Car-sharing is a transportation service consisting of vehicles distributed over an urban area that any driver registered to the system can use. This paper focuses on one-way electric car-sharing systems. The success of such systems relies strongly on operations management and attractive rental conditions. Immediate availability and possibility of reservation in advance are key points. This induces strong constraints for the operator especially when some stations attract more trips as a destination than as an origin and vice versa. These imbalances must be corrected by performing vehicle relocations in a smart way to maximize vehicle availability and minimize operator’s costs. In order to understand the demand patterns and explore relocation possibilities, an event-based simulator is built in C#.

We develop a new relocation strategy to minimize the demand loss due to vehicle unavailability. Implemented in parallel to rentals, it relies on the regular update of the relocation plans based on an optimization framework which utilizes the current state of the system and partial knowledge of near-future demand. This strategy is compared to three other strategies on a case study based on real data from Nice, France. We show that it maximizes the number of served demand and succeeds in keeping the system in a balanced state contrary to the other strategies considered.