(Source: Room for Debate, a New York Times blog)

(Photo: Librado Romero/The New York Times) In Times Square, pedestrians often find themselves maneuvering among cars blocking the intersections.

The pedestrian mall, the urban planner’s failed attempt to revitalize Main Streets during the 1960s and 70s, is back!

This week, Mayor Michael Bloomberg announced that cars would be barred from several blocks of Broadway, including Herald Square and Times Square. He said the changes would relieve traffic congestion and crowded sidewalks – far different problems from what spawned the pedestrian malls of the 70s. And it’s not just New York that’s rethinking this old idea. San Francisco is considering restrictions on private cars on Market Street, the city’s main artery.

When do these car-free zones succeed? And why have they left streets deserted and unappealing in the past?

• Robert Sullivan, author
• Sam Staley, co-author of “Mobility First”
• Alexander Garvin, architect and former Planning Commission member
• Steve Davies, Project for Public Spaces
• Randal O’Toole, author of “The Best-Laid Plans”

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