It's Time to Talk Frost Laws!

U.S. states with frost laws include: ID, IA, ME, MI, MN, MT, NE, NH, NY, ND, PA, SD, VT, WA, WI, WY

To get current information on these laws visit: FHWA 511 Travel Information Telephone Services

Canadian provinces with frost laws include: AB, BC, MB, NB, NS, ON, PEI, QB, SK, YT

To get current information on these laws visit: How to View Road Conditions Across Canada and the U.S. | AMA

Frost laws, which are seasonal load/weight restrictions imposed by certain states or local governments when the ground begins to thaw are typically in effect from early March through mid-June depending on how cold the temperature was during the winter months. Frost laws typically restrict the weight of vehicles to 5-10 tons per axle.

Frost laws are designed to prevent heavy vehicles from operating on soft/thawing roads and bridges and to prevent damage to those roads and bridges such as shifting or sinking ground, potholes and cracks. This damage can prove costly and is also a threat to driver/carrier/public safety. 

Additionally, frost laws can protect the environment preventing soil erosion and pollutants running into nearby water sources.

While frost laws are important, they can be difficult to enforce and can lead to costly delays and route recalculations for business that rely on heavy loads to transport their products. Outreach programs to carriers and drivers are often the best way to educate and enforce these laws.

States with frost laws differ by state and can change throughout the effective period. Some are based on axle weight, while others depend on max speeds.