The state of Iowa passed a statute restricting vehicle length on its highways. Most vehicles were limited to 55 feet, but trucks that pulled two trailers could be as long as 60 feet. Iowa was the only state in that part of the country to disallow 65-foot long vehicles. Consolidated Freightways Corp. (P) challenged the statute's constitutionally, claiming that it burdened interstate commerce. The district court and the court of appeals found the statute to be unconstitutional, stating that it seriously impeded interstate commerce while providing only slight, if any, safety. The Court of Appeals for the Eighth Circuit affirmed. It accepted the District Court's finding that 65-foot doubles were as safe as 55-foot singles. The only apparent safety benefit to Iowa was that resulting from forcing large trucks to detour around the State, thereby reducing overall truck traffic on Iowa's highways. This was not a constitutionally permissible interest. The several statutory exemptions suggest that the law benefits Iowa residents at the expense of interstate traffic. The combination of these exemptions weakened the presumption of validity normally accorded a state safety regulation. The Court of Appeals agreed with the District Court that the Iowa statute unconstitutionally burdened interstate commerce. Kassel (D) appealed on behalf of the state.