Iowa Primary Highway System - Secondary Roads

Secondary Roads

Secondary roads are defined simply by the Iowa Code as those roads under county jurisdiction. The 99 counties in Iowa divide the secondary road system into farm-to-market roads and area service roads. Farm-to-market roads, which connect principal traffic generating areas to primary roads or to other farm-to-market roads, are maintained by the route's respective county and are paid for by a special fund. The Farm-to-Market Road Fund consists of federal secondary road aid and 8% of Iowa's road use taxes. The farm-to-market road system is limited to 35,000 miles (56,000 km).

Unlike other states in the United States, Iowa's signed secondary roads are not numbered on a county-by-county basis. With exception to County Road 105, secondary roads use a uniform numbering grid using one letter and two or three numbers, e.g., E41. County roads running primarily east and west assigned letters (from north to south) A through J. County roads running primarily north and south are assigned letters (from west to east) K through Z. The letters I, O, Q and U are not used to avoid confusion with numbers and other letters.