Mitchell reconstruction succeeds with shrewd decisions

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Mitchell Interchange

The little things made the difference on the massive Mitchell Interchange reconstruction in Milwaukee County.

The construction team, for instance, temporarily widened the lanes of Interstate 894 earlier than expected. The lane widening was designed to maintain traffic flow while crews built the tunnels that now define the area, which connects 894 to interstates 43 and 94 near General Mitchell International Airport in Milwaukee.

The plan was to start tunnel work in February 2011. Instead, hoping to buy some time in case something went wrong, crews started in October 2010.

It paid off when tunnel excavation began, said Tom Collins, project engineer with Wisconsin Construction Partners, which managed construction. The team, he said, hit a snag with a water main and then ran into larger-than-expected boulders.

“If we hadn’t planned ahead and switched traffic earlier,” Collins said, “it would have really hurt us.”

It took 200 to 250 workers in the field each day, sometimes working 24 hours a day, seven days a week, to build three tunnels, five interchanges and 29 bridges. Carving out the tunnels alone meant hauling an estimated 1 million yards of dirt, or 50,000 truckloads, off the canyon-like site.

That was in the winter, with commuter and construction traffic buzzing all around. That was under relentless deadlines, with businesses on both ends of the tunnels counting on crews to finish on time.

The construction team had 11 months to complete the project, which temporarily severed direct access to the city of Milwaukee.

“That drove most of the project, and it was probably the hardest part of the project,” said Kurt Flierl, construction project manager with the Wisconsin Department of Transportation’s southeast freeways team.

Keeping things on track took compromises, such as when the crew paved part of its work zone to maintain access to the airport.

“That was not in our plans, but we said, ‘That’s a great benefit to our stakeholders,’” said Ryan Luck, WisDOT’s southeast freeways construction chief.

The project also took a high level of coordination to keep business owners, contractors and local law enforcement informed about lane changes, overnight freeway closures and delivery access.

To keep law enforcement in the loop, the construction team developed a coded delivery system, labeling entries and exits for deliveries and setting up lanes for emergency responders. Managers met each week to update the system map and discuss changes.

“I’ve been building projects for 20 years,” Luck said, “and I had never seen such a well thought out and fully functioning system.”

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