Schade, W.W.SchadeKrail, M.M.Krail2022-03-102022-03-102006https://publica.fraunhofer.de/handle/publica/353733Though the size of System Dynamics models should be compact focusing on the main feedback loops determining system behavior one kind of model can become quite large: multi-national, multi-sectoral spatially differentiated models. The paper briefly presents such a model called ASTRA (=Assessment of Transport Strategies), which is developed in several versions over the past eight years. The purpose of the paper is to describe an approach how such a system dynamics model despite its size can be calibrated to make it applicable for Europeanwide policy analysis, of transport policies. The approach is designed as a sequential process involving an automated tool combining a C++-coded steering programme with the Vensim® optimizer to enable calibration of large numbers of similar equations that only differ by their parameterization.enNational modelCalibrationTransport policyASTRAMulti-regional-multi-sectoral303600conference paper