This paper presents a traffic network simulation model for real-time applications in IVHS. The proposed model has incorporated three key features essential for IVHS operations: (1) the capability of simulating both freeways and surface street networks as an integrated network; (2) a path-processing capability for representing drivers' route choice behavior at an individual/vehicle level; and (3) the capability of simulating different subnetworks at different levels of detail so as to increase the execution speed for real-time operations. Three simulation methodologies are implemented in the real-time traffic simulation model to satisfy the above requirements. These three methodologies are macroparticle traffic simulation model (MPSM), modified NIPSM (M-MPSM), and microscopic (MICRO) model. Due to the real-time operating requirement, the proposed simulation model has been parallelized to take advantage of the parallel computers since they can offer the required computational power at an economical cost/performance ratio. Several simulation experiments have been carried out to compare the execution speed of each methodology. The preliminary research results indicate that parallel computing architecture offers a very promising alternative for the implementation of real-time traffic simulation.