National audienceSustainable city, new technologies, new ecology. These are, among others, some of the terms commonly used to refer to the globalization of the self-service bicycle programmes. Valued for their " planet friendly " character, these systems have become a hallmark for cities that want to become part of what is known as the " green culture ". Drawing from the experience of the Vélib' programme in Paris, this essay questions the notions of sustainable city and mobility and describes the controversies surrounding the elaboration of and decisions regarding such an infrastructure.Ville durable, nouvelles technologies, nouvelle écologie : tels sont, entre autres, les termes habituellement employés pour qualifier le phénomène de mondi...