This article probes the duality of marginalisation yet omnipresence of walking in cities. Using innovation in traffic light technology in Stockholm as a case study, it seeks to understand the attempts to regulate and safeguard pedestrians in the first decade after the Second World War. The article argues that traffic lights and other technologies were part of experts’ efforts to make urban mobility “systemic”, linking streets with vehicles and road users with the aim to optimize traffic. In doing so, their approach to pedestrian control was ambiguous. On the one hand, experts wanted to fit pedestrians into the emerging city traffic system: make them predictable, while also seeing to their safety. On the other hand, their designs and corresponding legislation often accepted pedestrian sovereignty, and walking was not systemised in Stockholm during the period studied here.