Abstract
Long term developments within the traffic and transportation system are uncertain in many aspects. With the use of scenarios these uncertainties can be analysed in a systematic way. However, forecasting models used for scenario analysing have to meet specific demands. They should offer an integrated, flexible and transparent model structure. They should also give substantial support in the process of scenario building. With the design of the Scenario Explorer it is tried to deal with these demands. In the instrument an interactive and highly automated scenario building process is worked out.