ABSTRACT
Under this rubric there is a whole cluster of problems and potential solution techniques. In the most general sense the traffic assignment problem is one of assigning to the links of a network some set of trips or flows from a set of origin zones (or nodes) i to a set of destination zones j. The zones, used as a discrete representation of a continuous spatial distribution of activities, are connected by a set of links which are intended to represent the transportation facilities. We accept as given that the zones and the links are adequate representations of reality for our current purposes, but we acknowledge that in other contexts these matters are open to question. It is also helpful to begin by accepting as given a matrix of flows or trips from each origin to each destination, while noting that the essence of integrated modelling is in the fact that these flows are not fixed in the context of the overall model system. With these stipulations the traffic assignment problem, then, is concerned with the routes or paths taken by these trips in traversing the network from their origins to their destinations.
