Global citizens get few moments to rethink streets and make decisions that will both serve the basic purposes of transportation and address urgent challenges like climate change, rising obesity, social isolation and conflict— all while expanding opportunities for general happiness throughout society. Such a pivotal moment is upon us, as autonomous vehicles represent a potentially disruptive technology that can re-make the city for good or for ill. City planners, policy makers and community residents have a unique, and immediate, opportunity to rethink their streets with purposeful and creative consideration about how this critical public good may best serve the public for generations to come.