%0 Journal Article
%T Logistic modeling of the equilibrium speed-density relationship
%J Transportation research part A: policy and practice
%D 2011
%A Wang, Haizhong
%A Li, Jia
%A Chen, Qian-Yong
%A Ni, Daiheng
%V 45
%N 6
%P 554-566
%X 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 />
%G en
%I Elsevier Publishing
%@ 0965-8564
%U http://dx.doi.org/10.1016/j.tra.2011.03.010