@article{ref1,
title="A traffic fundamental diagram calibrating methodology to avoid unbalanced speed-density observations",
journal="Transport",
year="2021",
author="Zhang, Chunbo and Huang, Zhaoguo and Wang, Yonggang",
volume="36",
number="1",
pages="13-24",
abstract="Traffic fundamental diagram is extremely important to analyse traffic flow and traffic capacity, and the central part of traffic fundamental diagram is to calibrate speed-density relationship. However, because of unbalanced speed-density observations, calibrating results using Least Square Method (LSM) with all speed-density points always lead to inaccurate effect, so this paper proposed a selecting data sample method and then LSM was used to calibrate four well-known single-regime models. Comparisons were made among the results using LSM with all speed-density points and the selecting data sample. <br><br>RESULTS indicated that the selecting data sample method proposed by this paper can calibrate the singleregime models well, and the method overcomes the inaccurate effect caused by unbalanced speed-density observations. Data from different highways validated the results. The contribution of this paper is that the proposed method can help researchers to determine more precise traffic fundamental diagram.   Keyword : traffic fundamental diagram, least square method, speed-density relationship, unbalanced speed-density observations, single-regime models, selecting data sample method<p /> <p>Language: en</p>",
language="en",
issn="1648-4142",
doi="10.3846/transport.2021.14302",
url="http://dx.doi.org/10.3846/transport.2021.14302"
}