Abstract
From the annual trip behaviour survey groups travelling similar distances and with homogeneous car availability have been formed. Changes in planning variables which explain differences between groups lead to time series. For the period 1965-1981 calculated time series were compared with those observed. Future changes in carmileage will be determined by the adult population, the increase in car ownership and the rise in net personal income. When income will increase with 15% from now till the year 2000, car mileage could grow with some 40%.