Abstract
A dynamic demand-supply model for regional public transport developed by TNO-INRO is described. The model is still in the prototyping phase. Aim of the model is to get more insight into the effects of simultaneous changes of demand and supply of public transport, in relation to the costs and the benefits. Therefore a demand model is used in which the price is an important variable. The supply model is based on a quality and quantity element of the supply of public transport. The simultaneous effects of supply on demand and vica versa, is modeled using system dynamics techniques. The first results show a significant difference between a static and a dynamic model. (A)