You’ve seen them all over: the textured, bumpy pavement on sidewalks around town. The majority of people don’t know what they are for because the majority of people don’t need the help that they provide.
As the above video explains, the textures are to help partially sighted and blind people navigate intersections safely. Different textures mean different things, like curb drop-offs into an intersection, or a train platform or stairs ahead. It really is, excuse the pun, eye-opening to learn the complexity of this system that most people will never actually use.