Grades K–2 · Societies
Why are some sidewalk tiles covered in bumps?
Near some crossings, the smooth sidewalk changes into a patch of raised bumps. These bumps are there on purpose. A person may feel the change underfoot or with a long cane.
In the diagramTexture gives information about a placesidewalkwarning patchcrossingCane or feet can notice a changed surfaceThe bumps mark a location; they do not say traffic has stopped.
The changed surface gives a clue that an important edge is near. It can help someone who cannot see the edge clearly. A different color can make the patch easier to notice with vision too.
The bumps do not say when traffic has stopped. They give information about the place. Street signals, the shape of the crossing and other clues help people understand different parts of the journey.
About this explanation
Starting knowledge: Recognize a sidewalk, a crossing and a change in surface texture.
Sources
- U.S. Access Board — Public Right-of-Way Accessibility Guidelines: Detectable Warning Surfaces