Axle Weight

There are a number of trailer axle configurations, weight limit rules and regulations, and terms that can make understanding axle weight intimidating. Understanding the basic terms and calculations of axle weight, along with access to the right resources will have you talking and calculating axle weight with confidence. TruckingAgents.net provides the resources and education to help make drivers, agents, brokers, and dispatchers have a better understanding of axle weight and how they affect shipments.

As with any profession, knowing the terms is necessary to have a productive conversation. Below, is a basic tractor trailer axle configuration and the axle types. When discussing axle weights, refer to the axles by the terms listed below.

An axle group can consist of 1 or more axles, and are commonly seen and referred to as the following:

Now that we can label the axle types and groups we can talk about axle weight.

Axle Weight - Refers to the legal allowable gross axle weight on any particular axle group and type.

Although the state's and province's axle weight limits can vary, we can discuss what is most common. A common five axle tractor trailer combination has the following axle weight limits.

When you add the axle group limits you get a total of 80,000 lbs, which is the standard max gross weight a tractor trailer can be without an overweight permit. This max gross weight is going to include everything:

Here is an example of the advantage gained by using a tri-axle trailer group. In this example image, the commodity is setting toward the back half of the trailer and so more of the commodity weight is on the trailer axles than on the drive axles. Because the trailer axle group is a tri-axle configuration it can carry more weight legally. It's important to point out that this example still does not exceed the gross weight limit of 80,000 lbs.

A van trailer has the same rules as open deck trailer equipment on axle weights, but because van trailers typically haul palletized goods the weight is generally evenly distributed over the trailer and gross weight does not exceed the 80,000 lbs limit.

If the commodity hauled exceeds the axle group weight limit, then an overweight permit is required. A shipment would require an overweight permit even if only one axle group exceeds the axle group limit and the gross shipping weight does not exceed the 80,000 lbs.

The gross limit in this example does not exceed 80,000 lbs, but the trailer tandem axles exceeds the 34,000 lbs gross weight limit. The driver could try and reposition the load to move more weight from the rear trailer axles to the drive axles. If that is not possible, the driver would be required to haul this ship​ment with an overweight permit.