The latest Freedom of Information Act (FOIA) acquisition by leading U.S. Highway 12 megaloads opponents Lin Laughy and Borg Hendrickson raises new questions about potential physical damage to the wild and scenic road.
In 30 pages of two now-defunct documents issued to ConocoPhillips by the Idaho Transportation Department (ITD) permitting “overlegal” shipments from the Port of Lewiston to Billings, Laughy and Hendrickson spotted numerous revelations. (The Conoco permits are no longer valid because a formal hearing will begin Dec. 8 in Boise to determine whether the loads should be allowed to traverse the highway.) Many of the revelations are summarized in a message the two sent to media outlets and other concerned parties this week.
The Idaho couple’s message highlighted the potential for wear-and-tear on the highway, which is an indispensable lifeline for residents and provides access to the scenic region’s principal industry, tourism.
Laughy and Hendrickson have long been interested in the question of highway damage by megaloads. They obtained copies of the transport management plans required by ITD of the contracted carrier of the Conoco loads, Emmert International, and of Mammoet, which would be the carrier of another 207 overlegal loads that Imperial Oil/ExxonMobil intends to haul over the highway.
The Emmert transport plan presents many size and weight statistics, among the most revealing of which are the axle loads. The legal limit is 20,000 pounds per axle. Emmert would transport four loads, each of which would differ in weight. The lightest of the four would have estimated axle loads of 36,491 pounds on the trailer, and the heaviest would bear an estimated 48,207 pounds per axle.
Laughy found a briefing paper issued by the Washington State Department of Transportation that states, “The relationship between axle weight and pavement damage is not linear, but exponential. For example, a single axle loaded to 40,000 pounds (twice the legal load) causes 16 times more damage than a single axle legally loaded to 20,000 pounds.”
Hendrickson points out that shipment sizes can be difficult to parse, because a given load differs in weight and other measurements depending upon whether it includes the trailer, a pull truck, and a push-truck, or any combination of those elements. “To be fully accurate when talking of weight and roadbed wear and tear,” she notes, “it only makes sense to talk of the full combo of two trucks, trailer, and load.”
She adds that the length of a shipment also can vary, but when it includes flagger vehicles, pilot cars, state police cars, and maintenance support vehicles, each convoy will be about 500 feet long.