It is evident that compact development can lower auto ownership, reduce trip lengths, and increase the uses of alternative modes. Recently, several studies found that suburban development is associated with the unbalanced choice of light duty trucks (LDTs). These studies have not shed much light, however, on the underlying direction of causality- whether neighborhood designs as opposed to attitudes towards vehicle choice more strongly influence individuals' decisions on vehicle type choice. The available evidence thus leaves unanswered questions: if policies require more compact, mixed-use development, will more people choose to drive passenger automobiles? And if so, what are the implications for air quality? Using a survey of 1682 respondents in Northern California, this study applied correlational analyses and multinomial logit model (MNL) to investigate the causal link from the built environment to vehicle type choice. The results from correlational analyses showed that the built environment has a strong association with vehicle type choice. Specifically, traditional designs (exhibiting mixed land uses and/or high accessibility) are correlated with the choice of passenger automobiles, while suburban designs (including large yards and off-street parking) are associated with the choice of LDTs- especially minivans and pickup trucks. The MNL model suggests that attitudinal factors play an important role, and that the built environment impacts vehicle type choice after controlling for attitudinal and demographic variables. Therefore, this study provides supportive evidence for the argument that smart growth strategies have the potential to reduce the choice of LDTs, thereby reducing emissions. However, the mediating effects of attitudinal factors suggest that ignoring the role of attitudes will lead to an overestimation of the influences of smart growth strategies on vehicle type choice and thus emissions.
Abstract