The theme of this book is how spatial planning in urban areas can be used to influence the amount of travel and the proportions carried out by different modes of conveyance. A comprehensive research study in Copenhagen Metropolitan Area will be used as the book’s main case. This study has significantly improved the status of knowledge about the influence of urban structure on travel behaviour. Previous studies into this issue have been criticized for failing to control for other possible sources of influence and for not being able to establish whether a causal relationship exists between urban structure and travel behaviour. In important ways the Copenhagen Metropolitan Area study goes beyond the scope of previous investigations into the relationships between urban land use and travel. The traditional quantitative travel survey approach has been combined with qualitative interviews in order to identify the more detailed mechanisms through which urban structure affects travel behaviour. Rationales for location of activities and modal choice make up important links in these mechanisms. The statistical analyses include a broader range of urban structural, socio-economic and attitudinal variables than in any previous study. Differences between population groups in the way urban structure affects travel behaviour have also been investigated, as well as changes after moving from one residence to another.