delivered the opinion of the Court.
Undertaking to proceed under Paragraphs 18, 20 and 21, § 402, Transportation Act, 19201 (41 Stat: 456, 477, U. S. C. Title 49, § 1) petitioners, by bill filed December 30, 1938, in, the United States District. Court, Western District of Missouri, asked a decree .enjoining respondent from constructing or operating an alleged extension, 26 F. Supp. 721.
*298The bill describes them thus:—
“Plaintiffs are engaged in the business of buying and selling at wholesale and retail, fruits, vegetables and other food products within and adjacent to the so-called City Market of Kansas City, Missouri, located at and near the intersection of Fourth and Walnut Streets in said City, or are directly interested in or connected with said business. Said market has been in existence at said location for more than seventy-five years serving greater Kansas City and vicinity as a wholesale and retail produce market, and also serving numerous territories in other states to and from which perishable and other produce bought and sold in said market is transported. The City of Kansas City, Missouri, is now engaged in the construction of new wholesale arid retail market buildings and facilities in said vicinity at a cost of approximately $500,000.00. Said market is now and for a long period of time has been served by existing transportation facilities of various trunk line railroads, and said existing transportation facilities are suitable, convenient and adequate to meet the requirements of the market. The market is easily accessible to its customers through the facilities of said railroads and also by the use of streets and hard-surfaced highways radiating in every direction therefrom.”
Answering, the respondent alleged that petitioners were hot parties “in interest” within Paragraph 20, § 402, Transportation Act and had no right to sue. The District Court sustained this defense and dismissed the bill. 26 F. Supp. 721. Upon appeal its action, was affirmed. 109 F. 2d 493. The matter is here by certiorari.
The Circuit Court of Appeals made the following summation of the bill—
“The complaint of the plaintiffs shows that they are commission merchants doing business on the Kansas City, Missouri, produce market, an old and well-estab*299lished market which adequately serves the consuming public in its vicinity and receives produce from,, and ships produce to, other states; that Kansas City, Missouri, is now engaged in constructing new market buildings for this market at a cost of about $500,000; that the market has suitable and adequate transportation facilities of all kinds; that the adjoining city of Kansas City, Kansas, proposes to build and is building a ‘Food Terminal’ or produce market on a tract of land which it owns, at a cost of about $4,000,000, of which $1,710,000 is a grant from the Public Works Administration of the United States, and that the balance of the necessary funds will be procured by a sale of the City’s bonds to the defendant railroad company; that the defendant proposes, at an expense of some $500,000, to ftirnish trackage to serve this Kansas City, Kansas, market; that this trackage constitutes an extension of the defendant’s lines of railroad,, for the construction of which it has procured no certificate of convenience ánd necessity from the Interstate Commerce Commission as required .by law; that the construction and operation of the proposed extension in Kansas City, Kansas, will adversely affect and will destroy the business and properties of the plaintiffs and the large investments which they have made in and adjacent to the Kansas City, Missouri, produce market; that it will create an unnecessary and uncalled for rival market at an inconvenient place without creating any more produce' to be handled or any more customers to be served; .that it will result in the unnecessary duplication of railroad facilities at a cost of $500,000 without increasing the amount of freight to be handled; that it will divert traffic from other railroads which are now adequately handling the traffic to the Kansas City, Missouri, produce market, and will cause destructive competition between the defendant and other railroads and will cause a wasteful and needless expendi*300ture of money by the defendant; that ‘for each and all of the reasons aforesaid, the construction and operation, or the construction, or the operation of the said extension or extensions of railroad by the defendant to said proposed produce market in Kansas City, Kansas, will directly and adversely affect the property interests of the plaintiffs and the public generally by bringing about a material change in the transportation situation, and will constitute an unnecessary burden upon interstate commerce directly and adversely affecting the welfare of plaintiffs and the public interest.’ ” 109 F. 2d 493.
It is not alleged that the respondent has ever served the produce market in Kansas City, Missouri, or that petitioners make or receive shipments over its lines or that the proposed extension will deprive them of any shipping facilities. Evidently the real purpose was to obstruct construction of a competitor and the theory upon which the proceeding rests would permit petitioners to sue if any railroad should extend its lines to any market competing with the market at Kansas City, Missouri.
Concerning the purport of the allegations of the bill, the Circuit Court of Appeals rightly said:
“It is obvious that the only basis for the plaintiffs’ claim that the alleged extension of the lines of the defendant to the Kansas City, Kansas, market will particularly injure them is that they do business upon the Kansas City, Missouri, market, and that if the proposed rival market in Kansas City, Kansas, functions, it, will divert business from the market upon which they operate and will thus hurt them, their business, and their investments in Kansas City, Missouri, and that, since the proposed extension of its tracks by the defendant is necessary to enable the rival market to function, such .extension will therefore injure the plaintiffs. It seems equally obvious that, except for the fact that the pro*301posed extension is essential to the operation of the rival market in Kansas, it could not possibly have any direct or immediate effect upon the plaintiffs, their property or their business in Missouri, other than the effect which a wasteful expenditure by the defendant of its money would have upon the public generally. The proximate cause of the injury to the plaintiffs will be the competition created by the construction and operation of the rival market, and not the construction or operation of the transportation facilities furnished to it by the defendant or by others engaged in the transportation business.”
It- declared that the question whether petitioners were “parties in interest” within Paragraph 20 must be determined upon consideration of Western Pacific R. Co. v. Southern Pacific Co., 284 U. S. 47, and concluded—
“The plaintiffs have no definite legal right which is threatened. They are, however, persons whose welfare. may be adversely affected by the bringing about of. a material change in the transportation situation, in the sense that the extension proposed by the defendant, if built and operated, will enable a competitive market to function to their detriment. In that sense, we think it may safely be said that the proposed extension of dé--fendant’s lines may.adversely affect the plaintiffs’ welfare. We are of the opinion, however, that their complaint discloses that their welfare cannot be directly, but only indirectly and consequentially, affected by the proposed extension. They are not in competition with the defendant. They are not engaged in the transportation business. Their only peculiar interest in that business-is in the effect which changes in it may have upon the market where they do business and upon rival markets now or hereafter established in the territory which the plaintiffs serve. . . . We. conclude that the statute is not to be so liberally construed as to enable *302those who fear adverse effects upon their business from the establishment of competitive enterprises requiring transportation facilities, to maintain suits to enjoin railroads from constructing what are claimed to be unauthorized extensions to serve such enterprises.”
A dissenting opinion by Judge Stone likewise relied upon Western Pacific R. Co. v. Southern Pacific Co., but took the view that the challenged action might directly and substantially affect petitioners’ welfare -since their financial interests would suffer from the proposed rival market which could not come into existence without the proposed extension.
The purpose and effect of Paragraphs 18, 20 and 21 were much considered in Texas & Pacific Ry. Co. v. Gulf, C. & S. F. Ry. Co., 270 U. S. 266 and Western Pacific R. Co. v. Southern Pacific Co., 284 U. S. 47.
In the first of these causes a railroad sought to prevent another from building an extension. The meaning of the term “party in interest” was not discussed. But the opinion asserts that by the Transportation Act of 1920, “Congress undertook to develop and maintain, for the people of the United States, an adequate railway system. It recognized that preservation of the earning capacity, and conservation of the financial resources, of individual carriers is a matter of national concern; that the property employed must be permitted to earn a reasonable return; that the building, of' unnecessary lines involves a waste of resources and that the burden of this waste may fall upon the public; that competition between carriers may result in harm to the public as well as in benefit; and that when a railroad inflicts injury upon its rival, it may be the public which ultimately bears the loss.”
Also “the prohibition of Paragraph 18 is absolute. If the proposed track is an extension and no certificate has. *303been obtained, the party in interest.opposing construetion is entitled as of right to an injunction.”
In the second cause it was claimed that the Western Pacific was not “a party in interest” within the statute. The Circuit Court of Appeals accepted that view, 46 F. 2d 729; we concluded otherwise but did not undertake to announce an inclusive and exclusive definition of the term. The circumstances disclosed a special interest in that complainant with probabilityhf direct loss from what- the defendant — not another — -proposed to do. The portion of the opinion, presently specially important, follows—
"If, as the court below seems to have assumed, a. 'party in interest’ must possess some clear legal right for which it might ask protection under the rules commonly accepted by courts of equity, the paragraphs under consideration would not materially aid the Congressional plan for promoting transportation. On the other hand, there was no purpose to permit any individual so inclined to institute such a proceeding. The complainant must possess something more than a common concern for obedience to law. See Massachusetts v. Mellon, 262 U. S. 447, 488. It will suffice, we think, if the bill discloses that some definite legal right possessed by complainant is seriously threatened or that the unauthorized . and therefore unlawful action of the defendant carrier may directly and adversely affect the complainant’s welfare by bringing about some material change in the ■ transportation situation.”
The Transportation Act,. 1920, was designed to protect the public against action which might endanger its interest. In order to aid that general purpose, Paragraph 20, § 402, provides that suit for a.n injunction may. be instituted by the United States, the Commission (I. C. C.), any Commission or Regulative Body .of the state or states affected, or any “party in interest.” Such *304a suit cannot be instituted by an individual unless he “possesses something more than a common concern for obedience to law.* The general or common interest finds protection in. the permission to sue granted to public authorities. An individual may have some special and peculiar interest which may be directly and materially affected by alleged unlawful action. See Detroit & M. Ry. Co. v. Boyne City, G. & A. R. Co., 286 F. 540. If such circumstances are shown he may sue; he is then “party in interest” within the meaning of the statute. In the absence of these circumstances he is not such a party.
We cannot think Congress supposed that the development and maintenance of an adequate railway system would be aided by permitting any person engaged in business within or adjacent to a public market to demand an injunction against a’ carrier seeking only to serve a competing market by means of an extension not authorized by the Interstate Commerce Commission.
The right to sue under the- statute, is individual. Petitioners are not helped by uniting.
The Circuit Court of Appeals, after reviewing all the facts reached the conclusion that the welfare of petitioners could only be indirectly and consequentially affected by the proposed extension; that their interest in the transportation situation “is in the effect which- changes in it may have upon the market where- they do business and upon rival markets now or hereafter established in the territory which the plaintiffs serve.” It held this was not enough. We agree. A mere extension to the plant of a competitor which in no other way affects the complaining parties in no proper sense brings about a material change in the transportation system directly affecting their peculiar interest which they have the right to prevent by suit.
The challenged judgment must be affirmed.
*305No. 35.
The City of Kansas City, Missouri, sought to intervene in No. 34. The District Court denied its motion. The Circuit Court of Appeals affirmed. In view of what we have decided in No. 34 this denial necessarily must be affirmed.
Affirmed.
Mr. Justice Frankfurter:I quite agree with my Brother Stone that unfair loss may be cast upon a community by fhe unjustified extension of a railroad line, and that such loss is one consequence of the evils of unregulated railroad building which the Transportation Act was intended to check. But our immediate problem is to determine how a community can challenge such a proposed improper extension. Can a city, in other words, come into a Federal Court and urge its special relation to an alleged violation of § 1 (18-22), of the Transportation Act, 1920, 41 Stat. 456, 477, 49 U-. S. C. § 1 (18-22) ? The answer j of course, depends on the scheme of enforcement that Congress has devised for the Act. After making administrative provisions for securing a certificate from the Interstate Commerce Commission as a prerequisite to the construction of,an “extension,” the Act subjects any construction in violation of its licensing system to an injunction “at the suit of the United States, the Commission, any commission or regulating body of the State or States affected, or any party in interest.” § 1 (20).
A city deeming itself adversely affected by a proposed illegal extension would naturally turn to its state commission to assert its interests. If, for aiiy reason, the state agency does not employ its power under § 1 (20) on behalf of the city’s claims, the latter can invoke the law-enforcing authority of the Interstate, Commerce Commission and also enlist the power of the Attorney General to initiate litigation. It is reading § 1 (20) *306without illumination of the scheme and. purposes of the Transportation Act to expand the categories of public agencies explicitly named by Congress for enforcing § 1 (18) by including a city as a “party in interest.” To do so would disregard recognition of a state utility commission as the special repository of all the interests of a state'in this particular field, and of the Interstate Commerce Commission as the national organ for enforcing the body of interstate commerce acts. Clearly, therefore, Kansas City can not be deemed a “party in interest” for the litigious purposes of that phrase in § 1 (20).
But it would indeed be strange to' find that while the city was not given power to resort to a court, a private and more limited sufferer from the same economic threat may have such legal standing. Such a paradox exposes the appropriate scope óf ’“-party in interest” in § 1 (20). The guiding considerations in the application of that section are to be found in the reach of the functions of the Interstate Commerce Commission and of its state analogues. They are relied on for the enforcement of railroad legislation neither grudgingly nor with scepti-cism. In these agencies are lodged the resources for compounding the manifold ingredients of “the public interest.” To entrust the vindication of this public interest to a private litigant professing a special stake in the public ir ' erest is to impinge on the responsibility of the public ai horities designated by Congress. If there be insufficient assurance that unlawful railroad construction will be resisted by a state commission representing all the interests of a state that are affected, the Interstate Commerce Commission may be moved to enjoin illegality.
Who then is a “party in interest”? As a part of the very system through which the national policy is to be achieved, a railroad has been deemed by this Court a “party in interest” to effectuate the railroad policy intro*307duced by the licensing system of the Transportation Act. Texas & Pacific Ry. Co. v. Gulf, C. & S. F. Ry. Co., 270 U. S. 266, 277; Western Pacific R. Co. v. Southern Pacific Co., 284 U. S. 47. And one who in a proceeding initiated before the Interstate Commerce Commission has been treated by it as a party to the litigation, cf. Los Angeles Passenger Terminal Cases, 100 I. C. C. 421; 142 I. C. C. 489; Atchison, T. & S. F. Ry. Co. v. Railroad Commission, 283 U. S. 380, 393-94, may perhaps be deemed a “party in interest” in the further pursuit of claims before a court after adverse action by the Commission. Compare Interstate Commerce Comm’n v. Oregon-Washington R. Co., 288 U. S. 14, and Federal Communications Commission v. Sanders Bros. Radio Station, 309 U. S. 470. But to allow, any private interest to thresh out the complicated questions that arise out of § 1 (18-22)1 — as, for instance, whether a proposed construction is an “extension” or a “spur,” compare Texas & Pacific Ry. Co. v. Gulf, C. & S. F. Ry. Co., 270 U. S. 266 — is to invite dislocation of the scheme which Congress has devised for the expert conduct of the litigation of such issues.2 It also would put upon the district courts the. task of drawing fine lines in determining when a private claim is so special that it may be set apart from the general public interest and give the claimant power to litigate a public controversy. These inquiries are so harassing and unprofitable as to be avoided, unless Congress has explicitly cast the duty upon the courts. Against any such implication, in the absence of rather plain language, the whole course of *308federal railroad legislation and the relation of the Interstate Commerce Commission to it admonishes. The interests of merely private concerns are amply protected even though they must be channelled through the Attorney General or the Interstate Commerce Commission or a state commission.
Therefore, the court below made proper dispositions of these cases.
Mr. Justice Roberts, Mr. Justice Black, Mr. Justice Douglas, and Mr. Justice Murpity, having concurred in the Court’s opinion, also join in these views.Transportation Act, 1920, § 402:
“Paragraph '(18) ... no carrier by railroad subject to this Act shall undertake the extension of its line of railr'oad . . . unless and until there shall first have been obtained from the Commission a certificate that the present or future public convenience and necessity require or -will require the construction ... of such . . . extended line . . .’ Paragraph ‘(19) The application for and issuance of any such certificate shall be under such rules and regulations as to hearings and other matters as the Commission may from time to time prescribe, . . .’ Paragraph ‘(20) . . . Any construction . ... contrary to the provisions ... of paragraph (18) ... may be enjoined by'any court of competent jurisdiction at the, suit of the United States, the Commission, any commission or regulating body of the State or States affected, or any party in interest.
The fact that, in order to'raise the bare legal question of petitioner’s. right to sue, the illegality of the proposed extension was conceded by the pleadings,' does not touch the force of the argument.
With reference to the present circumstances themselves, the Attorney General, at the request of the Interstate Commerce Commission, has chosen a different remedy to protect the public interest. See United States v. Union Pacific R. Co., 32 F. Supp. 917.