Noise Fundamental Diagram deduced by Traffic Dynamics

Road traffic noise is a relevant issue in environmental impact studies. Many models have been developed to predict vehicles behaviour on one side, and noise produced by traffic on the other side. In this paper the authors propose the integration between statistical Traffic Noise predictive Models (TNMs) and traffic flow dynamics models. In particular, the starting point is a parametric formula that relates the hourly equivalent level to vehicle flow and speed. Thus, the speed-flow-density relationship is obtained with a "car-following" model approach and integrated in the noise prediction formula. The final result of this procedure is the dependence of the equivalent level from vehicle density and speed, in three different dynamics postulates assumed in the "car-following" model theory. This is the first step to the postulation of the Traffic Noise Fundamental Diagram, in analogy to the Fundamental Diagram, i.e. the set of graphs that exploits the speed-flow-density relationship.