2019 Iowa frost laws, seasonal load weight and restrictions. See also:Tire chain laws. Tire chain laws by location. Trucking regulations. Federal bridge formula. Exemptions from seasonal restrictions. Page 1 of 11 By WLSADMIN on August 23, 2019 / Frost law restrictions. / Leave a commentTags: frost, Iowa, laws, maps, restrictions, seasonal, speed, trucking, weight, winter Previous PostIdaho frost law restrictions. Next Post Michigan frost law restrictions.