Thanks for your comments. Darkwings, I agree that in the long run, I'll need >1 coverage for all squares due to capacity caps. However, my current city is about 110,000 and takes up the whole map. In the long run I can turn down the bus budget as I add educational facilities to deal with the increased population, but that would be too expensive right now. For now, I want to pay more for buses and cover everybody in my city with the facilities I have. I also want to *verify* I have everybody covered.
Is there any way to do this without doing something drastic like turning off buses entirely? I don't want to change the game mechanics quite so much.