## Facts

- Iowa generally limited truck combinations on its highways to 55 feet, while allowing multiple exceptions, including some 60-foot combinations and permits for longer vehicles in specified circumstances.
- Neighboring Midwestern and Western states generally permitted 65-foot double-trailer trucks, making Iowa’s rule a regional outlier.
- Consolidated Freightways, an interstate trucking company, used 65-foot double-trailer configurations in interstate operations.
- Because Iowa prohibited 65-foot doubles, the company had to use shorter equipment, break up doubles and shuttle trailers separately across Iowa, or reroute around Iowa.
- Iowa defended the restriction as a highway safety measure and also asserted that diverting long trucks to other states would improve safety and reduce road wear in Iowa.
- After trial, the district court found that 65-foot doubles were as safe as the shorter configurations Iowa allowed, relying on record evidence including statistical studies.
- The district court held the statute an unconstitutional burden on interstate commerce; the Eighth Circuit affirmed.

## Issues

1. Whether Iowa’s truck-length scheme, which barred 65-foot double trailers while permitting significant exceptions, imposed an unconstitutional burden on interstate commerce under the Dormant Commerce Clause.

## Decision

- The Supreme Court affirmed, holding Iowa’s truck-length limitations unconstitutional under the Dormant Commerce Clause.
- A plurality concluded that Iowa failed to show a meaningful safety benefit from banning 65-foot doubles and that the law imposed substantial costs and operational disruptions on interstate trucking.
- The plurality also viewed the statutory exceptions and structure as indicating an effort to shift traffic, accident risk, and road wear to other states while favoring certain in-state interests.
- A concurrence agreed the statute was invalid, emphasizing that protectionist state measures that shift burdens to nonresidents are forbidden even when framed as safety regulation.
- A dissent would have upheld the law, arguing for greater judicial deference to state safety judgments absent a showing that safety was a pretext for discrimination.

## Legal Principles

- State highway safety regulations affecting interstate commerce are assessed by weighing the strength of the safety justification against the burden imposed on interstate commerce.
- When a state cannot substantiate that a challenged restriction materially advances safety, the state interest is weak in the Commerce Clause balance.
- A state law that is out of step with surrounding states and forces rerouting, equipment changes, or inefficient operations can impose a substantial burden on interstate commerce.
- Statutory exceptions and design may show impermissible protectionism, including attempts to shift costs and risks to nonresidents or neighboring states.

## Conclusion

Iowa’s prohibition on 65-foot double-trailer trucks violated the Dormant Commerce Clause because the asserted safety rationale was not supported by the evidence and the statute materially burdened interstate transportation, especially given its exceptions and its tendency to push traffic and related costs onto other states.


Kassel v. Consol. Freightways Corp. of Del., 450 U.S. 662 (1981)