Bibb v. Navajo Freight Lines

Article I, section 8 of the Constitution grants Congress power "to regulate Commerce with foreign Nations, and among the several states, and with the Indian Tribes." However, the Constitution is silent as to whether the states (in addition to Congress) may or may not pass laws that affect interstate commerce.

The Supreme Court has recognized a state "police power" to regulate business and industry in order to protect public health and safety. Often state regulations significantly affect the movement of goods and service between the states. Nevertheless, the Court has upheld state laws that pass three tests. First, a state law can not conflict with a valid federal law. Second, the regulation has to be rationally related to a legitimate state end. Finally, the burdens (financial and otherwise) the regulation imposes have to be outweighed by the state's interest in enforcing the regulation.

When Bibb reached the Supreme Court, the justices unanimously affirmed the district court decision, with Justice Douglas delivering the Court's opinion. Justice Douglas began by affirming the principle that state "safety measures carry a strong presumption of validity." Citing Southern Pacific Co. v. Arizona (1945), Douglas declared that the Court overruled state safety laws only when their benefits in reducing accidents and causalities were "slight or problematical." In these cases, the small benefits do not "outweigh the national interest in keeping interstate commerce free from interferences which seriously impede it."