Center for Traffic Simulation Studies

In recent empirical studies on values of time and reliability, many researchers have suggested that travelers are not only interested in travel time savings but also in reduction in travel time variability. Variability introduces uncertainty for travelers such that they do not know exactly when they will arrive at the destination. Thus, it is considered a risk (or added cost) to a traveler. In this paper, we report our continuing research on route choice models and its effect on travel time reliability in an uncertain environment caused by demand and supply variations. The goal is to examine what the aggregate impact of changes in variability might be on network assignment and how individual travelers with different risk-taking behaviors respond to these changes.