01349724

Component

http://www.trb.org/Publications/Blurbs/165625.aspx

In conventional procedures for the assessment of traffic flow quality, the capacity of highway facilities is treated as a constant value. For freeways, the derivation of design capacities given in guidelines such as the Highway Capacity Manual or the German Highway Capacity Manual is based on speed-flow diagrams. More recent investigations, however, have demonstrated that freeway capacity has to be regarded as a random variable. The capacity distribution function represents the probability that a traffic breakdown is dependent on the flow rate. The objective of the paper is to compare stochastic capacities with conventional capacity values. For a considerable number of data samples from freeway sections in Germany, the breakdown probability that corresponds to the capacity obtained from the speed-flow diagram is determined. In conclusion, suitable breakdown probabilities that could be used for the definition of design capacities are derived.

01349716

English

pp 147-156

2011-6

Transportation Research Circular

Greenshields 75 Symposium

Web

Figures (5) ; References (13) ; Tables (1)

Design capacity; Distributions (Statistics); Freeways; Highway capacity; Probability; Stochastic processes; Traffic flow rate; Traffic flow theory

Speed-flow diagrams; Traffic flow breakdown

Germany

Highways; Operations and Traffic Management; I71: Traffic Theory

TRIS, TRB

Aug 15 2011 8:34AM

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• A Stochastic Macroscopic Modeling Framework to Interpret the Fundamental Diagram
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• Analysis of LWR Model with Fundamental Diagram Subject to Uncertainty
• Bird’s Eye Perspective on Traffic Flow: New Insights from Observing Traffic from a Helicopter
• Calibrating Speed–Density Functions for Mesoscopic Traffic Simulation
• Calibration of Steady-State Car-Following Models Using Macroscopic Loop Detector Data
• Effect of Lane-Change Maneuvers on a Simplified Car-Following Theory
• From Inductance Loops to Vehicle Trajectories
• Fundamental Diagram for Signalized Arterials: An Empirical Analysis Using High-Resolution Traffic Data
• Fundamental Diagram on Urban Roads: Myth or Truth?
• Greenshields’ Legacy: Highway Traffic
• Greenshields’ Legacy: Urban Streets
• Influence of Various Restrictions on Speed-Flow Models
• Lane-Change Maneuver Detection with Differential Global Positioning System Data from Probe Vehicle
• Measuring Traffic Flow Using Real-Time Data
• Modern Approaches to Basic Traffic Modeling: Three-Phase Traffic Theory
• Quality of Service Beyond the Traditional Fundamental Diagram
• Strategies to Improve Dissipation into Destination Networks Using Macroscopic Network Flow Models
• Traffic Flow Prospectives: From Fundamental Diagram to Energy Balance
• Traffic Flow Theory Historical Research Perspectives
• Treiterer’s Legacy: Traffic Flow Measurements and Characteristics