Taking a description directly from their website: San Francisco's streets and public right-of-ways make up fully 25% of the city's land area, more space than is found in all of the city's parks. Many of the streets are excessively wide and contain large zones of wasted space, especially at intersections. San Francisco's new "Pavement to Parks" projects seek to temporarily reclaim these unused swathes and quickly and inexpensively turn them into public plazas and parks. During the temporary closure, the success of these plazas are evaluated to understand what adjustments need to be made in the short term, and ultimately, whether the temporary closure should be a long term community investment.