Louis Brandeis, Bradley v. Public Utilities Commission of Ohio…
“ Its purpose was to prevent competition deemed undesirable. The test employed was the adequacy of existing transportation facilities; and since the transportation in question was interstate, denial of the certificate invaded the province of Congress. In the case at bar, the purpose of the denial was to promote safety; and the test employed was congestion of the highway. The effect of the denial upon interstate commerce was merely an incident.Protection against accidents, as against crime, presents ordinarily a local problem. Regulation to ensure safety is an exercise of the police power. ”
