Quick answer: Michigan's seasonal weight restrictions, often called frost laws, cut the legal axle weight on many roads while the ground thaws in spring. State law sets the reduction at 25 percent on concrete pavement and 35 percent on other roads during March, April and May, and road agencies post the exact dates for their roads. A loaded roll-off truck, a lowboy hauling an excavator, or a semi carrying pole barn materials can all be affected. Ask the provider whether your road is an all-season route, book heavy deliveries before or after the restriction period when you can, and confirm the current dates with your county road commission.
What frost laws are
When frost leaves the ground in spring, the soil under a road is soaked and soft, and heavy axles do the most damage. Michigan's motor vehicle code addresses this in MCL 257.722(8). During March, April and May, the maximum axle load is reduced by 25 percent on concrete or concrete-base pavement and by 35 percent on all other roads. The maximum wheel load drops to 525 pounds per inch of tire width on concrete and 450 pounds per inch on other roads.
The law requires the Michigan Department of Transportation and each local road agency to post the dates and the roads covered on their websites. It also lets them suspend the restrictions when conditions allow, or impose restricted loading at other times. In practice, restrictions start and end on dates each agency announces based on weather, so they differ from county to county and from year to year.
Who sets them on your road
- State highways (M-, US- and I- routes): MDOT. Its Truck Operators Map marks all-season routes, which keep normal legal axle weights, and seasonal routes, which take the 25 or 35 percent reduction. MDOT posts current restrictions at Michigan.gov/Truckers and on its restriction hotline, 800-787-8960.
- County roads: the county road commission. Most rural roads in mid-Michigan are county roads, and many are not all-season routes.
- City and village streets: the city or village.
Restrictions do not all end on one day. In 2026, for example, MDOT lifted restrictions on state routes in the Lower Peninsula and the eastern Upper Peninsula on April 30 while they stayed in place farther north.
What it means on a county road
County road commissions publish their own load tables. As one example, a Van Buren County information sheet lists these normal and restricted limits on seasonal roads:
| Axle spacing | Normal limit | Restricted limit |
|---|---|---|
| Axles 9 feet or more apart | 18,000 lb | 11,700 lb |
| Axles more than 3½ but less than 9 feet apart | 13,000 lb | 8,450 lb |
| Tandem axle assembly | 16,000 lb | 10,400 lb |
| Load per inch of tire width | 700 lb | 450 lb |
The same sheet limits trucks on restricted roads to 35 mph and says no overweight or oversize permits are issued above normal limits during the restriction period. Your county's figures and permit rules may differ, so treat this as an illustration and check with your own road commission.
How it affects common site services
Roll-off dumpsters
An empty container is light, but a full one is not. A hauler may need to pick up a container before it is full, use a smaller container, or route around a restricted road. Ask whether your road is restricted and whether the hauler will collect a full container during the restriction period, or only a partly filled one.
Equipment rental delivery
Compact equipment such as skid steers usually travels on a trailer behind a pickup or a single-axle truck. Larger machines, such as mid-size excavators, often move on a lowboy trailer, and the loaded rig may exceed restricted limits on a seasonal road. Ask the rental store which machines it can deliver to your address during the restriction period.
Pole barn and building materials
Trusses, steel and lumber for a post-frame building usually arrive on a semi. If your build starts in spring, ask the builder when the material delivery is scheduled and whether the driveway and road can take the load. A spring start may mean a delivery date set by the road agency rather than the builder.
Portable restrooms
Service trucks pump units on a schedule. On a restricted road the service truck may carry less, which can change the service day. Ask the provider how it handles service during the restriction period.
How to plan around frost laws
- Find out who maintains your road: MDOT, the county road commission, or the city or village.
- Check whether your road is an all-season route. All-season routes keep normal limits.
- Check the posted start and end dates on the road agency's website before booking a heavy delivery.
- Book deliveries of heavy equipment and materials before restrictions start or after they are lifted, when the schedule allows.
- Ask each provider how it handles the restriction period: smaller loads, partial pickups, a later delivery date, or a different route.
- Get any change to price or timing in writing before the job starts.
Questions to ask the provider
- Is my road a seasonal route, and are restrictions in place for my delivery date?
- Can you deliver and pick up during the restriction period, and with what limits?
- Will a restriction change the price, the container size, or the delivery date?
- If the road agency extends the restriction period, what happens to my booking?
Find providers who serve your county in our directories for roll-off dumpster rental, equipment rental and pole barn builders.
Sources
- Michigan Compiled Laws 257.722, seasonal load reductions in subsection (8) (FindLaw copy; check the current statute at legislature.mi.gov)
- MDOT: Annual spring weight restrictions continue to be lifted on Michigan's state roads (April 29, 2026)
- All-Season and Restricted Road System Load Limits, Seasonal Weight Restrictions information page (Van Buren County example)
- MDOT: Michigan.gov/Truckers, current restrictions
Last reviewed: 2026-10-12
This guide is general information, not legal, engineering or tax advice. Rules and prices change; confirm details with your local building or zoning office and with the provider before you commit.