatory actions of federal agencies.42 E.O. 12866 requires federal agencies to submit
“significant” regulatory actions at both the proposed and final rule stages to the Office of Information and
Regulatory Affairs (OIRA) in the Office of Management and Budget (OMB) for review.43 E.O. 12866
defines a “significant regulatory action,” in part, as having an “annual effect on the economy of $100
million or more or adversely affect[ing] in a material way the economy, a sector of the economy,
productivity, competition, jobs, the environment, public health or safety, or State, local, or tribal
governments or communities.”44 An agency is prohibited, “except to the extent required by law,” from
issuing a rule while OIRA review is pending.45 In addition, E.O. 12866 directs agencies to perform a cost-
benefit analysis for regulatory actions determined to be “economically significant” and “adopt a
regulation only upon a reasoned determination that the benefits” of the rule “justify its costs.”46 Failure of
an agency to comply with E.O. 12866 is not subject to judicial review.47
For the Phase 2 Rule, EPA and NHTSA determined that the rulemaking was an “economically
significant” regulatory action and submitted the rule on June 3, 2016 to OMB for review pursuant to E.O.
12866.48 The agencies prepared an analysis of the potential costs and benefits associated with this action
and posted the analysis, the “Regulatory Impact Analysis—Heavy-Duty GHG and Fuel Efficiency
Standards” to the Phase 2 Rule docket.49 OMB completed its review of the final Phase 2 Rule on August
16, 2016.50

41 This section does not address all executive orders or other statutory requirements related to the Phase 2 Rule or the Proposed
Repeal. For additional information regarding executive orders and statutes affecting the federal rulemaking process, see CRS
Report R41546, A Brief Overview of Rulemaking and Judicial Review, by Todd Garvey, CRS Report RL32240, The Federal
Rulemaking Process: An Overview, coordinated by Maeve P. Carey, and CRS Report RL32397, Federal Rulemaking: The Role
of the Office of Information and Regulatory Affairs, coordinated by Maeve P. Carey.
42 See, e.g., Exec. Order No. 12866, 58 Fed. Reg. 51735 (Oct. 4, 1993).
43 Exec. Order No. 12866 §§ 3, 6.
44 Id. at § 2(f). A “significant regulatory action” is also defined as any regulatory action that is likely to result in a rule that may
create a serious inconsistency or interfere with an action taken or planned by another agency; materially alter the budgetary
impact of entitlements, grants, user fees, or loan programs; or raise novel legal or policy issues. Id.
45 Id. at § 8.
46 Id. at § 1(b).
47 Id. at § 10.
48 Information regarding OMB’s review of the Phase 2 Rule is available on the OMB website at
https://www.reginfo.gov/public/do/eoDetails?rrid=126415 and https://www.reginfo.gov/public/do/eoDetails?rrid=125029.
49 EPA & NHTSA, GREENHOUSE GAS EMISSIONS AND FUEL EFFICIENCY STANDARDS FOR MEDIUM- AND HEAVY-DUTY ENGINES
AND VEHICLES - PHASE 2 REGULATORY IMPACT ANALYSIS (Aug. 16, 2016), https://nepis.epa.gov/Exe/ZyPDF.cgi/
P100P7NS.PDF?Dockey=P100P7NS.PDF.
50 Information regarding OMB’s review of the Phase 2 Rule is available on the OMB website at https://www.reginfo.gov/
public/do/eoDetails?rrid=126415 and https://www.reginfo.gov/public/do/eoDetails?rrid=125029.
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For the Proposed Repeal, EPA determined that the repeal was a “significant regulatory action” under E.O.
12866 and submitted a draft of the Proposed Repeal to OMB for review on October 20, 2017.51 OMB
comments on the draft Proposed Repeal and EPA’s responses to those comments are posted in the
docket.52 OMB concluded its review on the Proposed Repeal on November 8, 2017, determining that it
was “consistent” with OMB recommendations.53 Based on a search of the docket, EPA did not appear to
publish a regulatory impact analysis with the Proposed Repeal.54 According to OMB’s regulatory review
information, EPA has not submitted a final glider repeal rule to OMB for review.55
Rulemaking Requirements Concerning Small Businesses
Federal agencies must also review rulemaking impacts on small businesses. The Regulatory Flexibility
Act (RFA) generally requires an agency to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the APA or any other statute unless the agency
certifies that the rule will not have a significant economic impact on a substantial number of small
entities.56 EPA and NHSTA determined that the Phase 2 Rule could potentially have a significant
economic impact on small entities.57 Specifically, the agencies identified glider vehicle assemblers as one
of the four categories of directly regulated small businesses that could be impacted.58
In addition to preparing a regulatory flexibility analysis, Section 609(b) of the RFA, as amended by the
Small Business Regulatory Enforcement Fairness Act (SBREFA), directs specific federal agencies,
including EPA, to conduct additional outreach to small entities that may be affected by a rule.59 Pursuant
to the SBREFA requirements, EPA convened a Small Business Advocacy Review Panel (Panel) to obtain
advice and recommendations from representatives of the small entities that potentially would be subject to
the Phase 2 Rule’s requirements.60 The preamble to the final Phase 2 Rule summarizes the Panel’s
recommendations and EPA’s changes to the Phase 2 Rule based on those recommendations.61

51 The status of the OMB review of the Proposed Repeal is available on the OMB website at https://www.reginfo.gov/public/do/
eoDetails?rrid=127648.
52 See, e.g., Email from Chad Whiteman, Senior Policy Analyst, OIRA, OMB to Benjamin Hengst, EPA (Oct. 24, 2017, 10:16
EDT), https://www.regulations.gov/document?D=EPA-HQ-OAR-2014-0827-2406.
53 Information on the OMB review of the Proposed Repeal is available on the OMB website at https://www.reginfo.gov/public/
do/eoDetails?rrid=127648.
54 Several news outlets reported that OMB requested that EPA perform a regulatory impact analysis for the final repeal. See, e.g.,
Dawn Reeves, EPA’s Planned Glider Truck Repeal Appears ‘Stuck’ Absent Political Pressure, INSIDE EPA (June 12, 2018),
https://insideepa.com/daily-news/epas-planned-glider-truck-repeal-appears-stuck-absent-political-pressure; Michael Bastasch,
SOURCES: EPA’s Effort To Save An Industry From Obama Regulations Is Being Held Up By Bureaucratic Delays, THE DAILY
CALLER (May 2, 2018), http://dailycaller.com/2018/05/02/epa-obama-era-regulation-repeal-glider-kits/. Based on publicly
available information, it does not appear that OMB has issued a public request regarding a regulatory impact analysis for the
Proposed Repeal.
55 The status of the OMB review of the Proposed Repeal is available on the OMB website at https://www.reginfo.gov/public/do/
eoDetails?rrid=127648.
56 See generally 5 U.S.C. §§ 601–612. For additional information on RFA, see CRS Report RL32240, The Federal Rulemaking
Process: An Overview, coordinated by Maeve P. Carey.
57 Phase 2 Rule, 81 Fed. Reg. 73,478, 73,526 (Oct. 25, 2016).
58 Id. The agencies explained that “vehicles produced by installing a used engine into a new chassis are commonly referred to as
‘gliders,’ ‘glider kits,’ or ‘glider vehicles.’” Id.
59 5 U.S.C. § 609(b), (d).
60 Id.
61 See id. (discussing certain regulatory flexibilities included in the final rule to minimize impacts to glider vehicle assemblers
and other small entities). See also SMALL BUSINESS ADVOCACY REVIEW PANEL ON EPA’S PLANNED PROPOSED RULE GREENHOUSE
GAS EMISSIONS AND FUEL EFFICIENCY STANDARDS FOR MEDIUM- AND HEAVY-DUTY ENGINES AND VEHICLES: PHASE 2 (Jan. 15,
2015), https://www.epa.gov/sites/production/files/2015-08/documents/report-sbarpanel_heavydutyengines2.pdf (detailing the
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In the Proposed Glider Repeal, the EPA Administrator certified that repeal would not have “a significant
economic impact on a substantial number of small entities” under the SBREFA.62 An agency may certify
that a rule will not have a significant economic impact on a substantial number of small entities if the rule
relieves a regulatory burden, has no net burden, or otherwise has a positive economic effect on the small
entities subject to the rule.63 Because small glider manufacturers would be able to produce glider vehicles
without meeting Phase 2 Rule motor vehicle emission standards, EPA concluded that the Proposed Repeal
would have no adverse regulatory impact for any directly regulated small entities.64
EPA Science Advisory Board Review
As part of the rulemaking process, EPA must provide notice of its proposed rules to its Science Advisory
Board (SAB).65 Congress directed EPA to establish the SAB to provide scientific advice to EPA and
specific congressional committees.66 The Environmental Research, Development, and Demonstration
Authorization Act of 1978 requires EPA to provide the SAB with its proposed regulations and supporting
scientific and technical information.67 While the SAB may advise the EPA Administrator on the adequacy
of the scientific and technical basis of the proposed action, it may not impose requirements on EPA.68
EPA provided the proposed Phase 2 Rule to the SAB on June 11, 2014.69 According to EPA, the SAB
discussed its working group’s recommendations on the proposed rule and agreed that no further SAB
consideration of the rule or its supporting science was merited.70
For the Proposed Repeal, the SAB decided to review the “adequacy of the supporting science” of the
proposal on June 21, 2018.71 The SAB noted key questions that merit review, including:
 “What are the emission rates of glider trucks for GHGs, nitrogen oxides, particulate
matter, and other pollutants of concern? What are the key sources of variability and
uncertainty in these rates?
 How do these emission rates compare to those of conventionally manufactured trucks that
are: (a) new; and (b) used at prices comparable to the purchase price of a ‘new’ glider
truck? What are key sources of variability and uncertainty in the comparisons?
 What is the range of possible market penetration of glider trucks into the on road heavy
duty vehicle stock? What is the effect of glider truck penetration into the market on fleet

review and recommendations of Small Business Advocacy Review Panel on the Phase 2 Rule).
62 Proposed Repeal, 82 Fed. Reg. 53,442, 53,448 (Nov. 16, 2017).
63 5 U.S.C. § 605(b).
64 82 Fed. Reg. at 53,448.
65 42 U.S.C. § 4365(c).
66 See id. § 4365(a) (requiring EPA to establish a “Science Advisory Board which shall provide such scientific advice as may be
requested by the Administrator, the Committee on Environment and Public Works of the United States Senate, or the Committee
on Science, Space, and Technology, on Energy and Commerce, or on Public Works and Transportation of the House of
Representatives”).
67 Id.; Environmental Research, Development, and Demonstration Authorization Act of 1978, Pub. L. 95-155, 91 Stat. 1257
(1978).
68 42 U.S.C. § 4365(c).
69 Phase 2 Rule, 81 Fed. Reg. 73,478, 73,969 (Oct. 25, 2016).
70 Id.
71 Letter from Michael Honeycutt, Chair, Science Advisory Board to E. Scott Pruitt, Admin., EPA (June 21, 2018),
https://yosemite.epa.gov/sab/sabproduct.nsf/0/E7CB10891C8CAD8F852582B3006EFAF7/$File/EPA-SAB-18-002+.pdf.
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level emissions at national, regional, and local scales in the near-term and long-term,
compared to the status quo?
 What are implications of changes in emissions in the near-term and long-term from the
penetration of glider trucks regarding GHG emissions, air quality, air quality attainment,
and human health, compared to the status quo?”72
The SAB indicated that the review may begin with existing EPA documents, such as EPA’s “November
20, 2017 test report in which emissions of gliders and conventionally manufactured trucks were
compared, and focus on areas where updates are needed.”73 The SAB did not indicate a timeline for its
review.
Conclusion
CAA Section 307(d) provides detailed procedures that EPA must follow to promulgate, revise, or repeal
certain CAA regulations. These procedures apply to the Phase 2 Rule and the Proposed Glider Repeal. In
addition to CAA rulemaking requirements, EPA must also comply with various statutes and executive
orders relating to rulemaking.

72 Id. at 3.
73 Id.; see also EPA NATIONAL VEHICLE & FUEL EMISSIONS LABORATORY, CHASSIS DYNAMOMETER TESTING OF TWO RECENT
MODEL YEAR HEAVY-DUTY ON-HIGHWAY DIESEL GLIDER VEHICLES (Nov. 20, 2017), https://www.regulations.gov/
document?D=EPA-HQ-OAR-2014-0827-2417.
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Appendix. Biography of Linda Tsang
Linda Tsang is a Legislative Attorney in the American Law Division of the Congressional Research
Service (CRS). She works on legal issues related to environmental, energy, climate change,
administrative, and constitutional law. Before joining CRS in 2016, she served as the Director of Climate
and Air Quality at the American Forest & Paper Association from 2013-2016; an attorney at Beveridge &
Diamond, P.C. from 2008-2013, focused on statutory and regulatory issues under the Clean Air Act; and
as an environmental engineer at the U.S. Environmental Protection Agency, Region 1 from 2000-2005,
managing Safe Drinking Water Act regulations. She previously served as a project manager for the
Environmental Defense Fund’s corporate partnership program from 1997-2000. She earned her J.D. from
Vermont Law School and her B.S. in Environmental Engineering from the Massachusetts Institute of
Technology. She is a member of the District of Columbia bar.

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