Counties Passed through: Franklin
In 1957, the State Highway Commission passed a resolution adding the future I-35 to the state highway system. The interstate projects were let as an extension of US 50. By 1962, I-35 had been completed between Olathe and Ottawa and the US 50 designation was shifted to the new interstate. The existing US 50 was retained, with the segment between the end of the I-35 project and US 59 in Ottawa designated as a spur of US 50.
In October, 1979, AASHTO passed a resolution redesignating the spur as a Buisness loop. KDOT issued a resolution in 1981 confirming the redesignation, and extending the Buisnes loop to reconnect with I-35 via US 59 and K-68
In November, 2000, a state resolution was passed removing US 50B from the State Highway System upon the conclusion of a project to rebuild the I-35 roadbed in Franklin County. As part of the rebuilding, the bridge over I-35 on old US 50 was demolished and not replaced. The bridge taking old US 50 over southbound US 59 and a former Santa Fe railroad line was also demolished. The roadway leading up to these bridges was abandoned, with the remainder reverting to the city of Ottawa.