Continuum Traffic Flow Modelling: Network Approximation, Flow Approximation
Résumé
Continuum traffic modeling is designed for very large networks and relies on a double approximation. The network is assumed to be dense and is described as a two-dimensional medium, whereas the traffic in the network is described as a bi-dimensional fluid. Traffic on major arterials is described separately using the GSOM (Generic second order model) approach. The dense network is divided into macro-cells, typically one to 10 km in size. The dynamics of traffic in the two-dimensional medium result from the interplay of supply and demand inside and between macro-cells. The paper addresses important modeling issues such as how to estimate the average densities, how to determine the equilibrium traffic supply and demand functions, and how to evaluate traffic supplies and demands.