Keeping Milwaukee Moving: I-43 Hillside Interchange Rehabilitation Project

Posted By: Chris Fredrick Blog,

Chris Fredrick, P,E, Michael Baker International

human movement engineering discipline

Interstate 43 traverses more than 190 miles through Wisconsin, connecting Milwaukee with Beloit to the southwest and Green Bay to the north. Within Milwaukee, I-43 provides access to the arts and entertainment district, which includes the Wisconsin Center, Fiserv Forum, UWM Panther Arena and the Milwaukee Theatre, as well as the Milwaukee County Courthouse and other popular downtown destinations, via the underground Kilbourn Avenue tunnels.

Looking ahead, the Wisconsin Department of Transportation sought to extend the thoroughfare’s service life and reduce the risk of future infrastructure failure by performing preventative maintenance work.  The agency enlisted our team at Michael Baker International to provide construction management and inspection services for the I-43 Hillside Interchange Rehabilitation Project, which included maintenance for 14 structures along a one-mile stretch of I-43 from Wisconsin Avenue to Walnut Street in downtown Milwaukee. 

As part of the project, the Kilbourn Avenue tunnels were rehabilitated, which included surface repairs, lighting maintenance, cleaning, signing and pavement marking, as well as staining the tunnel’s walls and ceiling. This aspect of the project presented unique complexities. Since tunnels are a rarity in Wisconsin, working within the structures presented uncommon challenges. We were able to draw on expertise from Michael Baker offices across the country to provide input on this aspect of the project. 

Tunnel lighting

The lighting system within the tunnels needed to be updated and maintained. Maintenance access can be limited within tunnels and corrosive atmospheric conditions are common, making a reliable lighting system, with minimal maintenance requirements, critical. The lighting system allows traffic to enter, pass through and exit the enclosed section safely without impeding the flow of traffic. It also takes into account daytime travel, when the contrast between outside and inside light is significant, and at night, when it is less so but the high-light and low-light environments are reversed.

The team utilized hydro-demolition when working on the concrete overlay for the floors within the tunnels. This solution limits noise and dust pollution, is environmentally friendly and is both cost- and time-effective. The 2” overlay of these floors increased skid resistance, a major safety benefit in an area that sees large variations in temperature that can lead to icing and a high amount of snowfall. Vehicles now have greater grip of the pavement, leading to a reduced number of accidents. 

The tunnels are notably owned by two different entities: WisDOT maintains half the length of the tunnels and the other half is maintained by the City of Milwaukee. Our team closely coordinated with both entities throughout construction and made constant communication a key focus throughout the project. 

The project also included a concrete bridge deck overlay and painting of the 12th Street Bridge over STH 145/Fond du Lac Avenue and thin polymer overlays on 11 bridges over I-43. The latter is a newer technique in Wisconsin. A polymer overlay is two-layer system, approximately ¼” thick, comprised of a two-component polymer in conjunction with natural or synthetic aggregates.

Polymer overlays are used to seal and protect the bridge deck from deicing salts and other chemicals that cause deterioration of the bridge concrete and reinforcing steel, extending the life of the bridge. Additionally, the aggregate used in the application of the polymer overlay works well to provide traction.

The total time required to complete the polymer overlay depends on several factors including weather and size of the bridge, but can generally be performed overnight, as was the case in the I-43 Hillside Interchange Rehabilitation Project.

Additional project work included concrete and shotcrete surface repairs, steel girder repainting, cleaning and painting of bearings, concrete pavement, concrete curb and gutter, sidewalk, permanent signing and pavement marking. 

The upgrades and improvements have made the corridor safer for those traveling I-43, improved traffic flow and extended the service life of this important stretch of infrastructure.

About the Guest Blogger

Michael Baker International logoMichael Baker International, a leading provider of engineering and consulting services, including design, planning, architectural, environmental, construction and program management, has been solving some of the world’s most complex infrastructure challenges for more than 80 years with a legacy of expertise, experience, innovation and integrity.

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