The current literature on self-driving cars tends to focus on ethical complexities related to an individual vehicle, including “trolley-type” scenarios. This is a necessary but insufficient step towards determining how the technology will impact human lives and society more generally. Ethical, legal, and policy deliberations about self-driving cars need to incorporate a broader, system level of analysis, including the interactions and effects that these cars will have on one another and on the socio-technical systems in which they are embedded.1 Of course, there are many types of self-driving vehicles that are not cars, including autonomous trucks (Anderson 2015), and they carry with them their own interesting ethical issues. For example, self-driving public transportation, like taxis, could have environmental and other important benefits (Greenblatt and Saxena 2015). Though much of the discussion is applicable to a range of ground-based vehicles, the focus here is on privately owned cars.