New intersection, longer I-80 off-ramp open as 1st Avenue project reaches 90% completion

The finishing touches are being put on Coralville's First Avenue interchange project, just in time for an influx of weekend football traffic.

The project's extended eastbound Interstate 80 off-ramp is now open, less than 18 months after the reconstruction began, the city said in a release.

The expansion allows for additional space for car traffic, which is especially necessary as tens of thousands of fans come and go from Kinnick Stadium.

A shorter version of the ramp has connected the highway to the new diverging diamond interchange over the past few months as crews finished paint and asphalt work.

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Crews also opened a new intersection that connects directly to the Iowa River Landing on Friday. The new intersection opens up another route for traffic to flow into the popular business hub along the connection just north of Trader Joe's.

The interchange project is now approximately 90% complete. These two developments represent the final major road improvements in the interchange. Occasional lane closures will continue through the fall as crews wrap up work on "traffic signals, raised medians and landscaping," the city of Coralville said in a release.

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Work almost done for area's first diverging diamond

When the $42 million project began in March 2023, traffic navigated a two-lane bridge near the high traffic, fast-developing Iowa River Landing.

In the 16 months since, a second bridge was built and the traffic pattern was drastically rearranged for the Iowa City metro's first "diverging diamond" interchange , which the Iowa DOT says helps improve traffic safety and flow.

In diverging diamonds, drivers are directed to the opposite side of the road near on- and off-ramps. The Iowa Department of Transportation said the design "eliminates conflicts where traffic crosses," reducing the likelihood of collisions while providing a more efficient means of navigation.

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This is because, for example, drivers exiting the highway and turning left need only pull into the closest lane rather than crossing traffic.

The Coralville Interchange at First Avenue, between Ninth Street and Holiday Road, feeds traffic into the business heart of Coralville, including the Iowa River Landing and Xtream Arena to the south. It also connects to Highway 6, leading to the University of Iowa, and ever-developing residential areas to the north.

A separate pedestrian and cycling bridge and tunnel were also built.

One-lane traffic will continue on the two bridges in each direction until the project is complete at the end of 2024. The completed diverging diamond will route traffic through two lanes in each direction, matching the existing traffic pattern along First Avenue near the interchange.

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Ryan Hansen covers local government and crime for the Press-Citizen. He can be reached at rhansen@press-citizen.com or on X, formerly known as Twitter, @ryanhansen01.

This article originally appeared on Iowa City Press-Citizen: New intersection, longer I-80 off-ramp open as 1st Avenue project reaches 90% completion