Review and Outlook of Roundabout Capacity

Capacity is an important part of the operation efficiency at roundabouts. Through analyzing existing capacity models of roundabout, this paper focuses on the problem research principles and methods such as empirical regression model, gap acceptance model and model based on simulation software. The key technologies of modeling are also analyzed. Then the general approaches of modeling roundabout capacity are proposed, combined with some problems easily overlooked in previous study. Determining the interaction mechanism among each traffic flow and considering the significant impact factors, the capacity model is established on the whole. Finally, combing with the control objectives of roundabouts, an outlook is proposed for future studies on roundabout capacity.

摘要通行能力是环形交叉口运行效率的重要组成部分，是分析延误、排队长度及系统服务水平的基础.首先对现有的环形交叉口通行能力模型进行分析总结，如经验回归模型、间隙接受模型，以及基于仿真的通行能力模型等；从研究方法和研究思路两个层面对问题现状进行探讨，并对关键技术方法进行分析.结合研究中易忽略的问题，提出了环形交叉口通行能力模型构建的一般思路：明晰各股车流相互作用机理，考虑出口车辆及大车等影响因素，从整体上构建通行能力模型.最后结合环形交叉口的控制目标，对环形交叉口通行能力的研究进行了展望.