The PLANET model is a model of the Belgian Federal PLANning Bureau that models the relationship between the Economy and Transport. The model has been developed in a convention between the FPS Mobility and Transport and the Federal Planning Bureau. The aim of the model is to produce : medium- and long-term projections of transport demand in Belgium, both for passenger and freight transport; simulations of the effects of transport policy measures; cost-benefit analyses of transport policy measures. In this methodological report the main features of the PLANET model are described.