摘 要：目前环形交叉口信号设置信号的依据和标准均是通过建立微观的交通模型所得到，复杂的模型标定和计算导致这些方法所得数据信息的可靠性差，并不适用于实际情况。为此，本文直接利用环形交叉口实际采集的内、外环道车流车头时距及车头时距之差，采用模糊C-均值聚类方法对环形交叉口交通运行状态进行判别，根据判别结果，为交通管理者提供信号控制的时段依据。最后，本文采用VISSIM仿真对文章提出的方法进行有效性验证，结果表明，该方法能够准确的判别环形交叉口的交通运行状态，为交通管理者提供可靠的信号控制依据。

Abstract: The main intersection signal setting standard and basis are obtained through the establishment of microscopic traffic model, but the complexity of model calibration and calculation result in poor reliability of the data information, so it does not apply to the actual situation. Therefore, this paper directly using the data of the actual collection, the FCM( Fuzzy C-Means) clustering method is adopted to identify the roundabouts traffic state according to the headway changes inner and outer ring road traffic flow to provide the time basis of signal control for traffic managers. Finally, the method is verified on the VISSIM platform. The results show that the method can accurately distinguish the running state of the intersection traffic, provide reliable signal control basis for traffic management.