A simple, analog solution to SOSED (Sudden-Onset Subway Exit Disorientation): low-profile wayfinding signs on the stairway risers, designed by Ryan Murphy and documented by Vicky Gan. Much more useful than smartphone beacons, also discussed in the post: who wants to be staring at a screen when you and 1,000 of your new best friends are trying to get off the platform and into the light?