In this thesis, we study mathematical models describing the flow of a large number of objects, such as traffic flow in road networks and material flow on conveyor belts. The focus is to develop proper models, which depict the underlying movement correctly and cover the essential arising phenomena. These models are conservation laws that describe the space and time evolution of conserved quantities, like the density and the momentum. We present appropriate simulation schemes and discuss the properties of the models based on numerical evaluations. Using these schemes, we propose optimization approaches to control the flow.