The relation between circuity and mobility cultures: A study of 41 European cities

Abstract

Street network configuration shapes travel behavior, network performance, and accessibility. Analyzing how physical space relates to transportation becomes vital to assessing transportation systems and planning improvements. Such an assessment can be performed by evaluating the efficiency of the network through different metrics. Within these, circuity measures the ratio between the road network and straight-line distances. This work analyzes and compares circuity for walking, cycling, and driving networks across 41 European cities. Concurrently, we identify cities' mobility cultures (socio-cultural constructs related to mobility) to identify differences between cities' circuities and mobility patterns. Data-driven methods were employed to cluster cities into six groups according to their mobility culture: Cycling Champion Cities, Sustainable Transportation Advocates, Multimodal Metropolises, Car Dependent Cities, Walking Conducive Cities, and Pro Transit Cities. Both intra- and inter-city differences were discovered for average circuity levels, and statistical differences were found between different clusters' circuity values. Car Dependent Cities had the worst circuity levels across the three transport modes; Sustainable Transport Advocates had the lowest circuity overall; and Cycling Champions Cities exhibited low levels of circuity for cycling and walking but high for driving. Results show how circuity varies between European cities and their mobility cultures, drawing attention to how different types of urban street networks are correlated to cities' mobility constructs. Further, this work poses a benchmark for cities, e.g., cities aspiring to be Sustainable Transportation Advocates can use such an approach to understand how such cities' networks are constructed and how urban structure is related to network efficiency.