An equity indicator for free-floating electric vehicle-sharing systems

Sharing mobility is changing users’ behavior in urban areas, introducing a new way of movement. Electric vehicle-sharing systems are valid alternatives to the use of private modes of transport, since they allow users to cover short to medium distances with no emissions, promoting multimodality. There are two main types of vehicle-sharing systems: station-based and free-floating. The former allows for the use of a vehicle, renting and returning it from and to a fixed station. On the other hand, free-floating systems are not based on stations and a user can release a rented vehicle arbitrarily, within a predefined operating area, as close as possible to her/his destination. Although these systems are more attractive, given the freedom of parking, the spatial distribution of shared vehicles does not always allow for equitable access to the system. This research aims to propose a new way of looking at the needs of the most disadvantaged sectors of the population, evaluating the equity of free-floating electric vehicle-sharing systems. To reach this goal, a new indicator that emphasizes vertical equity is proposed. This indicator is based on the level of service intended as vehicle availability and their battery states of charge weighted by the disadvantaged population. To evaluate the effectiveness of the proposed indicator, it was applied to an electric scooter-sharing system in the city of Bari (Italy). The results obtained are interesting and show the properties of the proposal. A possible optimization model for vehicle redistribution and recharging can be based on the proposed indicator, allowing disadvantaged people to access electric vehicle-sharing systems more easily.