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About this book

The understanding of empirical traf?c congestion occurring on unsignalized mul- lane highways and freeways is a key for effective traf?c management, control, or- nization, and other applications of transportation engineering. However, the traf?c ?ow theories and models that dominate up to now in transportation research journals and teaching programs of most universities cannot explain either traf?c breakdown or most features of the resulting congested patterns. These theories are also the - sis of most dynamic traf?c assignment models and freeway traf?c control methods, which therefore are not consistent with features of real traf?c. For this reason, the author introduced an alternative traf?c ?ow theory called three-phase traf?c theory, which can predict and explain the empirical spatiot- poral features of traf?c breakdown and the resulting traf?c congestion. A previous book “The Physics of Traf?c” (Springer, Berlin, 2004) presented a discussion of the empirical spatiotemporal features of congested traf?c patterns and of three-phase traf?c theory as well as their engineering applications. Rather than a comprehensive analysis of empirical and theoretical results in the ?eld, the present book includes no more empirical and theoretical results than are necessary for the understanding of vehicular traf?c on unsignalized multi-lane roads. The main objectives of the book are to present an “elementary” traf?c ?ow theory and control methods as well as to show links between three-phase traf?c t- ory and earlier traf?c ?ow theories. The need for such a book follows from many commentsofcolleaguesmadeafterpublicationofthebook“ThePhysicsofTraf?c”.

Table of Contents

Frontmatter

Chapter 1. Introduction

Abstract
Vehicular traffic is an extremely complex dynamic process associated with the spatiotemporal behavior of many-particle systems. The complexity of vehicular traffic is due to nonlinear interactions between the following three main dynamic processes (Fig. 1.1)
Boris S. Kerner

Three-Phase Traffic Theory

Frontmatter

Chapter 2. Definitions of The Three Traffic Phases

Abstract
Traffic flow phenomena are associated with a complex dynamic behavior of spatiotemporal traffic patterns. The term spatiotemporal reflects the empirical evidence that traffic occurs in space and time. Therefore, only through a spatiotemporal analysis of real measured traffic data the understanding of features of real traffic is possible. In other words, spatiotemporal features of traffic can only be found, if traffic variables are measured in real traffic in space and time.
Boris S. Kerner

Chapter 3. Nature of Traffic Breakdown at Bottleneck

Abstract
For the understanding of the nature of traffic breakdown, probably the most important fundamental empirical feature of traffic breakdown is the possibility of both spontaneous and induced traffic breakdowns at the same bottleneck. Indeed, this feature leads to the conclusions about the nucleation nature of traffic breakdown and the existence of the infinite number of highway capacities of free flow at the bottleneck [1].
Boris S. Kerner

Chapter 4. Infinite Number of Highway Capacities of Free Flow at Bottleneck

Abstract
Highway capacity of free flow at a bottleneck (called also as bottleneck capacity) is limited by traffic breakdown at the bottleneck [1–19].
Boris S. Kerner

Chapter 5. Nature of Moving Jam Emergence

Abstract
Wide moving jams do not emerge spontaneously in free flow: no spontaneous phase transition from the free flow phase to the wide moving jam phase (F→J transition for short) has been observed in real measured traffic data (Sect. 2.4.5). Wide moving jams can emerge spontaneously only in the synchronized flow phase (S→J transition) [1–4].
Boris S. Kerner

Chapter 6. Origin of Hypotheses and Terms of Three-Phase Traffic Theory

Abstract
In Chaps. 3–5, hypotheses of three-phase traffic theory have been discussed and applied to explain traffic breakdown and moving jam emergence in vehicular traffic observed in real measured traffic data. In this chapter, we show that the origin of some of these hypotheses is the traffic phase definitions, i.e., the empirical criteria for traffic phases in congested traffic [S] and [J] considered in Sect. 2.4.1. In addition, we will try to explain why terms of natural science used in three-phase traffic theory are needed for transportation engineering.
Boris S. Kerner

Chapter 7. Spatiotemporal Traffic Congested Patterns

Abstract
There is a great variety of complex spatiotemporal congested patterns that appear due to traffic breakdown at a bottleneck. The nucleation nature of traffic breakdown and moving jam emergence in synchronized flow discussed in Chaps. 3 and 5 is the fundament for the understanding of pattern features. In this chapter, we present a brief review of some congested pattern features found in real measured traffic data
Boris S. Kerner

Part II Impact of Three-Phase Traffic Theory on

Chapter 8. Introduction to Part II:Compendium of Three-Phase Traffic Theory

Abstract
Empirical spatiotemporal features of traffic patterns determine all traffic flow characteristics, which are the basis for reliable methods of traffic control and dynamic management. As shown in Part 1, three-phase traffic theory explains the pattern features. In this chapter, we summarize the main definitions and hypotheses of this theory[1–3]
Boris S. Kerner

Chapter 9. Freeway Traffic Control based on Three-Phase Traffic Theory

Abstract
For most traffic control methods, a reliable traffic pattern reconstruction and prediction is of a great importance. For this reason, before we start with a consideration of traffic control methods, we briefly1 discuss methods for reconstruction, tracking, and prediction of spatiotemporal congested traffic patterns.
Boris S. Kerner

Chapter 10. Earlier Theoretical Basis of Transportation Engineering: Fundamental Diagram Approach

Abstract
Beginning from the classic work of Greenshields [1], the fundamental diagram of traffic flow is the basis for earlier traffic flow theories and models as well as the basic methodology for empirical studies of measured traffic data (see, e.g., reviews and books [2–27]).
Boris S. Kerner

Chapter 11. Three-Phase Traffic Flow Models

Abstract
The first microscopic three-phase traffic flow model that can reproduce empirical features of traffic breakdown and resulting spatiotemporal congested patterns was developed by Kerner and Klenov in 2002 [1]. Some months later, Kerner, Klenov, and Wolf developed a cellular automata (CA) three-phase traffic flow model (KKW CA model) [2]. Later other traffic flow models in the framework of three-phase traffic theory have been developed: Davis [3] as well as Kerner and Klenov [4] have proposed different three-phase microscopic deterministic models; Jiang andWu [5], Lee et al. [6], and Gao et al. [7] have developed various CA three-phase traffic flow models; Laval [8] and Hoogendoorn et al. [9] have developed macroscopic three-phase traffic flow models.
Boris S. Kerner

Chapter 12. Linking of Three-Phase Traffic Theory and Fundamental Diagram Approach to Traffic Flow Modeling

Abstract
A link between three-phase traffic theory and the fundamental diagram approach to traffic flow modeling can be created through the use of the averaging of an infinite number of steady states of synchronized flow shown in Figs.11.1 and 11.5 to one synchronized flow speed for each density. In this case, we should find rules for vehicle motion in a traffic flow model whose steady states are associated with a fundamental diagram, however, the model should show the free flow, synchronized flow, and wide moving jam phases as well as the F→S→J transitions.
Boris S. Kerner

Chapter 13. Conclusions and Outlook

Abstract
Freeway traffic flow can be free or congested. There are two phases in congested traffic, synchronized flow and wide moving jams. Thus there are three traffic phases: 1. Free flow. 2. Synchronized flow. 3. Wide moving jam. The synchronized flow and wide moving jam traffic phases are defined through spatiotemporal empirical criteria associated with propagation characteristics of the downstream fronts of these phases.
Boris S. Kerner

Backmatter

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