George W. Bush & Sons Co. v. Maloy, Public Service Commission of Maryland. Buck v. Kuykendall, Director of Public Works of the State of Washington

Background

A company challenged state laws in cases involving state public agencies in Maryland and Washington. The states have spent enormous sums building roads. A sudden increase in motor vehicles created new problems, and the company questioned state rules that limit vehicle use and protect roadways.

Reasoning

The core question was whether state rules about roads and motor vehicles unlawfully block or discriminate against interstate commerce or whether Congress must set uniform national rules. The opinion explains that the courts below reached correct conclusions: the challenged statutes do not discriminate against interstate commerce, do not seriously impede it, and aim honestly to prevent unnecessary destruction and to keep roads fit for travel. The opinion also states the federal government has not and cannot make precise regulation of these local problems, so control by the states must continue. The Court likened road regulation to harbor pilotage laws that states may enforce until Congress acts.

Real world impact

The decision leaves primary control of vehicle and road safety and maintenance with the states. State governments may enforce rules that protect pavement and travelers even if those rules impose costs or vary between states. Because the opinion treats these matters as local unless they clearly obstruct commerce, it reduces the expectation of immediate uniform federal rules and preserves state flexibility to address the practical challenges of motor traffic. This ruling affects drivers, state budgets for road upkeep, and businesses that rely on interstate travel by allowing states to set varying, practical rules.