In the case of United Railroads of San Francisco v. City and County of San Francisco et al., 1918, the Supreme Court examined whether a city ordinance requiring street railway companies to install safety appliances on their cars was constitutional. The United Railroads argued that this requirement constituted an unreasonable use of police power by infringing upon its property rights without due process. However, the court ruled in favor of San Francisco, stating that such regulations were within the scope of local government's authority to ensure public safety. It held that it is not unconstitutional for a municipality to require street railways to equip their cars with fenders or other devices designed for protection against accidents as long as these requirements are reasonable and not arbitrary or discriminatory.

In the dissenting opinion for United Railroads of San Francisco v. City and County of San Francisco, Justice Louis Brandeis argued that the majority's decision to strike down a city ordinance requiring streetcar companies to provide their employees with certain benefits was an overreach of judicial power. He contended that it was not within the court's purview to determine whether such regulations were reasonable or necessary; rather, this responsibility fell on legislative bodies who are more equipped to make these determinations based on expert testimony and investigation. Furthermore, he asserted that if every regulation affecting property rights could be challenged in courts as unconstitutional under due process clause, then there would be no limit to litigation and it would undermine regulatory powers vested in legislatures by constitution. Therefore, he disagreed with majority’s view which struck down city ordinance as violation of Fourteenth Amendment’s due process clause.