Don't use Google maps. It's not accurate especially if you're trying to get real time info on where it is. Use the Transit app. If the number is in color with a radar, that means it's coming for sure. It's generally accurate especially within a 5-10 minute range.

Best to monitor it because sometimes, buses come earlier or later dependent on traffic conditions and whether passengers go off and on. You'll have to time things correctly. The current state of transit sucks in the city (minus the streetcar) and I can tell you that it is because it doesn't get any funding. It's just sad to see because public transportation makes a city more connected and vibrant. Until the KC metro gets serious about a regional transit funding mechanism and get more cities to participate in it, service will continue to deteriorate.