In the case of Universal Interpretive Shuttle Corp. v. Washington Metropolitan Area Transit Commission et al., 1968, the Supreme Court ruled in favor of the Washington Metropolitan Area Transit Commission (WMATC). The dispute arose when Universal Interpretive Shuttle Corporation (UISC), a company providing shuttle services to tourists in Washington D.C., challenged WMATC's authority to regulate its operations. UISC argued that it was not a common carrier and therefore should not be subject to regulation by WMATC, which is authorized only over common carriers operating between states within its jurisdiction. However, the court held that UISC did qualify as a common carrier because it offered transportation services to general public on regular routes for compensation and thus fell under interstate commerce regulations due to transporting passengers across state lines during their tours around DC area landmarks.

In the dissenting opinion for Universal Interpretive Shuttle Corp. v. Washington Metropolitan Area Transit Commission et al., Justice Douglas argued that the majority's decision to uphold a regulation requiring shuttle services in Washington D.C. to obtain certificates of public convenience and necessity was an overreach of government power, infringing on free enterprise principles. He contended that this requirement stifled competition by creating barriers for new businesses entering the market, thereby limiting consumer choice and potentially leading to higher prices due to lack of competition. Furthermore, he expressed concern about potential corruption or favoritism within regulatory bodies deciding who gets these certificates, which could further distort market dynamics.