| Summary |
Wu, Shun-Cheng, 2008.01
Department of Transportation Technology and Management
National Chiao Tung University
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. |
