Wisconsin Department of Transportation

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US 41 Interstate Conversion
Wisconsin state line-Green Bay, in Kenosha, Racine, Milwaukee, Waukesha, Washington, Dodge, Fond du Lac, Winnebago, Outagamie, and Brown counties

Logo - US 41 Interstate Conversion
US 41 Interstate Conversion overview/location map
View US 41 (Wisconsin state line-Green Bay) Interstate Conversion project maps.

Project location

  • The study corridor is 175 miles long and located almost entirely within the state of Wisconsin.
  • The proposed interstate will begin at the I-94/US 41 interchange located approximately one mile south of the Wisconsin/Illinois border.
  • The route continues north concurrently with I-94 to the Mitchell interchange and then northwesterly concurrent with I-894 to the Zoo interchange.
  • From the Zoo interchange, the route will extend north along US 45 and US 41 through Fond du Lac, the Fox Valley, and Green Bay and end at the I-43 interchange.
  • Communities along the corridor include: Pleasant Prairie, Kenosha, Racine, Oak Creek, Franklin, Greenfield, Milwaukee, West Allis, Wauwatosa, Menomonee Falls, Germantown, Slinger, Lomira, Fond du Lac, Oshkosh, Neenah, Menasha, Grand Chute, Appleton, Little Chute, Kaukauna, De Pere, Ashwaubenon, Howard and Green Bay.

Project overview

In 2005, 142 miles of US 41 from Milwaukee to Green Bay were identified by the federal government for inclusion in the U.S. Interstate Highway System.

SAFETEA-LU legislation initially identified the south terminus as the Mitchell Interchange (I-94/I-894) in Milwaukee. However, the Interstate Conversion study team elected to extend the corridor concurrent with I-94 south approximately 33 miles to the I-94/US 41 interchange for a number of reasons, including:

  • It links Wisconsin metropolitan areas and markets to the greater Chicago metropolitan area. Chicago is the economic epicenter of the entire Midwest and a key hub near the end of the corridor.
  • With the extension into Illinois, the interstate route becomes a true interstate route with a total length of 175 miles.
  • The extension will allow the signing for the cardinal direction to be north/south rather than the current east/west signing. A long-term goal of reducing driver confusion when driving north on a roadway signed as “west” can be realized for the northern Illinois and southern Wisconsin areas.

Designating the highway as an Interstate is expected to bring economic growth, increase the safety of the road, create a corridor identity and bring broader benefits to the state of Wisconsin.

Planning for the Interstate conversion began in 2007, with a long-term planning study currently underway. In fall of 2012, AASHTO approved the I-41 route number designation conditional upon subsequent approval by FHWA. There are several items that must be completed before US 41 can be converted to an interstate, including:

  • A signed environmental document
  • Approved formal conversion request package
  • Federal grandfathering legislation to allow oversize/overweight trucks to continue to use the highway.

SSI - Contact information Questions about the content of this page:
US 41 Interstate Conversion Team, 41conversion@dot.wi.gov
Last modified: October 9, 2014

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