How much flexibility does rural public transport need? - Implications from a fully flexible DRT system

Rural regions in industrialised countries are facing problems in public transport (PT) provision against the backdrop of demographic change, urbanisation and austerity policies. However, innovative mobility concepts evolve under technological developments. Demand responsive transport (DRT) has been identified in research to meet the challenges and efficiently improve mobility through the concept of ride-pooling. Still, most of these DRT services are being investigated in urban settings with high mobility demand and population density. Research on low-demand regions, such as the Oberharz in Germany, is rarely considered. Moreover, the applied DRT services come with several restrictions regarding stop locations, customer target groups or spatial restrictions. Therefore, this paper fills this gap through spatial and temporal analysis of a real-life, fully flexible and true door-to-door DRT experiment. Over a 6-months period around 38,000 trips took place in the Oberharz. The analysis of these trips shows that an unrestricted DRT service between three main centres (Goslar, Clausthal-Zellerfeld and Osterode) results in main travel axes between these cities while the more remote areas forfeit mobility to these centres of public service provision. Consequently, a feeder-trunk system should be favoured for future DRT services in low-demand areas to sustainably improve mobility in remote regions. The complementary extension of the existing PT through such a DRT service should then meet mobility needs of rural areas to redeem car dependency and improve mobility for all population groups.