Kassel v. Consolidated Freightways Corp.

Consolidated Freightways (plaintiff) ran interstate trucking routes through Iowa and preferred using 65-foot twin trailers, which carried more cargo than standard semi-trailers. An Iowa law banned most trucks over 55 feet, forcing Consolidated to use different trailers, detach trailers at the border, or divert around the state entirely. Consolidated sued Kassel (defendant), the Iowa official enforcing the law, arguing it unconstitutionally burdened interstate commerce. Iowa defended the law as a highway-safety measure. The district court found no real safety difference between semi and twin trucks and struck down the law; the court of appeals affirmed, and the Supreme Court granted certiorari.