Analysis of cycling accessibility using detour ratios – A large-scale study based on crowdsourced GPS data

To create bicycle-friendly urban environments, policymakers need tools for identifying and mapping the most efficient routes in terms of cycling accessibility. Yet, few studies have empirically investigated cycling accessibility in terms of detours. Using crowdsourced GPS data, this study measures both realized detour ratios (RDRs), describing detours resulting from network constraints and intentional behavior, and behavioral detour ratios (BDRs), describing detours resulting solely from intentional behavior. The study analyzes the measures in narrowly defined grid zones of the Copenhagen region and visual examination shows that zones along radial corridors with good connections toward the city center have the lowest RDRs, while the city center zones have slightly higher BDRs. Furthermore, the study uses regression with spatial autocorrelation to examine factors affecting RDRs and BDRs. Well-equipped zones containing more roads, a lot of dedicated bicycle infrastructure, and cycle superhighways have significantly lower average RDRs. Zones with recreation areas and a high percentage of high-income residents significantly increase the average BDRs. The insights of the study enable policymakers to identify where and how to improve bicycle infrastructure from a detour perspective.