ABSTRACT
Classical transport models have been refined and developed over time such that several classifications may now be presented and discussed. The main classifications start from whether the model is termed ‘static’ or ‘dynamic’, that is whether the model represents a fixed time slice or if it includes time as a model variable. Static models assume that within a modelled period, time is invariant and the model outputs relate in the aggregate across that time period, whereas dynamic models allow the passage of time within the model. The next main classification is the level of unit modelled; models are described as ‘macroscopic’ where traffic is modelled as a fluid (where vehicles are aggregated into traffic flow) and ‘microscopic’ where individual vehicles are modelled explicitly. An intermediate version of these is termed ‘mesoscopic’. Finally there is a distinction between ‘deterministic’ models, those where model outputs are identical for each model run, and ‘stochastic’, which allow for random variations.
