The $239 million I-35W at I-94: Downtown to Crosstown project will reconstruct existing infrastructure and provide dedicated bus transit access into downtown Minneapolis.

“It's a massive construction project, and things are going really well,” says Steven Barrett, Project Manager for the Minnesota Department of Transportation (MnDOT).

Although the department has placed asphalt overlays on the highway, built in the 1960s, this is the first complete reconstruction. “The pavement and bridges in this corridor were at the end of their service life,” Barrett says.

Project goals include improving safety and additional access to the region, reduce congestion, and enhance pedestrian and bicycle options. The corridor runs through a densely populated area.

About 220,000 vehicles drive on I-35W daily and 190,000 drive on Interstate 94. The road currently has three lanes in each direction. “It's the busiest freeway in Minnesota,” he adds.

Scope of Work

In addition to reconstructing the 4.5-mile section of Interstate 35W, the project includes rehabilitation or reconstruction of 15 bridges, construction of two new exit ramps, replacement of two aging pedestrian bridges to fit with the new alignments, construction of 64 cast-in-place retaining walls, grading, drainage work, concrete paving, and eight blocks of reconstruction on Lake Street, an arterial road on each side of the freeway.

The bridges include a large, curved steel flyover at the I-35W and I-94 interchange, traditional prestressed concrete-beamed bridges and a cast-in-place box-girder bridge.

The department is extending a high-occupancy vehicle transit lane, called MnPASS. In some places, the new lane replaces a shoulder used during high-traffic volumes. In other sections the express lane is new. The project also will add a new bridge and transit ramp into downtown, rather than the current way Orange Lane busses exit the interstate with the regular traffic.

“It will make transit operations much more efficient,” Barrett says.

The project also includes a transit station at Lake Street, about one mile south of downtown.

Above and Beyond Specifications

MnDOT let the project as a design-bid-build best value contracting method – the first time the department has used this delivery approach. The department presented some goals for the project and then let the various contractors come up with innovative solutions. It awarded the contract to a joint venture among Ames Construction of Burnsville, Minnesota; Lunda Construction of Black River Falls, Wisconsin; and Shafer Contracting Co. of Shafer, Minnesota, known as ALS.

“It allowed our contractor to go above and beyond the specifications,” Barrett says. “They were awarded some bidding advantages based on the proposal they submitted.”

That included increasing workforce hiring of minority- and women-owned companies, sponsoring career fairs to recruit workers, providing extensive erosion and sediment control, and keeping the duration of key traffic interruptions to a minimum to reduce disruptions to the traveling public. The contractor placed a full-time safety officer on the site and reached out to neighboring communities, holding “coffee with the contractor” events at local businesses. The joint venture agreed to award $38.7 million in work to minority- or women-owned businesses, about 16 percent of the overall contract. “Those things made it a better project,” Barrett says.

The department designed the project in house with some consultants. It awarded a smaller, $64 million, contract to construct a 14-acre underground storage tank farm, with six storage tanks, to hold runoff during storms and reduce flooding on the interstate to the joint venture of Kraemer North America of Plane, Wisconsin, and Nicholson Construction Co. of Canonsburg, Pennsylvania. The shells of the tank have diaphragm walls. A pump station will move up to 4.5-million gallons of stormwater during a 72-hour period. The water eventually is discharged into the Mississippi River.

Construction Staging

ALS began construction in August 2017. The project was divided into five stages, each with its own milestones. The three ALS partners are working on separate aspects of the project, with Ames focused on grading, utilities and retaining walls; Lunda working on bridge and retaining walls; and Shafer removing roadways and paving. ALS recycles the old concrete.

Extensive utility work has been required, affecting frontage roads, Barrett says. Crews have had to maintain water and sewer lines serving the residential and commercial communities along the route. Additionally, they have to maintain access to driveways.

Crews ran into contaminated soil, removed it and disposed it appropriately. Otherwise there were not significant environmental impacts. “Everything drains into the Mississippi River, so it's important to minimize sediment and erosion and protect the runoff,” Barrett says.

The department is trying to minimize noise from the project in the residential corridor, with many homes and apartment buildings. Sounds walls are up.

Traffic has been maintained during construction. Some access ramps were temporarily closed, and some weekend and overnight closures took place during bridge demolitions, completing open-cut pipe crossings and during traffic switches. Some work takes place at night.

ALS began work on the two-story transit station in spring 2020, with earthwork and underground operations. The transit station, now under construction, sits on the cast-in-place box-girder bridge, spanning Lake Street, which is complete. Freeway traffic flows above Lake Street. Busses will ride in the median, with about 700 stopping at the station each day. People will have easy access to other buses on Lake Street.

The project is scheduled for completion this fall. “It will be a really nice enhancement for transit in Minneapolis,” Barrett concludes. “It rebuilds a corridor that really needed to be updated. It's a busy part of the metro area. … It will enhance mobility in the Minneapolis area.”

Photos courtesy of the Minnesota Department of Transportation