De wederzijdse afhankelijkheid van vervoervraag, de geografische spreiding van bevolking en arbeidsplaatsen en het vervoerstelsel : een direct vraagmodel met gegeven kwaliteit van het vervoerstelsel.

A model is presented dealing with the relationship between transportation flows, location of population and employment and the transportation system. This model is to be seen as generalization of the conventional singly or doubly constrained transportation models, as it has so-called elastic constraints. It is argued that these conventional transportation models can only be applied if the activity pattern can be forecast in equilibrium with the transportation system.