Incorporating the influence of latent modal preferences on travel mode choice behavior

Abstract

Latent modal preferences, or modality styles, are defined as behavioral predispositions characterized by a certain travel mode or set of travel modes that an individual habitually uses. They are reflective of higher-level orientations, or lifestyles, that are hypothesized to influence all dimensions of an individual’s travel and activity behavior. The objectives of this paper are to understand and quantify different modality styles, and to show how the modality styles construct can be operationalized within the context of traditional models of travel mode choice. We employ the six-week MOBIDRIVE travel diary and estimate behavioral mixture models in which the modality style provides a behavioral rationale to the way in which unobserved heterogeneity is specified in the travel model. Our analysis consists of two stages: First, we explore the presence and types of modality styles suggested by the data through the means of a descriptive analysis. Next, we develop a model that captures the influence of modality styles on two dimensions of an individual’s travel behavior: travel mode choice for work tours and travel mode choice for non-work tours. The modality styles are specified as latent classes; heterogeneity across modality styles include both the modes considered (choice set) and the values of taste parameters. The modality style of an individual then influences all of his/her travel mode choice decisions for work and non-work tours. In addition, error components capture unobserved correlation across travel mode choice decisions made by the same individual. Results indicate the presence of habitual drivers who display a strong bias for using the automobile and multimodal individuals who exhibit variation in their modal preferences. Multimodal behavior is further distinguished by those who appear to be sensitive to travel times and those who appear to be insensitive. Estimation results further find that modality styles are strongly correlated with more long-term travel decisions and life-cycle characteristics.