Chapter 4: The Aggregate-Disaggregate-Aggregate (ADA) Freight Model System

Most freight transport models that are used by national, international, and regional authorities are lacking important aspects of logistics decision-making such as the choice of shipment size and the use of consolidation and distribution centers (DCs). At the same time, these models often assume transport (mode) optimization at the aggregate zone-to-zone level, for which in reality no agents exist. The aggregate-disaggregate-aggregate (ADA) freight model system tries to overcome these limitations by modeling the generation of trade flows and assignment to networks in an aggregate way, but simulating the logistics decisions at the level of individual firm-to-firm flows. The disaggregate part of the system is the logistics model, where shipment size and transport chain choice (including the use of transshipment centers) are determined by minimizing the total logistics cost.