Traffic model

A traffic model is a mathematical model of real-world traffic, usually, but not restricted to, road traffic. Traffic modeling draws heavily on theoretical foundations like network theory and certain theories from physics like the kinematic wave model. The interesting quantity being modeled and measured is the traffic flow, i.e. the throughput of mobile units (e.g. vehicles) per time and transportation medium capacity (e.g. road or lane width). Models can teach researchers and engineers how to ensure an optimal flow with a minimum number of traffic jams.
Traffic models often are the basis of a traffic simulation.
In recent articles, percolation theory has been applied to model and study traffic congestion in a city. The quality of the global traffic in a city at a given time can be characterized by a single parameter, the percolation critical threshold. The critical threshold represent the velocity below which one can travel in a large fraction of city network. Above this threshold one can travel only within a relatively small clusters (neighborhoods). The method is able to identify repetitive traffic bottlenecks. Critical exponents characterizing the cluster size distribution of good traffic are similar to those of percolation theory. A method to identify functional clusters of spatio-temporal streets that represent fluent traffic flow in a city has been developed by Serok et al.
An empirical study regarding the size distribution of traffic jams has been performed recently by Zhang et al. They found an approximate universal power law for the jam sizes distribution.
A simulation model for urban traffic can be found in ref.