文章编号：1672-5328（2011）06-0028-06

吴　杰，韩宝睿，沈颖洁，刘思思
（南京林业大学汽车与交通工程学院，江苏 南京 210037）

摘要：在环形交叉口增加信号控制设备对改善交叉口拥堵和混乱有积极意义，但会导致车辆行驶不连续。针对这一问题，探讨既可保障连续行车又可适应各进口道流量变化、提高环形交叉口通行能力的方法。利用交织理论模型和间隙–接受理论模型计算不同车道数、不同环行流量下交叉口的通行能力。提出提高环形交叉口通行能力的两个方案：改变环岛半径和平移环岛位置。利用交通仿真技术对不同车道数的环形交叉口进行交通流模拟，分析两个方案的交通适应性。评价分析结果表明：改变环岛半径，可提高高峰时段的通行能力和平峰时段的服务水平；早晚高峰时段将环岛进行相应偏心移动，可为主交通流方向提供更多的车道，从而适应潮汐交通现象。

关键词：交通控制；环形交叉口；通行能力；交通仿真；环岛半径；偏心环岛

中图分类号：U412.35

文献标识码：A

Improving Roundabout Capacity Using Irregular Geometry

WU Jie, HAN Bao-rui, SHEN Ying-jie, LIU Si-si
(College of Automobile and Traffic Engineering, Nanjing Forestry University, Nanjing Jiangsu 210037)

Abstract：Signal control at a roundabout helps to manage traffic and relive traffic congestion but interrupts vehicles’ continuous flow. To address the problem, this paper researches a methodology to improve roundabout capacity by not providing uninterrupted flow but also accommodating all traffic maneuvers. Based on the weaving and gap acceptance theory, the paper calculates roundabout capacity with different number of lanes and traffic volume. By presenting two scenarios of improving roundabout capacity including changing roundabout radius and shifting the center of roundabout, the paper discusses the applicability of the two scenarios through simulating roundabout with different number of lanes. The evaluation results show that changing roundabout radius can improve the capacity at peak hour and level of service at non-peak hour; while shifting the center of roundabout during morning and afternoon peak hour provides adequate number of lanes for the main traffic flow.

Keywords：traffic control; roundabout; capacity; traffic simulation; roundabout radius; decentered roundabout