Roundabouts in general have a favourable effect on traffic safety, at least for crashes causing injuries. A meta-analysis on 28 studies in 8 different countries revealed a best estimate of a reduction of injury crashes of 30-50%. Other studies delivered similar results. All those studies reported a considerably stronger decrease in the number of severest crashes (fatalities and crashes involving serious injuries) compared to the decrease of the total number of injury crashes. Less is known about the safety effects of roundabouts for particular types of road users, such as bicyclists. Roundabouts seem to induce a higher number of bicyclist-involved crashes than might be expected from the presence of bicycles in overall traffic. In Flanders-Belgium bicyclists appear to be involved in almost one third of reported injury crashes at roundabouts while generally only 14.6% of all trips (5.7% of distances) are made by bicycle. The apparent overrepresentation of bicyclists in crashes at roundabouts was the main cause to conduct an evaluation study on the effects of roundabouts, more specifically on crashes involving bicyclists. (Author/publisher)
Samenvatting