城市快速路入口匝道控制研究综述

入口匝道控制是城市快速路交通缓堵的重要手段。为全面了解其研究现状及发展趋势，回顾了入口匝道控制自提出以来近60 年的发展历程，系统梳理了入口匝道控制逻辑与类别，聚焦入口匝道控制的方法论演进。 研究发现： 入口匝道控制范围从局部最优向全局最优发展；入口匝道控制对象由宏观交通流控制向微观车辆控制发展；入口匝道控制的建模方法从确定、均质和静态等模型假设向考虑交通流随机性、异质性和动态性方向发展；入口匝道控制的求解方法分为数学推导和搜索算法两类，在收敛性和普适性方面各具优势。最后，分析了入口匝道控制研究现状，并指出了未来4 个重要研究方向，包括宏观与微观交通流协同控制、入口匝道控制的抗干扰与自恢复能力提升、大规模快速路网控制的高效可靠求解，以及网联环境下的智能控制技术实现。

A review of ramp metering for urban expressway

Ramp metering is one of the most important measures to alleviate congestion for urban expressway traffic. For comprehensive understanding of the cutting-edge research on ramp metering and exploring its development trend, this paper reviewed the development of ramp metering over the last 60 years since it was initially proposed, summarized the control logic and classification of ramp metering, and focused on the evolution of ramp metering control methodology. Research has found that: the control scope of ramp metering develops from local optimum to global optimum; the control object of ramp metering develops from macroscopic traffic flow control to microscopic vehicle control; the model formulation of ramp metering evolves from deterministic, homogenous and static modeling with strong assumptions to stochastic, heterogenous and dynamic modeling; the solution methods of ramp metering include mathematical derivation and search algorithms, which have advantages in terms of convergence and applicability, respectively. Finally, this paper analyzed current researches on ramp metering and recommended four future research directions, including coordinated macroscopic and microscopic traffic flow control, robust and resilient ramp metering, efficient and reliable solution to large-scale control problems, and implementation of intelligent control technology in connected environments.