That route too.IMO, Missouri’s priority needs to be widening I-70 to 6 lanes between St. Louis and Kansas City.
I-44 would like to have a word...
Bottom line - I-44 and I-70 widenings are higher priorities, along with completion of I-57 (at least the two lane portion south of Poplar Bluff - the US-60 portion is 4 lanes divided / limited access (with intersections) and is less a priority, but should be complete at some point for basic continuity of the I-57 system)
As far as US-36 / “I-72”, I feel like eliminating all of the traffic signals (if there are any along the route?) and raising the speed limit to 70 mph consistently would be adequate. It would function as an interstate highway with the same speed limit, just with less traffic and intersections. As intersections and access control become problematic, they could be addressed.
But being a high value alternative route to the clogged I-70, bumping the speed limit to match that of I-70 (70 mph), and providing free-flow would make it more attractive, IMO. Honestly, with a 70 mph posted, one could more realistically maintain 5-10 mph over more consistently on US-36 than on I-70 due to the sheer amount of trucks and micropassing.
There is precedent for 70 mph speed limits on four lane divided highways in Missouri… a number of routes already boast this limit. I don’t see why it can’t be applied to not only US-36, but also US-60, US-67, etc. It would provide equal travel speeds to the interstates, and potentially help divert some traffic.