There are several factors that promote or limit the consideration of social equity in urban mobility policies. Depending on the case, this either contributes to more social justice or to increasing social and/or territorial inequalities. One of these factors is the conception that the actors involved in the implementation of urban mobility policies have of the aims that these policies should pursue, which determines the way in which this equity is taken into account. Therefore, the implementation of an urban mobility policy differs fundamentally according to the vision of social justice that the actors have of it, and therefore of the social or economic goals that they consider it should pursue. Furthermore, while this issue has already been addressed in large cities, this is much less the case in smaller cities. In order to account for these differences and to analyse the way in which local actors apprehend the social stakes in the mobility policies of their territory, this thesis has focused on the case of four small or medium-sized towns on a European scale, with different cultural sensitivities relating to each national and local context, as well as to their system of governance of mobility. These are the urban areas of Clermont-Ferrand and Perpignan in France, Mons in Belgium, and Norwich in Great Britain. A series of semi-structured interviews were conducted with urban mobility stakeholders in these four areas, including 17 stakeholders in Clermont-Ferrand, 14 stakeholders in Perpignan, 11 stakeholders in Mons, and 9 stakeholders in Norwich. The collected discourses were then analysed using an analysis grid based on the main theories of social justice, namely utilitarianism, Rawls' egalitarian liberalism and Sen's capability approach. At the end of the analysis, four main urban mobility issues emerge which relate to the environmental, economic and social problems of public action: these are issues of territorial accessibility, issues of pricing, issues related to improving the performance of public ...