The Aggregate-Disaggregate-Aggregate (ADA) Freight Model System

Disaggregate models –defined here as models using observations at the level of the traveler, the traveling group, the business establishment or the shipmenthave several advantages over aggregate models (which use groupings of those units as observations, e.g., groupings by geographic zone). Disaggregate models can be based on a foundation in behavioral theory, can include more detailed policy-relevant variables and do not suffer from the aggregation biases of aggregate models. Nevertheless, there are perfectly valid reasons why some of the components of a model system are modeled in an aggregate fashion. In this paper, we propose an ‘aggregate-disaggregate-aggregate’ (ADA) model system for freight transport.