Can anyone think of an example of this? I can't.
Does something like this counts?
https://www.google.com/maps/@41.1011794,-81.4421144,356m/data=!3m1!1e3
Not exactly a roundabout, but close
How about the Wantagh Parkway/Ocean Parkway traffic circle at Jones Beach on Long Island?
It's not unusual in my area. Here's one example: https://www.google.com/maps/@41.7087878,-86.2278934,171m/data=!3m1!1e3?hl=en (https://www.google.com/maps/@41.7087878,-86.2278934,171m/data=!3m1!1e3?hl=en)
Another on the same road: https://www.google.com/maps/@41.7093168,-86.2343406,171m/data=!3m1!1e3?hl=en (https://www.google.com/maps/@41.7093168,-86.2343406,171m/data=!3m1!1e3?hl=en)
If somebody wants to look at the Carmel, Indiana area, you should find a ton of them.
The Los Alamitos Circle in Long Beach - PCH (CA-1), Lakewood Boulevard (former CA-19) and Los Coyotes Diagonal are all six lanes.
Do you mean four entry lanes, like this?
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FyxKCyqu.png&hash=05222bc9fbaf71c4e9699ca35289590051c9678d)
If so, the Los Alamitos Roundabout in Long Beach (post above mine) is the only one I can readily think of. There are roundabouts in the midwest where the slip lane + entry leg = four or even five lanes, but four uninterrupted lanes, without some sort of channelizing island, is pretty well unheard of.
Quote from: theline on October 11, 2016, 10:56:23 PM
Another on the same road: https://www.google.com/maps/@41.7093168,-86.2343406,171m/data=!3m1!1e3?hl=en (https://www.google.com/maps/@41.7093168,-86.2343406,171m/data=!3m1!1e3?hl=en)
If somebody wants to look at the Carmel, Indiana area, you should find a ton of them.
If that's what the OP was talking about, tradephoric could provides pages of examples. They are extremely common. I would think what Jackroot provided is what would be the objective here.
Quote from: jakeroot on October 12, 2016, 01:24:45 AM
Do you mean four entry lanes, like this?
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FyxKCyqu.png&hash=05222bc9fbaf71c4e9699ca35289590051c9678d)
If so, the Los Alamitos Roundabout in Long Beach (post above mine) is the only one I can readily think of. There are roundabouts in the midwest where the slip lane + entry leg = four or even five lanes, but four uninterrupted lanes, without some sort of channelizing island, is pretty well unheard of.
Well I meant 2-3 entry lanes or more but that's sufficient!
Quote from: jeffandnicole on October 12, 2016, 08:06:02 AM
Jackroot
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.huffpost.com%2Fgen%2F2164964%2Fthumbs%2Fo-SAMUEL-570.jpg&hash=45750ee40ca7e33a94335493723eb0b5b16f5813)
ya carmel has a ton of these, just look at hazel dell pkwy and towne rd and illinois st.
Quote from: jakeroot on October 12, 2016, 12:52:01 PM
Quote from: jeffandnicole on October 12, 2016, 08:06:02 AM
Jackroot
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.huffpost.com%2Fgen%2F2164964%2Fthumbs%2Fo-SAMUEL-570.jpg&hash=45750ee40ca7e33a94335493723eb0b5b16f5813)
I blame spellcheck.
Here are some of the highest capacity roundabouts in USA and Canada (both proposed and existing):
Homer Watson roundabout (Kitchener, Ontario)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2FHomerWatson_zpsh3iapb1j.png&hash=44bce6fa15fe43f1dc42dcf4e85222fa0783c10a)
265/62 (Jeffersonville, Indiana):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2FRBIND_zpsuy1rfrld.png&hash=76ddf2763559b2ad4b5b8ef6048e7bc918375e40)
50/60 (Lakeville, MN)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2Flakeville_zpstd2gshqg.jpg&hash=c452db7187e51bd47a9b504ce2097924d8784df1)
Cony Circle, Maine
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2F15Untitled_zpsl7d1abyq.png&hash=81041420d44b5d8780fda89588bb25df415a8e94)
14 Mile & Orchard Lake (West Bloomfield, Michigan):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2FOrchRB_zpsgkylg3ca.png&hash=6be3ad490ad353e925b626f371e4cbd45eeba585)
M-5 & Pontiac Trail (Commerce, Michigan):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2FFOAQ274_zpsuw156c0o.png&hash=a5e472095a6331644ea9a5b3ab98f3a6fd0f1d97)
Northland & Richmond (Appleton, Wisconson):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2Froundabout20140723_zpsww4fqgep.jpg&hash=98bb1d09bedb197313ba59939c6204408e2b0f28)
State & Ellsworth (Ann Arbor, Michigan):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2FAnnArbor_zpsg9i7s1rq.png&hash=d6251921db83e4a3a9fae51eb66e41a945c04dda)
161/Riverside (Dublin, Ohio):
(https://mgtvwcmh.files.wordpress.com/2016/08/roundabout.jpg?w=650)
Lee Road roundabout (Brighton, Michigan):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2Froundabout_double_zps5g1j0uxh.jpg&hash=fda51a04115e022949c5e6fed1baa0c501c53e9d)
Taylor Street & Shawano Ave (Green Bay, Wisconsin):
(https://i.ytimg.com/vi/-h6StKOWVGU/maxresdefault.jpg)
Roundabouts near downtown Neenah, Wisconsin:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fc.ymcdn.com%2Fsites%2Fwww.acecwi.org%2Fresource%2Fresmgr%2Fimported%2FNeenah_Large.PNG&hash=69b6bc46cfcae1b9861b964115d14e3a4577dd94)
Think this is a proposed roundabout out of Wisconsin. not sure what intersection:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi478.photobucket.com%2Falbums%2Frr144%2Ftradephoric%2FTransportation%2520Pictures%2FRoundabouts%2FUntitledWisc_zpskozmbadz.png&hash=37a462699804bab45dbdb0aa8f2109b189f45227)
Smith Valley Road and Madison Avenue (Greenwood, Indiana):
(https://lintvwish.files.wordpress.com/2016/07/greenwood-roundabout.jpg)
^^ That's petty cool.
I guess the real question is, how do these handle high volumes of traffic? AADT 15k-30k for example.
Typically higher than that. I recall reading that the theoretical capacity of a single lane roundabout is around 20-22K vehicles per day. A multilane roundabout, of course, would have a higher capacity than your 15-30K range.
Since when was 15k 'high volumes'? All of the roundabouts near me (that aren't just some paint on the pavement) have more than two arms with higher traffic counts than 15k.
A roundabout with an AADT of 30k (add up all the arms, divide by two) seems to be fairly run-of-the-mill here. They might get short tailbacks at peak times, but normally the problem is somewhere else and just happens to gum up the roundabout. With the exception of this one (https://www.google.co.uk/maps/@51.6023826,-0.6321014,299m/data=!3m1!1e3) that is tiny, has nearly 40k use it each day (including an arm with 30k on it, that only has one lane heading away from the roundabout), but even there the problem is more that people block the arms of the roundabout stopping and parking up, or turning off a side turn and the lack of capacity on the approaches/exits than capacity at the roundabout.
The larger roundabout to the east (https://www.google.co.uk/maps/@51.6016737,-0.6244007,433m/data=!3m1!1e3) has something like 45k AADT and functions perfectly well.
Quote from: Buffaboy on October 13, 2016, 12:51:16 AM
^^ That's petty cool.
I guess the real question is, how do these handle high volumes of traffic? AADT 15k-30k for example.
That last one is going to function as a michigan left for smith valley road (the east west street) only.