If they ever upgrade U.S. 36 to I-72 in Missouri, then it needs to end at I-29, not I-35. That way, St. Joseph will be served by two Interstates.
One thing that needs to be done regardless is for the highway to be graded properly, especially in Linn County. Linn County widened U.S. 36 before anyplace else in northern Missouri, but all they did was build a new set of lanes alongside the original alignment, so they ended up with the new set of lanes being properly graded and relatively flat while the original alignment followed the lay of the land. The most glaring example of this is between Marceline and the Macon County line, where the westbound lanes are nice and flat, but the eastbound lanes are a roller coaster. There's a similar effect on U.S. 63 in Macon County between Macon and the Randolph County line, though the lay of the land there isn't quite as dissected as it is in eastern Linn County.
Basically, MoDOT needs to eliminate the roller coaster rides on some of their four-lane highways.