Determination of the Vehicle Relocation Triggering Threshold in Electric Car-Sharing System

The electric car-sharing system is an arising and promising urban transportation mode. Vehicle unbalance usually occurs in multi-station electric car-sharing systems. Threshold triggering method is the most practicable approach for vehicle relocation, while determination of thresholds is the key problem. This paper presents a method for the thresholds determination. First, a prototype of two-stage method is proposed to illustrate the function of upper and lower thresholds. Subsequently, an optimization-based model is derived to determine the thresholds under the objective of minimizing the out-of-service rate and number of moving vehicles. Order data of EVCard system in Shanghai, China was employed to test the method. The results indicate that the proposed calculative method lead to relative better service rate and less moving times.