A hybrid traffic flow model for real time freeway traffic simulation

Macroscopic traffic flow models play a significant role in the Intelligent Transportation Systems (ITS), especially for the urban traffic control and the dynamic traffic assignment, in which the traffic dynamics usually described by the nonlinear equations are difficult to be solved and limit the practice application. This paper presents a hybrid macroscopic and microscopic (macromicroscopic) traffic model by extending Daganzo's Cell Transmission Model (CTM) with the real time speed dynamic. A simple supplying and demanding function is defined to represent the traffic propagation between the adjacent cell boundaries, and the car-following model is integrated to specify the dynamics of average speed in each cell. Simulation results with data set collected from a 4-kilometre long urban freeway show the performance of the model compared to the METANET model.