Abstract
Transport planning and policy is increasingly being called to action in ways that differ from practices of yesteryear. Varied segments of society are increasingly looking to city streets-the workhorse of a city's transport system-as places to enact change. Namely, to change their character away from the type of streets pervasive in auto-oriented urban environments. Acutely experienced during the disruption of the COVID-19 pandemic, emergency response measures from many cities across the world abruptly altered the nature and purpose of street space. These "street experiments" fueled an opportunity, in part, to explore a transition to practices prioritizing forms of sustainable mobility such as walking and bicycling. This research inventories street-focused emergency response measures from the 55 largest cities in the US. We devise a rubric to systematically assess and locate characteristics of these measures that enable a transition. Results show that five "innovator" and several "early adopter" cities are using COVID conditions to test new forms of streets and in some cases, street networks. These cities excelled in conveying a vision for alternative future, articulating implementation pathways, leveraging political capacity, and circulating information. After six months, half of the cities continue their efforts, including only six which have expanded. The few showing continued strength demonstrate endeavors to evaluate the experiments, validate their feasibility, and embed the experiments into existing sustainability policy. These components, when leveraged together, could seed innovative break-throughs in how city streets are used, designed, and standardized. The paper establishes baseline evidence on which future research efforts can build and provides empirical evidence on early stages of the experimentation and transition processes of urban mobility systems.