Abstract
A model defining the interaction between transport demand, planning developments and traffic planning is dealt with. The model is a general form of traffic model, with one and with two fringe conditions. With the help of the dynamic version of the model and simple exogene assumptions it is possible to simulate developments, such as urbanisations, and suburbanisation; the springing up of a central town or or agglomeration; the shifting of activities to the periphery of big cities under the influence of increasing car ownership.