I believe it is protocol at SF STL. ALL employees waved at the train-no matter how un-enthusiastic they looked about it. It was basically someone still going about their business, talking working etc, and with no eye contact they began a "wax on wax off" movement towards the train, very unwelcoming if you ask me. The workers didn't even have the politeness to look up and smile, or make eye contact, or stop their talking, at least we didn't interrupt them!