A qualitative model of cross-lane inhomogeneities in traffic flow

The dilemma of traditionally quantitative methods in application to complex systems leads more and more researchers to emphasize the qualitative methods that can tackle the qualitative knowledge. Based on the concepts and ideas of qualitative reasoning, a preliminary qualitative method for modeling the traffic flow is proposed in this paper. Following new concepts, such as the homogenous measure index, which can be treated as an entropy to judge the homogeneity of traffic flow, a set of linear parameters-varying difference equations is used to describe the process of qualitative state transitions of the traffic flow. The procedures as well as the rationality of qualitative modeling for the traffic flow are illustrated by the data obtained from an actual traffic system-the Beijing Third Ring Road. Comparing the simulation results with actual data, it is proven that the results obtained by the proposed qualitative model coincide with the actual situation and the qualitative model can basically depict the nonhomogenous state transitions of traffic flow.