In a world where you might be stuck underground waiting for a subway train, a digital screen that can tell you when the next train is coming can be a godsend. If you live in a city with a modern train system, you are probably used to screens that announce train arrivals and don't think anything of it. In New York, this is novel like a great white buffalo.
Well, it depends what train line you are on. And, for me, it's not great. I take the A train and the train is often crowded or delayed; and when it is delayed, there's usually not a "countdown" clock in sight.