An Urban Intersection Model Based on Multi-commodity Kinematic Wave Theories

Traffic flow models of an urban intersection can be used to evaluate its performance and offer a base for traffic control strategies, road network design, and so on. The complex conflicts among traffic streams at an urban intersection, including zero conflict, merging conflict, diverging conflict and crossing conflict, have not been synthetically modeled by existing models. In this paper, we consider a four-leg urban intersection as a grid of 2 times 2 links (2 times 2 grid) and present a multi-commodity kinematic wave (MCKW) traffic flow model, in which all four conflicts are modeled. In this model, we use a fair merging rule and both strictly first-in-first-out (FIFO) and non-strictly FIFO diverging rules. Moreover the model is used to simulate conflicts at a signalized urban intersection, where there are no crossing conflicts. As a result, the recurrence of gridlock occurred at un-signalized case is prevented.