International audienceThis paper presents a reflection on how relevant it is to assess the vulnerability of the infrastructures on which people's daily mobility relies in order to understand, at an upper level, the territorial vulnerabilities. Once defined the concepts involved in this analysis and after a brief description of the research framework, the four steps thought process is detailed. The first step was to analyse people's daily mobility (motivation, trips volume, origin and destination) and the transportation system (offer and network) within the Metropolitan District of Quito (MDQ). This allowed pinpointing in a second step, key elements within road and transportation network referred to as critical infrastructures. The third ste...