旅行者潛在構面之量測：車輛使用依賴性之探索與老年人搭乘公車能力感認之衡量

Abstract

本研究之主要目的是針對文獻上未有完整架構與常模之潛在構面進行探索並加以量測。包含兩個影響旅行者交通行為之潛在構面之探索。一為一般旅行者對於車輛使用之依賴性，另一則為老年人對於自己搭乘公車之行為能力感認。 關於車輛使用依賴性之探索，本研究認為該構面乃是一綜合經濟考量、心理偏好與習慣制約之潛在心理評價。由於旅行者少有察覺並能清楚表示自己之車輛使用依賴程度，故本研究採用項目反應理論之探討架構，由各種旅次目的設計負面剝奪性問項以刺激旅行者對於該車輛使用之依賴性。同時以Rasch模式將收集得資料進行對該依賴性構面之測量。為驗證本研究提出之測量方法之有效性，實證研究針對台北市機車騎士進行其對機車使用之依賴性。並將各人所量測得之機車依賴水準連結至其社經變數以作進一步探討。實證研究中發現台北市民在單人旅次、短程旅次與多停點旅次對機車之依賴行為較高，而年齡較輕者、收入較低者與無汽車可使用之機車騎士對機車依賴性顯著較高。由於此欲探討之車輛使用依賴性乃透過有效且可靠的施測方法加以收集並衡量，量測之結果亦建立在等距尺度上，可直接引入為傳統模型之解釋變數。本研究之探索相信將可提供傳統個體選擇模型引入心理層面考量為變數探討之借鏡，使模型解釋能力更高並進而提升其預測能力。 本研究第二個主題則針對老年人對自己搭乘公車之行為能力感認加以探討。由於高齡化社會慢慢形成，老人之外出行為需求亟需重視並加以安排。受限於身體機能退化，老人自己駕駛小客車或騎乘機車或自行車之危險性相較於年輕人高出甚多，搭乘公車不但能確保老人安全，同時亦是較有效率之社會經濟資源配置。本研究以老年人之觀點出發，藉由搭公車過程所需要完成之各種動作，由老人自行評估其完成各類動作之掌握程度。藉由測驗理論方法，測度各項動作之相對難度。實證研究結果發現老年人在公車運行過程中之平衡感之保持與閱讀車站資訊及辨識來車路線號碼上最感到困難。本研究更針對這些較為老年人感到困難之項目，對公車系統之設施與服務上提出具體之改善建議。希望能為老人建立一個更為安全且友善之公車搭乘環境，以吸引更多老人利用公車進行旅行活動。

This study aims to demonstrate the exploration and measurement on two latent traits that underlie the travelers’ considerations. One of these two latent traits is the vehicle dependence of the travelers on a given vehicle usage; the other is the physical ability perceived by elderly travelers when using buses. In the first topic, vehicle dependence is conceptualized as the subjective considerations of individual travelers, including their economic considerations, psychological preference, and habitual behavior. The Rasch model is reviewed, and suggested as an instrument to measure such a latent construct. An empirical analysis of motorcycle dependence was performed using self-rated information about eight items from 321 motorcyclists in Taipei. The empirical results showed that motorcyclists in Taipei depend on their motorcycles to achieve unaccompanied, short-distance, multistop trips; motorcyclists under the age of 25 who were inferior in economic terms and did not use an automobile showed relatively higher measures of motorcycle dependence. This paper robustly conceptualizes vehicle dependence in terms of both its socioeconomic and its psychological nature. The results of exploring vehicle dependence could benefit researchers in modifying their formulations of mode choice, and policy makers in enacting more effective policies. In the second topic, it is proposed to measure the elderly bus passengers’ abilities and to explore their difficulties in accomplishing the actions and motions required to patronize the bus service. A conceptual framework about the required actions and motions in bus taking was established and a questionnaire with 18 items was designed to test their ability to use buses. A face-to-face survey was conducted to collect the self-rated information from 304 elderly bus passengers in Taipei. The Rasch model was applied to estimate the difficulty of each item and the ability of each person to use buses. Results showed the relatively difficult items are mostly about keeping balance on the moving bus and reading the information or discerning the approaching buses at the stations, and the considered levels of physical ability showed negative associated with respondents’ age. With relating the measures of person ability and item difficulty, the item-person map provides a straightforward and graphical illustration on the corresponding proportion of elderly bus passengers that can achieve in each given item with ease. Results from this study will help the traffic authorities or bus service providers in issuing instructions or enhancing the facilities and service to provide the elderly with a safer and friendlier environment for bus usage.