Recent trends in France and other developed countries such as a reduction in drivers’ license ownership and stagnation of daily urban mobility suggest that 'peak travel' within urban areas may have been reached. Are we assisting to cyclical or structural changes? We tried to answer to this question by applying a prospective demographic Age-Cohort model to the Metropolitan Area of Lille, calibrated from household travel surveys conducted in 1987, 1998 and 2006. The model permits to isolate age and generation effects linked to the life cycle. Population ageing explains only partially the decline of daily traveled distance per person. Indeed there are significant changes in behavior. According to the model the proportion of adults with a driver’s license should remain almost constant till 2030. Forecasts derived from the Age-Cohort model show a slowdown of travel distance increase, when the model is calibrated on 1987 and 1998 surveys, while it shows a slow decline from 2000 to 2030 when calibrated on the two most recent surveys. Concerning the revival of public transport observed around the year 2000, calibrated with the 1987-1998 surveys, the model shows an increase by 18% between 2000 and 2030, and it could reach +38% when calibrated with the 1998 and 2006 surveys. The Age-Cohort model, based on the case study of Lille, shows that population ageing explains only partially the saturation in daily mobility observed in the 2000’s. However, ageing, which gives less weight to the younger generations, amplifies the phenomenon. The significant differences observed in the behaviors until the 90’s and in the 2000’s, explain well the reversal of tendency observed which leads to diverging projections.
Le plafonnement de la mobilité des citadins : Changements de comportement ou effets de structure ? Le cas de Lille