If you're looking for a meeting place or a good stop around ½ or halfway between Kansas City and Humboldt, KS, you can try Beagle, KS, which is almost an hour southwest of Kansas City, or almost an hour northeast of Humboldt, KS.
Another possible place to stop near the midpoint is Lane.
About ¼ or a fourth of the way, you can stop at Spring Hill, KS. This is about half an hour southwest of Kansas City.
About ⅓ or a third of the way, you can stop at Wagstaff, KS. This is about half an hour south of Kansas City.
About ⅔ or two thirds of the way, you can stop at Garnett, KS. This is a little over 1 hour southwest of Kansas City, or almost an hour north of Humboldt, KS.
About ¾ or three fourths of the way, you can stop at Welda, KS. This is about 1½ hours southwest of Kansas City, or about half an hour north of Humboldt, KS.
If you drive straight through without stopping at all, the total distance is 113 miles. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 1 hour, 55 minutes.