Calculation of paths and costs

A path is a sequence of edges on which a vehicle can move through the road network. In the dynamic assignment, paths start at an origin parking lot and end at a destination parking lot. Since there are usually several different paths between an origin parking lot and a destination parking lot, Vissim must also model the decision of the driver as to the path he selects. In dynamic assignment, during path selection, Vissim identifies the number of paths available between an origin parking lot and a destination parking lot. The software then performs a path search for the path selection methods Sum of edge travel times and Measured path travel times according to Kirchhoff. The path selection is a special case of discrete selection because the selection probabilities must be calculated for a set of discrete alternatives. To do so, a utility function for evaluating the individual paths as well as a decision function are defined in the traffic assignment, which are based on these evaluations.

The evaluation is calculated in the form of generalized costs from expected travel time, travel distance and financial costs for all edges. The generalized costs of a path are defined as the total cost of edges from which the path is composed:

These include:

C = the generalized costs

R = a path

a = an edge that occurs in R