Future Interstate 435 Iowa

Overview

Added to the federal surface transportation bill in August 2026, Interstate 435 is the planned designation for the outer loop encircling the Greater Des Moines area in central Iowa. The route will supersede Iowa Highway 5 along the south leg of the beltway, from I-35 east to U.S. 65, and U.S. 65 along the eastern leg northward to I-80 in Altoona. Adding the freeway to the Interstate system will allow increased the legal truck weight and allow for higher speed limits (Seiler, 2026).

The Iowa House and Senate previously passed House File 1025 on April 22, 2025 and May 12, 2025 respectively. The bill includes language removing the minimum speed requirement from the freeway loop and authorized the Iowa Department of Transportation and the Des Moines Area Metropolitan Planning Organization to undertake an analysis of alternative routes for farm traffic currently using the roadway (Wood, 2025). An increase in the minimum speed from 40 to 45 miles per hour might preclude slower farm traffic from using the corridor. Farmers utilize the bridge along U.S. 65/Iowa 5 across the Des Moines River (Wood, 2025).

Advocates for the change include community leaders in Bondurant, Pleasant Hill and Carlisle, recognizing the economic significance and project prioritization of being located along the Interstate system. Additionally, Dylan Mullenix, executive director of the Des Moines Area MPO, recognized the opportunity to reduce motorist confusion. He cited the concurrency of U.S. 65 and Iowa 5, which use opposite cardinal directions such that Iowa 5 southbound overlaps with U.S. 65 northbound (Wood, 2025).

If the federal surface transportation bill is passed in early 2027 and signed into law, then the Interstate designation shifts into a regularly process with the Federal Highway Administration (FHWA) (Seiler, 2026).

History

An outer loop for Des Moines was constructed from south West Des Moines east around Des Moines to Carlisle, Pleasant Hill and Altoona. Completed in 2002, the freeway is designated Iowa 5 along the south leg and as part of U.S. 65 from U.S. 69 north to Interstate 80 along the east leg. Several communities along the bypass pushed to have the loop designated as an Interstate in 2012. Precluding the upgrade however is the use of the route by slow moving farm machinery, as such vehicles are prohibited from using Interstate highways. However, an exception to this restriction was granted for the establishment of Interstate 555 in Arkansas. Additionally the freeway is not set with a minimum speed (Des Moines Register, 2012). A story from Iowa Public Radio (2014) indicated that more time will be allowed to study the possibility of upgrading the route.

West End  ‐ West Des Moines, IA

North at

I-35 north at Iowa 5 and the future west end of Interstate 435 in West Des Moines. 07/14/26

South at

Interstate 35 crosses the Raccoon River south leading into the directional T interchange (Exit 68) with Iowa 5/Future I-435 east. 02/21/20

East End  ‐ Altoona, IA

North at

U.S. 65 connects with Interstate 80 at the east end of Future I-435 along the Altoona city limits northeast of Des Moines. 02/21/20