Rules foundation
Truck Weight Fundamentals
Start here when a scale ticket, shipper loading plan, or permit question depends on the federal vocabulary: axle, tandem, bridge, gross weight, and ratings.
- Bridge Formula Calculation Examples
Three worked bridge formula examples — drive tandem, five-axle spacing, and axle group over while gross is under — with real numbers and the FHWA formula.
- Bridge Formula Explained for Truck Drivers
A driver-focused explanation of the federal bridge formula, axle spacing, axle count, and why 80,000 lb is only one part of a legal-weight check.
- Bridge Formula Weights
How the federal bridge formula connects axle spacing, axle count, and the familiar 80,000 lb gross limit.
- Gross Vehicle Weight vs. Axle Weight
How gross vehicle weight, single axle weight, tandem axle weight, steer axle, drive axle, and trailer axle checks fit together.
- Why 80,000 Pounds Matters in U.S. Truck Weight Rules
Why the 80,000 lb federal gross weight figure matters, where it fits, and why axle and bridge checks still control the final answer.