Abstract
The increasing use of technologies like smart phones and mobile apps enables people to be actively involved in collecting data that can be the base of useful services to the whole citizenship. In the realm of volunteer data collection, this chapter addresses the problem of mobility and accessibility limitations for vulnerable citizens in today's cities. The MEP (Maps for Easy Paths) project proposes a set of tools and mobile apps for the enrichment of geographical maps with information about accessibility of urban pedestrian pathways, targeted at people with mobility problems. Different issues are considered and discussed in this chapter, including: the problem of collecting data of a user's route and of reconstructing it with novel sensor fusion techniques; the problem of correcting the positions obtained from low-cost GNSS receivers of mobile devices; the need of usable and accessible applications for the fruition of the collected data suitable for the target users.