Freeway-Merging Operations: A Probabilistic Approach

Abstract Existing traffic flow models generally assume that breakdown will occur at capacity flows only, and therefore capacity can be measured immediately prior to breakdown. Field observations at ramp-freeway merge areas however, showed that clusters of closely spaced vehicles from the ramp were the main cause of conflicts at the merge area. A probabilistic model was developed to estimate the probability of breakdown for given levels of flow on the freeway and on the ramp, considering the presence of vehicular clusters from the ramp. This model can serve as the framework for developing a microscopic simulation model for freeway merge areas.