The rapid deployment of technology in urban settings drastically changes the way urban safety is being governed. This article investigates smart governance of urban safety empirically through an in-depth case study of a project to improve the safety of a street in the Dutch city of Eindhoven. This collaboration between the city government, technology producers, knowledge institutes and owners of bars and restaurants entails the use of new technologies -noise detection, twitter analyses, data analysis, light interventions, gaming -for instantaneous monitoring and intervention. We analyze these smart governance practices from a socio-technological perspective. On the basis of our analysis, we qualify the case as a quantified street: enormous amounts of data are being collected to strengthen the governance of urban safety. The governance analysis showed that these actors shared the idea that more information results in better governance. External funding facilitated collaboration since money was no longer a scarce resource and technology became a 'lens' for building a shared understanding of the street. The relative absence of rules created the room for building innovative practices. In the conclusion, we raise questions concerning the strong focus on information as the key to a safer street and present an agenda for further research into the smart governance of urban safety.