Spring thaw and frost laws

When the ground thaws, roads weaken, and northern states cut the legal axle weights. An overweight move that is routine in February can be impossible in April. Here are the states and the windows.

Updated September 2026 · Figures from FreightDeck's audit of 51 US jurisdictions and its monthly market-rate check

Where and when

Windows shift with the weather; states post the exact start and end each year. Reductions are typically applied per axle on posted roads, and some routes close to overweight moves entirely.

What it means for heavy haul

• Overweight permits get harder or stop. Several states issue no overweight permits on frost-law roads during the window; the load waits or reroutes.
• Axle counts go up. A load that runs on a 7-axle in February may need 9 in April to meet the reduced per-axle limit, if a permit issues at all.
• Plan transformer deliveries around it. Northern data center and substation projects should schedule heavy deliveries before February or after the window.

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