Department of Geography and Environmental Management, University of Waterloo, 200 University Ave West, Waterloo N2L 3G1, Canada.
J Safety Res. 2018 Sep;66:151-159. doi: 10.1016/j.jsr.2018.07.001. Epub 2018 Jul 17.
Roundabouts, as a form of intersection traffic control, are being constructed increasingly because of their promise to improve both efficiency and safety. However, roundabout performance varies from one context to another; and information on their performance during inclement weather is limited.
To evaluate the safety effects of converting signal-controlled intersections to modern roundabouts in a region that historically was unfamiliar with this type of traffic control, an empirical Bayes approach was used to analyze. Second, to examine the potential effects of rainfall on roundabout safety, a matched-pair approach was used to compare risk estimates of collision occurrence at roundabouts and signalized intersections under inclement weather conditions.
Roundabout installation is shown as an effective safety intervention for serious collisions since conversion from signalized intersections to roundabouts translates into an overall 20% reduction in the occurrence of injury/fatal collisions. However, roundabouts witnessed more property-damage collisions than what would have been expected had the conversion not occurred. With respect to weather, there is no evidence of a statistically significant increase in crashes on days with rainfall relative to good weather conditions for roundabouts, whereas there is evidence of such an increase in crash risk estimated to be 4% to 22% for signalized intersections.
While injury collisions are consistently found to be lower at intersections that have been converted from signalized intersections to roundabouts, the same is not always that case for property-damage collisions, suggesting that drivers need time to adjust. In terms of weather, the evidence in this paper shows that roundabouts show less sensitivity to rainy conditions than signalized intersections.
The trade-offs between design, operation, and safety should be considered carefully when planning a new roundabout. More research is required on the specific problems users experience with roundabouts and the effectiveness of public education programs.
环岛作为一种交叉口交通控制形式，由于其提高效率和安全性的承诺，正在越来越多地被建设。然而，环岛的性能因环境而异；关于恶劣天气下其性能的信息有限。
为了评估在一个历史上不熟悉这种交通控制形式的地区将信号控制交叉口转换为现代环岛的安全效果，使用经验贝叶斯方法进行分析。其次，为了研究降雨对环岛安全的潜在影响，使用配对方法比较恶劣天气条件下环岛和信号交叉口碰撞发生的风险估计。
环岛的安装被证明是一种有效的安全干预措施，因为从信号交叉口转换为环岛可将严重碰撞的发生率总体降低 20%。然而，环岛发生的财产损失碰撞比没有发生转换时预计的要多。就天气而言，没有证据表明环岛在雨天发生碰撞的风险相对于良好天气条件有统计学意义上的增加，而对于信号交叉口，有证据表明这种碰撞风险增加了 4%至 22%。
虽然在从信号交叉口转换为环岛的交叉口，受伤碰撞始终较低，但对于财产损失碰撞情况并非总是如此，这表明驾驶员需要时间来适应。就天气而言，本文中的证据表明，环岛对雨天条件的敏感性低于信号交叉口。
在规划新环岛时，应仔细考虑设计、运营和安全之间的权衡。需要对用户在环岛遇到的具体问题以及公众教育计划的有效性进行更多研究。
