Spring freight season: produce, construction and frost laws

Spring load restrictions (frost laws)

Everything below was checked against the official sources at the bottom of this page on November 4, 2026. When frozen ground thaws, the base under a road is soft and heavy axles break it up. MnDOT's research page says each spring day does about 5 times the damage of a summer day. So northern states lower legal axle weights on weaker roads until the base firms up. What that means for a load:

• Michigan: MDOT sets restrictions from frost depth, road conditions and forecasts. On seasonal routes (red on its map) axle weights drop 25% on concrete and 35% on asphalt, with a 35 mph limit for some vehicles; all-season routes have no reduction. In 2026 they began 6 p.m. Feb 17 from the Indiana and Ohio borders north and the last were lifted May 15.
• Minnesota: restrictions start in a zone when the thawing index passes 25 degree-days on the 3-day forecast, with at least 3 days' notice. MnDOT's map shows the routes held to 5 or 7 tons during restrictions; state, U.S. and interstate routes not on the legend are 10-ton. County and city roads start and end with the state unless posted otherwise.
• Wisconsin: Class II road restrictions typically run from early March to the first or second week of May, and about 170 miles of state highway are posted because they can't carry even the 80,000 lb legal load in spring.
• North Dakota: NDDOT posts restrictions from subsurface temperature probes, forecasts and deflection testing, sometimes on short notice. It says the worst damage comes in the first four weeks after the thaw starts.

Local roads are often posted separately by counties and townships, so a pickup off a county road can be restricted even when the highway isn't. Check the state's page the day you book, not the week before. Our state dispatch pages cover each state's other trucking rules.

Where to check restrictions

• Michigan: MDOT's spring weight restrictions page, its weight bulletins and the Truck Operators Map, or 800-787-8960.
• Minnesota: MnDOT's load limits page and maps, or the recording at 1-800-723-6543. County roads are on each county's site.
• Wisconsin: WisDOT's seasonal weight restrictions and posted roads pages, or (608) 266-8417.
• North Dakota: NDDOT's load restrictions page and the current order on its travel information map, or 701-328-2545.

If a load would put you over a restricted axle weight, ask the broker for a lighter load, a different route on all-season roads, or a permit where the state offers one. See oversize and overweight permits and the bridge formula calculator for axle spacing.

Construction season freight

Building work slows in winter and picks up in spring. The Census Bureau publishes construction spending (value put in place) every month and adjusts it for season, because weather moves the raw numbers so much; its own example is the January drop in Northeast home building from cold and storms. For carriers that means more lumber, steel, pipe, block, aggregate and equipment moves as the ground thaws.

Construction loads are mostly flatbed, step deck and dump work, and the jobsites are often on the local roads that spring restrictions hit first. Plan the weight before you quote. Our guides on dump truck and construction hauling, flatbed tarping and coil loads and cargo securement cover the rules, and flatbed dispatch and step deck dispatch cover the loads.

Produce and the ag exemption

Reefer carriers follow produce north as the season moves. USDA's free National Truck Rate Report shows truck availability (surplus to shortage) and per-load rates by shipping area each week, which tells you where shippers are short on trucks. Our spring produce guide for reefers covers the regions, the report and FDA's temperature rules.

Hauling farm products? Under 49 CFR 395.1(k), during planting and harvesting periods as each state sets them, hours of service don't apply to drivers hauling agricultural commodities within 150 air-miles of the source, farm supplies within 150 air-miles of the distribution point, or livestock within 150 air-miles of the final destination. Past 150 air-miles the HOS rules apply. See livestock and the ag exemption.

A spring plan for a small carrier

• In February, sign up for the email alerts of every northern state you run (Michigan, Minnesota, Wisconsin and North Dakota all offer them).
• Before you quote a heavy load, check the pickup and delivery roads, including county roads, against that day's restrictions.
• Watch USDA's truck rate report for the regions turning short on reefers, and set up with produce brokers before the rush.
• For flatbed and dump work, line up building supply and aggregate shippers early. Our freight market calendar shows how spring fits the year.

Want a dispatcher to plan around the restrictions? Dispatch is a simple percentage of each load, quoted for your truck, and your first load is free if you have your own active MC. Call (747) 210-0227.

Questions carriers ask