Origin of Synchronized Traffic Flow on Highways and Its Dynamic Phase Transitions

H. Y. Lee; H.-W. Lee; D. Kim

doi:10.1103/PhysRevLett.81.1130

Origin of Synchronized Traffic Flow on Highways and Its Dynamic Phase Transitions

H. Y. Lee, H.-W. Lee, and D. Kim

Phys. Rev. Lett. 81, 1130 – Published 3 August 1998

Abstract

We study the traffic flow on a highway with ramps through numerical simulations of a hydrodynamic traffic flow model. It is found that the presence of the external vehicle flux through ramps generates a new state of “recurring humps” (RH). This novel dynamic state is characterized by temporal oscillations of the vehicle density and velocity which are localized near ramps, and found to be the origin of the synchronized traffic flow reported recently [Kerner and Rehborn, 79, 4030 (1997)]. We also argue that the dynamic phase transitions between the free flow and the RH state can be interpreted as a subcritical Hopf bifurcation.

Received 24 February 1998

DOI:https://doi.org/10.1103/PhysRevLett.81.1130

Authors & Affiliations

H. Y. Lee^1,2, H.-W. Lee¹, and D. Kim^1,2

¹Center for Theoretical Physics, Seoul National University, Seoul 151-742, Korea
²Department of Physics, Seoul National University, Seoul 151-742, Korea