The Michigan Department of Transportation announced on Apr. 20 that it will continue to lift spring weight restrictions on state trunkline highways, with the latest changes taking effect at 6 a.m. Thursday, April 23. The new policy applies to all state trunkline highways from the southern Michigan border north up to and including the Mackinac Bridge.
The adjustment is part of an annual effort by MDOT to protect roads during seasonal thawing when pavement and underlying soil are most vulnerable. These restrictions are important for preventing road damage as frozen ground begins to thaw and moisture becomes trapped beneath the surface, making roadbeds more susceptible to issues like potholes.
Frost restrictions remain in place for areas north of the Mackinac Bridge, covering the entire Upper Peninsula and Mackinac Island. In these regions, specific rules apply: routes marked as “all-season” have no reduction in legal axle weights; extended permits are valid for oversize loads within restricted areas; but single-trip permits will not be issued for overweight or oversized loads exceeding certain dimensions. On “seasonal” routes, posted weight reductions range from 25 percent for rigid pavements to 35 percent for flexible pavements, with a maximum speed limit of 35 mph imposed on some vehicles.
Drivers must follow posted speed limits and check online resources for details about truck speed restrictions as well as rules regarding propane fuel delivery and public utility vehicles. MDOT determines when weight restrictions begin each year by measuring frost depths along highways, monitoring weather forecasts, and observing road conditions until stability returns.
MDOT manages nearly 10,000 miles of state highways along with more than 4,800 bridges and other transportation infrastructure across Michigan according to its official website. The department employs over 2,800 people statewide through seven regions and numerous service centers according to its official website. Its mission is focused on serving communities and supporting economic activity through transportation efforts according to its official website.
Leadership at MDOT includes a director along with chief administrative officers overseeing broad operations according to its official website. The agency maintains not only M, I, and US highway routes but also bridges, rail services, aviation programs, non-motorized trails such as bike paths—and sets safety standards statewide according to its official website.
For further information or updates about weight restriction changes or related regulations affecting trucking companies—including those based in New Jersey or Canada—MDOT encourages individuals or businesses to visit www.Michigan.gov/Truckers under “Restrictions” or call designated hotlines.
