Iowa passed a statute restricting the length of vehicles that could use its highways. The length chosen was 55 feet. Semitrailers are generally 55 feet long; double or twin tracks (one cab pulling two trailers) are 65 feet long. Other states in the Midwest have adopted the 65-foot standard. Consolidated Freightways brought suit, challenging the Iowa statute as an unconstitutional burden on interstate commerce. The Iowa statute meant Consolidated could not use its twins in Iowa. The Iowa legislature claims the 65-foot doubles are more dangerous than the 55-foot singles. However, the statute did provide a border exception: Towns and cities along Iowa borders could make an exception to the length requirements to allow trucks to use their city and town roads. Can Iowa's statute survive a constitutional challenge? Is the statute an impermissible burden on interstate commerce? [Kassel v Consolidated Freightways Corp., 450 U.S. 662 (1981)]