Enhancing carbon efficiency in shared micro-mobility systems: An agent-based fleet size and layout assessment approach (Vol 443, 141209, 2024)

Shared micro-mobility systems (SMMS) have the potential to reduce CO2 emissions of urban transportation. However, the reduction varies with fleet sizes (i.e., the number of different types of bikes in the market) and layouts. The excessive commercialization of SMMS has resulted in a decline in carbon benefits. In this study, we propose an agent-based model integrated with a lifecycle assessment (LCA) approach to evaluating the carbon benefits of unknown shared bike scale scenarios by establishing a brand-new SMMS. The proportion of satisfied actual trip demand and bike utilization rates also be analyzed for exploring the inherent mechanisms of SMMS. Take San Francisco, California, as an example, the evaluation of free-floating shared electric bikes and station-based shared-bikes analyzes five different layouts, each consisting of 121 different combinations. The results indicate that, for an area of approximately 100 km2 with a daily travel demand of over ten thousand, a fleet size of 4500-7500 bikes is suggested, potentially leading to a weekly carbon reduction of 10,000-11,000 kg CO2-eq. This study will provide insights for launch plan and scale management of SMMS from a sustainable perspective.