In recent years, a growing interdisciplinary interest has showed up in the moving groups of intelligent agents, which include vehicular traffic, pedestrian flows, movement of robots and movement of animal groups. We first review various results and applications about the modelling of vehicular traffic via conservation laws, with special focus on networks. Then we discuss an alternative mathematical framework, based on time-evolving measures, which can be applied to pedestrian flows and to animal/robot groups. The latter is still macroscopic but takes into account microscopic issues.