Round and Round We Go - 3 Multi-Cache

Many studies have found that roundabouts are safer than other types of intersections. In particular, U.S. studies found that single-lane roundabouts are safer than two-way stop-controlled intersections. Although there may be just as many or more reported crashes, typically there are fewer injuries. Small and medium roundabouts typically are safer than large or multilane roundabouts. Studies show safety improvements are most pronounced for motorists, less pronounced for pedestrians, and mixed for cyclists.

Why do roundabouts have such a good safety record?

1. Fewer Conflicts. Roundabouts have fewer conflict points compared to conventional intersections. Roundabouts eliminate the potential for hazardous conflicts such as right-angle and left-turn head-on crashes. Roundabouts with single-lane approaches are safer than those with multilane approaches because of fewer potential conflicts between road users, and because pedestrian crossing distances are shorter.

2. Slower and more consistent speeds. Lower speeds in roundabouts allow drivers more time to react to potential conflicts, helping to make roundabouts safer. Most motorists travel at about the same speed through a roundabout, and that helps to reduce the crash severity compared to conventional intersections that mix slow and fast traffic.

3. Pedestrians cross one direction of traffic at a time. Pedestrians need only cross one direction of traffic at a time at each approach as they walk around a roundabout, compared with two-way traffic at most conventional intersections. There are just as many potential conflicts between vehicles and pedestrians at a roundabout compared to a conventional intersection, but at a roundabout the traffic all comes from the same direction where at a conventional intersection the pedestrian has to watch for traffic from all directions. In addition, motorists travel slower entering and exiting a roundabout compared to a conventional intersection. As with other road crossings where the pedestrian has to watch for a gap in traffic, roundabouts still present visually-impaired pedestrians with unique challenges.

That said, roundabouts are not always safer than other alternatives:

• For multilane roundabouts, some international studies found cycling safety at roundabouts to be poorer than at other intersections unless separate cycling or multi-use paths are provided around the outside of the roundabout.
  
  
• Pedestrians, especially visually impaired or blind pedestrians, can have difficulty when trying to judge gaps in traffic across entries or exits with more than one lane.