Oversize Load Frost Law Restrictions

Below are weight restriction, commonly referred to as “frost laws”, resources for planning oversize load travel. State Department of Transportations (DOT) and local agencies enact weight restrictions to protect roads.

What Are Frost Laws?

Frost laws are weight restrictions on certain state and county roads to reduce damage to roadways caused by heavy loads at the time of year when highway pavements are most vulnerable. DOTs set oversize load restrictions as weather and roadbed conditions require, then removes these restrictions when roadbeds are stable enough to carry legal weight traffic without damage.

Here is a list of state’s with frost laws in place which can affect oversize load travel.

Michigan

Effective 6 p.m. on Tuesday, February 17, 2026 weight restrictions will be imposed and enforced on all state trunk line highways from the Indiana/Ohio Border north to and including US-10 in Ludington in Mason County from the M-116 intersection then east to US-127 in Clare County then north on US-127 to M-61 then east on M-61 ending at the intersection of US-23 in the City of Standish, Arenac County.

Effective 6 a’.m. Monday, March 9, 2026 weight restrictions will be lifted on all state trunkline highways from the southern Michigan border north to and including the following route beginning on M-43 in the City of South Haven, then east on M-43 to US-131 in Kalamazoo County, then south on US-131 to I-94 in Kalamazoo County then east on I-94 to US-23 in Washtenaw County, then north on US-23 to I-96 in Livingston County then east on I-96 to M-59 in Livingston County then continuing east on M-59 ending at the I-94 interchange in Macomb County. North of the route listed, restrictions will be imposed and enforced on all state trunklines including all of the Upper Peninsula and Mackinac Island.

MI STATE ROUTES: https://mdotjboss.state.mi.us/APSWB/SWBHome.htm?bulletin=weight

MI COUNTY ROADS: https://micountyroads.org/business/seasonal-weight-restrictions/

MI Spring Weight Restrictions:
https://mdotjboss.state.mi.us/APSWB/SWBHome.htm?bulletin=weight

Minnesota

The Minnesota Department of Transportation will end winter load increases in the CENTRAL frost zone Friday, March 6, 2026 at 12:01 AM.

The Minnesota Department of Transportation will start spring load restrictions in the CENTRAL frost zone Friday, March 6, 2026 at 12:01 AM.

Spring load restrictions are scheduled to begin in the SOUTH, SOUTHEAST and METRO zones Tuesday, March 3, 2026.

Seasonal load limit (frost) zones and restricted routes can be found on the MnDOT load limits map.

Start and end dates and other load limit information are shown at mndot.gov/loadlimits.

Overweight permits for more than 80,000 pound gross vehicle weight will continue and new permits will be issued if all axle and group weights are legal (axle weight limits).

Full-summer overweight permits can be issued, during the spring load restriction period, for travel on the interstate system only.

Middle-range overweight permits become available within each SLL zone when spring load restrictions are lifted.

Ending dates for spring load restrictions are variable and based on how weather is affecting roadway strength.

MN STATE ROUTES: http://www.dot.state.mn.us/loadlimits/maps.html 

MN COUNTY ROADS: https://micountyroads.org/business/seasonal-weight-restrictions/

North Dakota

The NDDOT has observed that the most significant pavement damage occurs during the first four weeks after the onset of spring thaw. Accordingly, the NDDOT closely monitors weather forecasts and sub-base temperatures so load restrictions can be posted on short notice to limit damage to the highway system.

ND Updates: https://www.dot.nd.gov/driver/commercial/north-dakota-load-restrictions

Wisconsin

Spring thaw and Class II roadway restrictions begin in Zones 1 and 2 on Monday, March 9, 2026, at 12:01 AM CDT. Spring Thaw and Class II roadway restrictions were already in place in Zones 3, 4, and 5.

Posted Road restrictions begin in Zones 1, 2, and 3 Monday, March 9, 2026, at 12:01 PM CDT. Posted Road restrictions were already in place in Zones 4 and 5.

WI Updates: https://wisconsindot.gov/Pages/dmv/com-drv-vehs/mtr-car-trkr/ssnl-wt-rsrctns/frozenroad.aspx