How to Weigh a Semi Truck Before a Long Haul

Contents

• When to weigh
• Choosing a scale
• Weighing sequence
• Read the ticket
• Re-weigh after adjustment
• State checks before departure
• Sources

When to weigh

The most useful weigh-in happens after loading but before leaving the shipper’s facility or yard. That is the point where cargo position can still be adjusted, fifth-wheel position can be confirmed, and trailer tandem setting can be checked before the truck enters the road network.

A second weigh-in at a public scale near the route start is a confirmation step, not a substitute for getting the load right before departure. If the load is borderline, weigh at origin, adjust if needed, then weigh again before departure.

Choosing a scale

A public truck scale — such as a CAT Scale location at a truck stop — can provide steer, drive, trailer, and gross readings in one weigh. Some locations also offer a drive-axle-only position for a partial check.

For a full pre-trip check, use a scale that reads all axle groups simultaneously. A partial weigh that omits a group leaves part of the compliance check incomplete. Keep scale receipts with the load file.

Weighing sequence

1. Pull the full combination onto the scale with the steer axle, drive axles, and trailer axles all on the platform at the same time, if the scale length allows it.
2. Wait for a stable reading. Movement during weighing affects accuracy.
3. Collect the printed ticket or electronic record showing each axle group.
4. If the scale only handles partial groups, weigh each group separately and keep all tickets together in the load file.

Read the ticket

Separate the ticket into four numbers before comparing anything to a legal limit:

• Steer axle: compare to the steer or single-axle limit and tire/equipment ratings.
• Drive tandem: compare to the tandem limit and any applicable bridge-spacing rule.
• Trailer tandem: compare to the tandem limit and any applicable bridge-spacing rule.
• Gross weight: compare to the gross vehicle weight limit for the route.

Do not compare a drive axle reading to a gross limit, or a steer reading to a tandem rule. Each line has a specific legal category. Read How to Read a CAT Scale Ticket for a line-by-line breakdown.

Re-weigh after adjustment

If any axle group is over, or if cargo position, fifth-wheel slide, or trailer tandem position changes after the first weigh, re-weigh before departure. The second ticket is the confirmation record that the adjustment moved weight where it needed to move.

Keep both the pre-adjustment and post-adjustment tickets with the load file. If a question arises later about what the load weighed before and after correction, both records are useful.

State checks before departure

A scale ticket is a self-check record. It is not a state permit or route authorization. Before departure, compare each axle group reading to the limits for every state on the route, not only the loading state.

Use Axle Weight Limits by State as a starting point, then open each state page to check permit requirements, load-zoned roads, and route-specific restrictions before moving.

Sources

This page uses FHWA federal size and weight material for the legal categories.