- 80,000 pounds gross vehicle weight
- 20,000 pound single axle weight
- 34,000 pound tandem axle weight
To protect our nation’s bridges, axle spacing must be considered for Federal weight compliance. The number of axles and the spacing of axles carrying the vehicle load must be calculated. The Federal bridge axle spacing formula must be applied to commercial vehicles to determine compliance with Federal weight limits. The Federal bridge formula applies when the gross weight on two or more consecutive axles exceeds the limitations of the formula, except that two consecutive sets of tandem axles may carry a gross load of 34,000 pounds each if the overall distance between the first and last axle is 36 feet or more.
Federal Bridge Axle Spacing Formula:
W=500(LN/N-1 + 12N + 36); where W=overall gross weight on any group of 2 or more consecutive axles to the nearest 500 pounds. L=distance in feet between the extreme of any group of 2 or more consecutive axles, and N=number of axles in the group under consideration
Overweight Load Permits
The Federal government does not issue permits for oversize or overweight vehicles. Individual States offer permit options.
States may grant special use permits to motor vehicles that exceed the Federal 102 inch width limitation.