Informing car drivers is a cornerstone of policies of urban road governance. Through comparative analysis of Paris and Lyon from 1920 to 2010, we show that today’s driver information results from three technical and political strata. Through the period, Paris and Lyon basically followed the same traffic policies. Nonetheless Paris did not always act as a model for Lyon as the local context led to different technical responses to traffic management needs. From the 1920s to the 1940s, the driver was seen as an individual, to whom the road authorities needed to provide regulation and guidance, mainly through static signposting. Then, from the 1950s to the late 1970s, the authorities dealt with traffic flows rather than individuals. Central systems, relying on road sensors and dedicated to the authorities in charge, were developed along with new infrastructures. Following the oil crisis, driver information became multi-modal. The driver was once again an individual travelling and in need of information. By the 1990s, authorities provided centralized traffic information on variable message signs and on the Internet. Simultaneously, on-board devices allowed private companies to gather traffic data and provide traffic information to their driver-clients, independently of the road authorities. This has had consequences on how public and private actors govern traffic with diverging interests.