In late November, Randy Wade, the director of pedestrian projects at the Department of Transportation, stood in a room at the Casita Maria cultural center in the South Bronx, briefing local activists on a plan to redesign a nearby intersection. She pored over maps, blueprints and aerial photos, reviewed principles of traffic calming and offered examples of what DOT calls “Thinking Big” projects: pedestrian plazas in Manhattan, bus lanes in the Bronx.