Improved user equilibrium based method for estimating trip tables

An optimal trip table correction function for the user equilibrium based tr ip table estimation problem is derived and used in place of Turnquist and O ur's heuristic trip table correction function. The derivation of this new c orrection function is based on a new concept-path equivalent capacity-that unifies the individual capacities of the links in a path into a single path capacity. Once a path between two zones is represented as a link with a si ngle capacity, the travel time of the path can be computed directly for any path flow. This permits an optimal trip table correction function to be de termined at each iteration of Turnquist and Gur's trip table algorithm. Tes t results show that the new method yields more accurate and consistent solu tion trip tables than the heuristic method.