近幾年來，汽車共享系統已在許多國家推行，作為提升運輸機動性、紓解交通壅塞、減少停車位需求、降低污染排放的手段之一。為了提高汽車共享系統的便利性，業者提供使用者單向租賃服務，即俗稱的「甲租乙還」服務。單向租賃服務雖然增加了使用者的便利性，但每個場站的租賃需求與借還車型態不同，可能造成高運輸需求的場站沒有足夠的共享車輛讓民眾使用，而低運輸需求的場站則沒有足夠的停車位讓民眾歸還共享車輛，因而造成場站間的車輛分佈不均衡問題。
為了維持一定的服務水準，大多數業者會聘用員工來執行車輛調度工作，以解決車輛分配不均的問題；但如何有效地執行車輛調度工作，使業者的利潤最大化或成本最小化，也是重要的研究課題之一。考量共享車輛資源使用的最大化，本研究提出一項混合整數規劃模型，模式中考量調度工人的移動與電動車充電的特性，以最大化業者利潤為目標，據以建構以業者執行車輛調度為主的最佳化數學規劃模型，求解單向電動車輛共享系統中最適切的車輛與人員的調度組合，最終目標在於滿足用戶的使用需求，同時提升業者的營運收益。
鑒於國內尚未有大規模電動汽車租賃系統的營運案例，本研究利用高雄市公共自行車CityBike的相關營運資料，作為實證研究之案例，以驗證模型的正確性與可用性。經由實證分析結果顯示，本研究所建立的數學規劃模型可以提供有效的人車調度決策；此外，本研究針對車隊規模與調度工人兩項重要參數進行敏感度分析，研究結果顯示，車隊規模與調度工人數對於營運收益與需求滿足率均有正面的影響，其中以車隊規模的增加，對於營運收益與需求滿足率，影響較為顯著。

Carsharing systems have been introduced to a number of countries and/or cities as a means of improving mobility, alleviating traffic congestion, decreasing parking demand and reducing emission problems. In order to increase the convenience of carsharing applications, operators provide one-way rental services, which customers can pick up a vehicle at one station and return at any other stations. One–way rental increases convenience to customers, but it also incurs the vehicle imbalance problem. Because the rental demand of each station is different, some stations may confront the vehicle imbalance problem. Under such a circumstance, some stations may not have enough vehicles to be shared, and other stations may not have enough parking spaces for returning vehicles.
In oreder to deal with the vehicle imbalance problem, vehicle relocation is a necessary management strategy. However, how to conduct the work efficiently under the goal of profit maximization or cost minimization for the operator is an important issue. Addressed from a viewpoint of maximizing shared vehicle’s utilitization, this study proposes a mixed integer programing model for an one-way carsharing scheme by considering staff rebalancing and the recharge characteristics of electric vehicles. The ultimate goal is to solve the optimal vehicle relocation problem to meet the user's need, while maximizing the operator’s profit.
Since there is no large-scale, one-way carsharing system in Taiwan, we used the operational data of the public bike sharing system, CityBike in Kaohsiung as the inputs in the empirical study. The empricial study results show that the proposed one-way carsharing model is capable of providing desirable vehicle relation strategies. In addition, we also conduct sensitivity analysis by varying parameters related to fleet size and staff size. The sensitivity analysis results show that both fleet size and staff size have positive effects on daily profit and demand satisfied rate, in which fleet size is more sensitive in increasing daily profit and total demand satisfied rate.

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