Wisconsin’s $57.5 million highway improvement project on Interstate 94 near Knapp Hill will allow smoother travels for motorists.

“We have concrete pavement that is old and has gone through its complete life cycle,” says Nicole Passuello, Project Development Supervisor, with the Wisconsin Department of Transportation (WisDOT) Northwest Region in Eau Claire. “We’re at a place where we have to replace the pavement.”

The 59-mile stretch of I-94 between Hudson and Eau Claire was dedicated on October 29, 1959, according to WisDOT historical records. That same day, the 41-mile stretch of interstate between Hudson and Menomonie was opened to motorists waiting to try out the new concrete four-lane freeway.

The scope of work on the four-lane highway includes milling, concrete paving, placement of temporary roadway and structures, construction of six bridges wide enough to one day accommodate three lanes each, relocation of utilities and new signage. The three pair of bridges cross above roads: two local and County Highway Q. WisDOT designed the project in house.

WisDOT opted for concrete pavement again, because it lasts longer on high-volume interstates, Passuello says. More than 36,000 vehicles travel on this section of highway daily, with a heavy concentration of truck traffic.

“The concrete pavement withstands the truck traffic and provides longer durability and is resistant to rutting,” Passuello said.

The current 8.4-mile project follows an adjacent 4-mile long pavement replacement to the east on I-94, which finished up last year. The projects shared the same prime contractor Hoffman Construction Co. of Black River Falls, Wisconsin.

Peter Hoffman and Anna Hoffman founded the company in 1915 and incorporated in 1927. The company remains family owned and has grown. It employs about 400 people and operates a fleet of scrapers, dozers, off-road trucks, backhoes, and dump trucks. Jim Hoffman serves as the current CEO. The company manages between 30 and 50 major highways and site development projects annually.

Work began in March 2019. The heavy volume of traffic led the department to create a bold two-year schedule, with nine stages and interim completion dates. Hoffman completed the first three stages in 2019 and is working on the final six this year.

“We’ve asked the contractor to do a lot of work in a short amount of time,” Passuello says. “The biggest thing is the contractor was able to get the work done successfully last year, without major traffic disruptions.”

Hoffman has worked days, nights and Saturdays to keep on schedule, particularly through the wet weather in 2019, says Chad Sell, Project Manager for Hoffman Construction, adding, “It’s a very aggressive schedule. There’s a lot to get done.”

Sell reports, Hoffman has experienced “a lot of cooperation with the department in planning and bouncing ideas and switching things around. It was definitely a cooperative effort.”

Traffic flowing on two lanes in each direction presented a significant challenge to the project, since the interstate had to remain open, except for a few brief lane closures during non-peak times. To accommodate traffic, the contractor built a temporary road in the median and subcontracted three temporary bridges to Lunda Construction in Black River Falls, Wisconsin.

“If we didn’t build temporary roads and bridges, we would have significant backups in traffic,” Passuello says. “The drivers appreciate it.”

Preparing to build the 6-mile-long temporary road, crews found wet and soft material in the median that had to be excavated. The company removed 90,000 cubic yards of material. Then Hoffman brought in 275,000 cubic yards of borrow and good, rock materials to fill in the median and create a stable base. Once the project wraps up, crews will break up the temporary road and haul the asphalt to a recycler. Then at the end of the job, the company will bring in top soil to recreate the median.

A concrete barrier separates the construction activity from live traffic. “Once we get traffic out of our way, we can utilize working days, nights, weekends to make up time,” Sell says. “We are not restricted by lane closure times.”

In 2019, on the western portion of the project, traffic shifted to the two temporary lanes, while crews rebuilt the two lanes of westbound interstate. Then when those first two westbound lanes were complete, traffic shifted to the new pavement and work began on the eastbound permanent lanes in 2020.

Knapp Hill, on the 2 miles at the eastern end of the project, limited staging options, Passuello says. The steep hill has a deep ravine in the median and precluded building the two temporary lanes. Therefore, this portion of the project will have traffic flowing on what is called a three plus one counter flow. Two lanes will flow in one direction and one lane will go in the opposing direction on one side of I-94. On the other side, the other opposing lane will remain open while work proceeds on the other lane.

“We are building that piece of roadway half at a time,” she says. “It’s not a great way to do the work, but we were limited by the hill. It has a huge ravine, and it would have taken millions of dollars to fill in the ravine.”

Plus, the department would have run into environmental concerns, trying to fill in a natural ravine. The current work had no significant environmental concerns and is being constructed within the existing right of way.

After removing the old pavement, Hoffman uses an onsite portable concrete crusher to recycle the old concrete pavement and asphalt into gravel for the base for the new road.

“The contractor was able to crush the material and keep the material on site,” Passuello reports.

Three of the permanent bridges, those in the westbound direction, were replaced in 2019 and the other three on the eastbound side will be completed this year. One set of bridges are concrete-slab structures. The other four are concrete-girder structures. Interstate traffic was pushed to the temporary bridges while work progressed on the permanent bridges. However, the local roads below were closed for 60 days each to allow for pile driving, girder placement and form work removal.

The I-94 project will require 255,000 square yards of concrete paving and 150,000 tons of hot-mix asphalt for the temporary road and permanent shoulders.

The project remains on target for a November 2020 finish, including removal of the temporary roadway and structures.

“The contractor has been able to keep the work on track and provide us with a quality roadway,” Passuello says.