Frost/Spring/Thaw Restrictions (frost restrictions) are seasonal weight restrictions, most common in Northern states, to protect roadways during the spring thaw. Generally, frost restrictions start in early March and last eight weeks. Frost restrictions are kept in place until the roads, shoulders, and ground are thawed and dry, but can be reinstated if low temperatures refreeze the ground. Frost restrictions are focused in the Northern United States where there are low enough temperatures to freeze the ground. Frost laws can be variable in timing and apply to different roadways. A number of states such as Vermont, Illinois, and Ohio have restrictions only on roadways not maintained by the state such as city or county roadways.