Seeing the general area you were cruising about you might have just the info I need to help me out with my trip I am taking this summer. We are driving all the way to Boston before we fly out, and because I have been to every state in the eastern US except Kentucky I am taking a funky route that goes through Poplar Bluff then hitting a diagonal towards Lexington. What I was wanting to know is how fast is the speed limit is on Hwy 60 or 160 in Missouri in the southeast part there and is it 4 lanes some of it instead of the old 2 lane highway? You definitely seemed to have taken a slightly different way then I will end up trekking, but how are the highways right above the Arkansas/Missouri line there cause it looks like I will be hitting a lot of the same highway for a bit you did.
67 is 4 Lane most of the way through Missouri...(merges with I-55 at festus south of St Louis.)...Think it was all 65 mph speed limit except in a few places where it doesn't bypass towns closer to I-55 dropped to 55 at the slowest that I noticed....I may have been speeding quite a bit today..
60 is mostly divided 4 Lane from republic to West plains(never had a reason to go beyond west plains)...There are some stoplights outside of Springfield though(rogersville and Seymour). I think the speed limit is 60-65 for at least Springfield to West plains(approx 100 miles).
Hope that helps