Faster, greener, scooter? An assessment of shared e-scooter usage based on real-world driving data

In recent years, few transportation modes have gained so much attention so quickly as shared e-scooters. Debates focus on usage patterns over shift effects to environmental impacts. Previous research has mainly been conducted in Asia and North America and in metropolitan areas. Potential interdependencies have been analysed mostly towards public transport (PT). Surprisingly, investigations concerning the usage of shared e-scooters and other shared mobility services have been scarce. However, understanding possible (inter-)dependencies and potentials for inter- and multimodality is crucial for policymakers and transport planners to design efficient and sustainable transportation systems. This is why we draw on an original data set of 118,047 shared e-scooter trips in Karlsruhe, a non-metropolitan city in southwest Germany and add information about carsharing and PT. Apart from station information for both modes, we add departure information for tramways, and weather data. Shared e-scooter data is retrieved via the local providers from November 2020 to April 2021, information about the stations of carsharing and PT is added via OpenStreetMap, and tramway service data is retrieved via the local authority. We find an average trip distance of 1.40 km and substantially less usage on Sundays. The potential of combining shared e-scooters is higher for PT than for carsharing. Shared e-scooter trips show longer distances in times of lower or none PT service. Negative binomial regression models with fixed effects for the PT or carsharing stations show that the number of tram departures positively affects shared e-scooter usage, particularly at off-peak times. Applying mode shift scenarios and focusing on the usage phase, the energy consumption effect of shared e-scooters is found to be between −5 to +0.5 TWh. However, it requires providers to revisit their operations and policy to rethink regulation to get even close to the multimodal or energy consumption potential.