Abstract
With an increasing interest in roundabouts developing in Germany, this paper examines the capacity and safety of single- and two-lane roundabouts. The results of studies of German roundabouts are compared with those from Austria and the UK. Using data from German roundabouts capacity formulae are calculated. Capacity is found to be lower than the Austrian and UK formulae predict. Accident rates at German roundabouts are investigated including some before and after comparisons where roundabouts replaced junctions. The general design of roundabouts is discussed including diameter, lane widths, visiblility and pedestrian crosssings. Facilities for bicycles at roundabouts are discussed.