How to promote the environmental sustainability of shared e-scooters: A life-cycle analysis based on a case study from Lisbon, Portugal,

Electric scooter sharing systems have emerged as an innovative short distance transport mode. Since these systems are dockless, they require collection for maintenance and charging, as well as rebalancing operations citywide, justifying the need for an integrated analysis. This work performs a Life Cycle Analysis to assess the environmental impacts of all stages of a shared e-scooter, based on the use case of Lisbon, Portugal. Results indicate that an e-scooter emits 804 to 1679 g  $C{O}_{2eq}$/km, which is justified by its low use rates and reduced life span. Its production accounts for more than 70% of impacts, collection and distribution processes for 6% and vehicle use corresponds to 17%. Increasing the shared e-scooter life expectancy reduces environmental impacts by 26 to 47%, while increasing the kilometers per day reduces the impacts between 50% to 80%. Also, a less frequent collection of e-scooters would improve the results between 7 and 42%. These results enabled defining specific strategies and policies to guarantee a more sustainable deployment and operation of shared e-scooter systems.