Effects of the Number of Lanes on Traffic Characteristics: A Simulation Study

This paper attempts to investigate the impact of the number of lanes on freeway traffic characteristics. Methodologically, we provide a better understanding of the relationship between freeway traffic characteristics and its number of lanes upon the simulation method. An improved lane-changing model based on the Nagatani's method is proposed. Both the lane-changing process and the impact of the lane-changing vehicle on the adjacent vehicles are incorporated into the proposed model. The marginal decrease of lane capacity with the number of lanes is analyzed and validated upon the proposed lane-changing model. Moreover, the simulated results show that, the change of lane-changing activity and its associated disturbance to traffic stream causes significant differences among traffic characteristics on different-lane freeways. The results of the researches are the background support that tends to revise the highway capacity manuals, optimize planning and design of road network, and improve supervision and control of traffic network.