Oversize Loads: How Big is Too Big?

Avoiding a citation for an overweight load starts with understanding the limits, and that’s not as simple as it sounds.

There are two primary limiters of vehicle weight:

• Rated gross value, and
• Allowed gross value.

These two limits are not only applied to the vehicle; they are also applied to axle groups, axles, and tires.

The ratings are set by the manufacturer of the vehicle and by the manufacturers of the components. The allowed weights are set, regulated, and enforced by federal, state, and local government agencies.

Maximum may never be met

Usually, the maximum gross weight allowed will be the state’s maximum allowed gross. Be careful though, because unless the load is perfectly balanced across the axles and groups, the maximum is rarely met due to one of the other limits being reached first. These limits include:

• The allowed axle weight(s) based on the state or local statutes,
• The allowed axle group weight based on the bridge law (each combination of axles and distance is determined separately),
• The allowed weight per tire or inch of tire width,
• Each tire’s rating, and
• The registered vehicle weight.

Different roads, different limits, permits required

The Federal Highway Administration (FHWA) sets weights that the state must allow on interstate highways, including:

• Maximum gross vehicle weight at 80,000 pounds,
• Maximum gross weight upon any one axle at 20,000 pounds, and
• Maximum gross weight on tandem axles at 34,000 pounds.

States can set their own limits, which can be higher or lower, on state and other highways.

When a vehicle or load is nondivisible, the FHWA allows the states to issue special permits. The permit process and the weights allowed by them can be as varied as the states themselves. Permits may, in addition to an increase in the approved gross vehicle weight or gross combination weight, provide increases to the allowed axle and group weights.

To avoid citations, remember to consider:

• All the vehicle’s component weight ratings, and
• The allowances for the local, state, and federal roads on which the vehicle operates.

The larger the area of operation, the more difficult the compliance task is, but also the more important. Use the FleetMentor Permit Advisor to check your route and get a quick summary of the federal and jurisdictional permits you will need to operate and transport a specific shipment.

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Order your oversize/overweight permit at www.kellerpermits.com.