ARE WE CLOSE TO SATURATION - A DEMOGRAPHI C APPROACH TO THE NUMBER OFCARS PER HOUSEHOLD IN 3 URBAN REGIONS

Given the limited range of traditional models which are often based on an assessment of the effects of income at one point in time, we devel oped a longitudinal approach based on the study of the behaviour of su ccessive generations during their lifetime. The paper provides a synth esis of long-term projections of the motorization of households in the Ile-de-France area (11 million inhabitants), the Montreal metropolita n area (3 million) and the Grenoble urban area (0,5 million). The hist ory of motorization extends further back in North America than in Euro pe, and throws light on the saturation concept (a progressive slowdown towards the asymptotes). The second car becomes the principal source of growth in terms of the number of cars on the road, and urban sprawl leads to the prediction that the number of vehicles on the periphery of an area will increase, whereas growth will be more moderate in the more densely populated areas.