Multicommodity Kinematic Wave Simulation Model for Network Traffic Flow

A multicommodity discrete kinematic wave model that possesses the theoretical rigor and computational efficiency inherent in the kinematic wave theory is proposed for simulating network traffic flow. In this model, fluxes through boundaries and junctions are computed systematically under the supply-demand framework. In addition, traffic is modeled by commodity type so that the effects of geometric characteristics of a road network on traffic dynamics can be captured. Although traffic is not ordered down to the vehicle level as in existing kinematic wave simulation models, the noncompliance with the first-in-first-out property in this model is still of the order of Δt, the time increment. Hence travel times in the average sense can be defined from cumulative curves. Finally, the evolution of traffic dynamics in a sample road network is shown to demonstrate the stability, numerical convergence, and soundness of the proposed network kinematic wave model.