This book covers a selection of fundamental topics of traffic engineering useful for highways facilities design and control. The treatment is concise but it does not neglect to examine the most recent and crucial theoretical aspects which are at the root of numerous highway engineering applications, like, for instance, the essential aspects of highways traffic stream reliability calculation and automated highway systems control. In order to make these topics easy to follow, several illustrative worked examples of applications are provided in great detail. An intuitive and discursive, rather than formal, style has been adopted throughout the contents.
As such, the book offers up-to-date and practical knowledge on several aspects of traffic engineering, which is of interest to a wide audience including students, researchers as well as transportation planners, public transport specialists, city planners and decision-makers.
Author(s): Marco Guerrieri, Raffaele Mauro
Series: Springer Tracts in Civil Engineering
Publisher: Springer
Year: 2021
Language: English
Pages: 196
City: Cham
Preface
Contents
List of Figures
List of Tables
1 Macroscopic Variables and Fundamental Relationships of Traffic Flow Theory
1.1 Interrupted and Uninterrupted Traffic Flows
1.2 Inference of Macroscopic Flow Variables
1.2.1 Traffic Variables Referred to the Time Domain
1.2.2 Traffic Flow, Traffic Volume and Capacity
1.2.3 Peak Hour Factor
1.2.4 Estimating of Design Hourly Volume DHV
1.2.5 Traffic Variables Referred to the Space Domain
1.2.6 Fundamental Flow Relationship
1.2.7 Traffic Flow Stationarity
References
2 Macroscopic Traffic Flow Models
2.1 Transportation Demand, Capacity and Flow
2.2 Relationship Between Macroscopic Traffic Flow Variables
2.3 Properties of the Mathematic Traffic Flow Models and Operational Flow Conditions
2.3.1 Single-Regime Models
2.3.2 Levels of Service
2.3.3 Other Characterizations of the Operational Traffic Conditions
2.4 Experimental Definition of a Traffic Flow Model
2.5 Deterministic Multi-regime Traffic Flow Models
2.6 Physical Interpretation of the Capacity
2.7 Hysteresis in Traffic Flows
2.8 Kerner’s Three-Phase Traffic Theory
2.9 Case Study: Service Levels According to Greenshields’ Model
2.10 Case Study: Calibration of Greenshields’ Flow Model
2.11 Case Study: Calibration of May’s Flow Model
References
3 Continuity Flow Equation, Kinematic Waves and Shock Waves
3.1 Fluid Dynamic Analogy for the Traffic Flow
3.1.1 Deduction of the Continuity Equation
3.1.2 Boundary and Initial Conditions
3.1.3 Kinematic Waves
3.1.4 Perturbations of the Traffic Flow and Speed
3.2 The LWR Model and Shock Waves
3.2.1 Case Study: Queue Formation and Dissipation Due to Presence of a Heavy Vehicle on a Two-Lane Undivided Highway
3.2.2 Case Study: Estimation of the Effects of an Accident on the Flow in a Two-Lane Dual Carriageway Highway
References
4 Microscopic Models and Traffic Instability
4.1 Microscopic Models: Car-Following Theory
4.2 Linear Model
4.3 Impulsive Variations of Vehicle Speeds: Traffic Instability and Stop (‘phantom Traffic Jams’)
4.3.1 Local Instability and Asymptotic Instability
4.4 Non-linear Model
4.5 Derivation of Macroscopic Models from the Microscopic Non-linear Model
4.6 Traffic Model Genealogy
References
5 Fundamentals of Random and Traffic Processes
5.1 Traffic Processes
5.2 Counting Probability Distributions
5.2.1 General Criterion for Selecting the Appropriate Counting Probability Distribution
5.3 Probability Distribution for Time Headways
5.4 Speed Processes
References
6 Traffic Management and Control Systems
6.1 Preliminary Considerations
6.2 Flow Reliability on Highways
6.2.1 Case Study: Assessment of the Reliability Laws from Traffic Surveys
6.3 The Ramp-Metering
6.3.1 System Analysis for an Isolated On-Ramp
6.3.2 System Analysis for On-Ramps and Off-Ramps
6.4 Hard Shoulder Running System
6.4.1 Capacity Estimation of Highways with HSR System
6.4.2 Case Study: Traffic Flow Parameters Estimation After HSR System Activation
6.5 Variable Speed Limits (VSL)
6.6 Automated Highway System (AHS)
6.6.1 Estimation of the Increase in Lane Capacity
6.7 C-ITS, C-Roads and Smart-Roads
6.7.1 C-ITS
6.7.2 C-Road Platform
6.7.3 Smart-Roads
6.8 Crash Frequency Estimation: The HSM Method
6.9 Models for Estimating Traffic Pollutant Emissions
6.9.1 The Macroscopic Model COPERT
References
7 Interference Between Traffic Flows: The Gap Acceptance Theory
7.1 Estimation of the Critical Gap and Follow-Up Time
7.1.1 Estimation of the Average Critical Gap: Ashworth’s Method
7.1.2 Estimation of the Average Critical Gap: Miller’s Method
7.2 Characteristic Values of the Critical Gap and the Follow-Up Time
7.2.1 Tc and Tf for Unsignalized Intersections
7.2.2 Tc and Tf for Roundabouts
7.3 The Theoretical Capacity of Traffic Streams in an Unsignalized At-Grade Intersection
References
8 Queue Formation: General Models
8.1 Queuing Systems: Variables and Basic Relationships
8.1.1 Little’s Law
8.2 Operating Conditions and Models for Waiting Systems
8.3 Probabilistic Models for Steady-State
8.4 Deterministic Solutions in Congestion
8.5 Heuristic Solutions for Steady and Non-steady States
References
9 Unsignalized Intersections
9.1 Waiting Times and Delays in Unsignalized Intersections
9.2 The Levels of Service for Unsignalized At-Grade Intersections
9.3 Capacity, Delay and Queue at Three-Arm Intersections
9.3.1 Case Study: Delay Calculation in a T-Intersection
9.4 Capacity, Delays and Queues at Roundabout Intersections
9.4.1 Entry Capacities
9.4.2 Control Delays and Queues
9.4.3 Effect of the Pedestrian Flow on the Entry Capacity
9.4.4 Non Conventional Roundabouts: Turbo-Roundabouts
9.4.5 Case Study: Determination of Levels of Service in a Large-Sized Roundabout
References
10 Signalized Intersections
10.1 The Cycle Length
10.2 Traffic Signal Control Type
10.3 Phasing at Signalized Intersection
10.4 Pedestrian Phases
10.5 Capacity Calculation
10.5.1 Criterion for Calculating the Delay-Minimising Cycle Time
10.6 Delay Calculation
10.7 Determination of Service Levels for Signalized Intersections
10.7.1 Case Study: LOS of a Signalized T-Intersection
References
Index
