Iowa Department of Transportation

I-74 over the Mississippi River

Quad Cities (IL/IA)

The $1.2 billion I-74 corridor over the Mississippi River is an enormous undertaking, successfully delivering increased capacity along the interstate between the Quad Cities in Iowa and Illinois. Totaling seven miles of interstate expansion in addition to a new river crossing, improved arterial streets and increased access for pedestrians and bicyclists, the project required joint participation from the Iowa and Illinois Departments of Transportation and presented the opportunity for multiple lead consultant roles on the project. Benesch was selected for two of these roles: Corridor-Wide Coordinator and Central Section Design Lead.

As Corridor-Wide Coordinator, Benesch was tasked with ensuring uniformity and quality of design throughout the corridor’s many sections and contracts, paying special attention to project schedules and staging schemes and managing outreach to impacted stakeholders throughout the process.

As Central Section Design Lead, Benesch oversaw design services for the portion of I-74 crossing over the Mississippi River, which includes the corridor’s signature true arch bridges. Benesch designed the true arch bridge substructures and provided an independent structural review of the overall true arch design.

Project highlights

  • New Mississippi River crossing
  • Signature twin true arch bridge design
  • Coordination of multiple consultants and contracts throughout project corridor