I haven't really ridden enough buses in America to know how to compare them, but the Japanese bus drivers are a daily source of amusement for Nick and I on the commute to class. Actually, I think they are probably pretty similar to American bus drivers... But getting to the point, they say (or are supposed to say) "arigatou gozaimasu" ("Thank you very much") to each person as they get off the bus, but more often than not they mumble it beyond recognition. Usually they end up just dropping most of it and catching the end so it sounds like "moss" or "[mumble mumble] masu". Most people would ignore this or think "What did he say?" and then move on with their life, but not us. We make a game out of interpreting the bus drivers' garbled speech. From "getoffmybus" and "arollingstonegathersno-masu" to a duck's quack and things that sound nothing like the original phrase, as was the case the day our driver seemed to say "scotty diagus". There is quite a variety in our daily greetings from the bus drivers. Of course there are a few bus drivers who still enthusiastically and clearly thank everyone but I can only assume they're still new to the job. I also have to wonder how a bus driver's life at home is and whether their wife would grow accustomed to interpreting bus-driver-ese.
Well, at least the bus drivers aren't mean. They just seem very bored and dissatisfied with their jobs, but it's more amusing for us that way.