Gross Weight Limits by State: 2026 Trucking Guide
When a truck is grossed out, it has hit its maximum legal weight. But that maximum varies by state, road classification, and number of axles. This guide breaks down the federal 80,000 lb baseline, state-by-state exceptions, and the bridge formula that governs axle spacing.
Ahmad Qazi
Founder & CEO, O Trucking LLC
Fact-Checked by O Trucking Editorial Team
Written by Ahmad Qazi, founder of O Trucking LLC, drawing on 9+ years dispatching for owner-operators. Learn more about us.
O TruckingGross Weight Limits by State: 2026 Trucking Guide
Key Takeaways
- The federal Interstate gross weight limit is 80,000 lbs and no state can set it lower on Interstate highways.
- Federal axle caps are 20,000 lbs on a single axle and 34,000 lbs on a tandem — you can be legal on gross but over on an axle.
- Bridge Formula B limits weight per axle group based on axle count and spacing, even when total weight is under 80,000 lbs.
- States can allow higher weights on non-Interstate roads with added axles or permits; Michigan tops out near 164,000 lbs.
- Seasonal frost laws temporarily cut allowable weights on posted northern routes, so a legal February load can be illegal in March.
- Hauling over the limit without a permit can bring fines of $10,000 or more per violation depending on the state.
The Federal 80,000 lb Baseline
Under federal law, the maximum gross vehicle weight (GVW) for a standard 5-axle combination vehicle on Interstate highways is 80,000 pounds. This includes the weight of the tractor, trailer, fuel, driver, and cargo combined. The limit was established by the Surface Transportation Assistance Act of 1982 and has not changed since.
Within that 80,000 lb cap, federal law also sets per-axle limits: 20,000 lbs on a single axle and 34,000 lbs on a tandem axle (two axles spaced 40 to 96 inches apart). Steer axles are typically limited to 12,000-14,000 lbs depending on tire ratings. These individual limits mean you can be overweight on an axle even if your total GVW is under 80,000 lbs.
| Limit type | Maximum weight | Notes |
|---|---|---|
| Gross vehicle weight | 80,000 lbs | 5-axle combination on the Interstate system |
| Single axle | 20,000 lbs | One axle carrying the load |
| Tandem axle | 34,000 lbs | Two axles spaced 40–96 inches apart |
| Steer axle | 12,000–14,000 lbs | Set by tire and component ratings, not federal statute |
| Axle group | Per bridge formula | Depends on axle count and spacing (see below) |
State-by-State Variations
States cannot set weight limits lower than the federal standard on Interstate highways, but they can set their own limits on state and local roads. Some states also have “grandfather rights” that allow higher Interstate weights because those limits existed before the 1982 federal law.
Michigan
Michigan allows the highest gross weights in the nation — up to 164,000 lbs on certain state routes with an 11-axle configuration. Michigan uses an axle weight table instead of the federal bridge formula, rewarding carriers that add axles to spread the load.
Nevada, Utah, and Western States
Several western states allow higher weights with additional axles. Nevada permits up to 129,000 lbs on certain routes. Utah allows up to 129,000 lbs with proper permits and axle configurations. These higher limits reflect the mining and agricultural industries in these states.
Interstate vs Intrastate
The federal 80,000 lb limit applies to Interstate highways. State highways, county roads, and local roads may have different limits — some higher (with permits), some lower (especially on bridges and seasonal roads). Always check the specific route, not just the state.
Bridge Formula B
Overweight Permits and Special Routes
Every state offers overweight permits for loads that exceed standard limits. These permits specify exact routes, travel times (often restricted to daylight hours), and may require pilot cars or escort vehicles. Permit fees range from $15 to several hundred dollars depending on the state, weight, and distance. Multi-state hauls require separate permits from each state.
Certain routes are designated as overweight corridors — particularly for heavy industries like logging, mining, and agriculture. Knowing these routes is essential for carriers that regularly haul heavy freight. The overweight fines guide covers what happens when you exceed limits without a permit.
Always Verify at the State Level
Seasonal “Frost Law” Reductions
Many northern states — including Michigan, Minnesota, Wisconsin, and others — impose seasonal weight restrictions, often called frost laws or spring thaw restrictions. During the few weeks each spring when the ground thaws from the surface down, roadbeds lose strength and states temporarily cut allowable axle weights, sometimes by a large margin, on posted routes. These reductions appear suddenly and can change the same week you plan a haul.
Because the timing depends on weather, frost-law dates are not fixed on the calendar. Check the state DOT's seasonal restriction page or sign up for its load-restriction alerts before running heavy in late winter and early spring. A load that grosses out legally in February may be illegal on the same road in March.
Practical Advice for Staying Compliant
The safest approach is to treat 80,000 lbs as your hard cap on Interstate runs and verify state-specific limits for any non-Interstate route. Weigh your truck at CAT Scale locations before crossing state lines when you are running heavy. Keep permits accessible in the cab — not buried in a folder. And remember that individual axle weights matter as much as total gross weight. A truck that grosses 78,000 lbs can still be cited if a tandem axle is over 34,000 lbs.
Weight enforcement varies by state. Some states are aggressive with portable scales and frequent roadside checks. Others rely primarily on fixed weigh stations. Knowing which states prioritize weight enforcement helps you plan accordingly — but compliance should be your standard everywhere.
Common Weight-Compliance Mistakes
- Watching only the gross number and ignoring the per-axle caps — a 78,000 lb truck is still illegal with a tandem over 34,000 lbs.
- Assuming the 80,000 lb Interstate limit carries onto state highways, county roads, or weight-posted bridges, where limits can be lower.
- Forgetting to slide the trailer tandems or fifth wheel to balance the load before scaling.
- Running heavy in late winter or spring without checking the state DOT for active frost-law reductions.
- Crossing state lines on an overweight load with a permit from only one state instead of one for each state on the route.
- Trusting an onboard air-gauge estimate instead of a certified scale ticket that holds up at a weigh station.
Weight Limits FAQ
Common questions about truck weight limits by state
What is the federal gross weight limit for trucks?
The federal gross vehicle weight limit is 80,000 pounds for a standard 5-axle tractor-trailer combination on Interstate highways. This applies to all Interstate routes unless a state has been grandfathered with a higher limit. The 80,000 lb limit has been in place since the Surface Transportation Assistance Act of 1982.
Which states allow more than 80,000 lbs?
Several states allow higher gross weights on state roads. Michigan allows up to 164,000 lbs on certain state highways with enough axles. Other states with higher intrastate limits include Nevada, Utah, and several states that permit higher weights with special permits or additional axles. These higher limits generally apply to state highways, not Interstates.
What is the bridge formula?
Federal Bridge Formula B (also called Bridge Formula W) determines the maximum weight allowed on a group of axles based on the number of axles and the distance between them. The formula prevents excessive weight concentration that could damage bridges. Even if your total weight is under 80,000 lbs, you can still be overweight on a bridge formula calculation if axles are too close together.
Do I need a permit to haul overweight loads?
Yes. If your load exceeds the federal 80,000 lb limit or any applicable axle weight limit, you need an overweight permit from each state you will travel through. Permits specify the route, time of travel, and may require escort vehicles. Penalties for hauling overweight without a permit can reach $10,000 or more per violation depending on the state.
What is the maximum weight on a single and tandem axle?
On Interstate highways, federal law caps a single axle at 20,000 pounds and a tandem axle group (two axles spaced 40 to 96 inches apart) at 34,000 pounds. Steer axles are not set by federal statute but are usually limited to 12,000 to 14,000 pounds based on tire and suspension ratings. You can pass the 80,000 lb gross limit and still be cited if one axle group is over its individual cap, which is why sliding the trailer tandems and fifth wheel to balance the load matters.
Can you carry 80,000 lbs in every state?
Yes for the Interstate system — every state must allow at least 80,000 lbs on Interstate highways, and states cannot set a lower limit there. On state highways, county roads, and local roads the limit can be higher (with the right axles or permits) or lower, especially on weight-posted bridges and during spring thaw 'frost laws' that reduce allowable weights for several weeks. Always confirm limits for the exact route, not just the state.
How do you know if your truck is overweight before a scale?
Weigh the truck on a certified platform scale, such as a CAT Scale, which reports steer, drive, and trailer axle weights separately so you can spot an over-axle problem even when your gross is legal. Many trucks also have air-gauge or onboard scale readings that estimate axle weights, but those are approximations — a certified scale ticket is what holds up at a weigh station or in court.
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