The main aim of the research project was a safety analysis of single-lane roundabouts in build up areas. These roundabouts must have been constructed according to current guidelines for roundabouts in Germany. Furthermore, a critical analysis of the current design standards for pedestrians and cyclists at roundabouts had to be done.For the analysis of local accidents 100 roundabouts in different parts of Germany with different conditions (traffic volumes, pedestrian and cycle traffic, location parameters) were chosen. The traffic volume of the chosen roundabouts ranges from 5.000 vehicles/24 h up to 25.000 vehicles/24 h. A third of the roundabouts show a particularly high cycle traffic volume from more than 1.200 cyclists per 24 h. The analysis was based on police accident reports in the 2008 - 2010 period. For the given database the accident statistics were calculated. For the investigation the roundabouts were differentiated into four categories according to the facilities for cyclists (mixed traffic, separate cycle path with or without priority).On ten selected roundabouts a detailed analysis of the traffic flow based on a several hour video record took place. In the process typical behavioral patterns of traffic participants were studied. (Author/publisher)
Abstract