10 - Microscopic Three-phase Traffic Theory and Its Applications for Freeway Traffic Control

Abstract

This paper describes how there are a huge number of traffic flow theories and models that should explain diverse congested traffic patterns that are observed upstream of freeway bottlenecks. However, it is only recently that a “puzzle” of spatiotemporal features of congested patterns has adequately solved these pattern features. Consequently, earlier traffic flow theories and models that are in a serious conflict with many of these empirical spatiotemporal traffic pattern features. Therefore, the paper introduced “three-phase traffic theory.” In three-phase traffic theory, besides the “free flow” phase there are two phases in congested traffic: “synchronized flow” and “wide moving jam.” Thus, there are three traffic phases in this theory: (1) free flow; (2) synchronized flow; and (3) wide moving jam. Three-phase traffic theory explains the complexity of traffic based on phase transitions among the three traffic phases, and on their complex nonlinear spatiotemporal features.