Interstate 41 replaced U.S. 41 along the freeway corridor between Milwaukee and Green Bay via Fond du Lac and Appleton. This included the U.S. 41 overlap with I-894 and along I-94 southward from Milwaukee to Russell Road (Exit 1 A) and the Illinois state line. Resigning of U.S. 41 to Interstate 41 through Wisconsin took place between late May and November 2015. The $5.9 million project included the posting of 3,200 signs over the 180 mile long route.1
Interstate 41 created the unusual situation where a U.S. route changes into an Interstate route with the exact same number (U.S. 74 and I-74 do the same thing at Rockingham and Laurinburg, North Carolina). U.S. 41 is not acknowledged from intersecting routes or along freeway guide signs however.
High Priority Corridor
Interstate 41 is part of High Priority Corridor 32: Wisconsin Development Corridor and High Priority Corridor 57: U.S. 41 Corridor from Milwaukee to Green Bay for its entire length.
Started in 2012, the Zoo Interchange Project centered around the exchange where I-41, I-94 and I-894 converge on the west side of Milwaukee. Work upgraded the substandard exchange with left exits built in 1963 into a four level systems interchange. Adjacent work expanded and modernized I-41 southward to Lincoln Avenue and I-94 west beyond Wis 100 and east to S 76th Street. Ongoing work through 2023 reconstructs I-41 northward to Burleigh Street. Project elements for Interstate 41 include:
- Greenfield Avenue Interchange – the Greenfield Avenue bridge was replaced in 2013. Landscaping and the addition of a decorative wall were anticipated for 2016 or 2017. Ramp closures continued through early Summer 2018.
- Watertown Plank Road Interchange – upgrading the original diamond interchange into a free-flow directional cloverleaf interchange. This work was completed by the end of 2014.
- Bluemound Road Interchange – new ramps were added from the I-41/ U.S. 45 mainline to U.S. 18 (Bluemound Road). 2014-15 work reconstructed Bluemound Road over I-41. Ramp construction followed from 2015 to Summer 2018, with ramps to and from Wisconsin Avenue removed during the project.
- Zoo Interchange – crews constructed a four level interchange with 23 new bridges and 12 retaining walls. Additionally new lanes were added to I-41/U.S. 41 and along the connecting ramps. Core construction commenced in late 2014 and was completed following a ribbon cutting ceremony held August 27, 2018.
- North Avenue Interchange – reconstruct the parclo interchange with slight geometric changes to improve safety. Engineering and design work was finished in 2016, with construction underway as part of the overall North Leg project through 2023.
Illinois – 2.50*
Wisconsin – 172.50**
Source: December 31, 2021 Interstate Route Log and Finders List
* – 2.5 miles on I-94
** – 25.5 miles on I-94, 5 miles on I-43, 10 miles on I-894
Ramps at the north end of Interstate 43 closed on October 23, 2015 as part of the September 2013 to December 2016 project. The interchange fully reopened on August 26, 2016.
This new freeway corridor became an Interstate Corridor as a result of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) legislation (signed into law on August 10, 2005). This legislation not only added U.S. 41 between Milwaukee and Green Bay as High Priority Corridor 57, it also designated Corridor 57 as a future Interstate route. An earlier version of this law (HR 3, Section 1839) had language that indicated that High Priority Corridor 57 “is designated as Interstate Route I-41.” However, SAFETEA-LU does not have a similar provision that specifies the route number for the future Interstate to be routed over U.S. 41.2
Numbers discussed by the Wisconsin Department of Transportation (WisDOT) included I-47, I-243, I-594 and I-643 in addition to Interstate 41. The selections went to American Association of State Highway and Transportation Officials (AASHTO) at their meeting held on November 15, 2012 where an endorsement of the number “41” was selected for the future Interstate highway. The numbering moved to the Federal Highway Administration (FHWA) for approval before Interstate 41 was made official.3
A WisDOT map of the US 41 Conversion showed the proposal to extend Interstate 41 southward along all of I-894 and I-94 south from Milwaukee to the first exit in Illinois.3 Logic behind this overlap retained mileposts and exit numbers along the preexisting freeway along U.S. 41 between Milwaukee and Green Bay.
The non-freeway portion of U.S. 41 along Appleton Avenue from the Stadium Freeway/Miller Park Way northwest to I-41 at Exit 47 near Menonmonee Falls was renumbered as an extension of WIS 175.
Two projects along Interstate 41 and U.S. 41 involved upgrading the freeway through Brown and Winnebago Counties. The Brown County work involved a 14 mile long stretch from Orange Lane to Lineville Road (CTH-M). Construction commenced in 2010 and was completed in 2017. Aspects of work included rebuilding nine interchanges, adding 24 roundabouts and widening the freeway from four to six and ten overall lanes. More details are as follows:
- Lineville Road (County Trunk Highway M) interchange – work completed from June 2013 to May 2015.
I-41 was expanded to six lanes below a new overpass for CTH M while ramps were expanded to two lanes.
- I-41 and I-43 Interchange – work started in September 2013 and ran through December 2016. The new northbound ramp from I-43 to I-41 opened on July 27, 2015. Following was opening of the new I-41 north to I-43 south flyover opened on August 28, 2015. The new flyover from I-43 north to I-41 south opened on August 26, 2016.
Construction replaced all loop ramps with directional ramps as part of new directional T interchange. Adjacent work separated movements to Velp Avenue (U.S. 141) and eliminated weaving traffic to and from I-43.
- Packerland Drive – WIS 29 Interchange – work completed in early 2015 included construction to add flyovers from and to WIS 29/32 leading west from I-41/U.S. 41. The new directional T overlays a diamond interchange with roundabouts at Shawano Avenue.
- WIS 172 Ramps – construction started in Fall 2013 and concluded in Fall 2016.
Ramps were expanded and realigned to join new collector distributor lanes along Interstate 41.
Work in Winnebago County affected 17 miles of I-41/U.S. 41 from WIS 26 to Breezewood Lane. Construction was completed between 2009 and 2014. Upgrades included a new eight lane Lake Butte des Morts Causeway, reconstruction of four interchanges, and the addition of 16 roundabouts. Of this work, the interchange with U.S. 45 received a substantial makeover with free flow movements added from north I-41 to north U.S. 45 and from U.S. 45 south to I-41 south.
North End / Lineville Road – Suamico, Wisconsin
South End – Russell, Illinois
- “Dignitaries cheer Interstate 41.” WBAY, May 28, 2015.
- Fiscal Year 2005 Transportation Equity Act: A Legacy for Users (H.R. 3) – PDF file.
- “Interstate 41 a step closer to reality.” Fox 11 News, November 19, 2012.
Page updated June 28, 2022.