Modeling the Influence of Family, Social Context, and Spatial Proximity on Use of Nonmotorized Transport Mode

At the time of publication N. Ferdous and C.R. Bhat were at the University of Texas at Austin; R.M. Pendyala and K.C. Konduri were at Arizona State University.This paper presents a joint model of walking and bicycling activity duration using a hazard based specification that recognizes the interval nature of time reported in activity-travel surveys. The model structure takes the form of a multilevel hazard-based model system that accounts for the range of interactions and spatial effects that might affect walking and bicycling mode use. In addition to the individual-specific factors, family (household-specific) interactions, social group (peer) influences, and spatial clustering effects are also considered as potential factors that contribute to heterogeneity in non-motorized transport mode use behavior. The model system presented is capable of accommodating grouped duration responses often encountered in activity-travel surveys. A composite marginal likelihood estimation approach is adopted to estimate parameters in a computationally tractable manner. The model system is applied to a survey sample drawn from the recent 2009 National Household Travel Survey in the United States. Model results show that there are significant unobserved family-level, social group, and spatial proximity effects that contribute to heterogeneity in walking and bicycling activity duration. The unobserved effects were also found to have a differential impact on bicycling activity duration, thus suggesting the need to treat and model walking and bicycling separately in transportation modeling systems.Civil, Architectural, and Environmental Engineerin