Cooperative Control Method of Ramps Based on Proportional Homogenization of Vehicle Numbers in Multiple Areas

Abstract

The highway exit ramp is an important connection area between highways and downstream urban roads. However, exit ramps are often underutilized and unable to regulate traffic flow, which can lead to congestion on the highway and downstream urban roads. To fully exploit the real-time regulatory capabilities of exit ramps, minimize average vehicle delay time, and enhance utilization efficiency of road traffic, this work proposes a collaborative control approach based on the proportional equalization of the number of vehicles in each region. Multiple relevant areas were selected, including the exit ramp area of the expressway, the upstream expressway mainline, the downstream urban connecting road, toll stations, and toll plazas. The traffic flow influencing factors in each area were analyzed. With the optimization objectives of minimizing the average vehicle travel time and maximizing the number of vehicles passing through per unit time, and taking into account constraints such as dynamic speed limits and vehicle delays, a multiarea collaborative control model was established. Taking the typical expressway exit ramps in Huangshan City as the research object, the application effect of the regulation model was verified. The results show that, compared to the SUMO software (vehicle Krauss following model), and LC2013 lane-changing model, the method proposed in this paper significantly reduces the average vehicle passage time in the exit ramp area and increases the maximum number of vehicles passing per hour at different traffic flow ratios. When the traffic flow ratio is 0.45, the optimization effect is most significant, with an average vehicle passage time reduction of 14.08% and a 13.98% increase in the maximum number of vehicles passing per hour. The research results can be effectively applied to traffic flow regulation in highway exit ramp areas and related areas, improving the quality of traffic operation.