Intermodal mobility, the IT-enabled, seamless transition between different modes of transportation to reach one’s destination, is a promising approach towards reducing the environmental footprint of urban mobility. We introduce a prototype, a geospatial data analytics system, that allows decision-makers at the municipal level to better understand how different means of transportation interact and interfere with each other within their city. Through a demonstration case, we particularly focus on the relationship between public transportation and private sector carsharing services in the city of Berlin. We outline the methods employed by the prototype to investigate the spatial and temporal dimensions of carsharing usage and how they relate to public transport offers. Our results suggest that carsharing complements public transport in some ways – e.g. by linking parts of the city with an insufficient public transport connection but also low demand – while potentially cannibalizing customers from public transport in the city center due to the increased comfort. We conclude by discussing how stakeholders can transform these insights into actionable advice.