The designation will apply to 180 miles of current US-71 between Bannister Road (Route W) in south Kansas City and Route H at Pineville (McDonald County), which was upgraded to Interstate standards beginning in 2010.
U.S. 71 will carry the I-49 designation between Kansas City and Pineville beginning Dec. 12. Missouri DOT officials will host a public celebration and sign unveiling that day in Joplin.
The U.S. 71 upgrade, a two-year project, involved removing all at-grade intersections and constructing interchanges and overpasses at 15 sites between Harrisonville and Lamar. Officials say 185 miles of U.S. 71 are upgraded to interstate highway standards, with new interchanges, overpasses and outer roads.
I-49 will also run concurrently with Interstate 44 between I-44 interchanges 11 and 18 east of Joplin.
Long-term plans call for I-49 to be run from Louisiana to to Kansas City, where it will connect with other interstates and provide a seamless freeway link from Louisiana ports to the Canadian border in North Dakota via Interstate 29 and to other points north via Interstate 35. Highway officials in Arkansas and Louisiana also are working to complete Interstate 49 in their states.
Planning for the final series of projects was begun in the late 1980s, with construction beginning in the the early 1990s and continuing through 2012.
The first section of highway designated as I-49 was in 1984 in Louisiana.