Traffic assignment models are crucial for traffic planners to be able to predict traffic distributions, especially, in light of possible changes of the infrastructure, e.g., road constructions, traffic light controls, etc. There is a trend in the transportation community (science as well as industry) to base such predictions on complex computer-based simulations that are capable of resolving many elements of a real transportation system. Moreover, cities worldwide, driven by critical sustainability goals, are developing digital twins of their transportation networks to inform the design and the operations of these intricate networks. On the other hand, the theory of dynamic traffic assignments in terms of equilibrium existence, computability and efficiency, has not matured to the point matching the model complexity inherent in simulations. This Dagstuhl Seminar, which is the fourth in a row on this topic, aims at bringing together leading scientists in the areas traffic simulations, algorithmic game theory (AGT), and dynamic traffic assignment (DTA), as well as applied researches from industry.