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.
New routes
Former routes
Existing route changes NumberChange in length Southern or western terminus Northern or eastern terminus Formed Removed Notes mi km
Notes
References
See also List of Iowa state highways