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Estimating Macroscopic Volume Delay Functions with the Traffic Density Derived from Measured Speeds and Flows
Joint Authors
Kucharski, Rafał
Drabicki, Arkadiusz
Source
Journal of Advanced Transportation
Issue
Vol. 2017, Issue 2017 (31 Dec. 2017), pp.1-10, 10 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2017-02-26
Country of Publication
Egypt
No. of Pages
10
Main Subjects
Abstract EN
This paper proposes a new method to estimate the macroscopic volume delay function (VDF) from the point speed-flow measures.
Contrary to typical VDF estimation methods it allows estimating speeds also for hypercritical traffic conditions, when both speeds and flow drop due to congestion (high density of traffic flow).
We employ the well-known hydrodynamic relation of fundamental diagram to derive the so-called quasi-density from measured time-mean speeds and flows.
This allows formulating the VDF estimation problem with a speed being monotonically decreasing function of quasi-density with a shape resembling the typical VDF like BPR.
This way we can use the actually observed speeds and propose the macroscopic VDF realistically reproducing actual speeds also for hypercritical conditions.
The proposed method is illustrated with half-year measurements from the induction loop system in city of Warsaw, which measured traffic flows and instantaneous speeds of over 5 million vehicles.
Although the proposed method does not overcome the fundamental limitations of static macroscopic traffic models, which cannot represent dynamic traffic phenomena like queue, spillback, wave propagation, capacity drop, and so forth, we managed to improve the VDF goodness-of-fit from R2 of 27% to 72% most importantly also for hypercritical conditions.
Thanks to this traffic congestion in macroscopic traffic models can be reproduced more realistically in line with empirical observations.
American Psychological Association (APA)
Kucharski, Rafał& Drabicki, Arkadiusz. 2017. Estimating Macroscopic Volume Delay Functions with the Traffic Density Derived from Measured Speeds and Flows. Journal of Advanced Transportation،Vol. 2017, no. 2017, pp.1-10.
https://search.emarefa.net/detail/BIM-1170707
Modern Language Association (MLA)
Kucharski, Rafał& Drabicki, Arkadiusz. Estimating Macroscopic Volume Delay Functions with the Traffic Density Derived from Measured Speeds and Flows. Journal of Advanced Transportation No. 2017 (2017), pp.1-10.
https://search.emarefa.net/detail/BIM-1170707
American Medical Association (AMA)
Kucharski, Rafał& Drabicki, Arkadiusz. Estimating Macroscopic Volume Delay Functions with the Traffic Density Derived from Measured Speeds and Flows. Journal of Advanced Transportation. 2017. Vol. 2017, no. 2017, pp.1-10.
https://search.emarefa.net/detail/BIM-1170707
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1170707