Empirical Relation Between Stochastic Capacities and Capacities Obtained from the Speed-Flow Diagram
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 like the Highway Capacity Manual (HCM) or the German HBS is based on speed-flow diagrams. More recent investigations, however, demonstrated that freeway capacity has to be regarded as a random variable. The capacity distribution function represents the probability of a traffic breakdown in dependence 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.
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Corporate Authors:
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Authors:
- Geistefeldt, Justin
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Conference:
- Symposium on the Fundamental Diagram: 75 Years (Greenshields 75 Symposium)
- Location: Woods Hole Massachusetts, United States
- Date: 2008-7-8 to 2008-7-10
- Publication Date: 2008
Language
- English
Media Info
- Media Type: CD-ROM
- Features: Figures; References; Tables;
- Pagination: 12p
- Monograph Title: Symposium on the Fundamental Diagram: 75 Years (Greenshields 75 Symposium), July 8-10, 2008, Woods Hole, MA. Preprints
Subject/Index Terms
- TRT Terms: Design capacity; Freeways; Highway capacity; Random variables; Stochastic processes; Traffic flow rate
- Uncontrolled Terms: Fundamental diagram; Speed flow relationships
- Geographic Terms: Germany
- Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management; I71: Traffic Theory;
Filing Info
- Accession Number: 01109354
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Aug 25 2008 8:11AM