If you've driven on the Interstate highways of the West, you've seen the big trucks hauling two trailers, or "twins" as they are called. Many states, particularly in the East, still ban these giants from their roads.
This week those bans began to look weaker as the US Supreme Court for the second time struck down state regulations excluding the long trucks. It gave a permanent green light to the 65-foot trucks in Iowa.
Three years ago the Supreme Court struck down a similar ban in Wisconsin.
"We expect the facts to be the same" in the cases of some 13 other states that prohibit the twin trailers, says John D. Varda, a Madison, Wis., lawyer who represented Consolidated Freightways Corporation of Delaware in the Iowa case.
Consolidated Freightways, one of the top small-shipment truckers in the US, the company estimates that the double trailers save it millions of dollars a year in gas because the trucks can carry 26 percent more goods. Having two trailers also makes loading and unloading more efficient, accodring to a company spokesman.
Experts still are debating whether the double trailers are more dangerous than the standard 55-foot tractor-trailer. Iowa officials point to the fact that the long trucks tend to jackknife more easily and can be backed up only a short distance. But studies show that the longer trucks have better brakes, fewer total miles.
In its 6-3 decision this week, the Supreme Court struck down Iowa's ban as imposing an unconstitutional "burden" on interstate commerce. The Iowa decision goes further than merely opening the roads to bigger trucks in one state. It shows that the Supreme Court is willing to limit state power even in the area of safety, which traditionally has been left to the individual states.
University of Virginia law professor A. E. Howard says that the Iowa decision "signals the court's developing attitude" toward state powers. In the 1930s and '40s, the high court declined to limit state powers unless Congress had acted first. Now, he says, "the court sees itself as the legitimate arbiter of competing state and federal interests."
With the new attitude of the Supreme Court, states might have to produce more empirical studies to back up their laws, says Mr. Howard.
Supreme Court Justice William H. Rehnquist, chiding the majority for limiting state power, dissented from the Iowa ruling. The state's safety law is entitled to the "strongest presumption of validity" against constitutional challenges, he wrote. Chief Justice Warren E. Burger and Justice Potter Stewart also dissented.
Wrote Rehnquist: "The other states with truck length limits that exclude Consolidated's 65-foot doubles would not at all be paranoid in assuming that they might be next on Consolidated's 'hit list.' The true problem with today's decision is that it gives no guidance whatsoever to these states as to whether their laws are valid or how to defend them."