Travel Assignment with a Nonlinear Travel-Time Function.

This article deals with the problem of traffic assignment with a nonlinear travel-time function. The nonlinear travel-time function makes it possible to simulate congestion on urban streets. The optimal traffic assignment pattern is obtained by using a variational technique for a multicopy network problem with nonlinear travel-time functions and turn penalties. The distinguishing characteristic of this type of assignment using nonlinear travel-time-volume relations, is that as the number of vehicles on any path tends to increase, alternate paths tend to become more desirable and thus utilized by other vehicles.