delivered the opinion of the Court:

1. The argument that the charter of defendant amounts to a contract, the obligation of which may not be impaired, may be briefly considered. (1) In the first place, the prohibition of laws impairing the obligations of contracts applies to the States, and not to the United States. The prohibitions to the United States are those of the 5th Amendment, that no person shall be deprived of property without due process of law, and that private property shall not be taken for public use without just compensation. The application of these will be considered later.

(2) A contract between the United States and the defendant in error cannot be implied from the provision fixing a maximum rate merely. See Detroit United R. Co. v. Detroit, 229 U. S. 39, 44, 57 L. ed. 1056, 1059, 33 Sup. Ct. Rep. 697, and cases there cited.

(3) Even if the language relating to the fares to be charged amounted to a contract, it was subject to the expressly reserved power to alter, amend, or repeal. Greenwood v. Union Freight R. Co. 105 U. S. 13, 26 L. ed. 961; see also Missouri P. R. Co. v. Kansas, 216 U. S. 262, 274, 54 L. ed. 472, 477, 30 Sup. Ct. Rep. 330; Noble State Bank v. Haskell, 219 U. S. 104, 110, 55 L. ed. 112, 116, 32 L.R.A.(N.S.) 1062, 31 Sup. Ct. Rep. 186, Ann. Cas. 1912 A, 487; Metropolitan R. Co. v. Macfarland, 20 App. D. C. 421, 433.

*1202. The case turns upon the question whether the act of Congress in requiring the Capital Traction Company to receive and carry, without additional compensation, passengers on transfers from another and independent line, amounts to a deprivation of property without due process of law.

The streets of the city of Washington are public highways for the convenience of all citizens and other persons who may desire their use. The operation of street cars therein furnishes an additional convenience for the intended uses of the streets. • Instead of the governmental construction and maintenance of such additional conveniences, Congress has preferred to delegate the exercise of the power to private corporations. These, organized primarily for private profit, nevertheless perform a public function which renders them subject to regulation and control by the'power from which they derive their privileges. This power of regulation relates not only to fares, but also to the maintenance of tracks, schedules, etc., and connections with other lines in aid of the public safety, comfort, and convenience.

■ The reasonable exercise of this power of regulation does not abridge the right of private ownership. It is only when the regulation imposes such a burden upon private property lawfully engaged in the performance of a public service as to render the property .unremunerative, that it becomes unreasonable and amounts to a deprivation of private property without due process of law, or to its taking for public use without compensation. Then only is it a violation of the 5th Amendment.

■ Regulations requiring railway companies to make track connections with independent lines, connections with such other lines, and the operation of additional trains upon one’s own line, have been held valid, notwithstanding the particular act required might entail a serious loss, where it has not been made to appear that the loss would be so great as to render the entire property of the corporation unremunerative. Wisconsin, M. & P. R. Co. v. Jacobson, 179 U. S. 287, 301, 45 L. ed. 194, 201, 21 Sup. Ct. Rep. 115; Atlantic Coast Line R. Co. v. North Carolina Corp. Commission, 206 U. S. 1, 25, 51 L. ed. 933, 944, 27 Sup. Ct. Rep. 585, 11 Ann. Cas. 398; Missoiiri P. B. Co. v. *121Kansas, 216 U. S. 262, 279, 54 L. ed. 472, 479, 30 Sup. Ct. Rep. 330; Minneapolis & St. L. R. Co. v. Minnesota, 186 U. S. 257, 263, 46 L. ed. 1151, 1156, 22 Sup. Ct. Rep. 900.

Notwithstanding the apparent effect of the statutory regulation, if otherwise valid, may be to compel the carriage of the transferred passengers at a serious loss, so far as their carriage is concerned, the act is not void upon its face as depriving the Capital Traction Company of its property without due process of law, because it is to be presumed that the loss will not be such as to render the business of the corporation unremunerative as a whole.

Nor is the act objectionable on the ground that it creates a favored class, because its privileges are extended to all persons, alike, under the same circumstances.

3. It is contended, however, that the act is not a regulation of the rates of passenger fares, but amounts to a deprivation of property in that it compels the carriage of certain persons for nothing.

In -support of this contention are cited decisions of State courts denying the power of the legislature to compel the free carriage of policemen and other officers.

Without reviewing these decisions, it is sufficient to say that we do not regard them as applicable to the situation here presented. As before said, the operation of street car and coach lines at regular intervals is to promote the public convenience in the uses of the streets. Looking to the public convenience, Congress has conferred upon several independent corporations, of which the Metropolitan Coach Company is one, the privilege of engaging in the carriage of passengers upon the streets. These do not reach all parts of the city, but they do intersect, or approach each other so closely at the points designated as to make it highly convenient for passengers upon one line to be transferred to another in order to reach a part of the city that is served by one line only. A passenger who purchases a ticket from one line is entitled to demand and receive from that line a transfer ticket which, without additional charge, enables him to ride to his final destination, upon the connecting or adjacent *122line of another carrier. It does not follow, however, that the other line carries him wholly without compensation. He pays the full fare of the initial line and receives a transfer that enables him to proceed to his destination. He, in returning, or another person not on a return trip, may pay fare upon the second line, and receive a transfer to the first one. The arrangement is reciprocal. Presumably, one carrier receives as much benefit as the other. Any inequalities that may be developed may be remedied by regulation of the commissioners under the power delegated to them.

Congress, apparently, regarded the new arrangement as advantageous to both carrier and passenger. In the absence of facts showing that the regulation imposes an unreasonable burden upon the defendant in error, amounting to a deprivation of property in the constitutional sense, we are not prepared to s$y that it was beyond the power of Congress to enact.

The judgment of the Police Court quashing the information is reversed, with costs; and the cause is remanded to that court for further proceedings not inconsistent with this opinion.

Reversed.