By Frédéric Héran
“All car policy” is a retrospective chrononym intended to characterize a historical period after the fact, with a view to denouncing its excesses. However, it can be clearly defined as the priority given to the car in all circumstances; other modes of travel having the right to exist and even to develop, provided they do not hinder the use of the automobile. It is thus an operative concept that reveals the underlying logics of the solutions implemented during the car boom. Traffic generates, nevertheless, many negative externalities. The analysis of these problems and their impacts is constantly progressing, thereby fuelling growing opposition to individual motorised modes of transport.The questioning of all-car policy thus boils down to struggles towards no longer necessarily giving priority to the car. Three eras can be distinguished, depending on the depth and extent of the contestation. The first, which began in the 1920s in the United States, sought only to protect neighbourhoods by diverting traffic to the surrounding arteries. The second, which began in the 1960s, attempted to protect dense areas by diverting traffic to the outskirts. The third, more recent era now has the ambition to protect the planet, making protest more coherent. Yet, these periods overlap in part and are staggered in time, depending on the territories and the extent of the problems to which they are subjected.