There are lots of things about New Zealand I took for granted while I was living there and had forgotten about. Living in the States again has highlighted some of the little differences again, such as the Kiwi practice of everyone always thanking the bus driver when they get off a city bus.
Riding around in D.C., I just can't imagine anyone doing such a thing. I'm also not sure what the response would be; probably suspicion on the more local bus lines. Today I did see bus drivers patiently helping out tourists, which I wasn't expecting. Some of the grateful tourists thanked the driver, but those don't count in terms of the point I'm trying to make here.
I guess the point is, I'm far more rude here to my bus drivers when I leave their bus, at least if total indifference on both our parts is judged as rude.