Thomas F. Golob

An analysis of consumer preferences for a public transportation system

THIS PAPER DESCRIBES A METHODOLOGY FOR ANALYZING THE IMPORTANCE THE POTENTIAL USERS OF A NEW OR MODIFIED TRANSPORTATION SYSTEM PLACE ON VARIOUS DESIGN CHARACTERISTICS OF THAT SYSTEM. THE METHODOLOY INVOLVES THE SELECTION AND GROUPING OF SYSTEM CHARACTERISTICS, THE ADAPTATION AND INTEGRATION OF PSYCHOLOGICAL SCALING TECHNIQUES, THE STRATIFICATION OF CONSUMERS AND THE DESIGN OF AN ATTITUDINAL SURVEY AS THE BASIC DATA COLLECTION DEVICE. THE APPLICATION OF THE METHODOLOGY TO THE DESIGN OF A DEMAND-RESPONSIVE PUBLIC TRANSPORTATION SYSTEM FOR A CASE STUDY COMMUNITY IS DISCUSSED. RESULTS FROM THIS APPLICATION ARE PRESENTED AND INTERPRETED. (A)

THE ROLE OF ACCESSIBILITY IN BASIC TRANSPORTATION CHOICE BEHAVIOR

Accessibility measures reflect the level of service provided by transportation systems to various locations. Basic transportation choice behavior is defined to include those decisions of how many automobiles to own and how many trips to which destinations to make by automobile and by public transit. Here, these decisions are assumed to be made jointly by urban households and are conditional upon residential location decisions. It is the purpose of this paper to explore the role of accessibility as a causal factor in such basic transportation choice behavior.An economic utility theory model of choice behavior is postulated in which the benefits from making trips to specific destinations are reflected by measures of destination attraction. Through determination of utility-maximizing trip frequencies, indirect utility functions are developed which include accessibility concepts. Behavioral implications of these concepts are proposed and contrasts are drawn to accessibility measures used in conventional segregated models of trip distribution, modal choice, and automobile ownership.Sensitivity analyses of alternative empirical definitions of accessibility in the choice model are conducted using data from the Detroit Regional Transportation and Land Use Study — covering counties in southeastern Michigan. These analyses employ a multinomial logit estimation technique and focus on definitions of trip attraction. Results of these analyses indicate that more complicated attraction measures can be replaced by measures involving the proportion of either urban area population or urban area employment within a traffic analysis zone. Also, evidence is found that decision-makers in the case study area consider trips of up to 60 or even 90 minutes duration when evaluating accessibilities offered by alternative public and private transportation systems.

Multidimensional scaling of consumer preferences for a public transportation system: An application of two approaches

Abstract Consumer attitudes toward a proposed new public transportation system were assessed through the application of two multidimensional scaling models to data on preference choices for system attributes. Carrolls vector model and Kruskal and Carmones nonmetric unfolding model were compared on theoretical and empirical levels to determine their utility for exposing the latent structure of attitudes for a public project. While the unfolding model was attractive because of a theoretical property, the vector model was able to uncover latent dimensions for the attitudes which could be related via discriminant analysis to socio-economic and demographic characteristics of the respondents. The vector model also produced an outcome which was more closely related to a unidimensional analysis of these data. Therefore, even though both the vector and unfolding models produced plausible geometric representations of the attitudes which arc expected to aid urban transportation planners in designing systems, the vector model produced the more acceptable outcome.