Role of the built environment on mode choice decisions: additional evidence on the impact of density

Density is a key component in the recent surge of mixed-use neighborhood developments. Empirical research has shown an inconsistent picture on the impact of density. In particular, it is unclear whether it is the density or the variables that go long with density that affect people’s travel behavior. Many existing studies on density neglect confounding factors, for example, residential self-selection, generalized travel cost, accessibility, and access to transit stations. In addition, most still use a single trip as their observation unit, even though trip chaining is well recognized. The goal of this paper is to assess the role of density in affecting mode choice decisions in home-based work tours, while controlling for confounding factors. Using the dataset collected in the New York Metropolitan Region, we estimated a simultaneous two-equation system comprising two mutually interacting dependent variables: car ownership and the propensity to use auto. The results confirm the role of density after controlling for the confounding factors; in particular, employment density at work exerts more influence than residential density at home. The study also demonstrates the importance of using tour as the analysis unit in mode choice decisions. The study advances the field by analyzing the role of the built environment on home-based work tours. New knowledge is obtained in the relative contribution of density vs. a set of correlated factors, including generalized travel cost, accessibility, and access to transit stations.

Robert PaaswellEmail:

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Cynthia Chen   is an Assistant Professor in Civil Engineering at City College of New York. Her research expertise and interests are residential location and activity and travel choices and human’s interaction with the environment. Hongmian Gong   is an Associate Professor in Geography at Hunter College of the City University of New York. Her research interests are urban geography, urban transportation, and urban GIS. Robert Paaswell   is currently Distinguished Professor of Civil Engineering and Director of the University Transportation Research Center at the City College of New York. He currently serves on several NY MTA Commissions.