Abstract: | A cellular automaton (CA) model is proposed in this paper to analyze a bridge traffic bottleneck. The simulation results with this model show that there are several phase transitions in the traffic average density, velocity and flow for each lane under a periodic boundary condition. An unstable phase in the traffic average density and velocity for the upstream and downstream lanes of the bridge is shown in a range of initial traffic densities. The critical points of the phase transitions and the phenomenon of the unstable phase found in the simulation are also explained with the mean-field theory.The project supported by the National Natural Science Foundation of China(70371067 and 10347001), the Key Project of Chinese Ministry of Education(02115) and the New Century Talent Plan of Guangxi Province in China(2001204).The English text was polished by Ron Marshall. |