ABSTRACT

As roundabouts become increasingly popular, and as many communities promote bicycle use, the safety of roundabouts for people bicycling is of major concern. Although converting an intersection to a roundabout may reduce crashes overall, some research from northern Europe suggests that roundabouts may actually increase the frequency of bicycle crashes. We perform a systematic literature review on this topic, reviewing 49 different resources with empirical findings (most from Europe, some from Australia/New Zealand, few from the US). Many studies analyse (limited) bicycle crash data or observe driver/cyclist behaviours and interactions, while a few survey cyclists’ safety perceptions. Consistent with design guidance, bicycle safety performance is worse for higher-speed, multilane roundabouts and when on-roadway bike lanes are provided. Crash data and observations suggest that when cyclists “take the lane” and operate as vehicles – as is allowed or even recommended in some current design guidelines – this leads to conflicts and crashes between circulating cyclists and entering drivers who may have “looked but failed to see” (and thus failed to yield to) the cyclist. Providing separated cycle paths around the roundabout seems to be a lower-risk and more comfortable design solution, although care must be taken to encourage appropriate yielding at crossings. Future research should investigate more design features, socio-demographic characteristics, cyclist safety perceptions, and impacts outside of Europe. Studies should continue to explore ways to overcome limited bicycle crash and exposure data and to utilise naturalistic methods, driving simulators, and stated choice experiments.

摘要

随着环岛变得越来越流行，并且随着许多社区提倡使用自行车，人们骑自行车的环岛安全是一个主要问题。尽管将交叉路口改成环形交叉路口可能会总体上减少碰撞事故，但来自北欧的一些研究表明，环形交叉路口实际上可能会增加自行车碰撞的频率。我们对这个主题进行了系统的文献回顾，回顾了 49 种不同的资源和实证结果（大多数来自欧洲，一些来自澳大利亚/新西兰，少数来自美国）。许多研究分析（有限的）自行车碰撞数据或观察驾驶员/骑自行车者的行为和互动，同时也有一些调查骑自行车者的安全认知。与设计指南一致，在高速、多车道环形交叉路口以及提供公路自行车道时，自行车安全性能较差。碰撞数据和观察表明，当骑自行车的人“走车道”并作为车辆行驶时——这是允许的，甚至在一些当前设计指南中推荐的——这会导致循环的自行车手和进入的司机之间发生冲突和碰撞，他们可能“看起来但没有看到”（因此未能屈服）骑自行车的人。在环岛周围提供单独的自行车道似乎是一种风险较低且更舒适的设计解决方案，但必须注意鼓励在交叉路口适当让行。未来的研究应该调查更多的设计特征、社会人口特征、骑自行车者的安全观念以及欧洲以外的影响。研究应继续探索克服有限的自行车碰撞和暴露数据的方法，并利用自然主义方法、驾驶模拟器和陈述选择实验。