Interstate 41


Proposed Routing

Interstate 41 is the proposed designation for the U.S. 41 freeway corridor between Milwaukee and Green Bay via Appleton and for the U.S. 41 overlaps with Interstates 894 and 94 southward to Exit 1A (Russell Road) in Illinois.

High Priority Corridor

Proposed 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.

Route Status

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.

Numbers thrown around by WiSDOT included Interstates 47, 243, 594 and 643 in addition to Interstate 41. The selections went to American Association of State Highway and Transportation Officials (AASHTO) and at their meeting on November 15, 2012 an endorsement of the number "41" was given for the future Interstate highway. The numbering moves to the Federal Highway Administration for approval before Interstate 41 is made official.2

If signed as Interstate 41, this would create the unusual situation where a U.S. route changes into an Interstate route with the exact same number (U.S. 74 and Interstate 74 do the same thing at Rockingham and Laurinburg, North Carolina).

A WisDOT map of the US 41 Conversion includes the proposal to extend Future Interstate 41 southward along all of Interstate 894 and I-94 south from Milwaukee to the first exit in Illinois.2 Logic behind this overlap may be to keep the mileposts and exit numbers along the existing U.S. 41 freeway between Milwaukee and Green Bay.

Southern Terminus - Interstate 94 - Russell, Illinois
The split of U.S. 41 south from Interstate 94 at Exit 1B in Illinois is the proposed southern terminus of Interstate 41. Photo taken 09/02/05.
U.S. 41 merges onto Interstate 94 west at a partial "Y" interchange just ahead of Russell Road (Exit 1) and the Wisconsin state line. This is the proposed northbound start for Interstate 41. Photo taken 09/02/05.
Northern Terminus - Interstate 43 - Green Bay, Wisconsin
Future Interstate 41 will end at the same interchange where Interstate 43 concludes on the north side of Green Bay. U.S. 41 north joins U.S. 141 along a freeway beyond Suamico. Photo taken 05/30/11.
U.S. 41 & 141 split with Interstate 43 south at Exit 171 ahead of Green Bay. Future Interstate 41 will begin here and follow all of the U.S. 41 freeway south to Appleton and Milwaukee. Photo taken 05/30/11.
Interstate 43 ends at a folded-diamond interchange with the future north end of Interstate 41 and the U.S. 41 & 141 freeway leading south from Suamico. Photo taken 08/12/09.


  1. Fiscal Year 2005 Transportation Equity Act: A Legacy for Users (H.R. 3) - PDF file.
  2. "Interstate 41 a step closer to reality." Fox11, November 19, 2012.

Page Updated November 19, 2012.


State Wisconsin
Mileage TBD
Cities Milwaukee, Appleton, Green Bay
Junctions Interstate 94, Interstate 894, Interstate 43
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