How an army of digital sleuths are using AI to fix America’s crumbling sidewalks

Project Sidewalk pairs machine learning and community engagement to map—and improve—sidewalk accessibility. I’m on a tree-lined street in Lincoln Park, a city in Metro Detroit, studying a curb ramp—the part of the sidewalk that slopes down to meet the street at an intersection so that someone using a wheelchair can safely cross. I mark the ramp “good” and move on.