Assessing street vitality using functional density as a proxy

Maintaining street vitality, understood as a concentration of human activity, is a key priority for urban agendas, yet predicting and understanding it remains challenging. This paper examines street vitality in 10 European cities using functional density as a proxy, measured as the number of unique points of interest (POI) classes per street segment length. Leveraging OpenStreetMap (OSM) data and a spatial lag regression model with a log-transformed dependent variable, the analysis accounts for spatial dependencies while examining the determinants of functional density across cities and within street segments characterised by high functional density. Findings show that morphological factors influence functional density more consistently than transport-related ones. Higher clustering of functional density in city-wide models indicates the need for strategic planning around vitality, whereas the weaker clustering observed in models focused on streets with high functional density indicates greater consideration needed for local street-level attributes. Long street segments appear to enhance functional density at the city level, while compact urban forms support vitality in already vibrant areas. Commercial density enhances functional density city-wide, while residential presence is more significant in streets with high functional density. Transport infrastructure explains better street vitality clustering at the city level, but its role weakens among other variables in already dense areas.