August 6, 2007 (LPAC)--"The investigators into the Minneapolis incident still haven't looked at the primary cause," reported Hal Cooper, a rail and transportation consultant, in discussion with EIR today. "That cause is that bridges and highways are handling traffic volumes far beyond what they were erected to handle; the principal problem comes from the increasing load of heavy trucks, which are everywhere."
Indeed, this problem arises from the decades-old policy of the financier oligarchs, in alliance with the oil cartel, highway interests and real estate interests, in suppressing high-speed rail and maglev development, in favor of insanely massive petroleum-powered truck and car traffic.
According to an EIR investigation: In 2000, there were 8.74 million heavy trucks bearing freight on the roads in the United States. On top of that, between 1990 and 2000, the amount of miles that each one of these trucks logged, increased by a striking 48%.
Truck damage to the roads is beyond most people's imagination. The American Association of State Highway Officials (AASHTO), representing the officials of the state highway systems, has developed a function for the relation of axle weight (or truck weight) to pavement damage. According to the AASHTO, a 5-axle tractor-semi trailer truck having a fully loaded weight of 80,000 pounds does the same amount of damage to a roadway's pavement as would 10,500 cars, with each car weighing 3,000 pounds. Thus, even though collectively the cars weighed 31.5 million pounds, the single 80,000 pound truck did greater damage. The AASHTO study showed that as the weight of a truck would increase arithmetically, the damage it would do to the pavement would increase by a power function (e.g., increasing the weight of the 80,000 pound truck by one-fourth increases the damage by 300%). It is the concentration of the weight at each axle, that transmits the damage.
Even though current Federal law forbids trucks carrying loads of more than 80,000 pounds on U.S. Interstate highways, 20 states drew up exemptions, which permit trucks to carry 90,000 to 135,000 pounds on U.S . Interstate highways. This does immense damage, ripping up the top layer of bridges and roads, while putting excessive stress on their foundations. Impose this truck-load increase upon 158,912 bridges, 26.9% of the nation's total, which are either "structurally deficient or functionally obsolete," and an increased density of bridge collapse is pre-ordained.
