University of California Transportation Center

In the USA and Europe land-use based solutions to transportation problems have rapidly gained in popularity over the past decade. It appears that the principles of New Urbanism (in the USA) or the Compact City (Europe) have found a solid place in the profession’s thinking. This popularity is not least the result of numerous empirical studies demonstrating that living in higher-density, mixed-use neighbourhoods is associated with less car use compared to living in low-density, suburban environments (Frank and Pivo, 1994; Meurs and Haaijer, 2001; Naess et al., 1995; Sun et al., 1998). The academic literature is, however, equivocal about the effect of neighbourhood characteristics on reducing car use. Several ambiguities and criticisms can be discerned. First, there is disagreement about the importance of land use characteristics in explaining variations in travel behaviour. Opinions differ about the role of urban form vis-à-vis other sets of variables. Some authors claim, for instance, that factors, such as land-use mixing or density, are more important than factors related to travellers’ sociodemographic variables (Kockelman, 1997). Others are, however, more conservative and argue that sociodemographic variables explain a larger share of the variation in travel patterns than do land use characteristics (Crane and Crepeau, 1998; Snellen et al., 2001). Some studies claim that not only are sociodemographic variables more important than land use characteristics, but that this also applies to attitudes towards travelling, land use and the environment (Bagley and Mokhtarian, 2002; Kitamura et al., 1997). Part of the disagreement is no doubt attributable to differences in theoretical framework, research design, data, and geographical settings. However, the fact that the ambiguities persist calls for additional research.