Originally Posted by fastflyer
I don't believe tipping is by any means standard on Acela or the other Northeast services.
True – in business class. I meant just in first class (as was always done in parlor service) and also for consideration for meal and beverage service; somewhat like a diner in that way; as in a restaurant

or bar

. Such tipping is not unusual in Acela first class, although not everyone does it.