The report presents data on car ownership, on holding of driving licences, and on annual kilometres per car, mostly obtained in the 1978-79 national travel survey and the similar 1977-78 nationwide personal transportation study of the united states. The data are analysed in relation to household size and household income. It is concluded that household car ownership is strongly related to the number of adults, especially at high income levels. Forecasting models and the saturation levels used in them should therefore be expressed on a per-person basis, or alternatively models should be disaggregate by number of adults as well as by income. Data on numbers of driving licences support this conclusion. The data on car use confirm earlier data of the same kind. In particular, any reduction in average kilometres per car due to multiple car ownership is likely to be small and to be counteracted by the effect of rising incomes. (Author/publisher)
Abstract