HUMANISM:

FOR 30 YEARS, a 40-foot-high section of US Route 101 wove like a blackberry vine through a low, old neighborhood of Edwardian and Georgian buildings in San Francisco's Hayes Valley. Then, in 1989, the Loma Prieta earthquake, magnitude 6.9, fractured the elevated roadway. Some people wanted to repair it, but the city decided to tear it down--a rare unbuilding in a nation connected by highways.

Today it's hard to imagine that anyone defended the spur. The highway formed a wall between neighborhoods, and the right-of-way beneath it was a dark, unloved space. With the freeway pruned away, the city styled the newly revealed surface street--Octavia--after a grand Parisian boulevard, with an inner couple of lanes separated from parallel side streets by tree-lined islands. Octavia now terminates in a long, grassy park with a geodesic children's play structure at one end. Nearby are pricey shops and chic cafés.

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. Take away the veil of freeway and you get space for a more boogie-woogie street fabric. Less freeway, more park.

Tumlin has a preternatural awareness of urban ectoplasm. He's going to need it. Like the Loma Prieta quake, Tumlin is about to shake some things until they break--carve up a few more roads to create bike paths, new busways, parks ... whole new ways for people to move around. It won't be easy; lefty, crazy San Francisco becomes the most conservative city in the country when it comes to changing the look and feel of the place. But this is the revolution that Tumlin and a generation of new-wave planners are waging.

"Almost no matter what you want to do with cities, transportation is the fastest and most cost-effective way of achieving your goals," he says. "If you want to reduce 22CO2 emissions, if you want to advance social equity, if you want to foster small business success, if you want to increase land value, if you want to increase public health, if you want to reduce fatalities and injuries--transport is the place to do it."

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