Zoo Interchange crews drive project home, even during harsh winter

The Watertown Plank Road interchange is just a piece of the massive puzzle that is the Zoo Interchange overhaul.

But, as the project engineer Eyad Ghani says, “It was a critical piece of that puzzle.”

The $68 million project included eight bridges — two mainline structures, four ramps and two flyovers — and a pedestrian bridge, a long-missing link for families traveling from the Ronald McDonald House to the nearby Children’s Hospital of Wisconsin and the Froedtert medical campus.

As if the workload wasn’t enough, the timeline was also tight.

“This all had to be done in a one-year construction cycle in order for the larger Zoo Interchange construction to remain on schedule,” said Ghani, a project manager with the Wisconsin Department of Transportation.

Geography only added to the crews’ difficulties, since the project’s neighbors included not only Children’s and Froedtert, but also the Milwaukee Regional Medical Complex and the Milwaukee County Research Park.

And, of course, planners needed to maintain access for emergency services, while also keeping utilities online.

“That made things very complex,” Jeff Bohen, WisDOT project manager for the project’s design phase. “… Typically, we can handle some outages on power. People are without phone lines for an afternoon, and it’s not an enormous issue. With Froedtert and Children’s, you can just imagine if we had to take a power outage at the hospitals. That wasn’t going to happen.”

The project also incorporated 11-foot lanes to reduce right-of-way costs, 5-foot bike lanes and a trail ensuring the public can get to the nearby Monarch Butterfly habitat. What’s more, all of this was built during one of the harshest winters on record in Wisconsin.

“That January and February (of 2014), we had highs in single digits for weeks straight, and we were still pouring concrete for structures,” said Sara Fueling, structures lead with WisDOT. “If it had been another job, we would have said, ‘Nope, it’s too cold.’ But we didn’t have that flexibility, so we were heating concrete. We were blanketing concrete. We had heaters around the columns to make sure they could be welded.”

The ground didn’t exactly cooperate during the cold either, said Eric Vandixhorn, project manager at Waukesha-based Zenith Tech Inc., which had from 20 to 30 subcontractors onsite daily during the harshest times.

“There was some creativity on the DOT’s part,” Vandixhorn said. “They used soil drying agents to help a lot of the dirt work proceed. A lot of dirt had to be moved and the soil drying agent was the only reason that got done. During those months it was a lot of take two steps forward and one step back.”

Staying on budget, despite the extra efforts to deal with the weather, was also difficult. That was especially true for a project that saw the lowest six bids come within 0.0002 percent of the estimated $66.9 million needed to pay for the work.

“It forced creativity with how things were done, and the DOT was very good about that,” Vandixhorn said.

For instance, instead of creating tunneling for a storm sewer, which would have been costly and time-consuming, Vandixhorn said, “We essentially jacked the pipe underneath the freeway, which cost about half as much as the DOT was expecting.”

In the end, crews checked off a big item on the Zoo Interchange project’s “to do” list.

“It was a mess,” Vandixhorn said. “I think we drove people nuts for 15 months, but I think everyone is happy now that it’s done.”