Urban freight transport suffers from a significant modelling gap compared to passenger transport. The target of this paper is to expose one of the first widely operable methods used in urban freight modelling and its main outputs through the FRETURB design. By reviewing the complete process of its construction, starting with the identification of urban policy needs, the relevant survey and databases construction methods, the modelling allowing the simulation of the effects of governance, we illustrate through the French case what are the elements of success for such a scientific endeavour. The adaptation of freight models to the urban environment strongly relies on an efficient unit of observation, which is introduced as the spine of the model after discussing the main approaches of urban freight transport modelling. The main features of the model are then presented from the generation to the distribution of freight operations and are confronted to elements of validation. The robustness of the model is also discussed through time by analysing elements of its initial calibration 20 years ago and the latest results of urban freight surveys in order to highlight its strengths and weaknesses. We show that the model is able to summarize efficiently the urban freight transport phenomenon and is still statistically robust twenty years after its first design although it needs marginal adaptations on organisational elements.