The “pedestrian volume index” at 50 of the city’s most crowded intersections keeps rising, and transportation commissioner Janette Sadik-Khan is blinded by inexplicable optimism: “People like to be around people,” she said, while also noting the economic and health benefits of having congested sidewalks. “With 8.4 million people, you don’t live here unless you like people.” That is an interesting theory. Dear 8.4 million people: walk faster.