Starting at 6 a.m. on Monday, March 27, the Michigan Department of Transportation will be making changes to the spring weight restrictions that are put in place every year to safeguard the state’s roads. These new adjustments will allow all state trunkline highways from the southern border of Michigan to US-10, which runs from Ludington to Standish, to have their weight restrictions lifted. This includes the entirety of the thumb area in Michigan.

Weight restrictions will be enforced on all state trunklines located north of a certain line. These trunklines are typically marked with designations such as M, I, or US.

  • On routes designated as “all-season” (designated in green and gold on the MDOT Truck Operators Map), there will be no reduction in legal axle weights.
  • On routes designated as “seasonal” (designated in solid or dashed red on the MDOT Truck Operators Map), there will be a posted weight reduction of 25 percent for rigid (concrete) pavements and 35 percent for flexible (asphalt) pavements.
  • All extended permits will be valid for oversize loads in the weight-restricted area on the restricted routes. Single-trip permits will not be issued for any overweight loads or loads exceeding 14 feet in width, 11 axles, and 150 feet in overall length on the restricted routes.

As the weather warms up in spring, roads that have been frozen all winter start to thaw out from the surface downwards. This causes melting snow and ice to seep into the softened ground underneath. When the roadbed becomes saturated with trapped moisture during the spring thaw, it becomes more vulnerable to damage. This is why potholes become a bigger problem during this time, especially given the numerous freeze-thaw cycles that occurred over the winter.

The Michigan Department of Transportation (MDOT) decides when to begin the spring weight restrictions by measuring the depth of frost along state highways, observing the condition of the roads, and keeping an eye on weather forecasts. The weight restrictions will remain in effect until the frost line is deep enough to allow trapped moisture to escape, and the roadbeds become more stable.

For weight restriction information and updates, call 800-787-8960, or access this information on MDOT’s website at www.Michigan.gov/Truckers, under “Restrictions and Conditions.” All-season routes are designated in green and gold on the MDOT Truck Operators Map, which is available online. You also may sign up to receive e-mail alerts.