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Title:

An Automatic Calculation Method of Identifying the Hysteresis Loop Characteristics in Macroscopic Fundamental Diagram

Accession Number:

01517589

Record Type:

Component

Availability:

Transportation Research Board Business Office

500 Fifth Street, NW
Washington, DC 20001 United States

Abstract:

Recent studies showed that hysteresis phenomena are exhibited in macroscopic fundamental diagram (MFD) in urban freeway networks. This paper proposes an automatic calculation method of identifying MFD hysteresis loop characteristics and apply it to explore the characteristics of the hysteresis loops and the factors affecting the hysteresis pattern. Compared to the traditional observation method, this automatic calculation method extracts key characteristics of hysteresis loop directly from the network flow-density data. This method improves the efficiency to characterize hysteresis loop by identifying the direction of hysteresis loop, starting point and ending point of the hysteresis loop, and the maximum average network flow. To test this automatic calculation method, the macroscopic fundamental diagram for urban freeway network in Milwaukee is presented in this study. By analyzing the relationship between average network flow and average network density with the loop detector data in Milwaukee freeway network, we find that the MFD of Milwaukee freeway network exhibits clockwise hysteresis loop phenomenon, where higher average network flows are observed during the loading process of congestion, while lower network flows are observed during the offset of congestion with the same average network density. Key characteristics of hysteresis loop are extracted by the automatic calculation method and calculation results are validated by empirical observation data. With the automatic identifying method, deeper investigation is conducted by analyzing the spatial spread of congestion in the network. The results indicate that the spatial distribution of congestion over the network will affect the characteristics of the hysteresis loops.

Supplemental Notes:

This paper was sponsored by TRB committee AHB45 Traffic Flow Theory and Characteristics.

Monograph Accession #:

01503729

Report/Paper Numbers:

14-2305

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Jin, Peter J
Zhang, Jian
Ran, Bin

Pagination:

21p

Publication Date:

2014

Conference:

Transportation Research Board 93rd Annual Meeting

Location: Washington DC
Date: 2014-1-12 to 2014-1-16
Sponsors: Transportation Research Board

Media Type:

Digital/other

Features:

Figures; References; Tables

Uncontrolled Terms:

Fundamental diagram

Geographic Terms:

Milwaukee (Wisconsin)

Subject Areas:

Data and Information Technology; Highways; Operations and Traffic Management; I71: Traffic Theory; I72: Traffic and Transport Planning

Source Data:

Transportation Research Board Annual Meeting 2014 Paper #14-2305

Files:

TRIS, TRB, ATRI

Created Date:

Jan 27 2014 2:49PM