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South Carolina Highway Department v. Barnwell Bros., Inc.

Supreme Court of the United States · Constitutional Law

Constitutional LawDormant Commerce ClauseState Police PowerHighway Regulationcommerce clausedormant commerce clausestate highwaystruck width limits

Facts

South Carolina enacted a statute prohibiting motor trucks and semitrailer motor trucks on state highways if they exceeded 90 inches in width or 20,000 pounds gross weight including load. The statute treated a semitrailer motor truck as a single unit for purposes of the weight limit. The district court found that many interstate trucks commonly used were wider and heavier than the statute allowed and concluded the law would seriously impede interstate trucking through South Carolina. Congress had not regulated truck size or weight for interstate motor traffic, and the statute applied alike to interstate and intrastate vehicles.

Issue

Whether South Carolina's nondiscriminatory statutory limits of 90 inches in width and 20,000 pounds gross weight on trucks using its highways imposed an unconstitutional burden on interstate commerce when Congress had not legislated on the subject. Also, whether a court may invalidate such limits by substituting its own judgment for the legislature's on the preferable standards of truck width and weight.

Rule

Absent congressional action, a state may prescribe uniform, nondiscriminatory regulations reasonably adapted to promote highway safety and conserve the use of its highways, applicable alike to interstate and intrastate traffic. In reviewing such regulations, courts do not weigh competing policy choices or select the best standard; the legislation is presumed constitutional and will be sustained unless the legislative choice is without rational basis.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

Nevada enacts a statute limiting all freight trucks using its state highways to 88 inches in width and 19,000 pounds gross weight. The statute applies equally to trucks registered in Nevada and trucks registered elsewhere, and Congress has not enacted any law setting national truck width or weight standards for these vehicles.

An interstate carrier from Oregon challenges the statute, arguing that most trucks commonly used in western interstate shipping exceed the limit and must reroute around Nevada. Which is the strongest answer?

Explanation. The majority rule is that, when Congress has not acted, a state may prescribe uniform regulations adapted to highway safety and conservation, applicable alike to interstate and intrastate traffic. The incidental burden on interstate commerce is permissible so long as the law is nondiscriminatory and has a rational basis; courts do not require the state to adopt the best nationwide standard. (Derived from South Carolina Highway Department v. Barnwell Bros., Inc. (n.d.).)