A bill for an act relating to certain state highways not designated as part of the interstate road system, including the operation of implements of husbandry on such highways, and including applicability provisions.

SF 643 concerns the designation of a segment of State Highway 5 and US Highway 65 in Iowa and the operation of agricultural vehicles, known as implements of husbandry. It prohibits the Department of Transportation from designating this specific highway segment as part of the interstate system unless the U.S. government provides an exemption for vehicle weight and size, allowing current vehicles to continue operating there. If the segment is designated an interstate, implements of husbandry currently authorized on parts of it may continue to use it until an alternative bypass route is developed. The bill also requires the DOT to collaborate on a study to create this alternative route for agricultural vehicles.