Rapidly evolving mobility technologies and the associated behavioral adjustments of travelers are bringing about dramatic changes to the morphology of cities, some of which have already begun to take root. With the seemingly endless amounts of data that technology is producing about life in cities, new mathematical modeling techniques will be required to fully understand the impact these changes will have on society. As a consequence of innovation in personal mobility technologies, a combination of autonomous and electric vehicles is being seen by many as the solution to personalized and inexpensive urban transport. In this chapter, we explore some of the ways in which this version of the future of streets could reverse decades worth of efforts by cities to reduce congestion and contain sprawl unless policy-makers are proactive in responding to these disruptive forces. Without active efforts to prioritize shared, public, and active mobility, the introduction of automated modes for transporting both humans and goods in an already contested public realm could mean a reversion to Modernist practices of privileging speed, efficiency, and function over human-scale interactions and serendipity. Politically contentious decisions will need to be made around questions of social, environmental, economic, and public health priorities to ensure that streets are made livable and accessible, particularly for vulnerable and marginalized groups. Ultimately, recognizing that the interests of pedestrians, bicyclists, public transit users as well as stationary street users should take priority over those of personal vehicles (autonomous ones in particular) is key to guiding changing urban morphologies in a way that places sustainability and human-focused development at the forefront.