Abstract
Transportation models can be divided into three groups, i.e. growth factors, aggregated and disaggregated models. Those ultimately using the results obtained with these models are mostly inexperienced in the field of transportation modelling like policy makers, representatives, civil servants and pressure groups. They require the models and their applications being clear and they want to single out the best of the alternatives themselves. This article states that aggregated models meet these requirements best and presents the development of the simple PRES-model.