Answer
The list below describes the safety of single-lane roundabouts, multiple-lane roundabouts, and turbo roundabouts:
- Single-lane roundabout. Four-legged, single-lane roundabouts are safer than four-legged intersections. Their safety is due to the lower number of conflict points, speed restriction for all traffic flows and the difference in entry and impact angles [9].
- Multi-lane roundabouts. These are less safe than single-lane roundabouts, but still safer than other types of intersection [22]. Multi-lane roundabouts are less safe because they have a larger number of conflict points, they are more complex, driving speed is higher, and they have a less sharp entry angle [23].
- Turbo roundabouts (with or without raised lane separators). The road safety effect of turbo roundabouts is almost identical to that of single-lane roundabouts, provided the data are corrected for traffic volume [9]. Converting conventional intersections to single-lane roundabouts (68,1% - 78,7% crash rate reduction) and to turbo roundabouts (76,1% crash rate reduction) generates almost equal road safety benefits [23] [24].
