Pedestrian social groups modeling & simulation: a state of the art

The paper focuses on pedestrian social groups. A social group is formed by individuals that have social ties and intentionally walk together, such as friends or family members. The percentage of people in social groups within a crowd is large. Pedestrian crowds have been studied, modeled and simulated for different purposes. The simulation of crowds is employed to support pedestrian environment designs. It allows to elaborate "what if" scenarios and to evaluate the environment design with reference to specific criteria. Virtual worlds, to become more lively and appealing, are populated by large number of characters. Typically, these characters should be able to navigate through the virtual environment in a human-like manner. The study of pedestrian social groups plays a very important role also in the case these groups include mobile robots as individuals and as a robot team. The papers presents empirical evidences of social group walking behavior. Then, briefly presents the most relevant pedestrian microscopic models, focusing on the ones that take into account social groups. A critical review of the current approaches and future developments end the paper.