Taking already too-few parking spaces for cars (the largest people transportation system in the country) away to make 'parklets', is not real good public policy, but that is what some cities are doing, as reported by SF Streets Blog.
An excerpt.
“With scores of people crowding the sidewalk and taking up one lane of traffic on Divisadero in front of Mojo Bicycle Cafe, Mayor Gavin Newsom, Supervisor Ross Mirkarimi and city department heads heralded a new "parklet" sidewalk extension as a piece of a growing trend of re-purposing street space for people instead of cars. The new trial parklet was built into the space formerly occupied by two parked vehicles, providing several hundred square feet of public space and benches, tables, planters and bike racks.
"This is a change in philosophy and how we think of the public rights-of-way," said Department of Public Works Director Ed Reiskin, who noted that approximately 25 percent of the public space in San Francisco is taken up by streets.
"There's an extraordinary amount of the public realm that is not park space, that's actually in the public rights-of-way, that's actually the streets," said Reiskin. "Unfortunately most of it is covered with concrete and asphalt and it was designed for cars and not for people."
“The Mojo Cafe parklet is the first of several forthcoming parklets, which are technically part of the Pavement to Parks initiative spearheaded by Mayor Newsom. Though the projects are pilots, they have proven very successful and have quieted some of the early critics in neighborhoods where they've been implemented.”