TCRP Report 16 presents the results from Project H-1, An Evaluation of the Relationships Between Transit and Urban Form. The research team was under the direction of Parsons Brinckerhoff Quade & Douglas, Inc., and included Dr. Robert Cervero, Howard/Stein-Hudson Associates, Inc., and Jeffery Zupan. Six reports were produced by the research team; a decision was made by the project panel to publish four of the six reports as a two-volume set, in the regular TCRP series.
Findings from an empirical analysis to test the impacts of land-use mix, population density, and employment density on the use of the single-occupant vehicle (SOV), transit, and walking for both work trips and shopping trips are presented. The hypothetical relationships tested fo-cused on whether there is a relationship between urban form and modal choice, whether this relationship exists when controlling for non-urban form factors, whether this relationship is linear or nonlinear, and whether a stronger relationship exists between modal choice and urban form when they are measured at both trip ends as opposed to either the origin or the destination. A review of the literature and experiences sug-gested that a fair amount of information is known about the impacts of density on mode choice. However, considerable debate exists over whether density itself is actually the causal stimulus or a surrogate for other factors.