The influence of truck traffic on macroscopic motorway simulation

The modeling of the influence of truck traffic on the simulation of traffic flow in street networks is an important factor for increasing models' accuracy. In this paper a modeling method is described that is suitable for the application in all models that are based on a speed-density relationship, without requiring a new calibration of them. The basic concept is to vary two parameters of the speed density relationship, the free-flow speed and the maximal density, as a function of the percentage of trucks on the road. The determination of two functions describing this relationship and their application to a macroscopic traffic flow model is the main purpose of this paper.