This paper reviews the dynamic traffic assignment models in some well-known computer packages. It describes demand estimation, supply presentation, methods for computing dynamic user equilibria, and convergence among these packages with a concentration on TRANSIMS. TRANSIMS tries to take advantage of both precision and computational speed by estimating second-by-second movements of individual travelers and applying parallel processing and cellular automata methods. Although TRANSIMS addresses some of the existing problems in dynamic traffic assignment models, more studies on it and improvements in it are still needed.