建構汽機車傳統車型及替代能源車型之顯示性與陳述性偏好整合型選擇模式

Abstract

近年來因經濟快速成長以及公路不斷擴建導致私人運具之持有與使用快速成長，此狀況不僅造成嚴重的交通堵塞，也產生了過多的能源消耗以及污染排放。根據相關研究以及全球經驗，要有效的減緩私人運具成長量是有困難度的。相反地如實施適當之管理策略，於民眾有購車或汰換車輛需求時，鼓勵他們選擇低污染或低能源消浩之車型，將可達到較佳之效果。無庸置疑地，構建家戶車型車齡選擇行為的模式實具重要性，以藉此研擬及分析相關管理策略。 由客觀之角度而言，車型對於減少能源消耗及污染排放之影響與排氣量大小、車齡有關。相關研究結果顯示，車輛的排氣量與車齡對於能源消耗及污染排放具有相當顯著的影響。而於傳統車型選購行為中，所得之資料屬於真正的選擇行為，即為顯示性偏好；然而大多數人對於替代性能源車型並不熟悉，故他們對於此種車型之偏好必頇通過敘述性偏好之實驗設計問卷進行資料收集。為了解傳統車型以及替代性能源車型之間之選擇機率，故本研究擬整合顯示性與敘述性偏好建構汽機車車型選擇模式。 基此，本研究針對台灣地區23 縣市持有車輛之家戶採用分層抽樣方法進行全國問卷調查，採用近三年有購車之家戶資料，分別校汽機車整合型車型選擇模式。又整合型模式可經過顯示性偏好模式與敘述性偏好模式之校估得到基礎模式結構，故需先進行上述兩類模式之校估，再使用兩類資料進行整合式模式之校估。由汽機車整合型車型選擇的最佳羅吉特模式校估結果顯示車輛的燃油成本、車輛價格、燃油可及性、購車補助、續航力、污染量，以及主要駕駛所得、性別、教育程度和部分家戶背景變數如家戶私人運具組成及駕照持有數、家戶戶長年齡等解釋變數會影響汽機車車型的選擇行為。為驗證模式之可應用性，本研究模擬提高油價、提供購車補助以及提升車輛性能等相關管理策略，並進行策略之比較。可得知於汽車及機車模式中，若欲提高家戶選擇替代能源車型的意願，則以提供購車補助轉移至替代性能源車型之效果均為最佳。另基於補充能源時不便之因，家戶亦會大為降低選擇替代能源車型的意願，故可知車輛差價與燃油可及性成為替代能源車型無法普及的主要原因，由此可知若政府部門欲推廣替代能源車型時，除可提供購車補助外，提高其燃油可及性亦為重點工作之一。研究結果可供政府部門作為管理污染排放與能源消耗問題之參考。

The rapid economic growth and continuous construction of highways has inevitably led to greater ownership and usage of private motor vehicles in recent decades. This trend has not only created severe congestion on urban roadways and intercity highways, but also excessive emissions and energy consumption. According to many studies and worldwide experiences, it is rather difficult to effectively decelerate the growth trend of private vehicles. In contrast, it is possible to implement proper management strategies to encourage people to choose low-emitted and fuel economy vehicles once they want to purchase or replace a vehicle. However, to devise such strategies depends on the ability to understand the preferences of people in choosing vehicle types. Obviously, a disaggregate vehicle type choice model which can accurately capture people choice behaviors is essential. From the point-of-view of emissions and energy consumption reduction, vehicle type of interest should includes both engine size and age, since many studies have identified that emissions and energy consumption remarkably vary across engine sizes and ages. Preferences with regard to conventional vehicle types can be surveyed by observing their real choice behaviors i.e. revealed preference. However, since most people don’t own and are not familiar with alternative-fuel vehicles, their preferences regarding these vehicles should be surveyed through a well-designed stated preference questionnaire. To simultaneously determine the choice probabilities across conventional and alternative-fuel vehicle types, this study aims to propose an integrated model by combining both revealed and stated preference models. To this end, a nationwide questionnaire survey is conducted by disseminating questionnaires to private vehicle owners who bought a car or a motorcycle within recent three years. Based on the valid returned samples, two disaggregate choice models, revealed preference and stated preference, are first separately estimated and then integratedly estimated. The results show that fuel cost, purchasing price, accessibility of refuel stations, purchasing subsidy, pollution degree, income, gender, and education are significant estimated. To demonstrate the applicability of the proposed models, the changes in the choice probabilities of different vehicle types under various management strategies, including increase of fuel price, provision of purchasing subsidy, accessibility to refuel stations etc., are examined and compared. It shows that provision of purchasing subsidy is the most effective strategy for encouraging people to choose alternative-fuel vehicles. And if refuel stations are not easily accessible, the willingness to purchase alternative-fuel vehicles will be largely curtailed. High vehicle price and low accessibility to refuel stations are the main reasons to explain the low market concentration of alternative-fuel vehicles. Based on these results, corresponding strategies are then proposed accordingly.