1st Avenue & I-80 Interchange
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.
Updates: Current & Upcoming Work
Major construction started in March 2023. 1st Avenue is reduced to one lane in each direction over I-80 into fall 2024. Drivers should anticipate traffic delays and plan accordingly.
On 1st Avenue:
Between 9th Street and Holiday Road:
- April 12, 2023 through Fall 2023*:
- Northbound and southbound traffic shifted to the west side of 1st Avenue across I-80 and is one lane in each direction (head-to-head) through late 2024.
- August 29, 2023 (evening) through Fall 2023*:
- Northbound traffic on 1st Avenue wanting to head eastbound on I-80 will enter a right turn lane just north of E. 9th Street, and then turn right at the I-80 eastbound on-ramp.
- Southbound traffic on 1st Avenue wanting to head eastbound on I-80 will be detoured westbound on I-80, exit at Coral Ridge Avenue (Exit 240), turn left on Coral Ridge Avenue, and enter I-80 eastbound via the loop ramp.
- See images below for traffic movements through the interchange and a detour route for southbound 1st Avenue traffic heading eastbound on I-80.
On I-80 eastbound (Exit 242)*:
- March 6, 2023-December 31, 2023: Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.
On I-80 westbound (Exit 242):
- March 6, 2023-December 31, 2023*: Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.
*(Dates subject to change based on weather and unforeseen circumstances)
**(There will be intermittent closures and detours throughout the construction season which will be communicated prior to the closures)
Comment: Davenport RCE (800-262-5145)
Please check 511ia.org for the latest updates to the project.
The drone images below were captured by IDOT on May 30. The contractor, PCI, expects to place beams over I-80 for the easterly road bridge and trail bridge starting mid-June with completion mid-July. The beam setting will take place during overnight hours.
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 began in mid-March 2023, and reduces 1st Avenue to one lane in each direction over I-80. 1st Avenue will remain one lane in each direction over I-80 into fall 2024.
The prime contractor is Peterson Contractors, Inc., of Reinbeck, Iowa. The Iowa DOT is administering and inspecting the project.
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.
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.
- Drivers should anticipate traffic delays and plan accordingly.
- 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.
- September 2022: DOT letting.
- October 24-28 and November 7-11, 2022: Two trail closures of the 1st Avenue Trail where it crosses I-80. The trail closures allow for construction of temporary pavement in preparation for the start of major construction in spring 2023.
- October 24-November 18, 2022: Intermittent lane closures on 1st Avenue, one direction at a time.
- Starting in late March/early April 2023: Major construction work will begin with the demolition and reconstruction of the easterly (northbound) 1st Avenue bridge over I-80. 1st Avenue traffic will be reduced to one lane in each direction, with northbound traffic shifted onto the westerly (southbound) 1st Avenue bridge. 1st Avenue will remain in one direction into fall 2024.
- By spring/summer 2025: The road and bridge work is expected to be substantially complete.
- Summer/fall 2025: Final landscaping and related work should be complete.
The project is funded in part by a $20 million U.S. Department of Transportation BUILD grant awarded to the City of Coralville and transferred to Iowa DOT, with the remaining costs covered by the Iowa DOT.
The bid from Peterson Contractors Inc. was $35.6 million.
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