Urban street dynamics: Assessing the relationship of sidewalk width and pedestrian activity in Auckland, New Zealand, based on mobile phone data

This study empirically examines the adequacy of sidewalk widths in Auckland’s Central Business District in light of increasing active mobility and sustainable urban planning trends. Recognising the need to retrofit street spaces to prioritise pedestrians, we aim to determine whether current sidewalk dimensions meet the diverse requirements of users. We analysed average sidewalk widths and developed four mobility metrics – inflow and outflow travel distance, and density of visitors and locals – using a large-scale mobile location dataset comprising 113 million data points from 1.4 million users. These metrics, reflecting urban vibrancy and sidewalk use, were correlated with sidewalk widths to assess their adequacy. Furthermore, we applied cluster analysis to these mobility metrics, along with the diversity of Points of Interest, to categorise sidewalk segments, uncovering intricate usage patterns. Our findings indicate that sidewalks typically range from 2 to 5 m, catering to varied urban needs. Notably, we observed no direct correlation between sidewalk width and mobility patterns, but significant differences in inflow and outflow travel distances were evident, especially between key urban hubs and quiet residential neighbourhoods. Moreover, we identified seven distinct sidewalk categories, each reflecting unique qualities, suggesting that uniform widths do not define sidewalk utility or character. This highlights the need to rethink current capacity-focused sidewalk design, advocating for a nuanced approach that addresses the intricate demands of urban spaces. Our methodology offers flexibility and can be tailored to suit different urban contexts, providing a versatile tool for urban analysis and planning.