Old I-74 green bridge won’t go out with a bang, or a whimper

74 bridge
Spans of the old green Interstate 74 bridge remain visible to drivers crossing the new Interstate 74 Bridge. They’ll remain so for many months as contractors with Helm Group dismantle the old bridge primarily a piece at a time. CREDIT DAVE THOMPSON.

As promised, what’s left of the old Interstate 74 twin-span suspension bridge will most certainly come tumbling down, but don’t expect the old green bridge to go out with a bang – or very quickly.

On Tuesday, Sept. 20, the Illinois and Iowa Departments of Transportation (IDOTs) posted an update on the demolition effort entitled “Goodbye, old bridge! Demolition has begun!”

IDOT leaders said the mostly bit-by-bit work to deconstruct the remaining spans that still rise out of the Mississippi River waters will continue until the project is completed sometime in mid-2024 by the contractor, the Helm Group. The cost of the remaining demolition is expected to be $23.3 million.

Helm Group already is well familiar with the Quad Cities bridge, according to i74riverbridge.com. “They’ve been a great partner constructing all of the I-74 viaduct bridges in downtown Bettendorf and we look forward to working with them again,” the IDOTs said of the new I-74 bridge.

The Freeport, Illinois-based construction company said on its website its Helm Civil division built the westbound portion of the corridor on the Iowa side of the river in 2019 and the eastbound portion in 2021. Caissons, Y-shaped bridge piers and steel girders support a deck that now carries 100,000 vehicles a day, the company said. 

Now Helm has turned its attention to painstakingly removing the old bridge and Quad Citians will continue to have a front row seat for the next 20 months or so of demolition.

“We know you want to see the old bridge go out with a BANG,” the IDOTs acknowledged on the I-74 project’s website. “But we’ve decided to dismantle the majority of it piece by piece. At this time, the contractor is only planning to use explosives on select areas of the bridge.”

The reason for that is threefold, the IDOTs said. 

By carefully dismantling – rather than blowing up – the majority of the old green bridge remaining,  the demolition will have:

  • Less impact on river traffic.
  • Minimize the amount of debris that will need to be removed from the river after the project is completed.
  • And reduce impacts on the endangered mussels that breed and live in the old bridge area.

That doesn’t mean that the green bridge will go out with a whimper instead of the big bang Quad Citians were hoping for, the IDOTs say.

“It will still be fun to watch, though!” the IDOTs promised. “Be sure to check it out on your walks on the new bridge path and riverfront trails.”

The new unique basket-handled Interstate 74 Bridge opened to great fanfare on Dec. 1, 2021. The interstate bike and pedestrian path, which is a featured part of the structure, opened on April 27 with the official ribbon cutting held on May 18

The old I-74 bridge’s westbound span (most recently Illinois to Iowa) opened as a toll bridge in 1935. It cost $1.46 million to build. The original toll was 15 cents. In 1970, the eastbound Iowa to Illinois bridge opened. The project cost was $6.2 million.

The Quad Cities long battle to build a new bridge began several decades ago. It picked up steam thanks to a key transportation study conducted in 1998 to support building a new bridge.

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