We propose to study the complex motion of a crowd with a mesoscopic model inspired by the lattice gas method. The main idea of the model is to relax the exclusion principle by which individuals are not allowed to physically occupy the same location. The dynamics is a simple collision-propagation scheme where the collision term contains the rules which describe the motion of every single individual. At present, these rules contain a friction with other individuals at the same site, a search for mobility at neighboring sites, coupled to the capacity of exploring neighboring sites. The model is then used to study three experiments: lane formation, oscillations at a door and room evacuation.