Iowa enacted a statute prohibiting the use of sixty-five-foot double-trailer-truck combinations. All of the other Midwestern and western states permit such trucks to be used on their roads. Despite these restrictions, Iowa's statute permits cities abutting the state line to enact local ordinances adopting the length limitations of the adjoining state. Where a city has exercised this option, otherwise oversized trucks are permitted within the city limits and in nearby commercial zones.

Consolidated Freightways is adversely affected by this statute and brings suit against Iowa, alleging that the statute violates the Commerce Clause. The District Court found that the evidence established that 65-foot doubles were as safe as the shorter truck units. Does the statute violate the Commerce Clause? Explain.