Well, when I said it was a bit outdated, I was, shall we say, understating things a bit. There’s less than 2000 entries in the db, but I’ve seen estimates of about twice that many roundabouts in the US. So it’s quite a bit behind and they’ve disabled user updating it. However, I’ve sent them email with some additions and they made them after a week or so. If you’re really interested, perhaps you could send them info on the roundabouts in your area.
There’s a lot of text there - can you summarize which points lead you to conclude Fresh Pond is not a roundabout?
They view rotaries as an impediment to flow, not a benefit - have you ever merged onto Fresh Pond at 5:30 PM!?
A little more seriously, they make the distinction with rotaries being much larger, and to my point above, detrimental to flow during heavy traffic. So with roundabouts being typically smaller, and rotaries being larger, I hazarded a guess.
What am I, stupid? Hell no! 
But can you imagine what that intersection would look like as a signaled intersection? Probably a lot like the horror half a mile away at Rt 2 and 16.
Thanks, I think I understand your conclusion, but I honestly do think that both of the Fresh Pond rotaries help flow rather than hinder it, plus they’re pretty darn small. So I guess I just come to a different conclusion than you do. Let’s settle our differences with a race from Alewife to Mt Auburn via Fresh Pond!
If you are talking about these rotaries, one of the biggest things I can see missing is the lack of pavement markings inside the circle, and directional arrows before the circle.
A modern roundabout would have the lanes clearly marked. Someone already linked to a perfect example of the modern version, here. There are also pavement markings in advance of the roundabout that tell drivers which lanes go left, straight, and right, and so long as you pay attention to them, no lane changes within the roundabout, either on entry or on exit, are necessary.
One near me that I use sometimes has that problem. No pavement markings in the circle, and worse, coming from the North two lanes are clearly marked as continuing South, but when you get to the other side of the circle, there’s suddenly only one lane. There’s a merge sign, but by the time you get to it, you have to already be merging. And of course because it’s a roundabout, you’ve got a lot of other things to look at, and you’re zigging and zagging as it is, so you don’t see it until you’re right on top of it.
Tsk tsk. Apparently that’s NOT a roundabout and you’re not allowed to call it that. No lane markings, of course.
I believe it fits the definition of a plain-old roundabout, just not a modern one. At least, according to a road engineer I talked to once.
That is a roundabout, at least in official Ann Arbor parlance. It is absolutely not a traffic circle, again in official Ann Arbor parlance. I don’t believe Ann Arbor uses the term “rotary” at all.
It’s six years old, opened in the summer of 2007.
ETYA: Cites for this post and my previous one, in case anyone cares.
No chance. I love Mt Auburn, especially in the fall, but I’m only approaching it via Watertown Square. 