Such "Ciclovias," which Peñalosa started in Colombia, are planned this August in New York City and San Francisco.
"There are people from all over the world doing amazing work," said local conference coordinator Elly Blue of the Portland group Shift, which organized the conference to coincide with Portland's annual Pedalpalooza, two weeks of fun bike events and other festivities.
Many attendees noted that global warming, high gasoline prices (and the specter of Peak Oil), worsening public health, and persistent traffic congestion have made many big city leaders more open to carfree concepts than they're ever been.
"The climate is changing," League of American Bicyclists director Andy Clarke said. "This is our time. It's our moment to seize the opportunity and change our communities."
Mia Birk, Portland's former bicycle-policy coordinator, added, "We're not anti-car, but we're trying to create a system where walking and biking are viable transportation options." Birk now runs Alta Planning and Design, which is working on carfree and car-light projects with hundreds of cities around the world, including some in the Bay Area.
"What we're talking about is a true cultural revolution to encourage that kind of shift," Birk said, inviting the crowd to "be a part of that revolution."