The transport satellite accounts (TSA) show the total transport expenditure in Belgium in 2000. The TSA are a complement to the information in the national accounts for transport activities, which are only partially described in this general framework. Transport generates externalities that are not taken into account in the total expenditure as defined in the satellite accounts. The study assesses the external costs of various transport modes and contains a joint analysis of the externalities and of the main TSA results for 2000. The analysis reveals the extent of the transport costs and externalities, especially of road transport. The estimated external costs concern air pollution, climate change, accidents, noise and congestion.