Understanding and predicting private motorised urban mobility

Dimensional analysis is used to derive a simple model of private motorised mobility for any urban area based on detailed land use and travel pattern data from a large international sample of cities. This highlights the dependence of vehicle kilometres of travel on urban population and area and shows that despite time, social and cultural differences, urban areas behave in a systematic way. Private motorised mobility, although arising from local decisions, is in the mean determined by the structure of the urban environment. As private motorised mobility is based on vehicle kilometres of travel, which in turn is a surrogate for urban transportation emissions, urban air quality is directly linked to urban structure. This has implications for further research in urban air pollution and supports arguments in favour of the compact city