Simulation of a car-sharing transport system for urban mobility

An innovative car-sharing systems for urban areas is proposed. The proposed system is based on a fleet of Personal Intelligent City Accessible Vehicles (PICAVs). The following specific services are provided: instant access, open ended reservation and one way trips. All these features provide users with high flexibility, but create a problem of uneven distribution of vehicles among stations. Therefore, relocations must be performed. Different relocation procedures are proposed: in the first relocation scheme relocations are performed by users while in the other two vehicles relocate automatically thanks to their automation. In the first two management strategies vehicles can be accessed and returned only at stations while in the last one they can be accessed also along the roads. In order to provide transport managers with a useful tool to test the proposed systems in different realities, an object-oriented micro simulator has been developed. The simulation gives in output the transport system performance, in terms of distribution of user waiting times, and the transport system efficiency, which is inversely proportional to the fleet dimension and the number of relocation trips. A meta heuristic optimization algorithm has been developed to optimize the transport system’s characteristics. The optimization algorithm recalls the micro simulator to calculate the optimization’s input data. The micro simulator has been calibrated and validated, and afterwards applied to study two scenarios: Genoa historical city centre, Italy, and Barreiro old town, Portugal. Finally, a sensitivity analysis has been performed in order to study the performances of the system according to modifications of the demand, or of the fleet dimension or of the transport system characteristics.