The journey of a thousand miles begins with a single step—but only if you can take that step out your door and navigate the path ahead. For people with mobility disabilities, the built environment between origin and destination determines whether travel is possible at all. Sidewalks, curb cuts, ramps, crosswalks, and the countless details of pedestrian infrastructure either enable or obstruct movement through communities. This infrastructure is so basic it's often invisible to those who don't face barriers—and so consequential that its absence traps people in isolation.