QUAD CITIES, IA AND IL – On December 3, 2021, a new Mississippi River bridge opened fully to traffic, bringing to life a vision several decades in the making for both the Iowa and Illinois Departments of Transportation. Designed as part of a seven-mile corridor improvement to increase capacity, safety and access through the Quad Cities region on I-74, the iconic structure represents a successful collaboration between two state DOTs and their respective FHWA Divisions; several local agencies; large preliminary engineering, final engineering and construction teams; and a deeply invested community.
“It was the people of the Quad Cities who wanted to see a signature structure at this location,” Benesch Project Manager Diane Campione explained. “They have a lot of pride for the project and were highly involved in its evolution, including the selection of the twin basket handle true arch design.”
That civic pride was evident on December 1, as more than 5,000 area residents joined members of the project team and government officials to walk onto the bridge before it opened to traffic. Mayors from each of the Quad Cities shared sentiments with the crowd echoing similar themes: this was a bridge for the people, by the people—and it was well worth the wait.
At a cost of approximately $1 billion, the I-74 Central Section Corridor project is the largest-ever to be let by the Iowa DOT. The corridor comprises dozens of new bridges, six reconfigured interchanges, widened and reconstructed interstate roadway, and several miles of local roadway improvements.
The original suspension bridge—with a westbound structure completed in 1935 and an eastbound in 1960—was designed to support 48,000 vehicles per day. When construction began for the new crossing in 2017, average daily traffic counts surpassed 74,000; they are expected to hit 100,000 within the next 10 years.
Benesch has played a significant role in this project since 2009, serving as corridor-wide design manager and engineer of record for many portions of the corridor on behalf of the Iowa and Illinois DOTs. Benesch led design plans for the extended Central Sections of the project, which included the substructures that support the twin arch superstructure (designed by Modjeski & Masters, who also designed the original suspension bridges) as well as the approach span superstructures and substructures at either end of the bridge.
Benesch also provided lighting design and oversaw the subconsultant in charge of aesthetic lighting on the bridge.
The eastbound river crossing includes a 14-foot-wide bike and pedestrian path with a scenic overlook at the center of the arch which will tie into existing trailways in Bettendorf and Moline. The path is expected to open by the end of January 2022.