Interesting article about roundabouts. I have often wondered why they are so popular in England, but so rare in the US. Instead of a stop light or stop sign, traffic interections in England are often one way rotaries, or roundabouts. Traffic does not have to stop, but proceeds slowly around the rotary until they reach their exit.
The system requires drivers to slow down to navigate the roundabout, but does not require a stop unless traffic warrants. Fatal fatalities are probably reduced - someone missing a stop sign or stop light can create a dangerous high speed crash with both cars traversing the intersetion at high speed. The slow speeds required by the roundabout probably reduces high speed crashes. But there may be more fender benders.
My observations in Europe is that they work best in low traffic areas. They are confusing and difficult when traffic heavy.