Interstate 235 (Iowa)

Interstate 235 (Iowa) is an auxiliary Interstate route that forms a 13.8-mile east–west connector through the core of Des Moines and its western suburb West Des Moines. It links Interstate 35 and Interstate 80 with downtown Des Moines and provides primary access to institutions such as Iowa State Capitol, Des Moines University, Iowa State Fairgrounds, and cultural destinations including the Des Moines Art Center and Science Center of Iowa. The route is maintained by the Iowa Department of Transportation and serves as a major urban corridor for regional traffic, freight movements, and commuter flows connecting to U.S. Route 69, U.S. Route 6, and U.S. Route 65.

Route description

Interstate 235 begins at a full interchange with Interstate 35/Interstate 80 near West Des Moines and proceeds eastward, paralleling the Des Moines River through mixed commercial and residential zones adjacent to Jordan Creek Town Center, Valley West Mall, and the Pioneer Park area. The freeway crosses the Raccoon River and provides interchanges to arterial routes including U.S. 6 and Iowa 28, facilitating access to destinations such as Des Moines International Airport via connecting corridors and to civic centers including Principal Park and the Iowa Events Center. Approaching downtown Des Moines, I-235 runs parallel to MLK Jr. Parkway and Locust Street with interchanges serving Des Moines Civic Center, State Historical Building, and the John and Mary Pappajohn Sculpture Park. Eastbound lanes cross the Des Moines River again before terminating at an interchange with I-35/I-80 ramps and connections to U.S. 65 and Iowa 5, providing continuity to suburbs such as Ankeny and Waukee.

History

Planning for the Des Moines bypass and urban connector dates to mid‑20th century federal authorizations that produced the Interstate Highway System; early proposals involved coordination among the Iowa State Highway Commission and municipal leaders from Des Moines, West Des Moines, and Urbandale. Construction for what became I-235 advanced in phases during the 1960s and 1970s, influenced by funding from the Federal-Aid Highway Act of 1956 and local bond issues; notable engineering work included river crossings near the Des Moines River and complex interchanges with Iowa 281 alignments. Subsequent decades saw rehabilitation projects tied to urban renewal initiatives championed by mayoral administrations in Des Moines and by officials in the Iowa Department of Transportation, with major reconstruction in the 1990s and again in the 2010s to update pavement, bridges, and noise mitigation for neighborhoods adjacent to Ingersoll Avenue. Community responses mirrored nationwide debates similar to those in Portland and San Francisco about freeway impacts, leading to design compromises that incorporated aesthetic enhancements and improved pedestrian crossings near landmarks such as the Iowa State Capitol and the Des Moines Riverwalk.

Exit list

The exit sequence on I-235 provides connections to local and regional routes and is organized to serve downtown Des Moines and adjoining suburbs. Major interchanges include: - Western terminus: interchange with Interstate 35/Interstate 80 near West Des Moines, providing movements toward Kansas City and Davenport. - Exits to U.S. Route 6, linking to corridors toward Grinnell and Council Bluffs. - Interchanges with arterial streets such as Merle Hay Road, 42nd Street, and University Avenue, offering access to institutions like Drake University and Warren County commuter routes. - Downtown exits providing access to Iowa Events Center, Principal Park, and the Des Moines Arts Festival site near the Des Moines River. - Eastern terminus: reconnection to Interstate 35/Interstate 80 and ramps toward Ankeny and Cedar Rapids via U.S. Route 65.

Future plans and improvements

The Iowa Department of Transportation and regional planning agencies have proposed phased improvements addressing capacity, resilience, and multimodal access on I-235. Planned projects include bridge deck replacements, ramp reconfigurations influenced by studies from the Des Moines Area Metropolitan Planning Organization, and implementation of intelligent transportation systems similar to deployments on Interstate 80 and Interstate 35 corridors. Initiatives coordinate with city programs for Des Moines Riverwalk expansion, streetscape upgrades promoted by the Downtown Community Alliance, and transit integration with providers like Des Moines Area Regional Transit Authority. Funding strategies reference federal competitive grants used on projects in Minneapolis and St. Louis for urban freeway modernization, and community engagement processes are modeled after stakeholder efforts in Seattle and Boston.

Traffic and safety statistics

I-235 carries high daily volumes with seasonal variations tied to events at Iowa State Fairgrounds and sports venues such as Principal Park; average annual daily traffic counts are monitored by the Iowa DOT and reported alongside crash statistics compiled by the National Highway Traffic Safety Administration. Accident analyses identify peak incident hours consistent with commuter patterns to employment centers including Advocates Aurora Health, Principal Financial Group, and MercyOne Des Moines Medical Center. Safety improvements have included barrier upgrades, lighting enhancements near the Des Moines River crossings, and enforcement partnerships with the Polk County Sheriff's Office and Des Moines Police Department; similar countermeasures were adopted in other midwestern urban corridors like I-70 through Columbia and I-94 in Detroit. Ongoing monitoring projects use traffic sensors and coordination with statewide incident management systems to reduce congestion and improve emergency response times.

Category:Interstate Highways in Iowa