A recent study conducted by the University College London (UCL) finds shared e-scooters can contribute in reducing greenhouse gas (GHG) emissions, but it depends on their use and efficiency of their operations.
Shared e-scooters have been promoted by some as new mobility solution that could help make urban transport more sustainable. At the same time however, critics have pointed out that many e-scooters trips replace trips previously made with more sustainable modes, i.e. walking and cycling. In addition, the efforts to collect, redistribute, service and repair e-scooters left by users across a city, have also raised questions over sustainability.
In a new study commissioned by the e-scooter company Voi, researchers at UCL have assessed the environmental impacts of shared e-scooters, based on use data from a trial conducted in Bristol and a Life Cycle Assessment based on raw data provided by Voi and independent reports.
The use data were obtained from e-scooter operations in Bristol, encompassing some 190,000 e-scooter trips over a three-month period in 2021. Participants in the trial were also asked to complete in-app surveys, allowing researchers to gauge the modal shift and gather insights into user experiences and preferences.
According to the survey results, shared e-scooters have largely replaced trips that would have been taken by other modes of transportation. Specifically, 37% of the trips examined would have been taken by foot, 19% by car, 14% by bus, 10% by cycling, 2% by another public transport mode, and 2% by motorbike. Some 5% of the trips that were done by the e-scooter would otherwise not occur. The study did not consider the potential impact of e-scooters on intermodality. E-scooters could increase accessibility of public transport, acting as a first/last-mile solution for longer trips, replacing private cars or taxis.
To assess the environmental impact of this modal shift, the study used scenarios modelling with differing carbon intensities of shared e-scooters depending on e-scooter kilometre lifespans and operations distance travelled per e-scooter distance travelled. The study shows that with an average lifespan (6,500km) and operations impacts (e.g. 0.06 operational km/e-scooter km), the shared e-scooters lead to a reduction GHG emissions of some 28%. In case the lifespan could be increased to 10,000km, the emission reduction could increase to 46%. At the same time, the analysis also shows that when operational distances shift towards the higher end (e.g. 0.15 operational km / e-scooter km) and / or the e-scooter lifespan is shorter (in this case 3,000 km), the impact of e-scooters on GHG emission reductions quickly diminishes and may even lead to an increase in GHG emissions.
The findings highlight that when considering potential environmental benefits from shared e-scooters, attention should be paid to the type of e-scooters being deployed by operators, including their recycled content and material management, fleet utilisation and kilometre lifespan, and the operations necessary to support this deployment. Potential variation in the sustainability of e-scooter fleets and their operations is thus an important element for city authorities when planning, monitoring and regulating shared e-scooter programmes.
- Publication date
- 20 July 2023
- Clean and energy-efficient vehicles
- United Kingdom