Microscopic simulation of traffic at a suburban interchange.

Recent advances in computer hardware and software technology have led to the increased use of traffic simulation models. Depending on the required objective of the simulation, models range from microscopic models, which detail the movement of individual vehicles, to macroscopic models that use gross traffic descriptors such as flow. Because of the fine level of detail required in a microscopic model, applications tend towards traffic operations over a relatively small geographical area. Macroscopic models are generally applied over a much larger, system-wide, geographical area and are more useful for transportation planning rather than traffic engineering.