- The purpose of this paper is to explore various traffic modeling aspects and theories that may overcome some of the limitations in existing microscopic simulation models. A multiregime microscopic traffic simulation approach has been formulated featuring realistic and comprehensive car-following and lane-changing logic. A prototype implementation of the multiregime approach was developed in C++ and extensively tested. The multiregime simulation results demonstrate the efficiency and validity of the proposed models for a broad range of traffic scenarios. The test and validation results indicate that the model and program outperformed traditional methods and other existing traffic simulation programs. The validity and efficiency of the model is attributed to the fact that the regimes were added to the model incrementally to reflect increasing agreement with real-world traffic flow. The techniques and corresponding models will be used to improve existing microscopic traffic simulation models and programs.