Highway 12 to be detoured as final connections made in Willmar Wye roadwork Drivers will need to take a detour on U.S. Highway 12 on the west side of Willmar, as construction crews make the final connections between the old Highway 12 and the new. 10:42 am, Apr. 16, 2021 × As the final connections are made on U.S. Highway 12 in Willmar as part of the Willmar Wye project, traffic will be detoured for about a week. Map courtesy of MnDOT WILLMAR — The old and new U.S. Highway 12 will soon come together as one. Construction crews are scheduled to tie in the existing highway with the new segments constructed on the western side of Willmar as part of the Willmar Wye project, starting Monday, April 19, announced the Minnesota Department of Transportation District 8.