The regions participating in the TWIST project are characterised by a lack of service and infrastructural balance in rural and mountain areas. The growing isolation of these populations, mostly older people, is the cause and the effect of the progressive abandonment of these territories. As a consequence, the resources assigned to the local transport services have been reduced, forcing the local populations to use their own means of transport and causing more traffic and road-related accidents as well as higher levels of exhaust emissions. The TWIST project aims at reducing the social and economic gap between mountain/rural areas and urban areas through the local implementation of different patterns of DRT (Demand Responsive Transport). The introduction of on-demand bus services in the territories is expected to facilitate access in disadvantaged and remote areas to more developed areas, offering opportunities of commercial exchanges, job search and social/health assistance. Starting from the supply and demand survey of the public transport in the territories of the pilot projects, the TWIST project will implement the experimentation of different on-demand bus services. A model to organise and evaluate these services will be elaborated and transferred to other regions with similar characteristics. The project will develop methodologies to determine the best technical and economic solutions for Demand Responsive Transport, and will help to harmonise the local transport services to safety, qualitative and quantitative European standards. The final output will be a sort of vademecum of best practices and methodologies to be transferred at regional and local level to the authorities in charge of planning and managing the transport system.