Iowa-bound I-74 expected to open by end of month

The Iowa-bound span of the new Interstate 74 bridge is expected to open before the end of November, with the exact date to be announced soon by the Iowa Department of Transportation, George Ryan, Interstate 74 corridor manager told the Bettendorf City Council Monday evening.

Ryan is a consultant coordinating the entire 5½ miles of the project, from south of Avenue of the Cities in Moline to south of Middle Road in Bettendorf. He was invited by the city to give an update on the multi-year public works project that is estimated to cost $1.2 billion, including related interstate expansions and other improvements.

The next major adjustment in traffic patterns will be sometime between when the Iowa-bound (westbound) span opens later this month and April 1 when eastbound traffic will be switched to the new span in a shared arrangement so that old viaducts can be removed, Ryan told the council.

There will be “a lot of public outreach, a lot of announcements” to explain this to drivers, he said.

In another update, he said that setup has begun at the construction site for two new tower cranes that will be taller than any that have been used in the project so far at 400 feet.

They will be used to install the substructure of the eastbound span; their extra height is needed because the work will be trickier due to how close the existing bridge is to the new eastbound span, he said.

Because of all the lessons learned in the building of the westbound span, construction of the eastbound span should go more quickly, being finished about a year after the westbound span opens, or late 2021.

But even with the experience, the eastbound span poses new challenges not faced on the westbound. In addition to its close proximity to the existing bridge, the arch-building process will not be quite the same. The outside rib of the eastbound arch will be different from the inside rib because it has to support the added weight of a 14-foot concrete multi-use path cantilevered off the side of the deck, Ryan explained.

Other points:

• The reconstruction of 14th Street in Bettendorf should be complete before the end of the year.

• The deck of the spans have stainless steel reinforcement that is more resistant to the corrosion caused by road salt, so they should last longer than those built with regular steel.

• Alderman Scott Nauman commended everyone working on the project for how smoothly traffic has flowed during construction. “Traffic management has been extraordinary,” he said. Many people, including city leaders on both sides of the river, were worried about long delays, backups and confusion, but the way it has been managed, it has been “a non-event,” he said. “It’s been very well handled.”

City Administrator Decker Ploehn added that both DOTs “pivoted rapidly” to make changes in ways of getting on and off the bridge to make traffic flow more smoothly. “It was pretty phenomenal, frankly.”

• Bid-letting will be in September 2021 for the removal of the existing bridge and for the building of an elevator that will take people from the ground under the bridge to the multi-use trail.

• After construction of the westbound span fell behind schedule, two changes helped to make up some time — pre-assembly of the floor system and combining the pouring concrete into three different times rather than 10. Those time-saving moves will be used on the eastbound span as well.