(Slip Opinion)              OCTOBER TERM, 2012                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

 AMERICAN TRUCKING ASSOCIATIONS, INC. v. CITY
      OF LOS ANGELES, CALIFORNIA, ET AL.

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE NINTH CIRCUIT

       No. 11–798.      Argued April 16, 2013—Decided June 13, 2013
The Port of Los Angeles, a division of the City of Los Angeles, is run by
  a Board of Harbor Commissioners pursuant to a municipal ordinance
  known as a tariff. The Port leases marine terminal facilities to oper-
  ators that load cargo onto and unload it from docking ships. Federal-
  ly licensed short-haul trucks, called “drayage trucks,” assist in those
  operations by moving cargo into and out of the Port. In 2007, in re-
  sponse to community concerns over the impact of a proposed port ex-
  pansion on traffic, the environment, and safety, the Board imple-
  mented a Clean Truck Program. As part of that program, the Board
  devised a standard-form “concession agreement” to govern the rela-
  tionship between the Port and drayage companies. The agreement
  requires a company to affix a placard on each truck with a phone
  number for reporting concerns, and to submit a plan listing off-street
  parking locations for each truck. Other requirements relate to a
  company’s financial capacity, its maintenance of trucks, and its em-
  ployment of drivers. The concession agreement sets out penalties for
  violations, including possible suspension or revocation of the right to
  provide drayage services. The Board also amended the Port’s tariff to
  ensure that every drayage company would enter into the agreement.
  The amended tariff makes it a misdemeanor, punishable by fine or
  imprisonment, for a terminal operator to grant access to an unregis-
  tered drayage truck.
     Petitioner American Trucking Associations, Inc. (ATA), whose
  members include many of the drayage companies at the Port, sued
  the Port and City, seeking an injunction against the concession
  agreement’s requirements. ATA principally contended that the re-
  quirements are expressly preempted by the Federal Aviation Admin-
2       AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                                  Syllabus

    istration Authorization Act of 1994 (FAAAA), see 49 U. S. C.
    §14501(c)(1). ATA also argued that even if the requirements are val-
    id, Castle v. Hayes Freight Lines, Inc., 348 U. S. 61, prevents the Port
    from enforcing the requirements by withdrawing a defaulting compa-
    ny’s right to operate at the Port. The District Court held that neither
    §14501(c)(1) nor Castle prevented the Port from proceeding with its
    program. The Ninth Circuit mainly affirmed, finding only the driver-
    employment provision preempted and rejecting petitioner’s Castle
    claim.
Held:
    1. The FAAAA expressly preempts the concession agreement’s
 placard and parking requirements. Section 14501(c)(1) preempts a
 state “law, regulation, or other provision having the force and effect
 of law related to a price, route, or service of any motor carrier . . .
 with respect to the transportation of property.”               49 U. S. C.
 §14501(c)(1). Because the parties agree that the Port’s placard and
 parking requirements relate to a motor carrier’s price, route, or ser-
 vice with respect to transporting property, the only disputed question
 is whether those requirements “hav[e] the force and effect of law.”
 Section 14501(c)(1) draws a line between a government’s exercise of
 regulatory authority and its own contract-based participation in a
 market. The statute’s “force and effect of law” language excludes
 from the clause’s scope contractual arrangements made by a State
 when it acts as a market participant, not as a regulator. See, e.g.,
 American Airlines, Inc. v. Wolens, 513 U. S. 219, 229. But here, the
 Port exercised classic regulatory authority in imposing the placard
 and parking requirements.          It forced terminal operators—and
 through them, trucking companies—to alter their conduct by imple-
 menting a criminal prohibition punishable by imprisonment. That
 counts as action “having the force and effect of law” if anything does.
    The Port’s primary argument to the contrary focuses on motives ra-
 ther than means. But the Port’s proprietary intentions do not con-
 trol. When the government employs a coercive mechanism, available
 to no private party, it acts with the force and effect of law, whether or
 not it does so to turn a profit. Only if it forgoes the (distinctively gov-
 ernmental) exercise of legal authority may it escape §14501(c)(1)’s
 preemptive scope. That the criminal sanctions fall on terminal oper-
 ators, not directly on the trucking companies, also makes no differ-
 ence. See, e.g., Rowe v. New Hampshire Motor Transp. Assn., 552
 U. S. 364, 371–373. Pp. 6−10.
    2. This Court declines to decide in the case’s present, pre-
 enforcement posture whether Castle limits the way the Port can en-
 force the financial-capacity and truck-maintenance requirements up-
 held by the Ninth Circuit. Castle rebuffed a State’s attempt to bar a
                     Cite as: 569 U. S. ____ (2013)                   3

                               Syllabus

  federally licensed motor carrier from its highways for past infringe-
  ments of state safety regulations. But Castle does not prevent a
  State from taking off the road a vehicle that is contemporaneously
  out of compliance with such regulations. And at this juncture, there
  is no basis for finding that the Port will actually use the concession
  agreement’s penalty provision as Castle proscribes. Pp. 10−12.
660 F. 3d 384, reversed in part and remanded.

   KAGAN, J., delivered the opinion for a unanimous Court. THOMAS, J.,
filed a concurring opinion.
                       Cite as: 569 U. S. ____ (2013)                              1

                            Opinion of the Court

    NOTICE: This opinion is subject to formal revision before publication in the
    preliminary print of the United States Reports. Readers are requested to
    notify the Reporter of Decisions, Supreme Court of the United States, Wash-
    ington, D. C. 20543, of any typographical or other formal errors, in order
    that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                  _________________

                                  No. 11–798
                                  _________________


    AMERICAN TRUCKING ASSOCIATIONS, INC.,

      PETITIONER v. CITY OF LOS ANGELES, 

              CALIFORNIA, ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE NINTH CIRCUIT

                                [June 13, 2013] 


   JUSTICE KAGAN delivered the opinion of the Court.
   In this case, we consider whether federal law preempts
certain provisions of an agreement that trucking compa-
nies must sign before they can transport cargo at the Port
of Los Angeles. We hold that the Federal Aviation Admin-
istration Authorization Act of 1994 (FAAAA) expressly
preempts two of the contract’s provisions, which require
such a company to develop an off-street parking plan and
display designated placards on its vehicles. We decline to
decide in the case’s present, pre-enforcement posture
whether, under Castle v. Hayes Freight Lines, Inc., 348
U. S. 61 (1954), federal law governing licenses for inter-
state motor carriers prevents the Port from using the
agreement’s penalty clause to punish violations of other,
non-preempted provisions.
                              I

                              A

 The Port of Los Angeles, a division of the City of Los
Angeles, is the largest port in the country. The Port owns
marine terminal facilities, which it leases to “terminal
2    AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                     Opinion of the Court

operators” (such as shipping lines and stevedoring compa-
nies) that load cargo onto and unload it from docking
ships. Short-haul trucks, called “drayage trucks,” move
the cargo into and out of the Port. The trucking compa-
nies providing those drayage services are all federally
licensed motor carriers. Before the events giving rise
to this case, they contracted with terminal operators to
transport cargo, but did not enter into agreements with
the Port itself.
   The City’s Board of Harbor Commissioners runs the
Port pursuant to a municipal ordinance known as a tariff,
which sets out various regulations and charges. In the
late 1990’s, the Board decided to enlarge the Port’s facili-
ties to accommodate more ships. Neighborhood and envi-
ronmental groups objected to the proposed expansion,
arguing that it would increase congestion and air pollution
and decrease safety in the surrounding area. A lawsuit
they brought, and another they threatened, stymied the
Board’s development project for almost 10 years.
   To address the community’s concerns, the Board imple-
mented a Clean Truck Program beginning in 2007.
Among other actions, the Board devised a standard-form
“concession agreement” to govern the relationship between
the Port and any trucking company seeking to operate on
the premises. Under that contract, a company may
transport cargo at the Port in exchange for complying with
various requirements. The two directly at issue here
compel the company to (1) affix a placard on each truck
with a phone number for reporting environmental or
safety concerns (You’ve seen the type: “How am I driving?
213–867–5309”) and (2) submit a plan listing off-street
parking locations for each truck when not in service.
Three other provisions in the agreement, formerly dis-
puted in this litigation, relate to the company’s financial
capacity, its maintenance of trucks, and its employment of
drivers.
                 Cite as: 569 U. S. ____ (2013)            3

                     Opinion of the Court

  The Board then amended the Port’s tariff to ensure that
every company providing drayage services at the facility
would enter into the concession agreement. The mecha-
nism the Board employed is a criminal prohibition on
terminal operators. The amended tariff provides that “no
Terminal Operator shall permit access into any Terminal
in the Port of Los Angeles to any Drayage Truck unless
such Drayage Truck is registered under a Concession
[Agreement].” App. 105. A violation of that provision—
which occurs “each and every day” a terminal operator
provides access to an unregistered truck—is a misde-
meanor. Id., at 86. It is punishable by a fine of up to $500
or a prison sentence of up to six months. Id., at 85–86.
  The concession agreement itself spells out penalties for
any signatory trucking company that violates its require-
ments. When a company commits a “Minor Default,” the
Port may issue a warning letter or order the company to
undertake “corrective action,” complete a “course of . . .
training,” or pay the costs of the Port’s investigation. Id.,
at 81–82. When a company commits a “Major Default,”
the Port may also suspend or revoke the company’s right
to provide drayage services at the Port. Id., at 82. The
agreement, however, does not specify which breaches of
the contract qualify as “Major,” rather than “Minor.” And
the parties agree that the Port has never suspended or
revoked a trucking company’s license to operate at the
Port for a prior violation of one of the contract provisions
involved in this case. See Tr. of Oral Arg. 42–43, 49–51.
                            B
  Petitioner American Trucking Associations, Inc. (ATA),
is a national trade association representing the trucking
industry, including drayage companies that operate at the
Port. ATA filed suit against the Port and City, seeking an
injunction against the five provisions of the concession
agreement discussed above. The complaint principally
4     AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                          Opinion of the Court

contended that §14501(c)(1) of the FAAAA expressly
preempts those requirements. That statutory section
states:
     “[A] State [or local government] may not enact or en-
     force a law, regulation, or other provision having the
     force and effect of law related to a price, route, or ser-
     vice of any motor carrier . . . with respect to the trans-
     portation of property.” 49 U. S. C. §14501(c)(1).1
ATA also offered a back-up argument: Even if the re-
quirements are valid, ATA claimed, the Port may not
enforce them by withdrawing a defaulting company’s right
to operate at the Port. That argument rested on Castle v.
Hayes Freight Lines, Inc., 348 U. S. 61 (1954), which held
that Illinois could not bar a federally licensed motor car-
rier from its highways for prior violations of state safety
regulations. We reasoned in Castle that the State’s action
conflicted with federal law providing for certification of
motor carriers; and ATA argued here that a similar con-
flict would inhere in applying the concession agreement to
suspend or revoke a trucking company’s privileges. Fol-
lowing a bench trial, the District Court held that neither
§14501(c)(1) nor Castle prevents the Port from proceeding
with any part of its Clean Truck Program.
   The Court of Appeals for the Ninth Circuit mainly af-
firmed. Most important for our purposes, the court held
that §14501(c)(1) does not preempt the agreement’s plac-
——————
  1 ATA also contended that a separate provision, 49 U. S. C. §14506(a),

preempts the agreement’s placard requirement. That section bars state
and local governments from enacting or enforcing “any law, rule,
regulation[,] standard, or other provision having the force and effect of
law” that obligates a motor carrier to display any form of identification
other than those the Secretary of Transportation has required. Ibid.
The just-quoted language is the only part of §14506(a) disputed here,
and it is materially identical to language in §14501(c)(1). We focus on
§14501(c)(1) for ease of reference, but everything we say about that
provision also applies to §14506(a).
                       Cite as: 569 U. S. ____ (2013)                        5

                            Opinion of the Court

ard and parking requirements because they do not
“ ‘ ha[ve] the force and effect of law.’ ” 660 F. 3d 384, 395
(2011) (quoting §14501(c)(1)). The court reasoned that
those requirements, rather than regulating the drayage
market, advance the Port’s own “business interest” in
“managing its facilities.” Id., at 401. Both provisions were
“designed to address [a] specific proprietary problem[ ]”—
the need to “increase the community good-will necessary
to facilitate Port expansion.” Id., at 406–407; see id., at
409.      The Ninth Circuit also held the agreement’s
financial-capacity and truck-maintenance provisions not
preempted, for reasons not relevant here.2            Section
14501(c)(1), the court decided, preempts only the contract’s
employment provision. Finally, the Ninth Circuit rejected
ATA’s claim that Castle bars the Port from applying the
agreement’s penalty clause to withdraw a trucking com-
pany’s right to operate at the facility. The court thought
Castle inapplicable because of the narrower exclusion in
this case: “Unlike a ban on using all of a State’s freeways,”
the court reasoned, “a limitation on access to a single Port
does not prohibit motor carriers” from generally partici-
pating in interstate commerce. 660 F. 3d, at 403.
    We granted certiorari to resolve two questions: first,
whether §14501(c)(1) of the FAAAA preempts the conces-
sion agreement’s placard and parking provisions; and
second, whether Castle precludes reliance on the agree-
ment’s penalty clause to suspend or revoke a trucking
company’s privileges. See 568 U. S. ___ (2013). Contrary
to the Ninth Circuit, we hold that the placard and parking
requirements are preempted as “provision[s] having the
force and effect of law.” That determination does not
——————
  2 For those curious, the court held that the financial-capacity re-

quirement is not “ ‘related to a [motor carrier’s] price, route, or service,’ ”
and that the truck-maintenance requirement falls within a statutory
exception for safety regulation. 660 F. 3d, at 395, 403–406 (quoting
§14501(c)(1)); see §14501(c)(2)(A) (safety exception).
6       AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                          Opinion of the Court

obviate the enforcement issue arising from Castle because
the Ninth Circuit’s rulings upholding the agreement’s
financial-capacity and truck-maintenance provisions have
now become final;3 accordingly, the Port could try to apply
its penalty provision to trucking companies that have
violated those surviving requirements. But we nonethe-
less decline to address the Castle question because the
case’s pre-enforcement posture obscures the nature of the
agreement’s remedial scheme, rendering any decision at
this point a shot in the dark.
                                 II
  Section 14501(c)(1), once again, preempts a state “law,
regulation, or other provision having the force and effect of
law related to a price, route, or service of any motor car-
rier . . . with respect to the transportation of property.” All
parties agree that the Port’s placard and parking require-
ments relate to a motor carrier’s price, route, or service
with respect to transporting property. The only disputed
question is whether those requirements “hav[e] the force
and effect of law.” The Port claims that they do not, be-
cause the “concession contract is just [like] a private
agreement,” made to advance the Port’s commercial and
“proprietary interests.” Brief for Respondent City of Los
Angeles et al. 19 (Brief for City of Los Angeles) (internal
quotation marks omitted).4
——————
    3 ATA’spetition for certiorari did not seek review of the Ninth Cir-
cuit’s determination that the truck-maintenance provision is valid. The
petition did ask us to consider the court’s ruling on the financial-
capacity provision, but we declined to do so.
  4 The Port’s brief occasionally frames the issue differently—as whether

a freestanding “market-participant exception” limits §14501(c)(1)’s
express terms. See Brief for City of Los Angeles 24. But at oral argu-
ment, the Port emphasized that the supposed exception it invoked in
fact derives from §14501(c)(1)’s “force and effect of law” language. See
Tr. of Oral Arg. 31 (“[W]hat we are calling the market participant
exception . . . is generally congruent with[ ] what is meant by Congress
                      Cite as: 569 U. S. ____ (2013)                        7

                           Opinion of the Court

   We can agree with the Port on this premise: Section
14501(c)(1) draws a rough line between a government’s
exercise of regulatory authority and its own contract-based
participation in a market. We recognized that distinction
in American Airlines, Inc. v. Wolens, 513 U. S. 219 (1995),
when we construed another statute’s near-identical “force
and effect of law” language. That phrase, we stated, “con-
notes official, government-imposed policies” prescribing
“binding standards of conduct.” Id., at 229, n. 5 (internal
quotation marks omitted). And we contrasted that quin-
tessential regulatory action to “contractual commitment[s]
voluntarily undertaken.” Id., at 229 (internal quotation
marks omitted). In Wolens, we addressed a State’s en-
forcement of an agreement between two private parties.
But the same reasoning holds if the government enters
into a contract just as a private party would—for example,
if a State (or City or Port) signs an agreement with a
trucking company to transport goods at a specified price.
See, e.g., Building & Constr. Trades Council v. Associated
Builders & Contractors of Mass./R. I., Inc., 507 U. S. 218,
233 (1993) (When a State acts as a purchaser of services,
“it does not ‘regulate’ the workings of the market . . . ;
it exemplifies them” (some internal quotation marks
omitted)). The “force and effect of law” language in
§14501(c)(1) excludes such everyday contractual arrange-
ments from the clause’s scope. That phrasing targets the
State acting as a State, not as any market actor—or other-
wise said, the State acting in a regulatory rather than
proprietary mode.
   But that statutory reading gets the Port nothing, be-
cause it exercised classic regulatory authority—complete
——————
by the term ‘force and effect of law’ ”); id., at 39–40 (“I’m . . . relying on
the language . . . force and effect of law,” which “invites a market
participant analysis”). We therefore have no occasion to consider
whether or when a preemption clause lacking such language would
except a state or local government’s proprietary actions.
8    AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                     Opinion of the Court

with the use of criminal penalties—in imposing the plac-
ard and parking requirements at issue here. Consider
again how those requirements work. They are, to be sure,
contained in contracts between the Port and trucking
companies. But those contracts do not stand alone, as the
result merely of the parties’ voluntary commitments. The
Board of Harbor Commissioners aimed to “require parties
who access Port land and terminals for purposes of pro-
viding drayage services” to enter into concession agree-
ments with the Port. App. 108 (Board’s “Findings”). And
it accomplished that objective by amending the Port’s
tariff—a form of municipal ordinance—to provide that “no
Terminal Operator shall permit” a drayage truck to gain
“access into any Terminal in the Port” unless the truck is
“registered under” such a concession agreement. Id., at
105. A violation of that tariff provision is a violation of
criminal law. And it is punishable by a fine or a prison
sentence of up to six months. Id., at 85–86. So the con-
tract here functions as part and parcel of a governmental
program wielding coercive power over private parties,
backed by the threat of criminal punishment.
  That counts as action “having the force and effect of
law” if anything does. The Port here has not acted as a
private party, contracting in a way that the owner of an
ordinary commercial enterprise could mimic. Rather, it
has forced terminal operators—and through them, truck-
ing companies—to alter their conduct by implementing a
criminal prohibition punishable by time in prison. In
some cases, the question whether governmental action has
the force of law may pose difficulties; the line between
regulatory and proprietary conduct has soft edges. But
this case takes us nowhere near those uncertain bounda-
ries. Contractual commitments resulting not from ordi-
nary bargaining (as in Wolens), but instead from the
threat of criminal sanctions manifest the government qua
government, performing its prototypical regulatory role.
                  Cite as: 569 U. S. ____ (2013)            9

                      Opinion of the Court

  The Port’s primary argument to the contrary, like the
Ninth Circuit’s, focuses on motive rather than means. The
Court of Appeals related how community opposition had
frustrated the Port’s expansion, and concluded that the
Clean Truck Program “respon[ded] to perceived business
necessity.” 660 F. 3d, at 407. The Port tells the identical
story, emphasizing that private companies have similar
business incentives to “adopt[ ] ‘green growth’ plans like
the Port’s.” Brief for City of Los Angeles 30. We have no
reason to doubt that account of events; we can assume the
Port acted to enhance goodwill and improve the odds of
achieving its business plan—just as a private company
might. But the Port’s intentions are not what matters.
That is because, as we just described, the Port chose a tool
to fulfill those goals which only a government can wield:
the hammer of the criminal law. See United Haulers
Assn., Inc. v. Oneida-Herkimer Solid Waste Mgmt. Auth.,
438 F. 3d 150, 157 (CA2 2006), aff ’d, 550 U. S. 330 (2007).
And when the government employs such a coercive mech-
anism, available to no private party, it acts with the force
and effect of law, whether or not it does so to turn a profit.
Only if it forgoes the (distinctively governmental) exercise
of legal authority may it escape §14501(c)(1)’s preemptive
scope.
  The Port also tries another tack, reminding us that the
criminal sanctions here fall on terminal operators alone,
not on the trucking companies subject to the agreement’s
requirements; hence, the Port maintains, the matter of
“criminal penalties is a red herring.” Tr. of Oral Arg. 31;
see Brief for City of Los Angeles 39–40. But we fail to see
why the target of the sanctions makes any difference. The
Port selected an indirect but wholly effective means of
“requir[ing] parties . . . providing drayage services” to
display placards and submit parking plans: To wit, the
Port required terminal operators, on pain of criminal
penalties, to insist that the truckers make those commit-
10   AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                     Opinion of the Court

ments. App. 108; see supra, at 3, 8. We have often rejected
efforts by States to avoid preemption by shifting their
regulatory focus from one company to another in the same
supply chain. See, e.g., Rowe v. New Hampshire Motor
Transp. Assn., 552 U. S. 364, 371–373 (2008) (finding
preemption under the FAAAA although the State’s re-
quirements directly targeted retailers rather than motor
carriers); Engine Mfrs. Assn. v. South Coast Air Quality
Management Dist., 541 U. S. 246, 255 (2004) (finding
preemption under the Clean Air Act although the re-
quirements directly targeted car buyers rather than
sellers). The same goes here. The Port made its regula-
tion of drayage trucks mandatory by imposing criminal
penalties on the entities hiring all such trucks at the
facility. Slice it or dice it any which way, the Port thus
acted with the “force of law.”
                              III
  Our rejection of the concession agreement’s placard and
parking requirements does not conclude this case. Two
other provisions of the agreement are now in effect: As
noted earlier, the Ninth Circuit upheld the financial-
capacity and truck-maintenance requirements, and that
part of its decision has become final. See supra, at 5, and
n. 2. ATA argues that our holding in Castle limits the way
the Port can enforce those remaining requirements. Ac-
cording to ATA, the Port may not rely on the agreement’s
penalty provision to suspend or revoke the right of non-
complying trucking companies to operate on the premises.
  As we have described, Castle rebuffed a State’s attempt
to bar a federally licensed motor carrier from its highways
for past infringements of state safety regulations. A fed-
eral statute, we explained, gave a federal agency the
authority to license interstate motor carriers, as well as a
carefully circumscribed power to suspend or terminate
those licenses for violations of law. That statute, we held,
                  Cite as: 569 U. S. ____ (2013)           11

                      Opinion of the Court

implicitly prohibited a State from “tak[ing] action”—like a
ban on the use of its highways—“amounting to a suspen-
sion or revocation of an interstate carrier’s [federally]
granted right to operate.” 348 U. S., at 63–64.
   The parties here dispute whether Castle restricts the
Port’s remedial authority. The Port echoes the Ninth
Circuit’s view that banning a truck from “all of a State’s
freeways” is meaningfully different from denying it “access
to a single Port.” 660 F. 3d, at 403; see Brief for City of
Los Angeles 49. ATA responds that because the Port is a
“crucial channel of interstate commerce,” Castle applies to
it just as much as to roads. Brief for Petitioner 18.
   But we see another question here: Does the Port’s en-
forcement scheme involve curtailing drayage trucks’ oper-
ations in the way Castle prohibits, even assuming that
decision applies to facilities like this one? As just indicat-
ed, Castle puts limits on how a State or locality can punish
an interstate motor carrier for prior violations of truck-
ing regulations (like the concession agreement’s require-
ments). Nothing we said there, however, prevents a State
from taking off the road a vehicle that is contemporane-
ously out of compliance with such regulations. Indeed,
ATA filed an amicus brief in Castle explaining that a
vehicle “that fails to comply with the state’s regulations
may be barred from the state’s highways.” Brief for ATA,
O. T 1954, No. 44, p. 12; see Brief for Respondent, id.,
p. 23 (A State may “stop and prevent from continuing on
the highway any motor vehicle which it finds not to be in
compliance”). And ATA reiterates that view here, as does
the United States as amicus curiae. See Reply Brief 22;
Brief for United States 29–30. So the Port would not
violate Castle if it barred a truck from operating at its
facilities to prevent an ongoing violation of the agree-
ment’s requirements.
   And at this juncture, we have no basis for finding that
the Port will ever use the agreement’s penalty provision
12   AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                      Opinion of the Court

for anything more than that. That provision, to be sure,
might be read to give the Port broader authority: As noted
earlier, the relevant text enables the Port to suspend
or revoke a trucking company’s right to provide dray-
age services at the facility as a “[r]emedy” for a “Major
Default.” App. 82; see supra, at 3. But the agreement
nowhere states what counts as a “Major Default”—and
specifically, whether a company’s breach of the financial-
capacity or truck-maintenance requirements would qual-
ify. And the Port has in fact never used its suspension or
revocation power to penalize a past violation of those
requirements. See Tr. of Oral Arg. 43, 50–51. Indeed, the
Port’s brief states that “it does not claim[ ] the authority to
punish past, cured violations of the requirements chal-
lenged here through suspension or revocation.” Brief for
City of Los Angeles 62 (internal quotation marks omitted).
So the kind of enforcement ATA fears, and believes incon-
sistent with Castle, might never come to pass at all.
   In these circumstances, we decide not to decide ATA’s
Castle-based challenge. That claim, by its nature, attacks
the Port’s enforcement scheme.           But given the pre-
enforcement posture of this case, we cannot tell what that
scheme entails. It might look like the one forbidden in
Castle (as ATA anticipates), or else it might not (as the
Port assures us). We see no reason to take a guess now
about what the Port will do later. There will be time
enough to address the Castle question when, if ever, the
Port enforces its agreement in a way arguably violating
that decision.
                            IV
  Section 14501(c)(1) of the FAAAA preempts the placard
and parking provisions of the Port’s concession agreement.
We decline to decide on the present record ATA’s separate
challenge, based on Castle, to that agreement’s penalty
provision. Accordingly, the judgment of the Ninth Circuit
                Cite as: 569 U. S. ____ (2013)                 13

                    Opinion of the Court

is reversed in part, and the case is remanded for further
proceedings consistent with this opinion.

                                                 It is so ordered.
                 Cite as: 569 U. S. ____ (2013)            1

                    THOMAS, J., concurring

SUPREME COURT OF THE UNITED STATES
                         _________________

                          No. 11–798
                         _________________


    AMERICAN TRUCKING ASSOCIATIONS, INC.,

      PETITIONER v. CITY OF LOS ANGELES, 

              CALIFORNIA, ET AL. 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

            APPEALS FOR THE NINTH CIRCUIT

                        [June 13, 2013] 


   JUSTICE THOMAS, concurring.
   I join the Court’s opinion in full. I write separately to
highlight a constitutional concern regarding §601 of the
Federal Aviation Administration Authorization Act of 1994
(FAAAA), 108 Stat. 1606, a statute the Court has now
considered twice this Term. See Dan’s City Used Cars,
Inc. v. Pelkey, 569 U. S. ___ (2013).
   The Constitution grants Congress authority “[t]o regu-
late Commerce . . . among the several States.” Art. I, §8,
cl. 3 (emphasis added). Section 14501 of Title 49 is titled
“Federal authority over intrastate transportation.” (Em-
phasis added.) The tension between §14501 and the
Constitution is apparent, because the Constitution does
not give Congress power to regulate intrastate commerce.
United States v. Lopez, 514 U. S. 549, 587, n. 2 (1995)
(THOMAS, J., concurring).        Nevertheless, §14501(c)(1)
purports to pre-empt any state or local law “related to
a price, route, or service of any motor carrier . . . with
respect to the transportation of property.” By its terms,
§14501(c) would pre-empt even a city ordinance establish-
ing a uniform rate for most transportation services origi-
nating and ending inside city limits, so long as the services
were provided by a motor carrier. Such an extraordinary
assertion of congressional authority cannot be reconciled
2    AMERICAN TRUCKING ASSNS., INC. v. LOS ANGELES

                    THOMAS, J., concurring

with our constitutional system of enumerated powers.
   The Supremacy Clause provides the constitutional basis
for the pre-emption of state laws. Art. VI, cl. 2 (“This
Constitution, and the Laws of the United States which
shall be made in Pursuance thereof . . . shall be the su-
preme Law of the Land”). Because the Constitution and
federal laws are supreme, conflicting state laws are with-
out legal effect. See Crosby v. National Foreign Trade
Council, 530 U. S. 363, 372 (2000). However, the constitu-
tional text leaves no doubt that only federal laws made “in
Pursuance” of the Constitution are supreme. See Gregory
v. Ashcroft, 501 U. S. 452, 460 (1991) (“As long as it is
acting within the powers granted it under the Constitu-
tion, Congress may impose its will on the States” (empha-
sis added)); Wyeth v. Levine, 555 U. S. 555, 583–587 (2009)
(THOMAS, J., concurring in judgment).
   Given this limitation, Congress cannot pre-empt a state
law merely by promulgating a conflicting statute—the pre-
empting statute must also be constitutional, both on its
face and as applied. As relevant here, if Congress lacks
authority to enact a law regulating a particular intrastate
activity, it follows that Congress also lacks authority to
pre-empt state laws regulating that activity. See U. S.
Const., Amdt. 10 (“The powers not delegated to the United
States by the Constitution, nor prohibited by it to the
States, are reserved to the States respectively, or to
the people”).
   In this case, the Court concludes that “[s]ection
14501(c)(1) . . . preempts the placard and parking provi-
sions of the Port’s concession agreement.” Ante, at 12.
Although respondents waived any argument that Con-
gress lacks authority to regulate the placards and parking
arrangements of drayage trucks using the port, I doubt
that Congress has such authority. The Court has iden-
tified three categories of activity that Congress may
regulate under the Commerce Clause: (1) the use of the
                 Cite as: 569 U. S. ____ (2013)            3

                    THOMAS, J., concurring

channels of interstate commerce; (2) the instrumentalities
of interstate commerce, and persons or things in interstate
commerce; and (3) “activities having a substantial relation
to interstate commerce . . . i.e., those activities that sub-
stantially affect interstate commerce.” Lopez, supra, at
558–559. Drayage trucks that carry cargo into and out of
the Port of Los Angeles undoubtedly operate within the
“channels of interstate commerce”—for that is what a port
is. Congress can therefore regulate conduct taking place
within the port. But it is doubtful whether Congress has
the power to decide where a drayage truck should park
once it has left the port or what kind of placard the truck
should display while offsite. Even under the “substantial
effects” test, which I have rejected as a “ ‘rootless and
malleable standard’ at odds with the constitutional de-
sign,” Gonzales v. Raich, 545 U. S. 1, 67 (dissenting opin-
ion) (quoting United States v. Morrison, 529 U. S. 598,
627 (2000) (THOMAS, J., concurring)), it is difficult to say
that placards and parking arrangements substantially af-
fect interstate commerce. Congress made no findings
indicating that offsite parking—conduct that falls within
the scope of the States’ traditional police powers—
substantially affects interstate commerce. And I doubt
that it could. Nevertheless, because respondents did not
preserve a constitutional challenge to the FAAAA and
because I agree that the provisions in question have the
“force and effect of law,” I join the Court’s opinion.
