Patterns of automobile dependence in cities: an international overview of key physical and economic dimensions with some implications for urban policy

Automobile dependence, expressed through comparative levels of car ownership and use and transit service and use, varies widely and systematically across a large sample of international cities. US cities exhibit the most extreme dependence on the automobile, followed by Australian and Canadian cities, with European and Asian cities having very much more transit-oriented cities with greater levels of walking and cycling. These patterns are not strongly related to differences in wealth between cities, but do vary in a clear and systematic way with land use patterns. The total fixed and variable cost of cars per kilometre is also significantly related to the degree of automobile dependence in cities, though not as strongly as land use. The data suggest that the most auto-dependent cities are less wealthy than some other more transit-oriented cities. They have the worst operating cost recovery in transit, have far higher road construction and maintenance costs, spend the highest proportion of their wealth on passenger transportation but have roughly similar journey-to-work trip times and much longer trip lengths. These patterns suggest some important policy implications which stress the need to strategically reshape urban land use, to emphasise investment in non-auto infrastructure and to ensure that any physical planning strategies aimed at reducing automobile dependence work in concert with economic policies directed at increasing the real cost of both car ownership and car use.