Abstract
In practice there are many possibilities to increase the capacity of a transport network, in order to decrease congestion (e.g. building a new road, adding additional lanes to an existing road etc.). To help the planner in finding a feasible solution a model has been developed which selects the optimal combination of possibilities on the basis of minimum traveltime costs and investments. This model has been applied to determine the optimal structure of the main road network in Noord-Oost Brabant.