Résumé en anglais

The land use conflicts occasioned by the creation or the extension of public transport networks or structures raise the question of the equality of the citizens vis-à-vis these works of public interest. In this paper, we try to understand if and how the two main fields of the public decision, namely economic calculation and administrative procedures, are able to take into account social justice to determine the opportunity, the appropriateness, the design, and the realisation of transportation systems. The text is organised in two parts. The first one highlights the failure of the costs-benefits approach to integrate any consideration of equity while the second shows that the French administrative law organizes the procedures in a way which is not likely to correct the limits of the economic approach.