Parameters of activity behavior for use in travel analysis

Abstract Increasingly in the last decade, transportation researchers have begun examining travel in the context of activities which are demanded at the end of trips. Before the results of this research can be used in planning, the boundaries of activity-related behavior need to be made explicit. The research reported here helps to delineate these boundaries by developing a theoretical model of activity-related choices and exploring it using data from a conventional home interview survey. A number of the variables are used for the first time and in ways which could be incorporated into most existing transportation models. Both general data analysis and estimation of coefficients in multivariate equations are carried out. In general, the findings support the judgement made about the causal factors operating to influence the behaviors of interest: whether someone participates in an activity and if so, for how long. Further, the empirical results tend to support the division of the causal factors into the three categories of activity program/needs, temporal constraints and spatial constraints. One of the unique features of the empirical analysis is the division of the day into five time periods, each with its own associated equations to be estimated. As a result of developing this feature, the interrelatedness of a person's decisions made in the different time periods is captured. The mixed results for the variables used to proxy the effect of interdependence within a household and within a daily activity schedule show both the complex nature of the behaviors in question and the need for further research in this field.