The stock-flow-service nexus of personal mobility in an urban context: Vienna, Austria

Abstract Sustainable resource use calls for substantial changes to existing infrastructures, which lock societies into current resource use patterns. Urban mobility is a case in point: existing material stocks of infrastructure and vehicles require large amounts of materials and energy for maintenance and operation in order to provide mobility services, thereby causing considerable emissions. Understanding the stock-flow-service nexus of urban mobility is crucial for achieving progress towards absolute reductions of resource use and emissions. In this article, we investigate personal mobility in an urban context - Vienna. We use stock-driven material and energy flow analysis to quantify mobility stocks and flows for four different modes of mobility:pedestrian, bicycle, public transport and motorized individual traffic (MIT). We quantify material flows for maintenance, expansion, as well as primary energy use and emissions linked to personal mobility within city territory and compare a number of stock-flow-service indicators. Public transport was found to deliver most mobility services (38%), when services were measured as trips. Pedestrian mobility showed the lowest stock intensity of services while using less energy and generating lower emissions per service than any other mobility mode. Trips crossing the city border showed high shares of motorized individual traffic (62–63%). Traffic surfaces dominated material requirements of mobility and are mainly (78%) used by MIT. We conclude that considering stock-flow-service relations can support prioritizing future urban mobility planning, highlight the importance of infrastructure-related measures in doing so and the need for better monitoring especially of mobility service indicators.