Shared bicycle systems are widely promoted as sustainable urban mobility solutions due to their potential for resource sharing and emission reduction. However, assessments of their sustainability performance often rely on aggregate usage indicators, providing limited insight into how shared mobility assets are actually utilized across time and space. From a circular economy perspective, uneven utilization patterns may undermine resource efficiency and long-term infrastructure sustainability. This study examines shared bicycle systems as circular urban infrastructure by analyzing temporal and spatial patterns of resource utilization during a public holiday period. Using large-scale shared bicycle order data from Shenzhen during the Labor Day holiday, the study investigates how demand is distributed within daily cycles and across urban space, with particular attention to concentration and inequality in usage. The results reveal pronounced temporal and spatial concentration of shared bicycle trips. A substantial proportion of trips is concentrated within a limited number of peak hours, while spatial usage remains highly clustered in specific urban zones. Importantly, these concentration patterns persist even during peak demand periods, indicating limited temporal and spatial elasticity of the system under stress conditions. These findings suggest that the sustainability of shared bicycle systems depends not only on overall demand levels, but also on the structure of resource utilization. By highlighting distributional inefficiencies in time and space, this study contributes to ecological economics and management research on circular urban infrastructure and offers practical insights for the governance and operation of shared mobility systems.
Hu et al. (Sat,) studied this question.