Review of Freeway On-Ramp Metering Control Methods

To alleviate traffic congestion and improve freeway operation efficiency, advanced technologies are proposed. On-ramp control is one of the most effective methods to realize the efficient management of the highway. This paper first describes several widely used management and control technologies and then focuses on the basic control principles, advantages, and disadvantages of the most attractive on-ramp control algorithms, such as local ramp control algorithm, cooperative ramp control algorithm, competitive ramp control algorithm, and integrated ramp control algorithm. Finally, based on summarizing the existing ramp control algorithms, the future research direction of the on-ramp control method is analyzed and prospected.