Mobile phone traffic data for territorial research Opportunities and challenges for urban sensing and territorial fragilities analysis

Mobile phone tracking data collected by telecommunication companies allow recording and reconstructing the practices of mobilities and the presence of users with significant spatial-temporal detail. If properly managed, analysed, and possibly combined with other sources of information, mobile phone data can represent an interesting opportunity for urban research and mobility studies as they shed light on complex socio-territorial dynamics difficult to infer from conventional data analysis. At the same time, reports of numerous experiments using these sources reveal some of the challenges that researchers face in accurately capturing the behaviours of individuals through digital data and translating them into useful research knowledge. Referring both to the direct experience of managing and analysing mobile phone data within the Department of Architecture and Urban Studies of the Politecnico di Milano and to the relevant literature, the paper proposes an overview of the potentialities and limitations of telephone data for urban research and their usability in different territorial contexts characterised by varying socio-spatial and demographic conditions. Besides positioning themselves within and enriching an already lively debate, the issues discussed here will be useful in reading the contributions of the special section that this paper introduces.