a regular square raised above the level of the asphalt road beveled on all sides. overcoming an obstacle means slowing down the ve

all asphalt beveled black bump city concrete cross crosswalk curb czech dangerous edge elevate empty gray interlocking island jump lawn level means navigation obstacle orientation overcoming pattern pavement pedestrian raised regular road roundabout safety school sides sidewalk sign slanted slow slowing speed square street surface symbol tactile terrain texture tile tiles track traffic triangle urban walk way white woman zebra