The Traffic Characteristics of Three-Merge-One Road with Cellular Automaton Model

A mainline merged two on-ramps is known as three-merge-one road, which three roads merged into one road. The emphasis of this study lies in traffic flow characteristics and the design optimization for buffer lane, which restrict traffic flow of the three-merge-one road that become a congested traffic bottleneck in urban traffic. This study presents traffic flow model with cellular automaton. It is based on operating mechanism and driving characteristics in three-merge-one road. Simulation shows the spatio-temporal patterns with the different length of buffer lane, which present the length can affect the traffic capacity of bottleneck. The result indicates that compulsory lane-changing and waiting vehicles are focused on the bottleneck zone. The capacity is decreasing with shorter buffer lane. Furthermore, lane-changing vehicles are mainly in the adjustment zone and the capacity hold the line with longer buffer lane. The proposed model shows its promise for the design optimization of buffer lane.