opinion: Mr. Justice Blackmun
  announced the judgment of the Court and an opinion, in which The Chief Justice, Mr. Justice White, and Mr. Justice Rehnquist join.
  This case presents the question whether a city which operates a public rapid transit system and sells advertising space for car cards on its vehicles is required by the First and Fourteenth Amendments to accept paid political advertising on behalf of a candidate for public office.
  In 1970, petitioner Harry J. Lehman was a candidate for the office of State Representative to the Ohio General Assembly for District 56. The district includes the city of Shaker Heights. On July 3, 1970, petitioner sought to promote his candidacy by purchasing car card space on the Shaker Heights Rapid Transit System for the months of August, September, and October. The general election was scheduled for November 3. Petitioner’s proposed copy contained his picture and read:
  “HARRY J. LEHMAN IS OLD-FASHIONED! ABOUT HONESTY, INTEGRITY AND GOOD GOVERNMENT
  “State Representative — District 56 [X] Harry J. Lehman.” App. 39A.
  Advertising space on the city’s transit system is managed by respondent Metromedia, Inc., as exclusive agent under contract with the city. The agreement between the city and Metromedia provides:
  “15. . . . The Contractor shall not place political advertising in or upon any of the said Cars or in, upon or about any other additional and further space granted hereunder.”
  When petitioner applied for space, he was informed by Metromedia that, although space was then available, the management agreement with the city did not permit political advertising. The system, however, accepted ads from cigarette companies, banks, savings and loan associations, liquor companies, retail and service establishments, churches, and civic and public-service oriented groups. There was uncontradicted testimony at the trial that during the 26 years of public operation, the Shaker Heights system, pursuant to city council action, had not accepted or permitted any political or public issue advertising on its vehicles. App. 30A-32A.
  When petitioner did not succeed in his effort to have his copy accepted, he sought declaratory and injunctive relief in the state courts of Ohio without success. The Supreme Court of Ohio concluded that “the constitutionally protected right of free speech with respect to forums for oral speech, or the dissemination of literature on a city’s streets, does not extend to commercial or political advertising on rapid transit vehicles.” 34 Ohio St. 2d 143, 145-146, 296 N. E. 2d 683, 685 (1973). There was no equal protection violation, the court said, because, “[a]s a class, all candidates for political office are treated alike under the Shaker Heights Rapid Transit System’s commercial advertising policy.” Id., at 148, 296 N. E. 2d, at 686. The three dissenting justices viewed the transit system’s advertising space as a free speech forum and would have held that no valid governmental interest was furthered by the differential treatment between political and other advertising. A policy excluding political advertisements, in their view, would therefore deny political advertisers the equal protection of the law. We granted certiorari in order to consider the important First and Fourteenth Amendment question the case presented. 414 U. S. 1021 (1973).
  It is urged that the car cards here constitute a public forum protected by the First Amendment, and that there is a guarantee of nondiscriminatory access to such publicly owned and controlled areas of communication “regardless of the primary purpose for which the area is dedicated.” Brief for Petitioner 14.
  We disagree. In Packer Corp. v. Utah, 285 U. S. 105, 110 (1932), Mr. Justice Brandéis, in speaking for a unanimous Court, recognized that “there is a difference which justifies the classification between display advertising and that in periodicals or newspapers.” In Packer the Court upheld a Utah statute that made it a misdemeanor to advertise cigarettes on “ ‘any bill board, street car sign, street car, placard/ ” but exempted dealers' signs on their places of business and cigarette advertising “ ‘in any newspaper, magazine, or periodical.' ” Id., at 107. The Court found no equal protection violation. It reasoned that viewers of billboards and streetcar signs had no “choice or volition” to observe such advertising and had the message “thrust upon them by all the arts and devices that skill can produce. . . . The radio can be turned off, but not so the billboard or street car placard.” Id., at 110. “The streetcar audience is a captive audience. It is there as a matter of necessity, not of choice.” Public Utilities Comm'n v. Pollak, 343 U. S. 451, 468 (1952) (Douglas, J., dissenting). In such situations, “[t]he legislature may recognize degrees of evil and adapt its legislation accordingly.” Packer Corp. v. Utah, 285 U. S., at 110. Cf. Breard v. Alexandria, 341 U. S. 622 (1951).
  These situations are different from the traditional settings where First Amendment values inalterably prevail. Lord Dunedin, in M’Ara v. Magistrates of Edinburgh, [1913] Sess. Cas. 1059, 1073-1074, said: “[T]he truth is that open spaces and public places differ very much in their character, and before you could say whether a certain thing could be done in a certain place you would have to know the history of the particular place.” Although American constitutional jurisprudence, in the light of the First Amendment, has been jealous to preserve access to public places for purposes of free speech, the nature of the forum and the conflicting interests involved have remained important in determining the degree of protection afforded by the Amendment to the speech in question. See, e. g., Cox v. New Hampshire, 312 U. S. 569 (1941); Breard v. Alexandria, supra; Poulos v. New Hampshire, 345 U. S. 395 (1953); Cox v. Louisiana, 379 U. S. 559 (1965); Adderley v. Florida, 385 U. S. 39 (1966); Red Lion Broadcasting Co. v. FCC, 395 U. S. 367 (1969); Police Department of Chicago v. Mosley, 408 U. S. 92 (1972); Grayned v. City of Rockford, 408 U. S. 104 (1972); Columbia Broadcasting v. Democratic National Committee, 412 U. S. 94 (1973); Pittsburgh Press Co. v. Pittsburgh Comm’n on Human Relations, 413 U. S. 376 (1973).
  Here, we have no open spaces, no meeting hall, park, street corner, or other public thoroughfare. Instead, the city is engaged in commerce. It must provide rapid, convenient, pleasant, and inexpensive service to the commuters of Shaker Heights. The car card space, although incidental to the provision of public transportation, is a part of the commercial venture. In much the same way that a newspaper or periodical, or even a radio or television station, need not accept every proffer of advertising from the general public, a city transit system has discretion to develop and make reasonable choices concerning the type of advertising that may be displayed in its vehicles. In making these choices, this Court has held that a public utility “will be sustained in its protection of activities in public places when those activities do not interfere with the general public convenience, comfort and safety.” Public Utilities Comm’n v. Pollak, 343 U. S., at 464-465.
  Because state action exists, however, the policies and practices governing access to the transit system’s advertising space must not be arbitrary, capricious, or invidious. Here, the city has decided that “[pjurveyors of goods and services saleable in commerce may purchase advertising space on an equal basis, whether they be house builders or butchers.” 34 Ohio St. 2d, at 146, 296 N. E. 2d, at 685. This decision is little different from deciding to impose a 10-, 25-, or 35-cent fare, or from changing schedules or the location of bus stops, Public Utilities Comm’n v. Poliak, 343 U. S., at 465. Revenue earned from long-term commercial advertising could be jeopardized by a requirement that short-term candidacy or issue-oriented advertisements be displayed on car cards. Users would be subj ected to the blare of political propaganda. There could be lurking doubts about favoritism, and sticky administrative problems might arise in parceling out limited space to eager politicians. In these circumstances-, the managerial decision to limit car card space to innocuous and less controversial commercial and service oriented advertising does not rise to the dignity of a First Amendment violation. Were we to hold to the contrary, display cases in public hospitals, libraries, office buildings, military compounds, and other public facilities immediately would become Hyde Parks open to every would-be pamphleteer and politician. This the Constitution does not require.
  No First Amendment forum is here to be found. The city consciously has limited access to its transit system advertising space in order to minimize chances of abuse, the appearance of favoritism, and the risk of imposing upon a captive audience. These are reasonable legislative objectives advanced by the city in a proprietary capacity. In these circumstances, there is no First or Fourteenth Amendment violation.
  The judgment of the Supreme Court of Ohio is affirmed.
  It is so ordered.
  Metromedia has a written Metro Transit Advertising Copy Policy setting forth the following criteria:
  “(1) Metro Transit Advertising will not display advertising copy that is false, misleading, deceptive and/or offensive to the moral standards of the community, or contrary to good taste. Copy which might be contrary to the best interests of the transit systems, or which might result in public criticism of the advertising industry and/or transit advertising will not be acceptable.
  “(2) Metro Transit Advertising will not accept any political copy that pictorially, graphically or otherwise states or suggests that proponents or opponents of the persons or measures advertised are vulgar, greedy, immoral, monopolistic, illegal or unfair.
  “(10) Political advertising will not be accepted on following systems: Shaker Rapid — Maple Heights — North Olmsted — Euclid, Ohio.” Shaker Heights’ Exhibit A.
  Mr. Lehman testified: “We are using various methods [of pro-promoting my candidacy], including newspaper advertising . . . . We plan to use direct mail advertising, postcards, and circulars of various types.” App. 14A.
  The system operated only 55 cars, App. 15A, each with 20 advertising spaces. Tr. of Oral Arg. 23-24.
  Receipts from the sale of advertising amounted to $12,000 annually. Tr. of Oral Arg. 27. These receipts supplemented operating revenues generated from the fares paid by the passengers who used the system daily.
  Cf. Wirta v. Alameda-Contra Costa Transit District, 68 Cal. 2d 51, 434 P. 2d 982 (1967); Kissinger v. New York City Transit Authority, 274 F. Supp. 438 (SDNY 1967); Hillside Community Church v. City of Tacoma, 76 Wash. 2d 63, 455 P. 2d 350 (1969).