UC Irvine Institute of Transportation Studies

Although there exists a sizeable body of literature involving complex travel behavior most of this literature is of a highly fragmentary nature due to the lack of a comprehensive theoretical framework. Within the last decade transportation research has addressed such issues as activity time allocation (duration), destination choice, trip linkages, activity participation, activity scheduling, spatial/temporal constraints and the structure of multi-purpose travel but few studies have attempted to incorporate more than one or two of these concepts into a methodological framework. Similarly, a full range of models, from conceptual to empirical involving a wide range of techniques (e.g., Markov processes, Monte Carlo simulation, multiple regression analysis, utility maximization, etc.) have been employed with varying results. Although a descriptive review of all the existing literature would provide substantial background, a critical analysis of the most relevant sources serves as a better means to identify potential "building blocks" (i.e., variables, constraints, interactions, etc.) for use in the design and construction of a comprehensive theoretical framework. In general, three types of research were considered relevant to this study: 

(1) studies that isolated critical variables and investigated their influence on individual's observed behavior 

(2) studies that employed multivariate frameworks to examine the interactions between sets of variables, and 

(3) studies that developed behavioral theories and empirically tested various theoretical constructs. 

The hypotheses generated and the inferences drawn have been compared and contrasted so that both similarities and differences in the studies are revealed. To facilitate multiple comparisons between the various approaches, a literature taxonomy has also been constructed and is included in the appendix to this paper.