The book's major themes emphasize an approach to the street as a space with multiple, competing utilities that have experienced substantial transformations. Briefly, we describe what the street has meant to Rio's urban residents, and what it has become. Streets are conceived as a commons, a unique network of spaces open to all that in a sense replaced the rural commons that were being enclosed and privatized as rural peoples and former slaves migrated toward the city. The street as the definitive urban space is about the only commons in signficant expansion in the 20th century. However, the car, due to its size and permanence on public spaces, forcibly changed physical access to the street and the choices in how residents might use it. We address valid concerns about the place of nostalgia in describing past places, note more recent activism in reclaiming the street from motordom’s near monopoly, and confess an interest in history’s role in informing current policy choices about the possibilities of public spaces.