Emmet County Road Commission

For 69 years, Michigan law has provided for seasonal weight restrictions to protect vulnerable paved and unpaved roads during March, April and May, due to the prolonged time required to thaw frost in the roadbed and adjacent right-of-way.
 
Engineers responsible for the 121,000 total miles of Michigan roads make these decisions locally to protect infrastructure based on research and experience with the time needed to stabilize the roadbed after winter.
 
The 63,000 miles of local roads (low traffic volume) maintained by county road commissions and road departments are some of the most vulnerable. Most are not all-season roads, making them much more fragile than state DOT highways or county all-season primary roads.
 
Note: County road agencies make seasonal weight restriction decisions utilizing standardized methods to determine frost depths, as well as coordinating with neighboring counties with similar soil/climate conditions in order to facilitate commerce.