TY - JOUR
T1 - Logistic modeling of the equilibrium speed-density relationship
AU - Wang, Haizhong
AU - Li, Jia
AU - Chen, Qian Yong
AU - Ni, Daiheng
PY - 2011/7
Y1 - 2011/7
N2 - The fundamental diagram, as the graphical representation of the relationships among traffic flow, speed, and density, has been the foundation of traffic flow theory and transportation engineering. Seventy-five years after the seminal Greenshields model, a variety of models have been proposed to mathematically represent the speed-density relationship which underlies the fundamental diagram. Observed in these models was a clear path toward two competing goals: mathematical elegance and empirical accuracy. As the latest development of such a pursuit, this paper presents a family of speed-density models with varying numbers of parameters. All of these models perform satisfactorily and have physically meaningful parameters. In addition, speed variation with traffic density is accounted for; this enables statistical approaches to traffic flow analysis. The results of this paper not only improve our understanding of traffic flow but also provide a sound basis for transportation engineering studies.
AB - The fundamental diagram, as the graphical representation of the relationships among traffic flow, speed, and density, has been the foundation of traffic flow theory and transportation engineering. Seventy-five years after the seminal Greenshields model, a variety of models have been proposed to mathematically represent the speed-density relationship which underlies the fundamental diagram. Observed in these models was a clear path toward two competing goals: mathematical elegance and empirical accuracy. As the latest development of such a pursuit, this paper presents a family of speed-density models with varying numbers of parameters. All of these models perform satisfactorily and have physically meaningful parameters. In addition, speed variation with traffic density is accounted for; this enables statistical approaches to traffic flow analysis. The results of this paper not only improve our understanding of traffic flow but also provide a sound basis for transportation engineering studies.
KW - Fundamental diagram
KW - Generalized logistic curve
KW - Logistic speed-density model
UR - http://www.scopus.com/inward/record.url?scp=84866299506&partnerID=8YFLogxK
U2 - 10.1016/j.tra.2011.03.010
DO - 10.1016/j.tra.2011.03.010
M3 - Article
AN - SCOPUS:84866299506
SN - 0965-8564
VL - 45
SP - 554
EP - 566
JO - Transportation Research Part A: Policy and Practice
JF - Transportation Research Part A: Policy and Practice
IS - 6
ER -