An Approach to Developing Online Traffic Flow Model

Online traffic flow modeling is attracting more attention due to intelligent transport systems and technologies. The flow-density relation plays an important role in traffic flow modeling and provides a basic way to illustrate traffic flow behavior under different traffic flow and traffic density conditions. Until now the research effort has focused mainly on identifying the shape of the relation. The time-traced plot of the relation has not been identified and utilized properly even though the time-traced plot of the relation reflects the upstream/downstream traffic conditions and should be considered in the traffic flow modeling. In this paper the flow-density relation is analyzed considering the time-development of the relation and interpreted as a states diagram. The time-traced plot of the flow-density relation is quantified by applying fuzzy logic. The quantified time-traced plot of the flow-density relation builds the basis for online application of a macroscopic traffic flow model. The new approach to online modeling of traffic flow applying the time-traced plot of the flow-density relation alleviates parameter calibration problems stemming from the flow-density relation.