Modeling Residential Sorting Effects to Understand the Impact of the Built Environment on Commute Mode Choice

Land use and transportation system attributes are often treated as exogenous variables in models of travel behavior, ignoring the potential self-selection processes that may be at work. This study examines the significance of residential sorting or self-selection effects in understanding the impacts of the built environment on travel choices. A simultaneous model of residential location choice and commuting mode choice that accounts for the observed and unobserved lifestyle and transportation preferences, attitudes and values that may contribute to residential self selection is estimated using a sample selected from the 2000 San Francisco Bay Area household travel survey. Although model results show that both observed and unobserved residential self selection effects do exist, findings suggest that built environment attributes can indeed significantly impact commute mode choice behavior. Implications of the model findings for policy planning are discussed