Modern roundabouts are the safest form of intersection in the world - the intersection type with the lowest risk of fatal or serious injury crashes - (much more so than comparable signals).  Visit the Insurance Institute for Highway Safety for modern roundabout FAQs and safety facts.  Modern roundabouts, and the pedestrian refuge islands approaching them, are two of nine proven safety measures identified by the FHWA.
https://safety.fhwa.dot.gov/intersection/innovative/roundabouts/