Exploring The Positive Utility Of Travel And Mode Choice

Why do people travel? Underlying most travel behavior research is the derived-demand paradigm of travel analysis, which assumes that travel demand is derived from the demand for spatially separated activities, traveling is a means to an end (reaching destinations), and travel time is a disutility to be minimized. In contrast, the "positive utility of travel" (PUT) concept suggests that travel may not be inherently disliked and could instead provide benefits or be motivated by desires for travel-based multitasking, positive emotions, or fulfillment. The PUT idea assembles several concepts relevant to travel behavior: utility maximization, motivation theory, multitasking, and subjective well-being. Despite these varied influences, empirical analyses of the PUT concept remain limited in both quantity and scope. There is a need for more fundamental development and classification of the PUT idea and its multifaceted nature. The wide variety and quality of ways to measure PUT attributes are further research challenges. Additionally, few studies investigate both major aspects of the PUT concept--travel activities and travel experiences--simultaneously. Finally, research is only beginning to examine empirical associations between PUT measures and travel behaviors such as mode choice. This dissertation addresses many of these gaps in conceptualizing, measuring, and modeling the PUT concept. First, a literature review strengthens the definition, classification, and empirical support for a PUT, defined as "any benefit(s) accruing to a traveler through the act of traveling." The two primary PUT categories are travel activities (travel-based multitasking) and travel experiences (travel subjective well-being), and the most useful PUT measures involve gathering self-reported assessments of these topics. Based on this review, an online questionnaire is designed and administered to nearly 700 commuters in the Portland, OR, region. The survey includes detailed questions about commute mode choice, activity participation, travel usefulness, positive emotions and fulfillment, and travel liking for a recent home-to-work trip. Next, these PUT measures are empirically examined using factor analyses, finding groupings of activities and common unobserved constructs of hedonic and eudaimonic subjective well-being. Many of these factors exhibit large variations among travel modes--walking and bicycling commuters are the most satisfied and appear to value time spent exercising--and are predicted (somewhat less strongly) by other trip and traveler characteristics in ordered logit regression and structural equation models. Finally, integrated choice and latent variable models are estimated to examine relationships between measures of the PUT concept and commute mode choice. This is made possible by the unique dataset that collects PUT measures for not only the chosen mode but also modal alternatives. Measures of travel-based multitasking are significantly related to mode choice, suggesting people may be doing things more to pass the time than to be productive. A validated measure of travel subjective well-being is also a significant and positive factor, suggesting people are more likely to choose a mode that makes them happier. Overall, PUT measures greatly increase the explanatory power of the mode choice model. These findings make significant contributions to travel behavior research methods and knowledge. They also offer important implications for transportation policies around promoting nonautomobile travel and planning for autonomous vehicles.