[jdeisenberg]

Having looked at some of the links in the article, I just realized that one extra feature of roundabouts is that they allow U-turns (which is not always the case at an intersection).

[harperlee]

They even allow you to do a couple turns until you decide next action (although my wife hates it).

[o11c]

Not always - teardrop-shaped roundabouts do exist - but those usually come in pairs (and often involve some one-way-roads) anyway.