I-235 Pedestrian Bridges

The reconstruction of I-235 through downtown Des Moines offers the opportunity to fulfill the community’s goal of improving the appearance of 14 miles (22km) of interstate highway and of re-uniting neighborhoods along the roadway.

As part of the highway corridor improvements plan a series of three pedestrian bridges, located at 6th, 40th and 44th streets were constructed across the interstate to replace existing unattractive steel girder structures surrounded by chain link fences. These highly visible bridges act as icons, locating the neighborhoods for travelers along the freeway.

Design and Construction

The new design utilizes basket-handle steel arches with clear spans of approximately 230’ (80m). Inclined cables connect the steel blue arches to the pre-stressed concrete deck. By selecting a tied arch form, the Iowa Department of Transportation was able to keep disruption of traffic to a minimum during construction. An innovative curved screen system is used to enhance security and the appearance of the structure creating a visually appealing experience for pedestrians and bicyclists using the bridge. The resulting series of bridges has created a distinctive form that is unique to the city and the state. These highly visible bridges now act as icons marking the location of neighborhoods and landmarks such as the Botanical Center for travelers along the freeway.

The three Des Moines Pedestrian Bridges were completed in 2004. They include:
*Edna M. Griffin Memorial Bridge
*40th Street Pedestrian Bridge
*44th Street Pedestrian Bridge

Boston-based transportation architects Rosales + Partners, Inc. were the bridge architects in charge of preparing aesthetic guidelines for the entire 1-235 corridor, including the conceptual design of the three pedestrian bridges. Rosales + Partners, Inc. also worked with an advisory aesthetic committee and prepared visualizations and physical models. HNTB Corporation completed the final design.