Optimal Dispatcher Number for One-Way Carsharing Services Considering Break Requirement

This study investigates the dispatcher number (DN) of one-way carsharing services (CSSs), considering the critical yet overlooked aspect of dispatchers’ break requirement with vehicle relocation and dispatcher assignments. The DN problem aims to minimize the daily cost of one-way CSS operators by determining the fleet size, the number of dispatchers, vehicle relocation, and dispatcher movement under the restriction on the maximum accumulative working time of dispatchers. The novelty of the study lies in the incorporation of the break requirement consideration of dispatchers into the personnel assignment during the operation period. A nonlinear integer programming (NLIP) model is first developed for the DN problem. By exploring the structure of the proposed model, an effective heuristic solution method consisting of optimization and simulation modules is proposed to obtain the optimal solution to the problem. Numerical experiments based on EVCARD, a popular one-way CSS operator in China, are conducted to demonstrate the effectiveness of the proposed models and solution method and the rationality of incorporating the break requirement into the decision-making process. Furthermore, we investigated the impacts of critical parameters, such as payment for dispatchers and relocation cost, on the performance of the one-way CSS, providing valuable insights for carsharing service operators.

I. Introduction

Carsharing services (CSSs) are considered a promising transportation mode, providing users with an attractive alternative to using private cars without processing the cost of owning them [1], [2], which are divided into two kinds based on the operation modes. Compared to traditional two-way CSSs, users can return rented vehicles to different stations in the one-way CSSs. One-way carsharing services can relieve the pressure on transportation systems. However, the uneven distribution of demands inevitably causes temporal and spatial vehicle imbalance issues across stations. To maintain balance, some operators choose to conduct operator-based intervention strategies, i.e., employ dispatchers to conduct vehicle relocation tasks across stations in station-based one-way CSSs [3], [4]. Dispatchers take other transport modes to move across predesigned stations to take two separate relocation operations [5], whereas inappropriate movements of employed dispatchers could also result in an imbalance of dispatchers’ distribution [6]. Thus, dispatchers’ movements are also vital in solving the imbalance problem of one-way CSSs.