Wisconsin Department of Transportation

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US 41 Interstate Conversion - Frequently asked questions (FAQ)

Logo - US 41 Interstate Conversion
WI Congressman Petri (left) sponsored the federal transportation bill that identified the US 41 corridor for inclusion in the Interstate Highway System. WisDOT Region Direct Will Doresey (right) provides an update on planning.

Congressman Tom Petri (left) with WisDOT NE Region Director Will Dorsey.


Why is US 41 becoming an Interstate?

The US 41 corridor was identified in a 2005 federal transportation bill for potential inclusion in the Interstate Highway System. The Safe, Accountable, Flexible, Efficient, Transportation Equity Act: A Legacy for Users (SAFETEA-LU) was signed into law in August 2005 and identified the US 41 corridor as a potential future Interstate route.

How many miles of US 41 will be converted?

The Interstate will total 175 miles in length. The 43 miles along I-94 and I-894 are already signed as interstate highway. The remaining 132 miles from the Zoo interchange north to I-43 in Green Bay will be converted from US highway to new Interstate highway.

How much traffic uses US 41?

Traffic volumes on US 41 currently range from 27,000 to 150,000 vehicles per day. More than 80 million truck tons of freight originate in the eight counties along US 41, accounting for nearly 38 percent of Wisconsin’s originating truck tonnage.

Why convert US 41 to an Interstate Highway?

Designating the highway as an Interstate is expected to help create economic growth from Milwaukee to Green Bay; ensure the highest level of safety and mobility; create a corridor identity and bring broader benefits to the state of Wisconsin.

  • Interstates connect major metropolitan areas, cities and industrial centers.
  • About 40 percent of Wisconsin’s overall economic activity is located in the eight counties along the corridor between Milwaukee and Green Bay.
  • The cities of Appleton, Oshkosh and Fond du Lac are one of the only cluster of three cities (except for cities in California and Texas) in the U.S. with populations greater than 40,000 that are not within 25 miles of an Interstate highway.
  • Appleton, Oshkosh and Fond du Lac are the only cities in Wisconsin with a population base or more than 40,000 that are not served by an Interstate.
  • Although the local traveling public realizes that US 41 is currently a high quality freeway, those not familiar with the area would not associate a US highway with the type of facility that provides for the highest level of safety and mobility of an Interstate.

What are the advantages of an Interstate versus a US Highway?

There are multiple advantages, they include but are not limited to:

  • Interstates provide a corridor identify, which encourages growth. For example, of 26 major distribution centers in Wisconsin, 73 percent are located within five miles of an Interstate.
  • Designating US 41 as part of the Interstate system will help stimulate and accommodate economic growth from Milwaukee to Green Bay.
  • The design standards for the Interstate system ensure high levels of mobility and safety.
  • Interstate status will elevate US 41 from a regionally-known freeway to a nationally recognized corridor. This will allow communities along the route to be competitive when large corporations are looking for market expansion locations.

Why was I-41 recommended as the route number?

There are a number of reasons WisDOT, American Association of State Highway Transportation Officials. (AASHTO) and Federal Highway Administration (FHWA) conditionally approved I-41 in Nov. 2012 as the route designation, including:

  • I-41 follows the AASHTO guidelines of increasing route numbers west to east, with its location between I-39 and I-43.
  • I-41 is the route designation number anticipated and preferred by the general public.
  • I-41 allows for future Interstate loop or spur routes to be designated off of I-41.

Will Interstate 41 and US 41 follow the same route?

Yes. Because I-41 and US 41 will be concurrent the entire route, there should be no driver confusion about which “Route 41” to follow.

  • US 41 joins I-94 at the Russell Road interchange, approximately 1 mile south of the WI/IL state line, making it the logical starting point for the conversion.
  • The current route of US 41 in Milwaukee, along Lisbon Ave. and Appleton Ave, will be relocated to follow I-41 along I-894 and US 45.
  • Current US 41 from I-94 at the Miller Park interchange to the interchange with US 45 will be re-numbered to WIS 175.
  • The end point of I-41 will be in Green Bay at the I-43 interchange where US 41 will continue north to Michigan.

What other route numbers were considered?

A number of other route numbers were considered but, based on existing route numbering guidelines and public feedback, I-41 was deemed most appropriate.

Why extend I-41 to the Illinois border?

It is a logical starting point for the new Interstate. It will add 33 miles to the conversion, making the corridor 175 miles long. An economic assessment found Wisconsin will benefit from having the new interstate extended to Illinois.

How many signs will need to be revised or replaced?

Between the project termini:

  • About 1,300 signs would be replaced with a new sign and post in the same location.
  • 650 signs on existing posts will be revised.
  • 950 new signs with a new post will be installed.

What is the cost of changing signs from US Highway to an Interstate?

The installation of Interstate shields will cost between $8 and 12 million. This includes revising or replacing approximately 2,900 signs including both the large green signs and the smaller guide signs on the side roads directing traffic to the Interstate, revising existing sign bridges, installing new sign bridges, and performing traffic control.

Why is federal grandfathering legislation needed?

Federally mandated maximum weight limits will apply to the interstate system and vehicles that currently operate on US 41. It is estimated that 10-20 percent of the trucks currently operating on US 41 are hauling overweight or oversize loads by permit or allowed by state statute. Our current US 41 roadway and our new projects along the corridor are constructed to handle these loads. Truck traffic should be allowed to continue to use the corridor and not be diverted off of the Interstate onto state or county highways. To address this issue, federal legislation is needed which will grandfather the existing statutes and permitting process, so that those trucks that are currently able to utilize the US 41 corridor will be able to continue business as usual after the Interstate conversion.

What are the impacts to outdoor advertising?

The Ladybird Johnson Highway Beautification Act of 1965 was announced as an America the Beautiful initiative with its control of outdoor advertising along Interstate and primary highways. Provisions of this Act will apply once US 41 is converted to an Interstate. Interstate designation will change the status of most of the existing legally permitted billboards to non-conforming which means that they can remain, but will not be able to be improved or re-constructed. And in general, new billboards will not be allowed along the Interstate corridor. The Act does not address signs that are located on the property of businesses they advertise.

Will there be construction projects related to the Interstate designation?

An agreement between the Federal Highway Administration and WisDOT will address any deficiencies along the corridor. For example, a stretch of highway with substandard shoulders may be improved to bring those shoulders to the required width. These changes are expected to be included with normally programmed improvements for US 41 as part of the standard WisDOT process to maintain safety and mobility for this important route.

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SSI - Contact information Questions about the content of this page:
US 41 Interstate Conversion Team, 41conversion@dot.wi.gov
Last modified: July 22, 2014

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