汽車動態持有與車型選擇之整合模式

Abstract

隨著經濟發展，人民的生活水準提升，社會環境急遽變遷，整體旅運需求因而大幅增加，使得我國機動車輛持有與使用均呈現相當快速之成長。然因臺灣地區地狹人稠，道路長度成長有限，這種供需失調的結果，造成都市內交通壅塞，停車問題日益嚴重，並且增加了許多無形的外部社會成本。基於永續運輸之目標下，有效減少高排放污染與低能源效率之機動車輛數量為所需重視之重要課題，然而，欲研擬可有效降低用路者對於私人運具依賴性之管理策略則須仰賴於一能準確衡量預測其實施策略之方式，其中以個體選擇模式來研究汽機車持有數將可有效達成此目的。過去許多相關研究以發展汽機車持有數與車型選擇之個別靜態選擇模式為主，但實際上個體之持有狀態與車型選擇應為同時考慮且會相互影響，且決策過程係一受前期影響下之動態選擇行為。因此，在模式建構時，車輛持有與車型選擇應同時考慮且宜採動態選擇模式為佳。 基此，本研究利用重複性調查所蒐集之縱橫面資料進行車輛持有數量與車型選擇行為之模化分析。因縱橫面資料能夠提供動態性分析以瞭解受訪者其行為受前一時點之影響程度，且能藉由重複衡量相同受訪者來控制未觀察到之影響因子，將更能準確描述個體行為。其中，模式建模資料係透過大規模三年度追蹤家戶問卷調查(2007.8~2009.10)而得，有效樣本10,462筆。考量車輛持有方案間獨立性與個體異質性問題，本研究分別利用一次性估計方法建構車輛持有模式，並使用程序性估計方法將車型選擇模式與持有模式結合。此外，為考量車輛持有與使用成本對於選擇行為之影響，本研究也進一步考慮共生變數之跨期自我相關係數。模式推估結果顯示，結合包容值介於0與1之間，符合效用最大理論，顯示車輛持有與車型選擇確實需同時考慮。而家戶汽車之各項成本於不同期間具有顯著之正向關係，結果顯示車價較容易受到上一期價格所影響，且各期間對於車價的感受較無變化，而停車成本次之。與前期相關性最低的為燃油成本，表示前期之燃油成本對當期之燃油成本相關性並不大。 為驗證模式之可用性，本研究最終透過模式中顯著之成本變數進行價格手段之研擬，進一步模擬管制汽車持有及使用之績效。依各項管理策略進行模擬。研究結果顯示，就汽車持有而言，家戶對於徵收購車稅之策略最為敏感，其次為提高油價，提高停車成本則為最不敏感之策略。

The economic growth associated with the continuous construction of highway infrastructure for convenient movement of individuals and freight has inevitably led to rapid growth of numbers of private motor vehicles during recent decades. This trend has not only created severe congestion on urban roadways and intercity highways, but also excessive emissions and energy consumption. Towards sustainable transportation, it is crucial to propose countermeasures capable of effectively curtailing ownership and type of high-emissions and low fuel efficiency cars. However, to devise management strategies which can effectively relieve dependency on private vehicles depends on the ability to accurately examine the effects of corresponding strategies. Disaggregate choice models regarding the ownership and type choice of cars are required to achieve this. Although numerous previous related studies have developed static choice models of car ownership and type choice separately, the real ownership and type choice behaviors should be taking into account simultaneously, and be affected by previous choice. That is, the car ownership models should be developed in a dynamic manner. To this end, this study employs a large-scale questionnaire panel survey on vehicle owners and type choice to develop car ownership and type choice integrated model with consideration of the serial correlation. Considered random sample of 10,462 samples (2007.8~2009.10). The logit model is used to modeling the discrete choice behavior of vehicle ownership. In addition, to account for the independency substitution patterns among choice alternatives and heterogeneity among different respondents, this study used multinomial logit (MNL), sequential estimation and simultaneous estimation of nested logit (NL), for car ownership and type choice integrated model. In addition, this study consider the choice behavior effect of serial correlation with Generic Variables. The estimation results show that the inclusive value parameter in integrate model of car ownership and type choice is between 0 and 1, it seems car ownership and type choice should be taking into account simultaneously. And the last year status of ownership cost do exercise a significantly positive effect on the choice of this year, indicating that state dependency does exist in car ownership decisions. It seems that car price is more susceptible to the influence on a price at last period, the second is parking price, the last is fuel cost. To investigate the applicability of the proposed model, the effects of several pricing management strategies are predicted and examined. The results show that to levy car purchasing tax and increase fuel cost will effectively affect the decision of car ownership.