Walking is generally considered as a natural and obvious activity for utilitarian or recreation purposes. Yet, that activity is complex to conceptualize. First, it includes a continuum of pedestriausers with various abilities to move who can have to face the environment. Second, the mobility anwalking behaviours are also influenced by a set of criteria: feasibility, accessibility, usefulness safety, comfort and pleasure. Besicles, peoples' routes are also varying following the trips objective (lnclucled in an interdisciplinary approach, this research argues that to ensure a city suitable for daily walking, it is essential to take into account the specificities of everyone and of situations that may affect pedestrian travels. For this purpose, modelling pedestrian trips in an intra-urban area, via GIS not only provides a support of analysis and visualization but also a decision tool for both people and stakeholders. The innovation of this approach lies in an inclusive tool which integrates this interrelationships among a variety of pedestrian users and the environment in different contexts. Our methodology is also reproducible in different cities and able to adapt itself to specific local context through an urban audit and a questionnaire for users. This thesis is concluded by an empirical case of study in Luxembourg-city to gather information about the ability of a city to provide an efficient pedestrian network and some pedestrian users ' testimonies. ; La marche en milieu intra-urbain est considérée comme une pratique naturelle et évidente pour les déplacements à but utilitaire ou récréatif. Cependant, cette activité se révèle complexe à conceptualiser. Tout d' abord, elle inclut un continuum d'usagers piétons, aux capacités de mobilité diverses, pouvant être confrontés à des situations d' inadéquation avec l'environnement. Ensuite, les comportements de mobilité pédestre sont influencés par une série d'exigences : faisabilité,accessibilité, utilité, sécurité, confort ou encore plaisir des sens. Enfin, les ...