450 U.S. 662, 702-703 (1981)
The State of Iowa maintains a statute that restricts most truck combinations on its highways to 55 feet in overall length while allowing 60-foot doubles, 60-foot singles hauling livestock or farm equipment, and 65-foot singles.1
Consolidated Freightways Corporation of Delaware, a major common carrier operating in 48 states under an Interstate Commerce Commission certificate, regularly transports goods through Iowa on Interstate 80 and Interstate 35 using both 55-foot singles and 65-foot doubles.2 Because Iowa bars 65-foot doubles, Consolidated must either switch to shorter permitted vehicles, detach and shuttle the trailers separately, or divert its longer rigs around the state entirely, adding roughly $2 million per year to its own operating costs and an estimated $12.6 million annually to the industry as a whole.3
Iowa's length limits originated in a 1947 uniformity statute and were set at 60 feet in 1963.4 In 1974 the legislature passed a bill raising the limit to 65 feet for doubles.5 Governor Ray vetoed it, stating that the change would benefit out-of-state trucking firms at the expense of Iowa citizens.6 The legislature then enacted a border-cities exemption allowing municipalities abutting other states to adopt the neighboring state's longer limits.7 Additional exemptions permit Iowa truck manufacturers to ship 70-foot units and allow oversized mobile homes when moved from or to points inside the state.8
Consolidated filed suit in the United States District Court for the Southern District of Iowa seeking declaratory and injunctive relief.9 After a 14-day trial that included comparative accident data, braking and maneuverability tests, and testimony from state and federal transportation officials, the District Court found that 65-foot doubles were as safe as the vehicles Iowa permits.10 The court further found that the length restriction caused affected trucks to travel more miles over more dangerous roads in other states, increasing overall accidents, injuries, fatalities, fuel consumption, and highway wear.11
The Court of Appeals for the Eighth Circuit affirmed.12 Iowa appealed, and the Supreme Court noted probable jurisdiction.13 At trial Consolidated introduced 1978 accident statistics showing that its 65-foot doubles, driven 56 million miles on identical routes, produced 106 accidents with 17 injuries and one fatality, while its 55-foot singles produced 100 accidents with 27 injuries and one fatality.14 Iowa's own Department of Transportation study concluded that 65-foot twins had not been shown to be less safe than 60-foot twins or conventional semis.15 Iowa presented evidence that longer vehicles take more time to pass and clear intersections.16 Iowa also showed that longer trucks are somewhat more prone to jackknifing.17 No witness testified that 65-foot doubles were more dangerous overall than the trucks the state allows.18
Whether an Iowa statute that generally prohibits 65-foot double-trailer trucks while permitting 55-foot singles and 60-foot doubles violates the Commerce Clause?19
Under the dormant Commerce Clause, a state statute regulating evenhandedly to effectuate a legitimate local public interest is upheld unless the burden imposed on interstate commerce is clearly excessive in relation to the putative local benefits.20 When safety justifications are illusory and the regulation bears disproportionately on out-of-state interests, the statute is invalid.21
Yes. The Iowa statute forces Consolidated Freightways Corporation of Delaware to incur roughly $2 million per year in added costs and imposes an estimated $12.6 million annual burden on the trucking industry by requiring shorter vehicles, separate shuttling of trailers, or rerouting around the state.22 The District Court found after a 14-day trial that 65-foot doubles are as safe as the 55-foot singles and 60-foot doubles Iowa permits, rendering the asserted safety interest illusory.23 The border-cities exemption and livestock-hauler exemption, enacted after Governor Ray's veto citing benefits to out-of-state firms at Iowa citizens' expense, demonstrate that the law deflects through traffic rather than advancing safety.24
These facts establish an excessive burden on interstate commerce unjustified by local benefits.25
The Iowa statute violates the Commerce Clause.26
Related opinions on this issue
Joined by Marshall
Justice Brennan concurred in the judgment.27 He concluded that Iowa's actual legislative purpose was protectionist and aimed at discouraging interstate truck traffic through the state at the expense of neighboring states' safety interests.28 Brennan relied on the Governor's veto message and the subsequent border-cities exemption as evidence that the lawmakers sought to shift highway burdens rather than promote safety.29
This rendered the regulation impermissible under the Commerce Clause regardless of post-hoc safety arguments advanced by counsel.30 Brennan stressed that protectionist legislation violates the Commerce Clause even when framed in safety terms.31 He emphasized that a state may not shunt its fair share of interstate highway burdens onto neighboring states.32
Joined by Burger, Stewart
Justice Rehnquist dissented on the ground that Iowa's length limit is a valid exercise of the state's police power to promote highway safety.35 He argued that courts must accord substantial deference to such regulations even when they affect interstate commerce.36 Rehnquist maintained that the evidence supported a rational connection between vehicle length and safety.37
He concluded that the Court improperly second-guessed the legislature's line-drawing in an area traditionally reserved to the states.38 Rehnquist stressed that the strong presumption of validity for highway safety measures had not been overcome.39
Whether Iowa's asserted highway safety interests in the truck-length restrictions justify any resulting burden on interstate commerce?40
A state safety regulation survives Commerce Clause scrutiny only if the safety benefits are more than slight or problematical and the burden on commerce is not clearly excessive in relation to those benefits.41 When the record shows the safety interest is illusory, the regulation cannot be sustained.42
No. The District Court credited comparative accident data showing 65-foot doubles driven 56 million miles produced fewer injuries than 55-foot singles on identical routes.43 Iowa's own Department of Transportation study concluded that 65-foot twins had not been shown to be less safe than permitted vehicles.44 Iowa presented no witness who testified that 65-foot doubles were more dangerous overall than the trucks the state allows.45 The resulting burden, including increased total highway miles driven and accidents shifted to other states, is therefore not justified by any significant safety gain.46
Iowa's asserted safety interests do not justify the burden on interstate commerce.47
Related opinions on this issue
Joined by Burger, Stewart
Justice Rehnquist dissented.48 He maintained that Iowa adduced sufficient evidence of safety risks from longer passing times, splash and spray, and jackknifing potential to support the legislative judgment.49 Rehnquist argued that the strong presumption of validity for highway safety measures required upholding the statute.50
He noted that every state regulates truck lengths and that Iowa's 60-foot limit fell within the widely accepted range.51 Rehnquist concluded that the Court had overstepped its limited authority to review state legislation under the Commerce Clause.52
Whether statutory exemptions for border cities, livestock haulers, and other categories affect the validity of Iowa's truck-length law under the Commerce Clause?53
Statutory exemptions that secure benefits of longer trucks to in-state interests while imposing the costs of the length restriction on out-of-state carriers undermine the presumption of validity ordinarily accorded state safety regulations.54 Such exemptions indicate that the law is not a neutral safety measure.55
Yes. The border-cities exemption allows municipalities adjoining other states to adopt longer limits, benefiting Iowa residents near the borders while deflecting through traffic.56 The livestock and farm-equipment exemptions similarly favor local economic interests.57 These exemptions, combined with the history of the Governor's veto of a 65-foot bill on protectionist grounds, demonstrate that the statute operates to protect Iowa citizens at the expense of interstate commerce.58
The exemptions therefore weaken any claim that the law advances safety in a neutral fashion.59
The statutory exemptions undermine the validity of Iowa's truck-length law under the Commerce Clause.60
Related opinions on this issue
Joined by Marshall
Justice Brennan emphasized that the exemptions and legislative history confirmed the protectionist purpose of deflecting interstate traffic.61 He concluded that this purpose violates the Commerce Clause even when framed in safety terms.62 Brennan pointed to the Governor's admission that the veto aimed to protect Iowa citizens from out-of-state competition.63
He stressed that a state may not shunt its fair share of interstate highway burdens onto neighboring states.64 Brennan noted that the decision of Iowa's lawmakers to promote Iowa's safety and other interests at the direct expense of the safety and other interests of neighboring States merits no deference under the Commerce Clause.65