Review of demand models : forecast/recorded traffic comparison for urban and intercity transport : report of the fifty-eighth round table on transport economics held in Paris on 25th and 26th June, 1981.

A transport project cannot be planned or assessed in terms of economic feasibility unless medium or long-term traffic forecasts are established, since the volume of traffic, while not the only crierion, is fundamental to any decision to invest or to operate in a particular way. It is accordingly essential to know the extent to which one can rely on the technical instruments used for a priori estimates of future transport demand.