Road safety effects of roundabouts: A meta-analysis
Journal article, Peer reviewed
MetadataShow full item record
Original versionAccident Analysis and Prevention. 2017, 99 (February), 364-371. 10.1016/j.aap.2016.12.018
This paper presents a meta-analysis of the road safety effects of converting junctions to roundabouts. 44 studies containing a total of 154 estimates of effect were included. Based on a meta-regression analysis, converting junctions to roundabouts is associated with a reduction of fatal accidents of about 65% and a reduction of injury accidents of about 40%. The mean effect on property-damage-only accidents is ambiguous. Summary estimates of effect are robust for fatal and injury accidents, but vary depending on the model of meta-analysis and the treatment of outlying data points for property-damage-only accidents. A trim-and-fill analysis suggests a weak tendency for publication bias, with modest influence on summary estimates of effect. It is concluded that roundabouts are very effective in reducing traffic fatalities.