Fundamentals of traffic dynamics

Traffic flow theory is devoted to study the interactions between vehicles (or drivers) and the infrastructure, which is given by many components, such as the roadways, the road signs and the traffic control actuators. Traffic phenomena are very complex, since they depend on the interactions of a large number of inhomogeneous vehicles and on many external factors. The first attempts to develop a mathematical theory of traffic flow date back to about one century ago, and the technology advancement of the last decades (in computer processing capabilities, as well as in measurement devices) has further enabled the evolution of traffic flow theory. Nevertheless, the research in traffic flow modelling is still very active and different types of traffic models are nowadays available, both based on theoretical approaches and on empirical observations. Such models can be used by traffic managers to forecast traffic conditions, and consequently to properly inform users about the forthcoming traffic state they can encounter in their travel, or to adequately design the traffic control frameworks to be applied in freeway networks.