This paper presents a novel travel time reliability-based user equilibrium traffic assignment model in view of the day-to-day demand fluctuation. Because of the daily demand variations, path travel times are not constants and therefore they can be viewed as random variables. Assuming that the travelers are able to learn the variation of the path travel time based on the past experiences, this paper proposes a demand driven travel time reliability-based user equilibrium (DRUE) principle to characterize the travelers' path choice behavior under uncertainty in travel times raised from demand variation. This principle can be formulated as a variational inequality (VI) problem in terms of path flows. It is rigorously proved that there is at least one solution for the VI problem. A solution algorithm with the column generation procedure is adopted for solving the VI problem. Numerical examples are used to illustrate the applications of the proposed model and the solution algorithm.
Abstract