TY  - JOUR
PY  - 2011//
TI  - Logistic modeling of the equilibrium speed-density relationship
JO  - Transportation research part A: policy and practice
A1  - Wang, Haizhong
A1  - Li, Jia
A1  - Chen, Qian-Yong
A1  - Ni, Daiheng
SP  - 554
EP  - 566
VL  - 45
IS  - 6
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.<p />
LA  - en
SN  - 0965-8564
UR  - http://dx.doi.org/10.1016/j.tra.2011.03.010
ID  - ref1
ER  -