At the crossroads of transportation engineering and urban sociology, the dissertation deciphers the interactions between daily mobility and social inequalities, what I call the "social mechanics of mobility". To do so, I draw on a twofold survey, both quantitative and qualitative, in three cross-border regions of the Schengen area. This original geographical configuration, characterized by the local convergence of multiple national structures, allows me to highlight sources of daily mobility inequalities. I use three methods to address them, each corresponding to a sociological research program on daily mobility. In the first place, I use multiple correspondence analysis to show that daily mobility practices are distributed within localized and hierarchical social spaces. In a second step, I operationalize the concept of disposition using latent variables to detect to role of "pro cross-border" opinions on commuting behaviors to the neighboring country. Finally, the literature on the politicization of daily mobility leads me to study, using interviews, a controversy around a highway infrastructure where two associations claim competing "best practices" of travelling.

These three steps allow me to define four mechanisms responsible for daily mobility inequalities. First, "impulse" describes the effect of past spatial mobilities on people's present relation to daily mobility. Second, "inertia" characterizes the weight of social structures influencing each individual's daily mobility. Third, "entropy" represents the relational process differentiating individuals' daily mobility within a social space. Fourth, "refraction" measures the change in relative value of people's ressources as they move between two geographic spaces separated by thresholds. Taken together, these mechanisms explain the social specialization of daily mobility observed within cross-border regions.

The dissertation first provides new insights to the field of Border Studies by showing how socially homogeneous spaces of circulation are formed under the combination of integration policies and border differentials. In replicating the "social mechanics of mobility", the dissertation then contributes to shed light on the intrinsic inequalities of daily mobility, in contrast to theories of the mobility turn. Finally, the dissertation opens up interdisciplinary methodological perspectives by combining elements of quantitative sociology, transportation studies and fieldwork.