Samenvatting
It is shown that classical results concerning equilibrium traffic assignments and road network efficiency tolls are based on an implicit assumption: the homogeneity of flows. The main results are not valid when one considers several traffic flow types. First generalized and mathematical results concerning the existence and uniqueness of the equilibrium, efficiency of social marginal cost pricing, are presented. Secondly it is explained why the equilibrium is no longer uniquely defined and why social marginal cost pricing is not necessarily efficient.