A Place d'Étoile aerial image from the 1940s or 50s showing the lack of lanes, and a small percentage of the traffic you'd encounter there now. Imagine how many cars you can fit into that circle, leading to or fro 12 avenues, and you get the idea.
In July of 2007, The Seattle Times reported that the neighborhood upper Rainier Beach would be getting 2 roundabouts at the intersection of 51st South, Renton- and Roxbury Avenues. The traffic was and still is controlled by stop signs. According to the article in The Times the City Council voted 7-1 despite Council member Richard McIver's view that they are "about the most ridiculous expenditure I've ever seen." This while the city counted 60 collisions in that triangle in 2000. And I'm sure it hasn't got any better. We pass by there every day and it is impressive that we've never encountered a pile-up at a spot where three busy streets meet, showing a total of 6 stop signs.
The projected time of completion of the double roundabout is 2010.
In order to educate citizens the City of Olympia and the City of Lacey have created an excellent film on how to approach and drive on a roundabout.
To my great surprise (experienced) cyclists are permitted to use the same roundabout as the cars and trucks. In the Netherlands, you'd find a bicycle path around the pavement for automated traffic. To allow cyclists inside the roundabout is asking for trouble.
Watching the film made me think of the first time that I had to navigate roundabout of the Arc de Triomphe in Paris in 1983 or so. At the Place d'Étoile roundabout, which circles the Arc de Triomphe, twelve avenues meet! I recall going around three times before I was prepared to take the correct exit. The second time I almost made it, but a "gendarme" a French police officer who braved the traffic and stood in the middle of (not existing) "lanes" blew his whistle at me. Knitting his eyebrows and waving his "batton" in the air, threatening to bang on the hood of my vehicle, he ordered me to go around once more! I remember this happened right before lunch time, and that my blood sugar dropped like a brick from the Eiffel Tower.
So the prospect of a double roundabout in upper Rainier Beach won't faze me, but I do worry about the cyclists in Lacey and Olympia.