This paper outlines an ongoing project (MITOS), which aims to customize and deploy a software platform providing advanced transportation services in the city of Santander, Spain. The system will be presented with a focus on the design framework and the rationale for evaluating User Experience in such a framework. Concepts for Future Internet environments, such as participatory sensing, game-inspired practices, and ad hoc social networks, will be employed toward this purpose. A set of experiments will be conducted, aiming to qualitatively and quantitatively evaluate the deployed system and assess the impact that its services have on the city, on its citizens/commuters, and on their attitudes towards public transportation use. The project is expected to provide methodological insights on the design and evaluation of interactive location-based systems in hybrid urban contexts. The impact of the system will be manifold and fully aligned to all dimensions related to the impact of the SmartSantander project: environmental, transportation, societal and research/technological. The deployed platform will be available to the city for further experimentation and commercial exploitation, thus being a sustainable system that can affect the activities of the citizens even after the end of the SmartSantander project.