Build Cities for Bikes, Buses, and Feet—Not Cars

Back when Jeff Tumlin was on staff at the urban planning consultancy Nelson\Nygaard, he worked on this remaking of Octavia Street and Hayes Valley. Now Tumlin—tall, lean, and bearded—is the new head of San Francisco’s Municipal Transportation Agency. On a sunny winter morning, he and I head for that green space so he can show me the freeway’s ghost, barely visible in the odd, polygonal footprints of newer buildings along Hayes Street—they’re catawampus, tucked into the spaces where the concrete artery used to curve through, insensible to the city’s grid…

Transportation and housing are as intertwined as strands of DNA. But in California, legislation that would have made it easier to build clustered, multiunit housing near transit lines has failed to pass the state’s Senate two years in a row. If you make it illegal to build dense cities, it’s hard to cut carbon. “Housing policy is climate policy,” says Constantine Samaras, a climate and energy researcher at Carnegie Mellon University. “City policy is climate policy.”