What Are the Legal Axle Weight Limits for Commercial Trucks?

Over-dimensional freight, especially overweight freight, causes extra difficulties during transit — the mass of the freight makes it harder to stop quickly, and excess weight can damage the surface of the road and the ground underneath. 

Experienced drivers compensate for the extra stopping distance by allowing a greater following distance and traveling at a slow, steady speed. 

Damage to the ground can be mitigated by adding more axles to the vehicle. Just as a building’s foundation distributes the weight evenly over a larger area, multiple truck axles spread the weight of the loaded vehicle to prevent damage to the road. 

Each state has different regulations for the maximum gross vehicle weight (total weight of the loaded truck and trailer) allowed on their roads. These weight regulations are based on the state’s infrastructure and what the roads can safely support. 

In addition to a total weight limit for a loaded truck, most states have weight limits for single axle, double axle and tri-axle trucks. These limits help preserve the quality of the road and provide an important public safety function. 

Since 1955, Anderson Trucking Service (ATS) has been hauling freight nationwide. We have extensive experience with heavy-haul shipping and the rules that govern it in every state. 

Because we place such a high priority on safety, we want to help everyone on the road understand the state-by-state rules that govern overweight vehicles. Read this article for an explanation on why weight limits matter, and for a thorough explanation of each state’s guidelines. 

What Is the Federal Maximum Gross Vehicle Weight for a Truck? 

Safety guidelines set by the federal government mandate that loaded semi-trucks and trailers weigh no more than 80,000 pounds in total. 

This limit includes the weight of the freight, whether it’s one large object or a collection of individual pieces like steel I-beams that can be arranged for even weight distribution. 

The 80,000-pound limit includes the curb weight of the empty truck and trailer, which will vary depending on the type of vehicle. 

Dry van trailers, for instance, weigh more than flatbed and step-deck trailers due to the enclosed trailer that protects van freight from the elements during transit. This added weight means that dry van trailers have a lower load weight capacity than other trailer types.

The tractor that pulls each load must also be accounted for in the total gross weight. These usually amount to about 32,000 pounds. 

It is important to note that the construction of various trailer types also contributes to their overall weight, resulting in differences in load capacity. To provide a general reference, here are the typical freight-weight thresholds for the three most common tandem-axle trailer types:

• 53-foot refrigerated trailers: 43,000 to 45,000 pounds
• 53-foot flatbed trailers: 45,000 to 48,000 pounds
• 53-foot dry van trailers: 43,000 to 46,000 pounds

This freight capacity weight must be evenly distributed among the truck’s axles, including the steer axle and the two drive axles.

What Are the DOT Weight Limits for Steer Axles?

The front steer axles of a semi-truck are typically responsible for carrying 12,000-15,000 pounds (6,000-7,500 pounds on each tire). However, it's important to note that this weight capacity may vary slightly depending on the specific make and model of the vehicle, as well as the overall distribution of weight throughout the load.

What Is the DOT Weight Limit for a Truck’s Drive Axles?

To comply with the federal limit of 80,000 pounds for the total gross vehicle weight, the two drive axles of a class-8 semi-truck typically support a maximum of 34,000 pounds. 

This weight is divided between the two axles: 

• 17,000 pounds on each axle 
• 4,250 pounds on each tire

These are the federal limits for each axle. Each state also has individual weight limit guidelines based on the number of axles on the truck. 

What Are the Legal Weight Limits By Axle? 

Overweight loads that exceed 80,000 pounds gross total weight require permits from each state and local jurisdiction along the route. 

This is the point where legal axle weight limits also become important. Each state defines its thresholds for single, tandem, and tridem-axle freight movement. Let's delve into these weight limits and regulations further.

What Is the Legal Weight Limit For Single-Axle Trailers?

Single-axle transportation equipment is limited to a maximum cargo weight of 20,000-25,000 pounds. This restriction applies to trailers, boosters and stingers. 

Going beyond this weight limit poses a risk of damaging roads, bridges and cargo, and compromising the safety of the motoring public. Heavier cargo will require a larger trailer with more axles.

What Is the Legal Weight Limit For Tandem-Axle Trailers?

Tandem-axle trailers, which have each axle spaced between 45 inches and 96 inches apart, are legally allowed to carry up to 34,000 pounds of weight on two axles. 

When combined with the two drive axles on the semi-tractor, standard tandem-axle trailers like step-decks and flatbeds can accommodate a total weight of up to 48,000 pounds without requiring a permit.

However, it's important to note that each state has its own regulations for tandem-axle loads that exceed these limits. This is why it's crucial to consult with an experienced transportation provider before moving overweight freight. 

As a general rule of thumb, you can expect to be allowed a maximum of 22,000 pounds per axle (44,000 pounds total) in the majority of states.

For your reference, here are the legal weight thresholds for cargo carried on tandem-axle trailers in the United States and Canada: 

Download the PDF

How Much Gross Weight Is Allowed On a Tandem-Axle Trailer?

The weight limit for your tandem-axle trailer will depend on the states you will be traveling through and the specifications of your equipment. 

Once you have mapped out your route and learned the weight limitations in each state, finding a solution becomes easier. 

For instance, let's say you have to transport freight through North Dakota and South Dakota. 

• Both of these states allow up to 44,000 pounds on tandem-axle trailers 
• Plus 34,000 pounds from the drive axles
• And 12,000-15,000 pounds from the steer axle
• Equals up to 93,000 pounds with the proper permits

It is important to note that the weight of your load does not have to be evenly distributed as long as the weight placed on each axle grouping does not exceed the legal limits. 

In addition to the state requirements, it’s also vital to remember the capacity limits of your trailer.

Many tandem-axle trailers are not designed to bear excessive amounts of weight, which can result in disaster if they are overloaded.

Fortunately, tandem-axle trailers aren’t the only solution for extra-heavy freight. 

What Is The Axle Weight Limit For Tri-Axle Trailers?

As with tandem-axle setups, the weight limits for three-axle trailers, including flatbeds, RGNs and step-decks, vary by state. 

Generally, states located west of the Mississippi River have more lenient axle weight limits compared to their eastern counterparts. Most of this infrastructure was built more recently and was designed for larger, heavy vehicles. 

A good rule of thumb is that in most states, a tridem trailer can carry up to 20,000 pounds per axle, totaling 60,000 pounds. 

However certain states like California, Nevada, Oregon and Washington have significantly stricter regulations for overweight freight movement on three-axle trailers. For example, California only allows a total weight of 51,000 pounds, or 17,000 pounds per axle.

Here are the tri-axle weight limits for the contiguous United States and Canada:

Download The PDF

It's crucial to be aware of these weight limits and regulations when planning your freight transportation to ensure compliance and safety throughout your journey.

How Much Gross Weight Can You Get on a Tri-Axle Trailer?

The maximum cargo weight you can transport using a tri-axle trailer will depend on the specific regulations of the states you are traveling through. 

As the number of axles required for your shipment increases, so does the complexity of the process. It is crucial that you work with a knowledgeable provider to guide you through this process. 

To illustrate this further, let's consider another scenario. Imagine you need to transport a shipment within Texas, from Houston to Dallas. 

• 20,000 pounds per axle (60,000 pounds in total)
• Plus the two drive axles of the truck pulling your load provide an additional payload of around 34,000 pounds. 

Since the weight limits for each axle do not need to be evenly distributed, as long as the limits for each axle are not exceeded, you can use the total weight of 94,000 pounds in various ways depending on how the weight is distributed on the load. 

In this instance, it would not be unreasonable to have 58,000 pounds on the trailer axles plus 35,000 pounds on the drive axles.

Understanding these limits is important for shippers who want to stay in compliance with local laws, and for avoiding future liability for safety and damage issues that can be caused by overloaded vehicles. 

Why Do Axle Weight Limits Matter?

Ensuring the safe and efficient movement of oversize freight is crucial in the trucking industry. Without proper oversight and adherence to legal axle weight limits, there is a higher risk of mishaps and accidents. 

These weight limits play a significant role in promoting the well-being of the trucking industry and the motoring public. By regulating the weight distribution on axles, we can maintain safety standards and prevent potential issues that may arise during oversized freight transportation.

Axle Weight Limits Promote Safety

Transporting standard freight shipments can be a challenging task, even under normal circumstances. When it comes to hauling heavier loads, the complexity and difficulty increase exponentially. 

This is especially true for truckers who are responsible for navigating state highways and city streets. Excess weight on the rear axles can make it incredibly challenging to maneuver successfully, especially when turning. 

That's why legal axle weight restrictions play a crucial role in ensuring the safety of the motoring public during the transportation of oversize/overweight goods. Without these restrictions in place, the risk of significant mishaps and accidents harming people and property would be greatly heightened. 

Axle Weight Limits Prevent Damage to Roadways and Equipment

As the weight of a shipment exceeds the standard limitations and pushes the gross vehicle weight beyond 80,000 pounds, the risk of causing damage to equipment and roadways significantly increases.

State, city, and interstate roadways can crack, fray and weaken under the pressure of concentrated masses. State-level per-axle weight limits serve as a crucial safeguard to ensure the preservation and maintenance of roads while facilitating the smooth operation of supply chains.

The owner of the truck and trailer also benefit from per-axle weight limits. The strain placed on trailers carrying overly heavy loads can affect their mechanisms and tires, potentially resulting in permanent damage. Axle weight limits help transportation companies avoid unnecessary maintenance and replacement costs.

Of course, nothing in the trucking industry is easy. Like many other regulations, legal axle weight limits vary by state. 

What Are the Legal Axle Weight Limits in Each State?

Each state sets its own legal axle weight limits. It is important to know the limit for each state on your route before setting out. The best source of information is the Department of Transportation website for each state. The information below, taken from this resource, is provided for your convenience. 

Understand Heavy Haul Regulations Before Shipping Freight

Both state laws and public safety require partnering with a transportation provider who understands heavy haul shipping regulations. Failing to follow these laws will result in additional fees, delays and in some cases liability for damage. 

An experienced shipping provider is also likely to have a fleet of vehicles available to carry even your largest loads safely to their destination. 

After confirming your carrier’s ability to safely move your freight, your next question is probably how much it will cost. Find the answer in What Does Heavy Haul Trucking Cost, which walks you through the cost of shipping overweight loads. 

The Heavy Haul Carrier Selection Checklist can help you find the right heavy haul carrier for your needs. If you’re interested in ATS’ heavy haul services, contact us for a quote.