1969 Iowa highway renumbering

On January 1, 1969, the Iowa State Highway Commission, now known as the Iowa Department of Transportation, renumbered several state highways. The changes to the highway system fixed a number of issues: creating continuous route numbers across state lines, removing duplicate route numbers where they were unnecessary, and extending route numbers in some locations. Twenty-six sections of highway were assigned new route numbers, duplicate route numbers were removed on eleven sections, and one route number was extended to another section.

Existing route changes
{|class="wikitable sortable plainrowheaders" !scope="col" rowspan=2 | Number !colspan=2 class=unsortable|Change in length !scope="col" class="unsortable" rowspan=2 | Southern or western terminus !scope="col" class="unsortable" rowspan=2 | Northern or eastern terminus !scope="col" data-sort-type="date" rowspan=2 | Formed !scope="col" data-sort-type="date" rowspan=2 | Removed !scope="col" class="unsortable" rowspan=2 | Notes !scope="col" data-sort-type="number" | mi !scope="col" data-sort-type="number" | km