Both drivers and guards definitely do Signallers are fair game for waving too!That's made me think, bus drivers wave to their mates as they pass; but I doubt train drivers do? Thinking unless they are going slowly, a quick wave simply wouldn't be seen by the driver coming in the other direction?
As a pax I wouldn't see, so train drivers here can put me right!
As for thanking drivers, I did last week as he was leaving his cab!