by Arborwayfan
To add to mutandrew's list, display boards are used because every day tourists and business travelers come into South Station or 30th St or wherever for the first and maybe only time, and don't want to download an app just to find the next train to Needham Heights. Maybe these visitors discover they forgot to arrange for data service in the place they have just arrived in, or that their expected service doesn't work. Maybe they can read the display sign, but don't understand the local language well enough to find their way through the relevant app. And people hurrying through the station don't necessarily want to pull out their phones and enter their pins and navigate to the app and search in the app when they could just look up at the board. And if the cell phone networks the or the wifi go down, the board can probably still work -- hardwired connection to computer, maybe an emergency backup power supply.
For the same reason, we will continue to have street signs and traffic lights.
For the same reason, we will continue to have street signs and traffic lights.