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:
“Goodbye, boys; I’m under arrest. I may have to go to jail. I may not see you for a long time. Keep up the fight! Don’t surrender! Pay no attention to the injunction machine at Parkersburg. The Federal judge is a scab anyhow. While you starve he plays golf. While you serve humanity, he serves injunctions for the money powers.”
—Mother Jones (1830–1930)
“A circle swoop, and a quick parabola under the bridge arches
Where light pushes through;
A sudden turning upon itself of a thing in the air.
A dip to the water.”
—D.H. (David Herbert)
“We are ashamed to seem evasive in the presence of a straightforward man, cowardly in the presence of a brave one, gross in the eyes of a refined one, and so on. We always imagine, and in imagining share, the judgments of the other mind.”
—Charles Horton Cooley (1864–1929)
“The hurt is not enough:
I long for weight and strength
To feel the earth as rough
To all my length.”
—Robert Frost (1874–1963)
“Given for one instant an intelligence which could comprehend all the forces by which nature is animated and the respective positions of the beings which compose it, if moreover this intelligence were vast enough to submit these data to analysis, it would embrace in the same formula both the movements of the largest bodies in the universe and those of the lightest atom; to it nothing would be uncertain, and the future as the past would be present to its eyes.”
—Pierre Simon De Laplace (1749–1827)