Life Cycle Assessment of Free-Floating Bike Sharing on Greenhouse Gas Emissions: A Case Study in Nanjing, China

Abstract

The free-floating bike sharing (FFBS) system appears in the form of low-carbon transport mode. Life cycle assessment (LCA) is a method to analyze the environmental impact of FFBS but has rarely considered the trip chain if the intermodal transport modes were employed. This paper proposes a mathematical formalization of LCA in response to the trip chain. The environmental benefit of FFBS was analyzed by this method considering the production, use, operation, and disposal phases in Nanjing. An online survey was conducted to analyze the mechanism of modal shift influenced by FFBS. The results showed that most respondents only use FFBS in the trip, with savings of 63.726 g CO2-eq/p·km, mainly shifting from lower-emission modes (28.30% from bus, 14.86% from metro, and 33.97% from non-motorized modes), while the trip mode of connecting public transport with FFBS could better replace the motorized transport trip and generate better low-carbon benefits with savings of 300.718 g CO2-eq/p·km. One FFBS should be used for at least 227 days to generate positive environmental benefits based on the current number of FFBS and the assumption of the utilization of each bike, which is once a day on average. The research results can effectively support the environmental benefit analysis of FFBS, the subsequent planning based on the low-carbon concept, and the implementation of relevant incentive policies.