Linear User Cost Equilibrium: The New Algorithm for Traffic Assignment in VISUM

Abstract

This paper describes how Linear User Cost Equilibrium (LUCE) is the new algorithm designed to solve traffic assignment with deterministic route choice available in VISUM. The main idea of the paper is to seek at every node a user equilibrium for the local route choice of drivers directed toward a same destination among the links of its forward star. The cost function associated to each one of these travel alternatives expresses the average impedance to reach the destination by continuing the trip with that link, linearized at the current flow pattern. The solution to such linear program in terms of destination flows, recursively applied for each node, provides a descent direction with respect to the classical sum-integral objective function. The network loading is then performed through the corresponding splitting rates, thus avoiding explicit path enumeration. Exploiting the inexpensive information provided by the derivatives of the link costs with respect to link flows, LUCE achieves a very high convergence speed that compares favorably to the other methods, while it assigns the demand flow of each origin-destination (o-d) couple on several paths at once.

Cite this work

No public copy is stored for this record, so only the metadata is cited.

Stored only when both papers are in the corpus — 28 citations exist upstream.