Michigan Enforces Spring Weight Restrictions On Roads

MICHIGAN — Spring is coming up and that means Michigan officials are enacting seasonal weight restrictions to protect the roads. It's a move the Michigan Department of Transportation (MDOT) does each year.

Here's a look at what will be enforced:

Effective 6 a.m. Monday, Feb. 24, weight restrictions will be imposed and enforced on all state trunkline highways within the following area of Michigan:

- Highways north of a line on M-43 in the city of South Haven east to US-131 in Kalamazoo County, then south to I-94 in Kalamazoo County and east to I-69 in Calhoun County, then north to Lansing and continuing east on I-69 to Port Huron in St. Clair County.
- Highways south of a line on M-46 in Muskegon County from US-31 Business Route in the city of Muskegon east to US-131, then north on US-131 to M-46 and east to I-75 near Saginaw, then north on I-75 to M-25 near Bay City and continuing east on M-25 to M-46 in Port Sanilac in Sanilac County, including the entire Thumb region. All state trunk lines between these two lines will have weight restrictions imposed and enforced. State routes typically carry M, I, or US designations.

When roads that have been frozen all winter begin to thaw from the surface downward, melting snow and ice saturate the softened ground. During the spring thaw, the roadbed softened by trapped moisture beneath the pavement makes it more susceptible to damage. This also contributes to pothole problems already occurring due to this winter's numerous freeze-thaw cycles.

In the restricted areas, the following will apply, MDOT said:

- 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.

Background on the process

MDOT determines when weight restrictions begin each spring by measuring frost depths along state highways, observing road conditions, and monitoring weather forecasts. Weight restrictions remain in effect until the frost line is deep enough to allow moisture to escape and the roadbeds regain stability.

County road commissions and city public works departments put in place their own seasonal weight restrictions, which usually, but not always, coincide with state highway weight restrictions. Signs are generally posted to indicate which routes have weight restrictions in effect.