Frost Laws: What They Are and How They Impact Spring Construction

Sunday, February 18, 2018

Michigan’s winter temperatures pose challenges to beginning any new construction project.  Then, just as sub-freezing temperatures give way to milder ones, frost laws post yet another challenge.  And they go into effect tomorrow, February 19.

Frost laws are weight restrictions on roads.  They are meant to protect roads during the annual spring cycle of thawing and freezing.

As temperatures warm and frost melts beneath a paved road, water is trapped between the pavement and the remaining ice layer beneath.  Heavy trucks and equipment traveling over this “spongy” road bed can cause significant and permanent damage. Thus, road agencies impose weight restrictions.  

During the months of March, April and May (or earlier if warranted, such as this year), the Michigan Department of Transportation (MDOT) and the Washtenaw County Road Commission can impose weight restrictions on any roads not designated as “all season roads,” which are roads that are designed for year round trucking - I-94, for example.

Each spring, MDOT determines when weight restrictions begin and when they end.  The Washtenaw County Road Commission puts is own seasonal weight restrictions in place which usually, but not always, coincide with MDOT’s weight restrictions. Nearly all roads in Washtenaw County are subject to weight restrictions.

While frost laws are in effect, construction delays are inevitable because heavy trucks carrying equipment - such as excavators - or carrying materials - such as full concrete trucks, trusses or drywall - cannot travel over seasonally restricted roads.

We’ll keep you informed if frost laws impact construction of your home.

- Betsy de Parry, VP, Sales and Marketing, (734) 216-5872 or