Minnesota truck weight limits
On Interstate highways in Minnesota, federal weight limits apply. Four checks decide whether your truck is legal — and the one that surprises most drivers is the Federal Bridge Formula, which can fail a truck that passes every other limit.
Federal limits on Minnesota Interstates
| Limit | Maximum | Applies to |
|---|---|---|
| Single axle | 20,000 lb | Any one axle |
| Tandem axle group | 34,000 lb | Axles 40–96 inches apart |
| Tridem axle group | governed by the bridge formula | 3 axles in a group (no flat federal cap) |
| Gross vehicle weight | 80,000 lb | The whole rig |
| Bridge formula | varies by spacing | Every group of 2+ axles |
The bridge formula check
L is the spacing in feet between the outer axles of a group, N the number of axles. A standard 5-axle rig at 51 ft is capped at 79,500 lb by this formula — under the 80,000 lb gross limit. Full explanation with worked examples.
Minnesota-specific rules
Minnesota's weight rules are seasonal, which trips up out-of-state carriers. On the Interstate, federal limits govern: 20,000 lb single axle, 34,000 lb tandem, 80,000 lb gross, plus the Federal Bridge Formula. Off the Interstate, Minnesota classifies highways by how much they can carry (10-ton, 9-ton, 7-ton routes), and — because frozen ground carries more — it raises axle and gross limits by 10% each winter (Minn. Stat. § 169.826). The flip side is spring load restrictions: when the thaw hits, MnDOT cuts limits on posted routes. Gross over 80,000 lb needs a permit (Minn. Stat. § 169.824).
Minnesota exceptions to the federal limits
Minnesota controls gross weight with an axle-spacing schedule (Minn. Stat. § 169.824) and posts highways by tonnage class:
| Measure | Limit |
|---|---|
| Single axle (10-ton route) | 20,000 lb |
| Tandem axle group | 34,000 lb |
| Maximum gross (without permit) | 80,000 lb |
| Lower-class routes (9-ton / 7-ton) | reduced per posting |
- Winter increase: axle and gross limits rise 10% statewide from Jan 1 – Mar 7, plus a northern-zone increase in December and a harvest allowance for sugar beets and potatoes within 75 miles (Minn. Stat. § 169.826).
- On Interstates, federal limits govern — the winter increase does not apply there.
Seasonal & designated-route rules in Minnesota
This is where Minnesota is genuinely different. Winter weight increase: because frozen roadbeds carry more, weight limits go up 10% statewide from January 1 to March 7, with an added northern-zone bump in December — the opposite of most states. Spring load restrictions: as the ground thaws (typically March–May), MnDOT orders sharp reductions on posted routes (dropping 10-ton roads to 9-, 7- or 5-ton) to prevent pavement damage, with start and end dates published by district. Always check MnDOT's current load-limit postings before running heavy in spring, and confirm you still qualify for the winter increase before relying on it.
Overweight permits in Minnesota
Gross weights over 80,000 lb, or loads exceeding the posted route class, need an oversize/overweight permit from MnDOT (single-trip or annual), route-specific by bridge and pavement rating and by season.
Fines & enforcement in Minnesota
Enforced by the Minnesota State Patrol Commercial Vehicle Section at fixed scales and with portable/mobile enforcement. Overweight violations carry graduated per-pound penalties; running through a posted spring load restriction is a separate and costly violation.
What dispatchers should check in Minnesota
- Route tonnage class — off the Interstate, check whether the road is posted 10-ton, 9-ton or 7-ton; it sets your axle limit.
- Season — the 10% winter increase runs Jan 1 – Mar 7; spring load restrictions (Mar–May) cut limits hard on posted routes. Check MnDOT postings.
- Over 80,000 lb — needs a MnDOT permit.
- Interstate — federal 20,000 / 34,000 / 80,000 plus the bridge formula; no winter increase.
Minnesota truck weight — frequently asked questions
How much can a truck weigh in Minnesota?
On Minnesota Interstates the federal gross-weight limit is 80,000 lb, with a 20,000 lb single-axle limit, a 34,000 lb tandem limit and the Federal Bridge Formula. Minnesota sets its own limits on non-Interstate roads — see the Minnesota-specific rules on this page.
Does Minnesota follow federal truck weight limits?
On the Interstate system, yes — federal limits govern in every state. Off the Interstate, Minnesota applies its own axle, gross and permit rules, detailed on this page where they have been verified against the official state source.
What is the single-axle weight limit in Minnesota?
The federal single-axle limit of 20,000 lb applies on Minnesota Interstates. Some states set a different single-axle figure on non-Interstate roads — check the Minnesota-specific section above for the governing number.
What is the maximum tandem-axle weight in Minnesota?
On Minnesota Interstates the federal tandem limit is 34,000 lb. Several states allow a different tandem weight on non-Interstate roads — see the Minnesota exceptions above for the figure that governs.
Scaled heavy in Minnesota?
If the trailer tandems are over, the fix is usually a computed tandem slide, not unloading — see how sliding tandems shifts weight. And here's what an overweight ticket really costs before you decide to run it.
Run your scale-ticket weights through the federal and bridge-formula calculator in your browser. The full platform predicts axle loads from load placement before you load, computes the exact slide-to-legal fix, and applies Minnesota rules on top of the federal baseline.
Open the free calculatorOur calculator runs the federal single, tandem, gross and Bridge Formula checks in seconds. The full platform adds per-state limits, axle-load prediction and the slide-to-legal fix.
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