Abstract: As a special road intersection, roundabouts have the advantages of high safety and few conflict points. Through the microscopic simulation of the roundabout, the traffic capacity of the intersection after different improvement measures can be effectively calculated. In this paper, VISSIM simulation software is used to simulate the traffic capacity of roundabouts. Taking two specific cases as examples, the traffic capacity of roundabouts under two different signal control schemes: no signal-controlled roundabout and signal-controlled roundabout are studied. The results showed that the traffic capacity decreased after signal control was applied to the three-entry single loop roundabout; the traffic capacity was improved significantly after signal control was applied to the four-entry multi-loop roundabout.

Key words: Roundabout; Traffic capacity; VISSIM simulation; Signal control

摘要： 作为一种特殊的道路平面交叉口，环形交叉口具有安全性高、冲突点少等优点。通过 对环形交叉口进行微观仿真，能有效计算采用不同改进措施后交叉口的通行能力。文章采用 VISSIM 仿真软件对环形交叉口通行能力进行仿真研究，以两个具体案例为例，对无信控环岛、 有信控环岛两种不同信号控制方案下的环形交叉口通行能力进行研究。结果发现，对三出入 口单环道环形交叉口施加信号控制后其通行能力反而下降；对四出入口多环道环形交叉口施 加信号控制后其通行能力提升效果显著。

关键词: 环形交叉口；通行能力；VISSIM 仿真；信号控制