The final bill omitted the I-41 designation. In 2009, Green Bay officials began a campaign to have US 41 designated as a northern extension of I-55 from its current termination in Chicago, with the alternative being designated as a spur of I-43. At the spring meeting of the Special Committee on U.S. Route Numbers of AASHTO on May 18, 2012, the I-55 designation was discussed by the committee. Coordination would have been required with the Federal Highway Administration (FHWA) and the Illinois Department of Transportation (IDOT) on the I-55 designation. However, IDOT officials were not interested in signing an extension of I-55 from its Chicago terminus to the state line. Therefore, the Wisconsin Department of Transportation (WisDOT) decided to seek a different designation not requiring the cooperation of their Illinois counterparts. Four designations were proposed by WisDOT and put up for public review: two new primary designations (I-41 and I-47) and two auxiliary designations (I-594 and I-643). At the end of October 2012, WisDOT submitted I-41 to AASHTO for consideration at their fall Special Committee meeting, where it was conditionally approved on November 16, 2012, pending FHWA concurrence. Official approval of I-41 then hinged on weight limit exceptions being approved for the route, which initially passed the United States House of Representatives as H.R. 4745 and awaited a United States Senate vote as S. 2438, but there were later passed in a different bill (H.R. 83) on December 16, 2014. On April 9, 2015, Wisconsin Governor Scott Walker announced that the FHWA had approved I-41 as part of the Interstate Highway System. According to WisDOT, the approval came two days earlier. WisDOT replaced or modified 3,500 signs before and near September 2015 after coordination with IDOT and the FHWA (signs erected in 2014 and into 2015 before approval of the designation had the I-41 shield obscured until approval). Over the next 5–10 years, shoulders are slated to be rebuilt as older parts of the highway are upgraded. The redesignation to Interstate status also makes the route subject to the Highway Beautification Act, meaning current advertising billboards along the Milwaukee-to-Green Bay portion of the road can no longer be upgraded or enlarged nor can new signs be added. Exit list See also References External links Official US 41 Interstate conversion project page Interstate 41 at Interstate-Guide.com 41 41 41 Freeways in the Milwaukee area Transportation in Lake County, Illinois Transportation in