The Michigan Department of Transportation has once again implemented its annual spring weight restrictions to safeguard its roads. Starting at 8 a.m. on March 8th, the weight limitations will be enforced on all state trunkline highways located above a specific line, beginning at M-46 in Muskegon County and extending east to US-131, then north on US-131 to M-46, then east to the intersection of M-25 in Port Sanilac Sanilac County, and covering the entirety of the Upper Peninsula.

Weight restrictions will be enforced on all state trunk lines situated north of a particular demarcation line. State routes are usually identified by M, I, or US designations.

In the restricted areas, the following will apply:

  • 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 winter comes to an end and the roads begin to thaw, the melting snow and ice penetrate the ground, saturating it. This softening of the roadbed, caused by trapped moisture beneath the pavement, makes it more vulnerable to damage during the spring thaw. This issue exacerbates the already-existing problem of potholes, which have been created by the numerous freeze-thaw cycles that have occurred throughout the winter season.

The Michigan Department of Transportation (MDOT) decides on the starting date of weight restrictions each spring by assessing the frost depths along the state highways, observing the current road conditions, and tracking weather forecasts. These weight restrictions will remain in place until the frost line has sufficiently deepened to enable the moisture to escape and the roadbeds to regain their stability.

If you require details or updates on weight restrictions, you can call 800-787-8960 or visit MDOT’s website at www.Michigan.gov/Truckers, and access the information under “Restrictions and Conditions.” The MDOT Truck Operators Map identifies all-season routes in green and gold, and it is available on the website. Furthermore, you can sign up to receive email alerts about any updates.