Modern roundabouts in America

[jeffandnicole]

 

Out of all of these, I only think that the US 130 circle (last picture) is a roundabout - the others I can't tell whether they would be classified as a rotary or a traffic circle.

That last one at US 130 and NJ 47 is not a roundabout - note that entering traffic has right-of-way in two places.

The 130/47 Brooklawn circle is as far away from the definition of a roundabout that one can get.  Not only does 4 roads directly enter the circle; not only does traffic within the circle yield to those entering the circle in two locations, but there's these other differences:

This circle was built 60 years or so ago if not longer.  The first modern roundabout appeared in the US in 1990.

There is no stripping to denote lanes within the circle.  That in itself isn't absolutely proof of a roundabout, but is frequently found within a roundabout.

There are numerous driveways that lead into and out of the circle directly.  I believe I estimated about 6 driveways that one can enter or exit into the circle, along with the 4 enterences & 4 exits using the main roads.  And this doesn't even count the low curbing where people can easily drive over as well.

Creek Rd.  A modern roundabout would never have an intersecting road so close to a roundabout that isn't technically part of a roundabout.  This issue is supposed to be worked on in 2014.

Size.  Modern roundabouts would fit in the inner part of most Jersey traffic circles.

No but seriously, I think I'll continue to call them circles, seeing as how that's how New Jersey refers to them:

You're still a bit confused about the terminology.  NJ calls their traffic circles circles, and their roundabouts roundabouts.  A modern roundabout, such as this one in Glassboro (http://goo.gl/maps/2VEmy), or this cluster in the Gloucester/Sickleville area (http://goo.gl/maps/NTmcv), are true roundabouts.

[Zeffy]

No but seriously, I think I'll continue to call them circles, seeing as how that's how New Jersey refers to them:

You're still a bit confused about the terminology.  NJ calls their traffic circles circles, and their roundabouts roundabouts.  A modern roundabout, such as this one in Glassboro (http://goo.gl/maps/2VEmy), or this cluster in the Gloucester/Sickleville area (http://goo.gl/maps/NTmcv), are true roundabouts.

When I said "them" I was referring to rotaries and traffic circles, while excluding roundabouts. Though I do appreciate you explaining the key differences between circles / roundabouts in a clear and concise matter. Sorry if I'm a bit slow on the subject. 

[english si]

Mini-roundabout (circular island transversable)

Are there any in the US?

[NE2]

Mini-roundabout (circular island transversable)

Are there any in the US?

Here's one (at least if you ignore the stop sign): http://maps.google.com/maps?ll=28.423335,-81.410472&spn=0.015304,0.028346&gl=us&t=m&z=16&layer=c&cbll=28.423328,-81.410575&panoid=YzvwgDKggVqDdgBfyFJj-A&cbp=12,96.14,,0,11.22
Not coincidentally, this area gets a lot of truck traffic.

[tradephoric]

Here's a few examples of mini-roundabouts:
https://maps.google.com/?ll=39.215998,-76.810977&spn=0.000421,0.000603&t=h&z=21&layer=c&cbll=39.215998,-76.810977&panoid=rOhOkL-a7DGPMaPMNapO9Q&cbp=12,92.81,,0,8.21

https://maps.google.com/?ll=42.647441,-84.642697&spn=0.000565,0.000603&t=h&z=21

https://maps.google.com/?ll=47.513704,-122.347619&spn=0.000734,0.001206&t=h&z=20&layer=c&cbll=47.513612,-122.347699&panoid=ioEzeiU-bZaTLyEh60V72g&cbp=12,3.13,,0,0.9

[hm insulators]

PS: if it goes in and around a lake it's a roundabout.

But will it go 'round in circles?

[lordsutch]

You're missing a couple in Central Georgia:

32°48'51.87"N,  83°43'57.55"W
32°36'52.63"N,  83°36'30.51"W

Also, three under construction/proposed at:

32°51'6.15"N,  83°47'6.71"W (under construction)
32°36'47.04"N,  83°36'12.95"W (under construction)
32°36'47.52"N,  83°36'32.41"W (survey stakes down, likely to be built in spring)

[Tarkus]

PS: if it goes in and around a lake it's a roundabout.

But only if mountains come out of the sky, and they stand there.

[tradephoric]

The modern roundabouts added to the KMZ pretty much satisfy these 3 simple conditions:

#1.   Central island diameter (including the width of the truck apron if it exists) is between 50-200 feet.
#2.   Raised splitter islands are included for all major approaches (or have painted splitter islands at the very least).
#3.   Drivers must slow down before entering the circle (a driver should not be able to drive straight through the circle).

Here are some examples of circles that I wouldn't consider modern roundabouts because they fail to satisfy at least one of the conditions:

Satisfies #1 & #2, but doesn't satisfy #3 (Not a modern roundabout)


Satisfies #2 & #3, but doesn't satisfy #1 (Not a modern roundabout)


Satisfied #1 & #3, but doesn't satisfy #2 (Not a modern roundabout)

The submissions to this thread are very much appreciated.   Following these conditions should weed out a lot of the circles that really aren't modern roundabouts.

[1995hoo]

The modern roundabouts added to the KMZ pretty much satisfy these 3 simple conditions:

#1.   Central island diameter (including the width of the truck apron if it exists) is between 50-200 feet.
#2.   Raised splitter islands are included for all major approaches (or have painted splitter islands at the very least).
#3.   Drivers must slow down before entering the circle (a driver should not be able to drive straight through the circle).

Here are some examples of circles that I wouldn't consider modern roundabouts because they fail to satisfy at least one of the conditions:

Satisfies #1 & #2, but doesn't satisfy #3 (Not a modern roundabout)

....

I agree with you about this one not being a modern roundabout, although if you want to be technical about it, the driver following the highlighted route has to come to a stop because there is a very annoying stop sign at that entrance (I go through there fairly frequently). I suppose, though, you could validly say "a driver CAN traverse it without slowing down, it's just that he MAY NOT do so legally"–in other words, but for an artificial constraint (the stop sign) a driver going north could blow through without slowing.

[empirestate]

I wouldn't count the one in Caledonia, NY as a modern roundabout, though it does appear to have been painted to operate as one since my last visit. But its physical layout is what it's always been, your typical monument-in-the-middle-of-an-intersection-at-the-center-of-town sort of deal.

(Unless, that is, it's been further reconfigured since both my and StreetView's last visits.)