1st Avenue & I-80 Interchange

Coralville Diverging Diamond interchange rendering

Diverging Diamond Interchange
The Iowa Department of Transportation plans to reconstruct the interchange at I-80 exit 242 and 1st Avenue with a diverging diamond interchange (DDI). The Iowa DOT is the lead agency on this project.

Project at a Glance

The existing interchange at I-80 exit 242 is the original configuration constructed in the 1960s when I-80 was built through Iowa. The new diverging diamond interchange will provide safety improvements and is designed to handle projected traffic volumes. 

Major construction is scheduled to begin mid-to-late March, 2023, and will reduce 1st Avenue to one lane in each direction over I-80. 1st Avenue will remain one lane in each direction into fall 2024.

The prime contractor is Peterson Contractors, Inc., of Reinbeck, Iowa. The Iowa DOT is administering and inspecting the project.

Contact Us

  1. Iowa Department of Transportation

    Catherine Cutler
    Transportation Planner

    Iowa DOT logo

    City of Coralville

    Scott Larson
    City Engineer

    1512 7th St.
    P.O. Box 5127
    Coralville, IA  52241

    Ph: 319.248.1720
    Fx: 319.248.1894

    Staff Directory

Highlights Once Complete

  • Diverging diamond interchange design eliminates the left turn phase at signalized intersections. This reduces overall traffic delay while also providing a significant safety improvement since left-turning traffic is no longer crossing opposing traffic lanes.
  • New grade-separated trail with underpasses and a trail bridge over I-80.
  • New 1st Avenue bridges accommodate the potential future widening of I-80.
  • New, signalized intersection to serve Iowa River Landing Place and the Magellan Terminal. 
  • New stormwater management practices, traffic signals, roadway lighting, and aesthetic treatments. 

Updates: Current & Upcoming Work

On 1st Avenue:
Between 9th Street and Holiday Road: A lane is closed intermittently due to road construction work until April 1, 2023.

On I-80 westbound (Exit 242):
At the entrance ramp from 1st Avenue: Road construction work is in progress. A lane is closed intermittently until April 1, 2023. 

On I-80 eastbound: 
At the exit ramp to 1st Avenue: Road construction work is in progress. A lane on the ramp has intermittent partial closure until April 1, 2023. 

Comment: Davenport RCE (800-262-5145) 

Please check 511ia.org for the latest updates to the project.

  1. Traffic & Pedestrian Impact
  2. Timeline
  3. Cost

Traffic & Pedestrian Impact

  • The project will utilize staged construction, including temporary pavement and temporary traffic signals. 
  • One lane of traffic will be maintained in each direction on 1st Avenue at all times.  
  • After the 1st Avenue Trail closures in October and November 2022, pedestrian access along 1st Avenue over I-80 should not be impacted again for the remainder of the project.

Learn More
Iowa Department of Transportation
Iowa DOT project website

Watch Video: Navigating the Diverging Diamond Interchange

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