Truck Driver's Guidebook
Bridge Gross Weight Formula

Back | Next | General Bridge Formula Info

This combination has a bridge of 34' between axles 1 and 3. Using the B/F chart, this combination would be allowed a gross weight of 60,000 lbs. If this combination exceeds the B/F gross of 60,000 lbs., the combination would not qualify for bridge formula weights so only designated weights would apply (18,000 lbs. on a single axle).

This combination has a bridge of 48' between axles 1 and 4. Using the B/F chart, this combination would be allowed a gross weight of 74,000 lbs. If the combination exceeds the B/F gross of 74,000 lbs., it would not qualify for bridge formula weights so only designated weights would apply (18,000 lbs. on a single axle/16,000 lbs. for each axle on the tandem).

This combination has a bridge of 68' between axles 1 and 5.  Using the B/F chart, this combination would be allowed a gross weight of 80,000 lbs.  because the B/F only allows vehicles up to 80,000 lbs.  If this combination does not exceed 80,000 lbs., single axles will be allowed 20,000 lbs. each.  it should be noted that designated loading for this combination would exceed the B/F weights with 18,000 lbs. per single axle for a possible gross weight of 86,000 lbs. (14,000 lbs. on the steering axle).

Back | Next | General Bridge Formula Info

***The bridge formula allows up to 20,000 lbs. per single axle, if the vehicle is equipped with large enough tires.  Steering axle weights well vary depending on the gross weight of the vehicle.

Due to frequent changes in federal and state regulations, the Michigan Center for Truck Safety cannot ensure the accuracy of the material contained in the Guidebook beyond the date of publication. For current information, contact the Center at (800) 682-4682. This document is not intended for legal purposes.