Visualizing the Effects of Public Transportation Growth on Urban Demographics

We present Tidebanan (Time Way), an interactive visualization of the history of the metro system of Stockholm from 1949 to 2014 that includes a projection to 2025. The analytics tool visually correlates the growth of the metro system with the changing demographic density of Stockholm. Interestingly, we discover patterns of density decrease in central Stockholm as new metro lines open, in particular the southern red and northern blue lines in the 1970s. In fact, central Stockholm has never been as dense as it was in 1949, a surprising fact that is visually salient in our application. This paper presents the design process, architecture, data models and sources, interactive visual structures, and visual analytic trails discovered through Tidebanan.