Staged analysis: From evocative to comparative visualizations of Urban mobility

In this paper we examine the concept of staged analysis through a case study on visualizing urban mobility exhibited in a public gallery space. Recently, many cities introduced bike-sharing in order to promote cycling among locals and visitors. We explore how citizens can be guided from evocative impressions of bicycling flows to comparative analysis of three bike-sharing systems. The main aim for visualizations in exhibition contexts is to encourage a shift from temporary interest to deeper insight into a complex phenomenon. To pursue this ambition we introduce cf. city flows, a comparative visualization environment of urban bike mobility designed to help citizens casually analyze three bike-sharing systems in the context of a public exhibition space. Multiple large screens show the space of flows in bike-sharing for three selected world cities: Berlin, London, and New York. Bike journeys are represented in three geospatial visualizations designed to be progressively more analytical, from animated trails to small-multiple glyphs. In this paper, we describe our design concept and process, the exhibition setup, and discuss some of the insights visitors gained while interacting with the visualizations.