FOR PUBLICATION

UNITED STATES COURT OF APPEALS

FOR THE NINTH CIRCUIT

INTERNATIONAL BROTHERHOOD OF 

TEAMSTERS, LOCAL 2785;

EVERARDO LUNA,

Petitioners,

v.

FEDERAL MOTOR CARRIER SAFETY 

ADMINISTRATION,

Respondent,

WILLIAM B. TRESCOTT,

Intervenor.

No. 18-73488

FMCSA No.

2018-0304
2 IBT V. FMCSA

INTERNATIONAL BROTHERHOOD OF 

TEAMSTERS; INTERNATIONAL 

BROTHERHOOD OF TEAMSTERS,

LOCAL 848; CHARLES “LUCKY”

LEPINS; JULIO GARCIA; JESUS 

MALDONADO; JOSE PAZ,

Petitioners,

v.

FEDERAL MOTOR CARRIER SAFETY 

ADMINISTRATION; U.S. DEPARTMENT 

OF TRANSPORTATION,

Respondents.

No. 19-70323

FMCSA No.

2018-0304

LABOR COMMISSIONER FOR THE 

STATE OF CALIFORNIA,

Petitioner,

v.

FEDERAL MOTOR CARRIER SAFETY 

ADMINISTRATION,

Respondent.

No. 19-70329

FMCSA No.

2018-0304
IBT V. FMCSA 3

DUY NAM LY; PHILLIP MORGAN,

Petitioners,

v.

FEDERAL MOTOR CARRIER SAFETY 

ADMINISTRATION; U.S. DEPARTMENT 

OF TRANSPORTATION,

Respondents.

No. 19-70413

FMCSA No.

2018-0304

OPINION

On Petition for Review of an Order of the

Federal Motor Carrier Safety Administration

Argued and Submitted November 16, 2020

San Francisco, California

Filed January 15, 2021

Before: Jacqueline H. Nguyen, Andrew D. Hurwitz, and

Daniel A. Bress, Circuit Judges.

Opinion by Judge Bress
4 IBT V. FMCSA

SUMMARY*

Federal Motor Carrier Safety Administration

The panel denied petitions for review of the Federal 

Motor Carrier Safety Administration (“FMCSA”)’s 

determination that federal law preempted California’s meal 

and rest break rules (the “MRB rules”), as applied to drivers 

of property-carrying commercial motor vehicles who are 

subject to the FMCSA’s own rest break regulations.

The FMCSA only has the authority to review for 

preemption State laws and regulations “on commercial 

motor vehicle safety.” 49 U.S.C. § 31141(c).

The panel held the agency’s interpretation of the statute 

and the phrase “on commercial motor vehicle safety” 

merited deference under Chevron, U.S.A., Inc. v. Natural 

Resources Defense Council, Inc., 467 U.S. 837 (1984), 

where the FMCSA acknowledged that it was departing from 

its 2008 interpretation of § 31141 and provided a reasoned 

analysis why it was doing so. The panel rejected petitioners’ 

arguments that Chevron deference was inapplicable. 

Turning to Chevron’s two-step framework, the panel 

held that even assuming petitioners identified a potential 

ambiguity in the statute, the agency’s reading was a 

permissible one. The FMCSA reasonably determined that a 

State law “on commercial motor vehicle safety” was one that 

“imposes requirements in an area of regulations that is 

* This summary constitutes no part of the opinion of the court. It 

has been prepared by court staff for the convenience of the reader.
IBT V. FMCSA 5

already addressed by a regulation promulgated under 

[section] 31136.” 83 Fed. Reg. at 67,473 (Dec. 28, 2018). 

The FMCSA’s 2018 preemption decision also reasonably 

relied on Congress’s stated interest in uniformity of 

regulation. The fact that California regulated meal and rest 

breaks in a variety of industries did not compel the 

conclusion that the MRB rules were not “on commercial 

motor vehicle safety.” Finally, the panel held that the 

decision in Dilts v. Penske Logistics, LLC, 769 F.3d 637 (9th 

Cir. 2014), did not foreclose the FMCSA’s interpretation. 

The panel concluded that the FMCSA permissibly 

determined that California’s MRB rules were State 

regulations “on commercial motor vehicle safety,” so that 

they were within the agency’s preemption authority.

The panel held that the FMCSA’s determination that the 

MRB rules were “additional to or more stringent than” the 

federal regulation was reasonable and supported. 49 U.S.C. 

§ 31141(c)(1). The FMCSA reached this conclusion 

because California required more breaks, more often and 

with less flexibility as to timing. The panel rejected 

petitioners’ challenges to this determination.

The panel held that the FMCSA did not act arbitrarily or 

capriciously in finding that enforcement of the MRB rules 

“would cause an unreasonable burden on interstate 

commerce.” 49 U.S.C. § 31141(c)(4)(C). Petitioners’ 

counterarguments did not show that the agency acted 

arbitrarily or capriciously.

COUNSEL

Deepak Gupta (argued), Jonathan E. Taylor, Gregory A. 

Beck, and Neil K. Sawhney, Gupta Wessler PLLC,
6 IBT V. FMCSA

Washington, D.C.; Stan Saltzman, Marlin & Saltzman, 

Agoura Hills, California; for Petitioners Duy Nam Ly and

Phillip Morgan.

Miles E. Locker (argued), Attorney, Division of Labor 

Standards Enforcement, Department of Industrial Relations,

San Francisco, California; Xavier Becerra, Attorney 

General; Satoshi Yanai, Supervising Deputy Attorney 

General; Marisa Hernàndez-Stern, Deputy Attorney 

General; Office of the Attorney General, Los Angeles, 

California; for Petitioner Labor Commissioner for the State 

of California.

Julie Gutman Dickinson, Ira L. Gottlieb, Kiel B. Ireland, and 

Hector De Haro, Bush Gottlieb, Glendale, California, for 

Petitioner International Brotherhood of Teamsters, 

International Brotherhood of Teamsters, Local 848; Charles 

“Lucky” Lepins; Julio Garcia; Jesus Maldonado; and Jose 

Paz.

David A. Rosenfeld and Caitlin Gray, Weinberg Roger & 

Rosenfeld, Alameda, California, for Petitioners International 

Brotherhood of Teamsters, Local 2785, and Everardo Luna.

William B. Trescott, Bay City, Texas, pro se Intervenor.

Jennifer L. Utrecht (argued) and Mark B. Stern, Appellate 

Staff; Joseph H. Hunt, Assistant Attorney General; Civil 

Division, United States Department of Justice, Washington, 

D.C.; Steven G. Bradbury, General Counsel; Paul M. Geier, 

Assistant General Counsel; Charles E. Enloe, Trial Attorney;

United States Department of Transportation, Washington, 

D.C.; Alan Hanson, Chief Counsel; Charles J. Fromm, 

Deputy Chief Counsel; Sue Lawless, Assistant Chief 

Counsel; Tracy M. White, Attorney-Advisor; Federal Motor 
IBT V. FMCSA 7

Carrier Safety Administration, Washington, D.C.; for 

Respondents.

Adam Berger, Schroeter Goldmark & Bender, Seattle, 

Washington; Daniel F. Johnson, Breskin Johnson & 

Townsend PLLC, Seattle, Washington; Aaron Kaufmann, 

Leonard Carder LLP, Oakland, California; Ashley Westby, 

National Employment Lawyers Association/The Employee 

Rights Advocacy Institute for Law & Policy, Washington, 

D.C.; for Amici Curiae State and National Employment 

Lawyers Associations.

Robert W. Ferguson, Attorney General; Anastasia 

Sandstrom, Seattle, Washington; for Amicus Curiae 

Washington State.

David R. Krause-Leemon, Beaudoin & Krause-Leemon 

LLP, Sherman Oaks, California; Aaron Parker, PODS 

Enterprises LLC, Clearwater, Florida; Carl Bentzel, Bentzel 

Strategies LLC, Bowie, Maryland; Bob Fatovic, Ryder 

Systems Inc., Miami, Florida; for Amici Curiae Specialized 

Carriers & Rigging Association, PODS Enterprises LLC, 

Ryder System Inc., and Western States Trucking 

Association.

Richard Pianka, ATA Litigation Center, Arlington, Virginia, 

for Amici Curiae American Trucking Associations Inc., 

California Trucking Association, Washington Trucking 

Associations, Intermodal Association of North America, and 

American Moving and Storage Association.

Spencer C. Skeen, Tim L. Johnson, and Nikolas T. 

Djordjevski, Ogletree Deakins Nash Smoak & Stewart P.C., 

San Diego, California, for Amicus Curiae National Armored 

Car Association.
8 IBT V. FMCSA

Adam Smedstad, Scopelitis Garvin Light Hanson & Feary 

P.C., Seattle, Washington; James H. Hanson, Scopelitis 

Garvin Light Hanson & Feary P.C., Indianapolis, Indiana; 

for Amici Curiae CRST Expedited Inc., FAF Inc., Heartland 

Express Inc. of Iowa, John Christner Trucking LLC, Penske 

Logistics LLC, Penske Truck Leasing Co. L.P., Rail 

Delivery Services Inc., and U.S. Xpress Inc.

Malcolm A. Heinicke and Joseph D. Lee, Munger Tolles & 

Olson LLP, Los Angeles, California; Daryl Joseffer and Tara 

S. Morrissey, U.S. Chamber Litigation Center, Washington, 

D.C.; for Amicus Curiae Chamber of Commerce of the 

United States.

OPINION

BRESS, Circuit Judge:

The Federal Motor Carrier Safety Administration 

(FMCSA), an agency within the Department of 

Transportation, is tasked with issuing regulations on 

commercial motor vehicle safety. The FMCSA also has 

authority to determine that state laws on commercial motor 

vehicle safety are preempted, based on criteria Congress has 

specified. In this case, the FMCSA determined that federal 

law preempts California’s meal and rest break rules, known 

as the “MRB rules,” as applied to drivers of propertycarrying commercial motor vehicles who are subject to the 

FMCSA’s own rest break regulations. Compared to federal 

safety regulations, California’s MRB rules generally require 

that employers allow commercial truck drivers to take more 

rest breaks, at greater frequency, and with less flexibility as 

to when breaks occur.
IBT V. FMCSA 9

California’s Labor Commissioner, certain labor 

organizations, and others now petition for review of the 

FMCSA’s preemption determination. Because the agency’s 

decision reflects a permissible interpretation of the Motor 

Carrier Safety Act of 1984 and is not arbitrary or capricious, 

we deny the petitions for review.

I

A

Congress passed the Motor Carrier Safety Act of 1984 

“to promote the safe operation of commercial motor 

vehicles, [and] to minimize dangers to the health of operators 

of commercial motor vehicles and other employees.” Pub. 

L. No. 98-554, tit. II, 98 Stat. 2832, § 202 (originally 

codified at 49 U.S.C. app. 2501). Under the Act, the 

Secretary of Transportation “shall prescribe regulations on 

commercial motor vehicle safety” that contain “minimum 

safety standards for commercial motor vehicles.” 49 U.S.C. 

§ 31136(a). Among other things, federal regulations “shall 

ensure” that “the responsibilities imposed on operators of 

commercial motor vehicles do not impair their ability to 

operate the vehicles safely.” Id. § 31136(a)(2).

The Act also gives the Secretary the express power to 

preempt State law: “A State may not enforce a State law or 

regulation on commercial motor vehicle safety that the 

Secretary of Transportation decides under this section may 

not be enforced.” Id. § 31141(a). To carry out this duty, 

“[t]he Secretary shall review State laws and regulations on 

commercial motor vehicle safety.” Id. § 31141(c)(1).

The statute provides a multi-step process that the 

Secretary must follow in conducting this review. The 

Secretary must first compare the State law or regulation at 
10 IBT V. FMCSA

issue to a regulation prescribed by the Secretary under 

49 U.S.C. § 31136 and decide whether the State law “has the 

same effect as,” “is less stringent than,” or “is additional to 

or more stringent than” the federal regulation. Id.

§ 31141(c)(1). If the Secretary decides a State law or 

regulation has the “same effect” as the federal regulation, 

“the State law or regulation may be enforced.” Id.

§ 31141(c)(2). If a State law is less stringent than the federal 

regulation, “the State law or regulation may not be 

enforced.” Id. § 31141(c)(3).

If the Secretary decides that a State law is “additional to 

or more stringent” than a federal regulation, another decision 

tree applies. At that point, the State law “may be enforced 

unless the Secretary also decides that — (A) the State law or 

regulation has no safety benefit; (B) the State law or 

regulation is incompatible with the regulation prescribed by 

the Secretary; or (C) enforcement of the State law or 

regulation would cause an unreasonable burden on interstate 

commerce.” Id. § 31141(c)(4). When considering the 

burden on interstate commerce, “the Secretary may consider 

the effect on interstate commerce of implementation of that 

law or regulation with the implementation of all similar laws 

and regulations of other States.” Id. § 31141(c)(5).

The Secretary has delegated its rulemaking and 

preemption authority to the Administrator of the FMCSA. 

49 C.F.R. § 1.87(f).

B

Federal regulations impose limits on the driving time for 

commercial motor vehicle drivers. These are known as the 

hours-of-service regulations. Under federal law, a propertycarrying commercial motor vehicle driver “may not drive 

without first taking 10 consecutive hours off duty,” 
IBT V. FMCSA 11

49 C.F.R. § 395.3(a)(1) (2018),1 and “may not drive after the 

end of the 14-consecutive-hour period without first taking 

10 consecutive hours off duty,” id. § 395.3(a)(2). Within 

that 14-hour period, a driver may only drive 11 hours. Id.

§ 395.3(a)(3)(i). Federal regulations also impose weekly 

driving limits. Id. § 395.3(b) (prohibiting a driver from 

being on duty for more than 60 or 70 hours in seven or eight 

consecutive days, respectively).

In 2011, the FMCSA revised the federal hours-of-service 

regulations and adopted the rules on breaks for truck drivers 

that form the basis for the FMCSA’s 2018 decision to 

preempt California’s MRB rules. See Hours of Service of 

Drivers, 76 Fed. Reg. 81,134, 81,188 (Dec. 27, 2011) 

(codified at 49 C.F.R. § 395.3). Except for certain “shorthaul” drivers, a property-carrying commercial motor vehicle 

driver working more than eight hours must take at least one 

30-minute break during the first eight hours, although the 

driver has flexibility as to when the break occurs. 49 C.F.R.

§ 395.3(a)(3)(ii). That 30-minute break can be spent “offduty” or in a “sleeper berth.” Id.2 The 2011 break 

requirement supplemented longstanding federal regulations 

1 The FMCSA revised 49 C.F.R. § 395.3 in 2019, and again in 2020. 

See Hours of Service of Drivers—Restart Provision, 84 Fed. Reg. 48,077 

(Sept. 12, 2019); Hours of Service of Drivers, 85 Fed. Reg. 33,396 (June 

1, 2020). In this opinion, we cite the 2018 version of the regulation, the 

rule in place at the time of the FMCSA’s preemption determination. But 

the 2019 and 2020 changes do not affect the preemption analysis.

2 Under the 2020 revisions to the regulation, the 30-minute break 

requirement now applies “only when a driver has driven (instead of 

having been on-duty) for a period of 8 hours without at least a 30-minute 

non-driving interruption.” 85 Fed. Reg. at 33,396. Additionally, a driver 

can now satisfy the break requirement with “any non-driving period of 

30 minutes, i.e., on-duty, off-duty, or sleeper berth time.” Id.; see also 

49 C.F.R. § 395.3(a)(3)(ii) (2020).
12 IBT V. FMCSA

prohibiting a driver from operating a commercial motor 

vehicle if too fatigued or unable to safely drive. 49 C.F.R. 

§ 392.3. Employers may not coerce drivers to violate this 

rule or the hours-of-service rules. Id. § 390.6. The federal 

regulations do not require other breaks.

The California rules are different. California’s rules are 

contained in wage orders issued by the State’s Industrial 

Welfare Commission (IWC), which is tasked with protecting 

workers’ “health, safety, and welfare.” Martinez v. Combs, 

231 P.3d 259, 271 (Cal. 2010) (quoting Cal. Lab. Code 

§ 1173). To that end, the IWC has issued eighteen wage 

orders, mostly on an industry-wide or occupation-wide 

basis. Cal. Code Regs. tit. 8, §§ 11010–11170; Martinez, 

231 P.3d at 272–73. These orders cover all employees in 

California unless they are specifically exempted. See 

Brinker Rest. Corp. v. Superior Court, 273 P.3d 513, 521 n.1 

(Cal. 2012); Martinez, 231 P.3d at 273 & n.24; Cal. Code 

Regs. tit. 8, § 11170(1)(A). Seventeen IWC orders contain 

meal period requirements and sixteen contain rest period 

requirements. See Cal. Code Regs. tit. 8, §§ 11010–11170.

Wage Order 9-2001 applies to “all persons employed in 

the transportation industry,” which necessarily includes 

property-carrying commercial truck drivers. Id. § 11090(1). 

Under the order, an employee working more than five hours 

a day is entitled to a “meal period of not less than 

30 minutes.” Id. § 11090(11)(A). If, however, “a work 

period of not more than six (6) hours will complete the day’s 

work the meal period may be waived by mutual consent of 

the employer and the employee.” Id. An employee is 

entitled to “a second meal period of not less than 30 minutes” 

when working more than 10 hours in a day. Id.

§ 11090(11)(B). The employee and employer can only agree 

to waive the second meal break if the employee does not 
IBT V. FMCSA 13

work more than 12 hours in a day and did not waive the first 

break. Id.; see also Cal. Lab. Code § 512(a) (imposing these 

same meal break rules for all employees unless otherwise 

exempted).

The California Wage Order also entitles transportation 

industry employees to 10-minute rest breaks for every four 

hours worked throughout the day. Cal. Code Regs. tit. 8, 

§ 11090(12)(A). These rest breaks “insofar as practicable 

shall be in the middle of each work period.” Id. California’s 

Labor Commissioner can grant an employer an exemption 

from the rest break requirement if it “would not materially 

affect the welfare or comfort of employees and would work 

an undue hardship on the employer.” Id. § 11090(17).

Under California law, an employer who fails to provide 

a meal or rest break must “pay the employee one additional 

hour of pay at the employee’s regular rate of compensation 

for each workday that the meal or rest or recovery period is 

not provided.” Cal. Lab. Code § 226.7(c); see also Cal. 

Code Regs. tit. 8, § 11090(11)(D), (12)(B). Employees can 

bring a claim seeking such payment under California’s 

Private Attorneys General Act of 2004 (PAGA), Cal. Lab. 

Code §§ 2698–2699.6. See Cal. Lab. Code § 2699.3. 

Employees can also seek civil penalties on behalf of 

themselves and other employees; the State receives a portion 

of any award. Id. § 2699.

C

In response to a petition from a group of motor carriers, 

the FMCSA in 2008 declined to preempt California’s MRB 

rules as applied to commercial motor vehicle drivers subject 

to FMCSA’s hours-of-service regulations. See Petition for 

Preemption of California Regulations on Meal Breaks and 

Rest Breaks for Commercial Motor Vehicle Drivers; 
14 IBT V. FMCSA

Rejection for Failure to Meet Threshold Requirement, 

73 Fed. Reg. 79,204, 79,204–06 (Dec. 24, 2008). The 

FMCSA ruled that it lacked the authority to preempt because 

the MRB rules applied far beyond the trucking industry and 

were thus not “on commercial motor vehicle safety.” Id. at 

79,205–06.

In 2018, two industry groups, the American Trucking 

Association and the Specialized Carriers and Rigging 

Association, asked the FMCSA to revisit its 2008 “no 

preemption” determination. After seeking public comment 

on the preemption question, see California Meal and Rest 

Break Rules, 83 Fed. Reg. 50,142 (Oct. 4, 2018), the 

FMCSA declared California’s MRB rules preempted as 

applied to operators of property-carrying motor vehicles 

subject to the federal hours-of-service regulations.3 See

California’s Meal and Rest Break Rules for Commercial 

Motor Vehicle Drivers, 83 Fed. Reg. 67,470 (Dec. 28, 2018). 

The FMCSA determined that the MRB rules were in fact “on 

commercial motor vehicle safety” and could not be enforced 

under 49 U.S.C. § 31141(c). 83 Fed. Reg. 67,472–80.

California’s Labor Commissioner and three other sets of 

petitioners (labor organizations and affected individuals) 

filed timely petitions for review. See 49 U.S.C. 

§ 31141(f)(1). We have jurisdiction to review these 

consolidated petitions under 49 U.S.C. § 31141(f)(2). 

Although the petitioners place different weight on different 

points, for ease of reference we generally refer to them 

collectively as “petitioners.”

3 The preemption determination does not apply to drivers of 

passenger-carrying commercial motor vehicles. 83 Fed. Reg. at 67,470 

n.1.
IBT V. FMCSA 15

II

We review the FMCSA’s preemption determination 

under the Administrative Procedure Act (APA) framework 

for judicial review. The question is therefore whether the 

FMCSA’s preemption decision was “arbitrary, capricious, 

an abuse of discretion, or otherwise not in accordance with 

law,” or “in excess of statutory jurisdiction, authority, or 

limitations, or short of statutory right.” 5 U.S.C. 

§ 706(2)(A), (C). Petitioners argue both that the FMCSA 

lacks the statutory authority to preempt the MRB rules, and, 

to the extent it could do so, that the agency’s preemption 

decision was arbitrary and capricious. Based on our careful 

review of the FMCSA’s decision and after applying the 

deference that is due the agency, we conclude that 

petitioners’ challenges lack merit.

A

The FMCSA only has authority to review for preemption 

State laws and regulations “on commercial motor vehicle 

safety.” 49 U.S.C. § 31141(c). The initial question we must 

address is the meaning of this phrase.

In its preemption determination, the FMCSA concluded 

that a State law or regulation is “on commercial motor 

vehicle safety” if it “imposes requirements in an area of 

regulation that is already addressed by a regulation 

promulgated under [section] 31136.’” 83 Fed. Reg. 

at 67,473. Under this interpretation, the MRB rules are “on 

commercial motor vehicle safety” because federal 

regulations promulgated under section 31136 govern breaks 

for commercial motor vehicle drivers. Id.

The petitioners argue that laws “on commercial motor 

vehicle safety” are those specifically directed at commercial 
16 IBT V. FMCSA

motor vehicle safety. They maintain that the MRB rules do 

not qualify because they apply to many workers other than 

truck drivers and regulate employee health and wellbeing 

generally. The FMCSA counters that at the very least, the 

statute is ambiguous and that the agency’s interpretation 

merits deference under Chevron, U.S.A., Inc. v. Natural 

Resources Defense Council, Inc., 467 U.S. 837 (1984).

We reject, at the outset, petitioners’ arguments that 

Chevron deference is inapplicable. An agency usually 

receives Chevron deference in its construction of an 

ambiguous statute that it administers. See FDA v. Brown & 

Williamson Tobacco Corp., 529 U.S. 120, 159 (2000). 

Relying mainly on Wyeth v. Levine, 555 U.S. 555 (2009), 

petitioners argue that the FMCSA is entitled to no deference 

when it comes to preemption determinations. But Wyeth 

does not apply here.

In Wyeth, the Supreme Court declined to defer to the 

FDA’s preemption decision because “Congress ha[d] not 

authorized the FDA to pre-empt state law directly.” 

555 U.S. at 576. That is not the case here because Congress 

in 49 U.S.C. § 31141(a) expressly gave the agency authority 

to preempt “State law[s] and regulation[s] on commercial 

motor vehicle safety” when the agency “decides” certain 

criteria are met. Because the agency’s power to preempt is 

part of the overall power Congress expressly delegated to it, 

Wyeth does not diminish the deference due the agency’s 

interpretation of a statute it is charged with administering. 

See Wyeth, 555 U.S. at 576–77 (explaining that “agencies 

have no special authority to pronounce on pre-emption 

absent delegation by Congress” (emphasis added)); id.

at 576 & n.9 (contrasting the FDA’s lack of express 

preemptive power with statutes that gave agencies the power 

to preempt state laws); Durnford v. MusclePharm Corp., 
IBT V. FMCSA 17

907 F.3d 595, 601 n.6 (9th Cir. 2018) (agencies do not 

receive Chevron deference in interpreting a preemption 

provision “[i]n the absence of a specific congressional 

delegation of authority to interpret the scope of 

preemption”); see also City of Arlington v. FCC, 569 U.S. 

290, 297 (2013) (rejecting “[t]he misconception that there 

are, for Chevron purposes, separate ‘jurisdictional’ 

questions on which no deference is due”).

The petitioners also argue that the FMCSA should 

receive no deference because the 2018 preemption 

determination reversed the agency’s 2008 determination that 

it lacked the power to preempt California’s MRB rules. But 

we have explained that “[a]n initial agency interpretation is 

not instantly carved in stone” because “the agency . . . must 

consider varying interpretations and the wisdom of its policy 

on a continuing basis.” Resident Councils of Wash. v. 

Leavitt, 500 F.3d 1025, 1036 (9th Cir. 2007) (quoting 

Chevron, 467 U.S. at 863–64). As a result, “an agency’s 

‘new’ position is entitled to deference ‘so long as the agency 

acknowledges and explains the departure from its prior 

views.’” Id. (quoting Seldovia Native Ass’n v. Lujan, 

904 F.2d 1335, 1346 (9th Cir. 1990)); see also Nat’l Cable 

& Telecomms. Ass’n v. Brand X Internet Servs., 545 U.S. 

967, 981, 1001 (2005) (explaining that an agency “is free 

within the limits of reasoned interpretation to change course 

if it adequately justifies the change” and that “[a]gency 

inconsistency is not a basis for declining to analyze the 

agency’s interpretation under the Chevron framework”); 

Rust v. Sullivan, 500 U.S. 173, 186 (1991) (explaining that 

the Supreme Court “has rejected the argument that an 

agency’s interpretation is not entitled to deference because it 

represents a sharp break with prior interpretations of the 

statute in question” (quotations omitted)).
18 IBT V. FMCSA

These principles of administrative law recognize that 

democratic processes, improved understandings, or changed 

circumstances may prompt agencies to alter their own views 

over time. Petitioners have not articulated how a rule that 

precludes deference anytime an agency changes its mind 

could be justified under the basic delegation theory 

animating Chevron. See Smiley v. Citibank (S.D.), N.A., 

517 U.S. 735, 742 (1996) (“[C]hange is not invalidating, 

since the whole point of Chevron is to leave the discretion 

provided by the ambiguities of a statute with the 

implementing agency.”). Nor have petitioners explained 

why the agency would be required to hew to a statutory 

interpretation that it no longer believes is correct. See Good 

Samaritan Hosp. v. Shalala, 508 U.S. 402, 417 (1993) (“The 

Secretary is not estopped from changing a view she believes 

to have been grounded upon a mistaken legal 

interpretation.”).

In this case, the FMCSA acknowledged that it was 

departing from its 2008 interpretation of § 31141 and 

provided a reasoned analysis for why it was doing so. See 

Resident Councils of Wash., 500 F.3d at 1036. The FMCSA 

explained that its earlier 2008 interpretation “was 

unnecessarily restrictive” because “[t]here is nothing in the 

statutory language or legislative history that supports” its 

prior decision limiting the preemption provision to State 

laws specifically directed at commercial motor vehicle 

safety. 83 Fed. Reg. at 67,473. The FMCSA also explained 

how circumstances had changed since 2008, because the 

agency in 2011 had enacted specific break regulations for 

commercial motor vehicle drivers. Id. at 67,474. These are 

the types of explanations that an agency can offer to ensure 

that Chevron deference is applied to its new interpretation. 

See, e.g., Brand X Internet Servs., 545 U.S. at 981, 1001.
IBT V. FMCSA 19

Turning to Chevron’s familiar two-step framework, we 

first ask whether the statutory text is unambiguous. “If the 

intent of Congress is clear, that is the end of the matter; for 

the court, as well as the agency, must give effect to the 

unambiguously expressed intent of Congress.” Chevron, 

467 U.S. at 842–43. But if the statute is ambiguous, “the 

question for the court is whether the agency’s answer is 

based on a permissible construction of the statute.” Id.

at 843. Here, even assuming petitioners have identified a 

potential ambiguity in the statute, we hold that the agency’s

reading is a permissible one.

Once again, the operative statutory language is the 

phrase “on commercial motor vehicle safety.” 49 U.S.C. 

§ 31141(a), (c). The FMCSA reasonably determined that a 

State law “on commercial motor vehicle safety” is one that 

“imposes requirements in an area of regulation that is 

already addressed by a regulation promulgated under 

[section] 31136.” 83 Fed. Reg. at 67,473. Section 31136(a) 

allows the FMCSA to issue regulations “on commercial 

motor vehicle safety.” Given the parallel language used in 

sections 31136(a) and 31141(a), when the agency has issued 

a regulation under its section 31136(a) authority, it is 

reasonable for the agency to interpret section 31141(a) 

analogously to allow preemption of State regulation in that 

same area.

The FMCSA’s 2018 preemption decision also 

reasonably relied on Congress’s stated interest in uniformity 

of regulation. See 83 Fed. Reg. at 67,473 (explaining that 

the 1984 Act “clearly expresses Congress’s intent that ‘there 

be as much uniformity as practicable whenever a Federal 

standard and a State requirement cover the same subject 

matter’”) (quoting S. Rep. No. 98-424, at 14 (1984)); see 

also Motor Carrier Safety Act of 1984 § 203(2), 98 Stat. at 
20 IBT V. FMCSA

2832 (originally codified at 49 U.S.C. app. 2502) (finding 

safety benefits from “improved, more uniform commercial 

motor vehicle safety measures”). The FMCSA could 

reasonably conclude that a State law disrupts regulatory 

uniformity even when the law was not specifically directed 

at commercial vehicle motor safety because a broader State 

law could still cover the same subject matter as FMCSA 

regulations.

Petitioners argue that the word “on” must be read 

narrowly, so that the FMCSA can only preempt State laws 

“specifically directed” at commercial motor vehicle safety. 

Petitioners thus maintain that the MRB rules cannot be “on 

commercial motor vehicle safety” because they also regulate 

working conditions and ensure employee health and 

wellbeing. But that the MRB rules may serve these other 

purposes cannot insulate them from preemption when, as 

here, the rules also promote commercial motor vehicle 

safety. See, e.g., 83 Fed. Reg. at 67,474 (“[I]n her comments 

on this petition, the California Labor Commissioner 

acknowledged that the MRB Rules improve driver and 

public safety stating, ‘It is beyond doubt that California’s 

meal and rest period requirements promote driver and public 

safety.’”).

Nor does the fact that California regulates meal and rest 

breaks in a variety of industries compel the conclusion that 

the MRB rules are not “on commercial motor vehicle 

safety.” If California had specifically regulated the meal and 

break times of commercial motor vehicle drivers and no one 

else, that would of course be a regulation “on” commercial 

motor vehicle safety. But those drivers remain subject to the 

same regulations when California also applies its break laws 

to other types of workers. Because California’s MRB rules 

apply to drivers whose breaks are the subject of federal 
IBT V. FMCSA 21

regulation “on commercial motor vehicle safety,” the MRB 

rules can be described as laws “on” commercial motor 

vehicle safety as well. Or at least the FMCSA could 

permissibly conclude that was so. See Brand X Internet 

Servs., 545 U.S. at 989 (“[W]here a statute’s plain terms 

admit of two or more reasonable ordinary usages, the 

[agency’s] choice of one of them is entitled to deference.”).

Petitioners nevertheless suggest that the word “on” is 

inherently narrow and at least narrower than the phrase 

“pertaining to,” which was the Motor Carrier Safety Act’s 

original language. See §§ 206–08, 98 Stat. at 2832–37. But 

we conclude that the statute does not unambiguously require 

petitioners’ reading. See Chevron, 467 U.S. at 842–43. The 

word “on” is not inevitably as narrow as petitioners claim. 

See On, prep., Oxford English Dictionary (2d ed. 1989) 

(“22. a. In regard to, in reference to, with respect to, as to.”), 

https://www.oed.com/oed2/00163302.

The history of the 1994 revision also counsels against 

petitioners’ more confined reading. Congress changed 

“pertaining to” to “on” or “related to” in several provisions 

in a 1994 recodification. See Pub. L. No. 103-272, sec. 1(d), 

§ 31141(a)–(c), 108 Stat. 745, 1008–09 (1994). But 

Congress made clear that these changes “may not be 

construed as making a substantive change in the laws 

replaced.” Id. sec. 6(a), 108 Stat. at 1378. And “no changes 

in law or policy are to be presumed from changes of 

language” in a statutory recodification “unless an intent to 

make such changes is clearly expressed.” Finley v. United 

States, 490 U.S. 545, 554 (1989) (quotations omitted), 

superseded by statute on other grounds, as recognized in 

Exxon Mobil Corp. v. Allapattah Servs., Inc., 545 U.S. 546 

(2005). Given the circumstances of the 1994 amendments 

and the ambiguity that otherwise exists between “on” and 
22 IBT V. FMCSA

“pertaining to,” petitioners have not shown that the 1994 

recodification compels their preferred interpretation of the 

statutory text.

Given the language in the statute, the FMCSA could 

reasonably reject petitioners’ charge that its reading of “on” 

would give the FMCSA unlimited power to preempt any law 

that merely “affects” commercial motor vehicle safety in 

some tangential way. 83 Fed. Reg. at 67,473. Petitioners 

argue, for example, that the agency’s reading of “on” would 

allow the FMCSA to preempt state laws allowing for 

pregnancy disability leave or leave to serve on a jury. These 

concerns, however, are overstated. The agency has not 

ushered in an era of unbounded FMCSA authority through 

its interpretation of the preposition “on.”

The agency’s interpretation is more circumscribed than 

petitioners suggest: MRB rules are regulations “on 

commercial motor vehicle safety” because they are within 

FMCSA’s specific regulatory domain and the subject of 

existing federal regulation in the very same area. The 

agency has issued particularized regulations that govern 

break times for drivers of property-carrying commercial 

motor vehicles, and there is no dispute those are regulations 

“on commercial motor vehicle safety.” There is thus no 

reason to believe that the agency’s reading of “on” would 

allow it to issue regulations and preempt State laws in areas 

outside its delegated authority. Indeed, the agency expressly 

disclaims that power. See 83 Fed. Reg. at 67,473 (“This 

determination does not rely on a broad interpretation of 

section 31141 as applicable to any State law that ‘affects’ 

[commercial motor vehicle] safety.”). The FMCSA’s 

interpretation of “on” does not lead to such far-reaching 

authority, either. While petitioners stress that the MRB rules 

apply across many industries, the FMCSA has not 
IBT V. FMCSA 23

preempted those state laws generally, but only as applied to 

drivers of property-carrying commercial motor vehicles 

subject to federal regulation.

Nor is the FMCSA’s interpretation rendered 

unreasonable in the face of a claimed presumption against 

preemption. The Supreme Court has instructed that the 

“inquiry into the scope of a [federal] statute’s pre-emptive 

effect is guided by the rule that the purpose of Congress is 

the ultimate touchstone in every pre-emption case.” Hughes 

v. Talen Energy Mktg., LLC, 136 S. Ct. 1288, 1297 (2016) 

(alteration in original) (quoting Altria Grp., Inc. v. Good,

555 U.S. 70, 76 (2008)). When, as here, “the statute 

‘contains an express pre-emption clause,’ we do not invoke 

any presumption against pre-emption but instead ‘focus on 

the plain wording of the clause, which necessarily contains 

the best evidence of Congress’ pre-emptive intent.’” Puerto 

Rico v. Franklin Cal. Tax-Free Tr., 136 S. Ct. 1938, 1946 

(2016) (quoting Chamber of Com. of U.S. v. Whiting, 

563 U.S. 582, 594 (2011)); see also Atay v. County of Maui, 

842 F.3d 688, 699 (9th Cir. 2016) (same).

Petitioners maintain that the MRB rules are part of 

California’s traditional “police power” and that a 

presumption against preemption should therefore still apply. 

But a state’s traditional regulation in an area is not, standing 

alone, sufficient to defeat preemption in the face of an 

express preemption clause. As we have explained in the 

context of the MRB rules in particular, “[w]age and hour 

laws constitute areas of traditional state regulation, although 

that fact alone does not ‘immunize’ state employment laws 

from preemption if Congress in fact contemplated their 

preemption.” Dilts v. Penske Logistics, LLC, 769 F.3d 637, 

643 (9th Cir. 2014). In this case, the issue is not the general 

preemptive force of 49 U.S.C. § 31141(a), but the agency’s 
24 IBT V. FMCSA

decision to exercise its express statutory preemptive powers. 

Petitioners have not explained how a case-dispositive 

presumption against preemption could override an agency’s 

textually permissible interpretation of an express preemption 

provision it is charged with administering.

Finally, our decision in Dilts, 769 F.3d 637, does not 

foreclose the FMCSA’s interpretation. Dilts concerned the 

scope of an express preemption provision in the Federal 

Aviation Administration Authorization Act of 1994 

(FAAAA) that prohibits state laws that are “related to” 

prices, routes, or services of commercial motor vehicles. 

49 U.S.C. § 14501(c)(1). Although Dilts held that this 

provision did not preempt California’s MRB rules, see 

769 F.3d at 647–50, we did not interpret the preemption 

provision at issue here. Dilts therefore did not address 

whether the MRB rules could fall within section 31141’s 

scope. Indeed, the plaintiffs in Dilts worked exclusively in 

California as short-haul drivers and were thus not even 

“covered by . . . federal hours-of-service regulations.” Id. at 

648 n.2.

Similarly, although the United States filed an amicus 

brief in Dilts adhering to its 2008 determination that the 

MRB rules were not preempted under 49 U.S.C. § 31141, 

the government also noted that the agency had “broad 

discretion” in interpreting that statute. See Brief for the 

United States as Amicus Curiae, Dilts, 769 F.3d 637 (No. 

12-55705), 2014 WL 809150, at *26–27. The Dilts amicus 

brief did not maintain that the FMCSA’s 2008 interpretation 

was unambiguously compelled. Instead, it insisted the 

interpretation deserved Chevron deference. Id. Thus, 

neither our decision in Dilts nor the United States’ position 

in that case creates an impediment to the FMCSA’s current 

preemption determination.
IBT V. FMCSA 25

We therefore hold that the FMCSA permissibly 

determined that California’s MRB rules were State 

regulations “on commercial motor vehicle safety,” so that 

they were within the agency’s preemption authority. 

49 U.S.C. § 31141(a).

B

The FMCSA next was required to determine whether the 

MRB rules were “less stringent than,” had the “same effect” 

as, or were “additional to or more stringent than” the federal 

regulations. 49 U.S.C. § 31141(c)(1). The FMCSA found 

the third option correct. See 83 Fed. Reg. at 67,474–75. 

Petitioners argue this determination was arbitrary and 

capricious. Our review is “highly deferential, presuming the 

agency action to be valid and affirming the agency action if 

a reasonable basis exists for its decision.” Nat’l Mining 

Ass’n v. Zinke, 877 F.3d 845, 866 (9th Cir. 2017) (quotations 

omitted). We hold that the FMCSA’s determination on this 

point was reasonable and supported.

The FMCSA concluded that the MRB rules were 

“additional to or more stringent than” federal regulations 

because California requires more breaks, more often, and 

with less flexibility as to timing. 83 Fed. Reg. at 67,474–75. 

Federal regulations generally require that a driver working 

more than eight hours must take a 30-minute break during 

the first eight hours, while providing flexibility as to when 

the break takes place. See 49 C.F.R. § 395.3(a)(3)(ii). By 

contrast, California generally requires a 30-minute meal 

break within the first five hours of work, another 30-minute 

meal break over the next five hours, and additional 10-

minute rest periods every four hours. Cal. Lab. Code 

§ 512(a); Cal. Code Regs. tit. 8, § 11090(11)(A)–(B), (12). 

The 10-minute rest breaks “insofar as practicable shall be in 

the middle of each work period.” Cal. Code Regs. tit. 8, 
26 IBT V. FMCSA

§ 11090(12). The differences between California and 

federal law thus support the agency’s determination that the 

MRB rules impose requirements “additional to or more 

stringent than” federal law. 49 U.S.C. § 31141(c)(1)(C). 

Indeed, California acknowledges that its rules result in 

“more time off[] during the workday.”

Petitioners make two main arguments in response. First, 

petitioners argue that California law has some flexibility in 

its design. For example, employees may agree to waive 

certain meal breaks. Cal. Lab. Code § 512(a); Cal. Code 

Regs. tit. 8, § 11090(11)(A)–(B). Employers can also seek 

exemptions from the rest break requirements from 

California’s Labor Commissioner. Cal. Code Regs. tit. 8, 

§ 11090(17). And the California Supreme Court has noted 

that rest breaks may take place at a time other than the 

middle of the work period “where practical considerations 

render [that] infeasible.” Brinker Rest. Corp., 273 P.3d at 

530.

Nonetheless, as compared to the federal regulations, the 

California rules still require more breaks, with greater 

frequency, and with lesser ability to adjust the break time. 

See 83 Fed. Reg. at 67,474–75. The degree of flexibility that 

California law affords thus does not undermine the agency’s 

conclusion that California’s MRB rules are still “additional 

to or more stringent than” federal requirements.

Second, petitioners point out that, rather than provide the 

meal or rest breaks, an employer can “pay the employee one 

additional hour of pay at the employee’s regular rate of 

compensation for each workday that the meal or rest or 

recovery period is not provided.” Cal. Lab. Code § 226.7(c); 

Cal. Code Regs. tit. 8, § 11090(11)(D), (12)(B). Petitioners 

thus argue that California law does not really impose 

additional or more stringent requirements than federal law 
IBT V. FMCSA 27

because an employer may simply pay to avoid complying 

with the MRB rules. It is not apparent how petitioners’ 

characterization changes the analysis because employers 

under California law would still either need to provide 

breaks or make break-related payments that federal law does 

not require. See 83 Fed. Reg. at 67,475 n.9. Regardless, the 

agency’s decision was consistent with California law.

As the FMCSA noted, California treats its MRB rules as 

requirements, providing that employers “shall not” deny the 

required breaks while creating a monetary remedy for their 

“fail[ure]” to do so. Cal. Lab. Code § 226.7(b), (c); see also 

83 Fed. Reg. at 67,475. As California acknowledged at oral 

argument, an employer’s failure to provide the required 

breaks is also a misdemeanor under California law. See Cal. 

Lab. Code § 1199; Ward v. United Airlines, Inc., 466 P.3d 

309, 315 (Cal. 2020) (noting that California Labor Code 

§ 1199(c) “mak[es] violation of an IWC wage order a 

misdemeanor”). Although California represents that these 

misdemeanor prosecutions have rarely, if ever, occurred, the 

apparent availability of this remedy underscores that failure 

to comply with the break requirements is a legal violation.

And that is how the California Supreme Court has treated 

them, in a series of decisions on which the FMCSA relied. 

In Kirby v. Immoos Fire Protection, Inc., 274 P.3d 1160 

(Cal. 2012), that court explained that “Section 226.7 is not

aimed at protecting or providing employees’ wages. Instead, 

the statute is primarily concerned with ensuring the health 

and welfare of employees by requiring that employers 

provide meal and rest periods as mandated by the IWC.” Id.

at 1167. As a result, “the legal violation is nonprovision of 

meal or rest breaks.” Id. at 1168. The court was clear: 

“section 226.7 does not give employers a lawful choice 

between providing either meal and rest breaks or an 
28 IBT V. FMCSA

additional hour of pay” because “[t]he failure to provide 

required meal and rest breaks is what triggers a violation of 

section 226.7.” Id. at 1168.

Petitioners cite Augustus v. ABM Security Services, Inc., 

385 P.3d 823 (Cal. 2016), and Murphy v. Kenneth Cole 

Productions, Inc., 155 P.3d 284 (Cal. 2007). But neither 

case suggests that the FMCSA’s decision was arbitrary or 

capricious. In Augustus, the California Supreme Court noted 

that if employers “find it especially burdensome to relieve 

their employees of all duties during rest periods,” they have 

the “option[]” to “pay the premium pay set forth in . . .

section 226.7.” 385 P.3d at 834. But Augustus cautioned 

that the payment option does not “impl[y] that employers 

may pervasively interrupt scheduled rest periods, for any 

conceivable reason—or no reason at all.” Id. at 834 n.14. 

And Augustus clarified that payments instead of breaks 

“should be the exception rather than the rule, to be used 

when the employer—because of irregular or unexpected 

circumstances such as emergencies—has to summon an 

employee back to work.” Id.

Murphy likewise does not undermine the FMCSA’s 

reasoning. In Murphy, a pre-Kirby decision, the California 

Supreme Court held that claims for additional wages for 

violating the MRB rules were governed by the statute of 

limitations period for wage claims, not the shorter 

limitations period for penalties. 155 P.3d at 297. But this 

does not change the overall characterization of the MRB 

rules as requiring meal and rest breaks, so that failing to 

provide them is a “legal violation.” Kirby, 274 P.3d at 1167. 

As Kirby explained in reconciling Murphy, “[t]o say that a 

section 226.7 remedy is a wage . . . is not to say that the legal 

violation triggering the remedy is nonpayment of wages.” 

Id. at 1168. The FMCSA in its preemption determination 
IBT V. FMCSA 29

addressed petitioners’ reliance on Murphy and explained 

how (per the California Supreme Court) Murphy was 

consistent with Kirby. 83 Fed. Reg. at 67,475. That 

reasoning was not arbitrary or capricious.

In short, the FMCSA faithfully interpreted California 

law in finding that California’s rules were “additional to or 

more stringent than” federal regulations. 49 U.S.C. 

§ 31141(c)(1)(C).

C

At this point in its analysis, the FMCSA could preempt 

the MRB rules as applied to drivers of property-carrying

commercial vehicles if it decided that the State law (1) “has 

no safety benefit” or (2) “is incompatible with the regulation 

prescribed by the Secretary,” or (3) that “enforcement of the 

State law or regulation would cause an unreasonable burden 

on interstate commerce.” Id. § 31141(c)(4)(A)–(C). The 

agency found all three criteria met. 83 Fed. Reg. at 67,475–

80. Petitioners argue that each finding was arbitrary and 

capricious.

Any one of the three enumerated grounds is enough to 

justify a preemption determination. See 49 U.S.C. 

§ 31141(c)(4). We do not address the agency’s first two 

findings because we hold that the agency did not act 

arbitrarily or capriciously in finding that enforcement of the 

MRB rules “would cause an unreasonable burden on 

interstate commerce.” Id. § 31141(c)(4)(C).

In reaching that conclusion, the FMCSA found that the 

MRB rules “impose significant and substantial costs 

stemming from decreased productivity and administrative 

burden.” 83 Fed. Reg. at 67,479. The administrative record 

supports these conclusions. As to decreased productivity, 
30 IBT V. FMCSA

the FMCSA could reasonably determine that the MRB rules 

cause an unreasonable burden on interstate commerce 

because they “decrease each driver’s available duty hours.” 

Id. The FMCSA examined the federal and California 

schemes and explained how the MRB rules required drivers 

to spend more time on breaks. See, e.g., id. at 67,478 & n.12.

The FMCSA also relied on public comments 

demonstrating how the MRB rules’ more demanding break 

requirements affected productivity and, in turn, the efficient 

operation of an interstate delivery system. Id. at 67,479. For 

example, FedEx Corporation explained that “to take off-duty 

breaks, the ‘drivers must slow down, exit the roadway, find 

a safe and suitable location to park and secure their vehicles, 

and then exit the vehicle’ and that the company has to build 

additional time, up to 90 minutes, into the drivers’ routes.” 

Id. Other public comments and studies showed the financial 

impact of the lost productivity and its effect on distribution 

systems. Id. These costs were exacerbated by “California’s 

share of the national economy” and the fact that 

“California’s three major container ports carry 

approximately 50% of the nation’s total container cargo 

volume.” Id. at 67,478–79. The evidence in the 

administrative record thus supports the FMCSA’s 

determination that lost driving time leads to lost productivity 

and burdens interstate commerce.

The FMCSA also reasonably relied on “the 

administrative burden associated with complying with the 

MRB rules.” Id. at 67,479. This burden included higher 

compliance costs, increases in administrative and operations 

headcount, changes to delivery and logistics programs, 

revision of routes, and changes to compensation plans. Id. 

The agency also properly considered “the effect on interstate 

commerce of implementation of [the MRB rules] with the 
IBT V. FMCSA 31

implementation of all similar laws and regulations of other 

States.” 49 U.S.C. § 31141(c)(5). The FMCSA noted that 

twenty States had their own meal and rest break rules, and 

this “patchwork of requirements,” increased the burden on 

interstate commerce. 83 Fed. Reg. at 67,479–80. Among 

other things, companies had to create “elaborate schedules” 

to navigate the different State requirements. Id. Taken 

together, all these findings support the agency’s 

determination that the MRB rules “cause an unreasonable 

burden on interstate commerce.” 49 U.S.C. 31141(c)(4)(C).

Petitioners’ counterarguments do not show that the 

agency acted arbitrarily or capriciously. Contrary to 

petitioners’ assertion, the agency did weigh costs and 

benefits in concluding that the MRB rules posed an 

unreasonable burden on interstate commerce. The FMCSA 

“acknowledge[d] that the State of California has a legitimate 

interest in promoting driver and public safety.” 83 Fed. Reg. 

at 67,479. It explained, however, that “the Federal [hour of 

service] rules and the provisions in the [federal motor carrier 

safety regulations] relating to fatigued driving and employer 

coercion serve to promote that interest.” Id. Properly 

understood, the FMCSA simply determined that, in its view, 

federal regulations adequately and more appropriately 

balanced the competing interests between safety and 

economic burden. Id.; see also id. at 67,476 (explaining how 

federal regulations “balanc[e] the need to prevent excessive 

hours of continuous driving with a driver’s need for 

flexibility in scheduling a rest break”). Petitioners have not 

shown that conclusion was unreasonable. Nor was the

FMCSA required to conduct its preemption assessment in a 

manner identical to a dormant Commerce Clause undue 
32 IBT V. FMCSA

burden analysis. See Pike v. Bruce Church, Inc., 397 U.S. 

137 (1970).4

We likewise reject petitioners’ assertion that the 

FMCSA’s cumulative burden analysis was flawed because 

industry must already comply with varying State laws in 

other areas, such as environmental and anti-discrimination 

laws. In petitioners’ view, the “marginal cost” of complying 

with “one more set” of varying State laws is “negligible.” 

But this argument does not show that the FMCSA’s 

preemption determination, made under a statute which gives 

it the express authority to do so, was arbitrary or capricious.

As the FMCSA noted, many of the state laws that 

petitioners cite “are well outside the scope of the Agency’s 

statutory authority.” 83 Fed. Reg. at 67,480. And because 

motor carriers will always be subject to varying state laws to 

some extent, petitioners’ argument, if accepted, would 

significantly limit the FMCSA’s ability to determine that 

divergent state laws “on commercial motor vehicle safety” 

pose an unreasonable burden on interstate commerce. 

Nothing in the statute suggests the agency’s preemptive 

powers are so constrained. Indeed, the statute is directly to 

the contrary: it allows the agency to consider the cumulative 

“effect on interstate commerce of implementation” of the 

state law in question “with the implementation of all similar 

laws and regulations of other States.” 49 U.S.C. 

§ 31141(c)(5). In any event, the FMCSA here had more than 

4 One petitioner argues that the FMCSA did not consider the nonsafety benefits of the MRB rules, such as workplace dignity or higher 

wages for drivers. But there is no indication that the statute requires the 

FMCSA to consider such factors, which are likely outside its expertise.
IBT V. FMCSA 33

sufficient basis to conclude that the MRB rules burden 

interstate commerce in a way that is not merely “negligible.”

Finally, petitioners err in claiming that two of our 

decisions invalidate the FMCSA’s preemption 

determination. They do not. In Sullivan v. Oracle Corp., 

662 F.3d 1265 (9th Cir. 2011), we held that California’s 

overtime rules did not violate the dormant Commerce Clause 

because “California applies its Labor Code equally to work 

performed in California, whether that work is performed by 

California residents or by out-of-state residents.” Id.

at 1271. That holding has no apparent relevance to this case.

Nor did we resolve the cumulative burden question as a 

matter of law when we stated in Dilts that “applying 

California’s meal and rest break laws to motor carriers 

would not contribute to an impermissible ‘patchwork’ of 

state-specific laws, defeating Congress’ deregulatory 

objectives.” 769 F.3d at 647. As we have noted, Dilts did 

not concern the statute at issue here. And the above 

statement turned on Dilts’ determination that the meal and 

rest break laws were not “related to” prices, routes, and 

services under the FAAAA’s preemption provision. Id. 

Like Sullivan, Dilts does not foreclose the agency’s 

preemption determination.5

5 IBT Local 2785 briefly argues that the FMCSA also flouted 

numerous statutes and executive orders, but fails to explain how the 

agency violated these various laws. We do not address these arguments, 

as IBT Local 2785 “failed to argue” these issues “with any specificity in 

[its] briefing.” Carmickle v. Comm’r, Soc. Sec. Admin., 533 F.3d 1155, 

1161 n.2 (9th Cir. 2008).

Petitioners Ly and Morgan also ask us to review an FMCSA legal 

memorandum issued months after the preemption determination. In that 
34 IBT V. FMCSA

* * *

We appreciate petitioners’ arguments in favor of their 

preferred approach to governance in the area of commercial 

motor vehicle safety. But in this case, petitioners’ objections 

are ultimately as much to the statute Congress drafted as they 

are to the FMCSA’s preemption determination. Under the 

principles that govern our evaluation of the agency’s 

decision, the petitions for review must be

DENIED.

memorandum, an FMCSA lawyer opined that the agency’s preemption 

decision applied retroactively. This determination was not part of the 

preemption determination on review, see 49 U.S.C. § 31141(f), nor was 

it final agency action, see 5 U.S.C. § 704. We thus do not consider the 

retroactivity issue.

Finally, pro se intervenor William Trescott asks the court to vacate 

various federal regulations. These issues are also not part of the 

FMCSA’s preemption determination and are thus not before us. 

49 U.S.C. § 31141(f). Trescott’s motion to expedite the appeal is 

DENIED as moot.