The Federal Bridge Gross Weight Formula (also known as Bridge Formula B and the Federal Bridge Formula) is a mathematical formula in use in the United States by truck drivers and Department of Transportation (DOT) officials to determine the appropriate maximum gross weight for a commercial motor vehicle (CMV) based on axle number and spacing. The formula is part of federal weight and size regulations regarding interstate commercial traffic (intrastate traffic is subject to state limits). The formula is necessary to prevent heavy vehicles from damaging roads and bridges. CMVs are most often tractor-trailers or buses, but the formula is of most interest to truck drivers due to the heavy loads their vehicles often carry.
Early 20th-century weight limits were enacted to protect dirt and gravel roads from damage caused by the solid wheels of heavy trucks. As time passed, truck weight limits focused primarily on gross weight limits (which had no prescribed limits on length). By 1974, bridges received special protection from increasing truck weight limits. The bridge formula law was enacted by the U.S. Congress to limit the weight-to-length ratio of heavy trucks, and to protect roads and bridges from the damage caused by the concentrated weight of shorter trucks. The formula effectively lowers the legal weight limit for shorter trucks, preventing them from causing premature deterioration of bridges and highway infrastructure.
Compliance with the law is checked when vehicles pass through a weigh station, often located at the borders between states or on the outskirts of major cities, where the vehicle may be weighed and measured. The one exception to the formula allows a standard five-axle semi-truck configuration to weigh the maximum legal gross weight. This exception was specifically requested by the American Trucking Associations to allow tank trucks to reach the maximum legal gross weight without violating the bridge formula law.
Read more about Federal Bridge Gross Weight Formula: History, Usage, Bridge Collapse, Formula Law, Exception, Issues, Bridge Formula Table
Famous quotes containing the words federal, bridge, gross, weight and/or formula:
“The proposed Constitution ... is, in strictness, neither a national nor a federal constitution; but a composition of both.”
—James Madison (1751–1836)
“Oh, who will now be able to relate how Pantagruel behaved in face of these three hundred giants! Oh my muse, my Calliope, my Thalie, inspire me now, restore my spirits, because here is the ass’s bridge of logic, here is the pitfall, here is the difficulty of being able to describe the horrible battle undertaken.”
—François Rabelais (1494–1553)
“Hunger is never delicate; they who are seldom gorged to the full with praise may be safely fed with gross compliments, for the appetite must be satisfied before it is disgusted.”
—Samuel Johnson (1709–1784)
“Ah, mon cher for anyone who is alone, without God and without a master, the weight of days is dreadful.”
—Albert Camus (1913–1960)
“My formula for greatness in human beings is amor fati: that one wants to change nothing, neither forwards, nor backwards, nor in all eternity. Not merely to endure necessity, still less to hide it—all idealism is mendacity in the face of necessity—but rather to love it.”
—Friedrich Nietzsche (1844–1900)