| This article is part of the highway renumbering series. | |
|---|---|
| Alabama | 1928, 1957 |
| Arkansas | 1926 |
| California | 1964 |
| Colorado | 1953, 1968 |
| Connecticut | 1932, 1963 |
| Florida | 1945 |
| Indiana | 1926 |
| Iowa | 1926, 1969 |
| Louisiana | 1955 |
| Maine | 1933 |
| Massachusetts | 1933 |
| Minnesota | 1934 |
| Missouri | 1926 |
| Montana | 1932 |
| Nebraska | 1926 |
| Nevada | 1976 |
| New Jersey | 1927, 1953 |
| New Mexico | 1988 |
| New York | 1927, 1930 |
| North Carolina | 1934, 1937, 1940, 1961 |
| Ohio | 1923, 1927, 1962 |
| Pennsylvania | 1928, 1961 |
| Puerto Rico | 1953 |
| South Carolina | 1928, 1937 |
| South Dakota | 1927, 1975 |
| Tennessee | 1983 |
| Texas | 1939 |
| Utah | 1962, 1977 |
| Virginia | 1923, 1928, 1933, 1940, 1958 |
| Washington | 1964 |
| Wisconsin | 1926 |
| Wyoming | 1927 |
In late 1925, the Iowa State Highway Commission, now known as the Iowa Department of Transportation, announced plans to renumber several state highways. The changes to the highway system were a result of the creation of the United States Numbered Highway System. The new U.S. Highways replaced several of the state's primary roads and other routes were renumbered in order to eliminate driver confusion between the two systems. As the new highways were being signed, Iowa's state highways were given a new circular route marker. Previously, the primary road number was stenciled in black onto a telegraph pole over a band of yellow paint.