Using mesoscopic simulation

Mesoscopic simulation is a vehicle simulation that provides faster run speed when compared to microscopic simulated models. Mesoscopic simulation uses a simplified vehicle following model (Car following model for mesoscopic simulation) for modeling vehicle behavior. It allows for the fast simulation of large networks during dynamic assignment. Mesoscopic simulation is event based. Therefore, in contrast to microscopic simulation, vehicle data is not updated with every time step but only at times when changes occur in the network or vehicle behavior. These so-called events may be triggered by different situations, e.g.:

• Vehicle entering the network
• Change in traffic signal state
• Vehicle entering a node
• Vehicle entering a microscopically simulated area
• Vehicle exiting a microscopically simulated area

Mesoscopic and microscopic simulations can be combined to form a hybrid simulation (Using hybrid simulation). To do so, network sections where vehicles and their behavior are required to be simulated microscopically need to be defined. This can be particularly useful when:

• detailed evaluations are only needed for certain parts of the network, but a large network is required to model route choice.
• for parts of the network mesoscopic simulation is not precise enough and conflicts cannot be modeled realistically, e.g. in turbo roundabouts or complex intersections.

For the mesoscopic simulation of your network, the factors dealt with in detail in the following sections need to be considered.

In the mesoscopic simulation, vehicles take into account the toll calculation as with the dynamic assignment (Calculating toll using dynamic assignment). Neither the managed lanes routing decision nor the destination section of the managed lane or the general purpose route may be within a node that is used for the mesoscopic simulation.

You can find examples of mesoscopic simulation in the directory ..\Examples\Examples Training\Mesoscopic Simulation.