Car-sharing systems provide an attractive transportation alternative to their users with beneficial societal, environmental, and energy impacts. Alternative types of operational concepts of car-sharing systems have been proposed that are in operation around the world. One of these operational concepts allows for vehicles to be dropped at any station. The one-way car-sharing systems offer significant advantages to the users due to their flexibility. However, this flexibility may lead to accumulation and shortage of vehicles at certain stations that have limited capacity. To cope with this problem, operators of one-way car-sharing systems need to perform costly relocation operations. Electric vehicles apply an additional constraint of charging levels in the operational framework.

This research is focused on the modelling of vehicle relocation decisions of one-way electric car-sharing systems. A MILP formulation is proposed in order to optimally relocate vehicles and personnel among the system stations, and to optimally assign relocation personnel to shifts. The proposed model is solved using data from Nice, France and provided the opportunity to examine the trade-off between operational cost and vehicle availability.