A Joint Econometric Analysis of Temporal and Spatial Flexibility of Activities, Vehicle Type Choice and Primary Driver Selection

The current research effort examines the relationship among four individual level daily activity travel choice processes: spatial flexibility of the activity, temporal flexibility of the activity, activity vehicle choice, and primary driver (for auto users). Activity flexibility (spatial and temporal) has been suggested as a precursor to the observed activity travel pattern. The study examines the impact of activity flexibility through a unique data drawn from Quebec City, Canada from 2003 – 2006. In traditional travel behavior literature, vehicle fleet decisions are examined as a long term choice with annual usage metrics. However, the long-term vehicle usage observed (as studied in literature) is an aggregation of the household’s yearly vehicle type and usage behavior. Only recently, travel behavior models have started examining vehicle usage decisions (type and mileage) as a short-term decision. By examining short term vehicle usage we explore, at a disaggregate level, the interaction of activity behavior (defined as flexibility) and vehicle type choice. A panel mixed multinomial logit (MMNL) model was applied to analyze the four choices within the decision process to account for the intrinsic unobserved taste preferences across individuals. The analysis results revealed that several individual and household socio-demographic characteristics, residential location and activity attributes as well as contextual variables influence the packaged choice of temporal flexibility, spatial flexibility, vehicle type choice and primary driver selection. We also identify the presence of common unobserved attributes among the choice alternative dimensions.