The United States Supreme Court has held that a municipality does not violate a candidate's right of free speech and equal protection under the first and fourteenth amendments to the United States Constitution when it sells space on its transit vehicles for commercial and service advertisements but refuses to accept political advertising of a candidate for public office.
Lehman v. City of Shaker Heights, 418 U.S. 298 (1974).
Susan J. Webb,
Constitutional Law - Freedom of Speech - Public Forum - Captive Audience - Transit Advertising on Municipally Owned Transit System,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol13/iss4/14