Driving across Wyoming a couple of days ago, I noticed this unusual configuration (https://goo.gl/maps/IvE7d) on I-80 at Exit 209 (Johnson Road) just west of Rawlins. The westbound offramp is two lanes (and is signed as a "two lane exit" (https://goo.gl/maps/rQusq) on a snow emergency sign), but both lanes branch off the single right lane, rather than the common configuration of a dedicated exit-only #3 lane plus the optional #2 lane.
I'll assume that, in practice, the second exit lane is typically used only when the gates are down and I-80 is closed, and traffic simply moves from the left and right through lanes to both exit lanes, even though it isn't striped as such.
Snow emergencies aside, are there any other locations where a two-lane exit branches off a single lane? Is this even technically allowable under the MUTCD?
Incredibly common in England the UK (and other countries), less so here. One example near me (WA-509 at Port of Tacoma Road (http://goo.gl/4uFGKh) near Tacoma, Wash):
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fw4VsMza.png&hash=f86be9f07f216aa22dc8ba64161091fc19619629)
Just today I drove through an example of the opposite situation. On I-20 west of Fort Worth, I-30 exits to the left with three lanes. I-20 approaching the exit has four lanes. The second lane from the right doesn't go to both roads. It's what I call a "hard split," with each lane leading to one road. The right lane divides into two lanes, non-exit lanes carrying the through route. https://www.google.com/lochp?ll=32.725306,-97.580878&spn=0.003064,0.005681&t=k&z=18 (https://www.google.com/lochp?ll=32.725306,-97.580878&spn=0.003064,0.005681&t=k&z=18)
Another opposite situation is in Stephenville, TX, although it doesn't include a true exit. US 67/377 has two northbound lanes, and Business US 377 is straight ahead on both lanes, while US 67/377 "exits" into two lanes. The right lane divides before the "exit" and the short middle northbound lane soft splits, so it isn't a prime example, but it's still interesting. https://www.google.com/lochp?ll=32.20678,-98.231011&spn=0.000766,0.00142&t=k&z=20 (https://www.google.com/lochp?ll=32.20678,-98.231011&spn=0.000766,0.00142&t=k&z=20)
Until last year, there were good examples of this on I-270 either side of the Scioto River south of Columbus. Not only were there two-lane exits without dropped lanes, but two-lane entrances that merged completely into the right mainline lane.
The local drivers have decided that this exit (https://goo.gl/maps/t4KiJ) works that way. The ramp is two lanes wide immediately after exiting, so people regularly split themselves into two queues in the right lane at the gore point (and since the ramp always backs up during rush hours, this of course makes the right lane useless for its also-intended function as a through lane). Unfortunately, none of the Street View vintages shows traffic in its full glory, so you'll have to take my word for it.
As noted previously, Ohio sometimes does it this way. The US 250 split from I-77 at New Philadelphia is the same way. https://goo.gl/maps/86X93
The mainline of I-87 does this: https://www.google.com/maps/@42.6973125,-73.8383047,299m/data=!3m1!1e3
Thanks for all of the links.
Quote from: vdeane on May 03, 2015, 07:03:28 PM
The mainline of I-87 does this: https://www.google.com/maps/@42.6973125,-73.8383047,299m/data=!3m1!1e3
Some of the examples given are in kind of a gray area as to whether they're the same thing as what I described, but if you're referring to the 1W ramp to the toll plaza, then I'd say it's definitely a different setup. There, the right lane is a dedicated exit only lane which then expands to two lanes well after the gore point.
What I'm talking about (and what's shown in the example I linked) is a situation where there's no lane drop, and the striping is such that the right lane has the option of sliding into either of two exit lanes directly from the right through lane.
Quote from: Bitmapped on May 03, 2015, 03:06:44 PM
As noted previously, Ohio sometimes does it this way. The US 250 split from I-77 at New Philadelphia is the same way. https://goo.gl/maps/86X93
This is very close, although it's slightly different from the Wyoming example in that it doesn't have two definite, separate theoretical gores (one for each lane) touching the right hand edge line of the through lane. It's like 3/4 of the way between vdeane's example above (split well after the gore) and the WY example with the two very definite gores.
Quote from: empirestate on May 03, 2015, 11:29:53 AM
The local drivers have decided that this exit (https://goo.gl/maps/t4KiJ) works that way.
Same comment here, although as was pointed out, this has more to do with the way motorists use it rather than how it was striped.
Quote from: wxfree on May 03, 2015, 12:03:12 AM
Just today I drove through an example of the opposite situation....
I think you accidentally gave us the same link twice.
Quote from: jakeroot on May 02, 2015, 11:54:00 PM
One example near me (WA-509 at Port of Tacoma Road (http://goo.gl/4uFGKh) near Tacoma, Wash):
This is almost exactly the same thing–main visual difference is that the striping is less vivid. And there is another slight difference: even though WA 509 appears to be the through route here, it's signed as if it's the exit (a left exit), with the other branch to the right being unsigned. If they do want to treat WA 509 as an "exit" , the leftmost lane should be signed as "Only" .
Quote from: vtk on May 03, 2015, 01:04:46 AM
...but two-lane entrances that merged completely into the right mainline lane.
The NJ Turnpike's PA Extension onto the NJ Turnpike North mainline essentially works this way.
If I assume you are talking about a through lane branching off into a two lane exit, then the Southbound Garden State Parkway at Exit 129 does this.
Edit: It used to do this, I just checked on it and the NJTA widened (well not exactly, but shrunk the size of the travel lanes and shortened the shoulders) the Parkway to five lanes each way, so now this does not count. However it did probably, if that is what the OP is looking for as it was four lanes where one lane became two lanes.
Quote from: briantroutman on May 03, 2015, 07:30:40 PM
I think you accidentally gave us the same link twice.
I did. I'll correct it.
I-94 eastbound at Carmichael Road in Hudson, WI.
Quote from: briantroutman on May 03, 2015, 07:30:40 PM
Quote from: jakeroot on May 02, 2015, 11:54:00 PM
One example near me (WA-509 at Port of Tacoma Road (http://goo.gl/4uFGKh) near Tacoma, Wash):
This is almost exactly the same thing–main visual difference is that the striping is less vivid. And there is another slight difference: even though WA 509 appears to be the through route here, it's signed as if it's the exit (a left exit), with the other branch to the right being unsigned. If they do want to treat WA 509 as an "exit" , the leftmost lane should be signed as "Only" .
I drive the road quite regularly. I assure you, the signs are just fucking horrible WSDOT incompetence. The 509 mainline follows the lane lines shooting to the "left" (if you will).
Quote from: briantroutman on May 03, 2015, 07:30:40 PM
Quote from: empirestate on May 03, 2015, 11:29:53 AM
The local drivers have decided that this exit (https://goo.gl/maps/t4KiJ) works that way.
Same comment here, although as was pointed out, this has more to do with the way motorists use it rather than how it was striped.
That's what I mean. The way it's striped, it isn't quite what you're looking for, but the way people actually drive it, it exactly is, with the two "gores" and everything.
Quote from: vtk on May 03, 2015, 01:04:46 AMbut two-lane entrances that merged completely into the right mainline lane.
There are many ramps on I-76 the Schuylkill Expressway that do just that and the bottlenecks they create are the worst.
I-205 nb -> WA 14
Somewhat common in California, though CalTrans is rather fond of sudden lane adds, as seen from this shot of I-210's ramps coming off mainline sb I-5. https://www.google.com/maps/@34.31877,-118.493437,3a,75y,340.12h,94.95t/data=!3m4!1e1!3m2!1soZ4j0ww0oW8qV1dzX5Ejzw!2e0
I think the old PA / NJ turnpike interchange had 3 lanes that just kind of fanned out 1 right lane.
Quote from: jakeroot on May 02, 2015, 11:54:00 PM
Incredibly common in England the UK (and other countries), less so here.
Yes, virtually all exit ramps here have two lanes.
Was also standard for entrance ramps to have two lanes up to and including the merge point like this (https://www.google.co.uk/maps/@52.489888,-2.020972,3a,75y,222.96h,76.5t/data=!3m4!1e1!3m2!1sUUhOFqG9L56xpb9LvlwuCw!2e0). Junctions built after the early 1990s no longer had merges like this due to safety issues and the possibility of two cars side by side trying to join at the same time.
Not a highway nor an exit-like-thing, but here's an interesting situation here in Huntsville: https://www.google.com/maps/@34.763613,-86.573558,3a,66.8y,78.68h,72.29t/data=!3m4!1e1!3m2!1sRETdRkEcXd-zQBE_4Ci99w!2e0
^^ I've seen plenty of examples like that both here and abroad where one way streets are narrowed at the end to deter traffic from entering the wrong way.
There seems to be some misunderstanding as to what I'm talking about, so maybe a simplified diagram would be clearer.
(https://farm8.staticflickr.com/7738/17430516692_9edb7a41c8_o.png)
The two key characteristics are: 1.) No lane drop, and 2.) Two theoretical gore points (one for each exit lane) touching the edge line of the through lane.
There's a bit of a gray area between #1 and #5, but I think the distinction is relevant. With the striping in #1, two cars riding nose-to-tail in the right lane could exit simultaneously–easily and neatly. Even though the pavement surface is essentially identical in #5, the striping forces it to act more like #4, where vehicles would exit single file and then fan out to fill both lanes where the divider striping appears.
It does seem that people are having a hard time understanding what you are talking about.
I assume with the first illustration, it still counts if the normal dashes go all the way up to the split? Instead of the solid line you have illustrated.
Quote from: jakeroot on May 08, 2015, 04:17:48 PM
I assume with the first illustration, it still counts if the normal dashes go all the way up to the split? Instead of the solid line you have illustrated.
It would perhaps be a little less clear than the solid line example, but yes, I'd say it counts. I used the solid line primarily because that's what I encountered on I-80 in Wyoming.
Quote from: briantroutman on May 08, 2015, 04:29:40 PM
Quote from: jakeroot on May 08, 2015, 04:17:48 PM
I assume with the first illustration, it still counts if the normal dashes go all the way up to the split? Instead of the solid line you have illustrated.
It would perhaps be a little less clear than the solid line example, but yes, I'd say it counts. I used the solid line primarily because that's what I encountered on I-80 in Wyoming.
Okay, good. Washington and California's solid lane lines always end at the theoretical gore point, so example 1 would technically not be allowed (since the solid lane line extends past the theoretical gore).
Until I-64 was widened near Winchester, the exit to the Mountain Parkway qualified.
Brian,
The situation you describe doesn't seem terribly unsafe. During normal operations, drivers in the right lane can either stay on I-80 or exit directly onto either lane of the exit.
During snow periods, each lane of I-80 must transition onto this exit, so drivers in the right lane must be careful to make a hard right and leave room for the left lane, even though there is no signage or a lane line that show this transition (left lane turning right).
The Streetview shows cones. Do you know if they routinely use cones to help delineate the turn during snow emergencies?
Quote from: briantroutman on May 08, 2015, 03:58:47 PM
There seems to be some misunderstanding as to what I'm talking about, so maybe a simplified diagram would be clearer.
The two key characteristics are: 1.) No lane drop, and 2.) Two theoretical gore points (one for each exit lane) touching the edge line of the through lane.
So would you consider this (https://www.google.com/maps/@40.9216671,-73.8094186,146m/data=!3m1!1e3) a #1 or a #2? Like a #2, there is a solid line which makes makes the two split points not immediately adjacent, but on the other hand unlike a #2 there is no lane drop. It's kind of a #1/#2 hybrid, I guess.
At any rate, this used to be a single lane exit and an example of a #4 up until maybe about 15 years ago. Then NYSDOT restriped it in an attempt to move cars off the exit a little faster and alleviate a nasty bottleneck at this location. It of course hasn't helped one bit because the whole damn interchange is way underpowered and needs to just be blown up and rebuilt from scratch. But this is downstate New York, so that will never happen.
Quote from: Duke87 on May 14, 2015, 08:31:43 PM
Quote from: briantroutman on May 08, 2015, 03:58:47 PM
There seems to be some misunderstanding as to what I'm talking about, so maybe a simplified diagram would be clearer.
The two key characteristics are: 1.) No lane drop, and 2.) Two theoretical gore points (one for each exit lane) touching the edge line of the through lane.
So would you consider this (https://www.google.com/maps/@40.9216671,-73.8094186,146m/data=!3m1!1e3) a #1 or a #2? Like a #2, there is a solid line which makes makes the two split points not immediately adjacent, but on the other hand unlike a #2 there is no lane drop. It's kind of a #1/#2 hybrid, I guess.
At any rate, this used to be a single lane exit and an example of a #4 up until maybe about 15 years ago. Then NYSDOT restriped it in an attempt to move cars off the exit a little faster and alleviate a nasty bottleneck at this location. It of course hasn't helped one bit because the whole damn interchange is way underpowered and needs to just be blown up and rebuilt from scratch. But this is downstate New York, so that will never happen.
From my point of view, it looks like an exit only lane forms on the right for a very brief moment, with an option lane on the left as it exits.
Quote from: Duke87 on May 14, 2015, 08:31:43 PM
So would you consider this (https://www.google.com/maps/@40.9216671,-73.8094186,146m/data=!3m1!1e3) a #1 or a #2? Like a #2, there is a solid line which makes makes the two split points not immediately adjacent, but on the other hand unlike a #2 there is no lane drop. It's kind of a #1/#2 hybrid, I guess.
Yeah...kind of a #1/#2 hybrid. It's hard to tell from the satellite image, but measuring what looks to be the extent of the "exit lane" using Google Earth's ruler tool, it appears to be about 300 feet from the beginning of the exit lane striping to the gore point. Strictly on its measurable merits, I suppose it's closer to a #1, but subjectively, it strikes me more like the #2 type.
Quote from: briantroutman on May 08, 2015, 03:58:47 PM
(https://farm8.staticflickr.com/7738/17430516692_9edb7a41c8_o.png)
There's a bit of a gray area between #1 and #5, but I think the distinction is relevant. With the striping in #1, two cars riding nose-to-tail in the right lane could exit simultaneously–easily and neatly. Even though the pavement surface is essentially identical in #5, the striping forces it to act more like #4, where vehicles would exit single file and then fan out to fill both lanes where the divider striping appears.
The examples I came up with, which are no longer extant, were something between #1 and #5, closer to #5. The broken line between the two exit lanes began exactly at the gore point:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fvidthekid.info%2Fimghost%2Fe2d2.png&hash=2717ff721dc38cfadc785c6cc5e38326d132fe34)
In the Philly area, PA 291's SB exit to SB I-95 off the Platt Bridge does this, as well as the I-676 exit from SB I-95 as the two lanes of the ramp continue to the Vine Street Expressway, with two lanes peeling off for Callowhill Street and the Ben Franklin Bridge.
Both are more #5 than #1. #1 seems like a goofy way of striping it.
Sorry for bumping an old thread. Arizona's Loop 202 has a westbound double exit at Hawes Rd seen here https://goo.gl/maps/LKJLo that seems to be a mix of type 1 and 2. Drivers in the right lane can bear right into the far right exit only lane without any auxiliary lane. If drivers don't take this first exit lane, they can again choose to bear right for Hawes Road or remain straight for Loop 202. The right lane has the option to bear right twice with a thick solid white line between the exiting two lanes.
I think it looks like type 2 at first glance except that there is no dotted line marking the furthest right lane as an exit, it simply bears off from the right lane making it more like type 1. Before the construction of SR 24, this exit definitely was type 2 because the right lane was dotted and marked as exit only a good distance before the exit instead of branching off from the right lane.
Found a similar one around here: I-80 and IL-47, Morris, IL (https://www.google.com/maps/@41.391361,-88.4178366,203m/data=!3m1!1e3?hl=en).
Not a highway but nevertheless still an example at Florida SR50/SR520
https://www.google.com/maps/place/Orlando,+FL/@28.5396672,-81.0834836,51m/data=!3m1!1e3!4m2!3m1!1s0x88e773d8fecdbc77:0xac3b2063ca5bf9e!6m1!1e1?hl=en
Quote from: UCFKnights on August 22, 2015, 08:32:10 AM
Not a highway but nevertheless still an example at Florida SR50/SR520
https://www.google.com/maps/place/Orlando,+FL/@28.5396672,-81.0834836,51m/data=!3m1!1e3!4m2!3m1!1s0x88e773d8fecdbc77:0xac3b2063ca5bf9e!6m1!1e1?hl=en
If I remember the conversation correctly, this is an example of
exactly what the OP is/was looking for.
Meadowbrook Pkwy/Bay Pkwy interchange at Jones Beach State Park on Long Island has them-for every ramp (https://www.google.com/maps/@40.5939886,-73.5385675,1115m/data=!3m1!1e3). The loop in the SE quadrant goes to THREE lanes, then merges with 2 lanes of Bay Pkwy to form a 3-lane carriageway. There's another case on Wantagh Parkway not far from here.
Quote from: blanketcomputer on August 22, 2015, 06:05:01 AM
Sorry for bumping an old thread. Arizona's Loop 202 has a westbound double exit at Hawes Rd seen here https://goo.gl/maps/LKJLo that seems to be a mix of type 1 and 2.
That one kind of leans between #1 and #2, but I'm more inclined to put it in the #2 category.
Quote from: Brandon on August 22, 2015, 06:40:53 AM
Found a similar one around here: I-80 and IL-47, Morris, IL (https://www.google.com/maps/@41.391361,-88.4178366,203m/data=!3m1!1e3?hl=en).
I'd say that's definitely a #3.
Quote from: UCFKnights on August 22, 2015, 08:32:10 AM
Not a highway but nevertheless still an example at Florida SR50/SR520
https://www.google.com/maps/place/Orlando,+FL/@28.5396672,-81.0834836,51m/data=!3m1!1e3!4m2!3m1!1s0x88e773d8fecdbc77:0xac3b2063ca5bf9e!6m1!1e1?hl=en
Yes, that's exactly what I was looking for.
Quote from: cl94 on August 22, 2015, 07:10:59 PM
Meadowbrook Pkwy/Bay Pkwy interchange at Jones Beach State Park on Long Island has them-for every ramp (https://www.google.com/maps/@40.5939886,-73.5385675,1115m/data=!3m1!1e3). The loop in the SE quadrant goes to THREE lanes, then merges with 2 lanes of Bay Pkwy to form a 3-lane carriageway. There's another case on Wantagh Parkway not far from here.
I'd say those are all #3s, #4s, or maybe #5s, depending on whether the exit lane drops or not.
What's missing from a lot of these examples is the unusualness of the two-lane exit's broken lane divider line going all the way back to the edge line of the through lanes, as in the diagram for #1 illustrates–with no through lane being dropped. As mentioned before the #5 type is quite similar to #1, but the key difference is that these tend to behave more like standard one-lane exits that divide into two lanes, whereas #1 clearly creates two separate paths from the right through lane into the two different exit lanes.
Quote from: Roadsguy on June 21, 2015, 08:29:32 AM
#1 seems like a goofy way of striping it.
That's precisely why the arrangement caught my attention when I first saw it in Wyoming.
WB I-94 exit to I-75 in midtown Detroit is almost exactly a #1, with a little bit of an arc to the exit. Google maps doesn't have a clear view of it.
Quote from: briantroutman on August 23, 2015, 06:41:05 PM
Quote from: blanketcomputer on August 22, 2015, 06:05:01 AM
Sorry for bumping an old thread. Arizona's Loop 202 has a westbound double exit at Hawes Rd seen here https://goo.gl/maps/LKJLo that seems to be a mix of type 1 and 2.
That one kind of leans between #1 and #2, but I'm more inclined to put it in the #2 category.
What's missing from a lot of these examples is the unusualness of the two-lane exit's broken lane divider line going all the way back to the edge line of the through lanes, as in the diagram for #1 illustrates–with no through lane being dropped. As mentioned before the #5 type is quite similar to #1, but the key difference is that these tend to behave more like standard one-lane exits that divide into two lanes, whereas #1 clearly creates two separate paths from the right through lane into the two different exit lanes.
I lean more for #1, just with a bit of a curve. (https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F5BeMK4O.jpg&hash=6d4cef90b06b8db2c39b9b6f2da6457a8c019d4e) (Blue line is my emphasis on an imaginary right shoulder line continuing through the exit)
Two separate exits lanes are created from the right lane without dropping a through lane. It also meets an earlier stated requirement for two cars riding nose-to-tail being able exit simultaneously.
Quote from: briantroutman on May 08, 2015, 03:58:47 PM
There seems to be some misunderstanding as to what I'm talking about, so maybe a simplified diagram would be clearer.
(https://farm8.staticflickr.com/7738/17430516692_9edb7a41c8_o.png)
Here's a good example of #1. This is SB US-19 in Cranberry, PA ramp onto I-79 SB. https://goo.gl/maps/cscSY
Quote from: rickmastfan67 on August 24, 2015, 07:13:58 AM
Quote from: briantroutman on May 08, 2015, 03:58:47 PM
There seems to be some misunderstanding as to what I’m talking about, so maybe a simplified diagram would be clearer.
(https://farm8.staticflickr.com/7738/17430516692_9edb7a41c8_o.png)
Here's a good example of #1. This is SB US-19 in Cranberry, PA ramp onto I-79 SB. https://goo.gl/maps/cscSY
It looks like #5 to me.
#1 and #5 are basically the same thing. 1 just extends the line a little further. People probably treat 1 and 5 the same way.
Quote from: cl94 on August 24, 2015, 11:34:41 AM
#1 and #5 are basically the same thing. 1 just extends the line a little further. People probably treat 1 and 5 the same way.
I think the main difference between #1 and #5 is that two exiting cars would technically have to cross into the single exit lane one after another before the exit is marked as two lanes. With #1, two cars can decide to exit and cross the dashed exit line at the same exact time into the two separate lanes, and legally do it without crossing a gore or cutting into a lane only marked for one vehicle. For #5, depending on the distance between the exit and when the lane line begins, if drivers treated it like #1, two cars could be in an area technically marked for one vehicle.
Quote from: blanketcomputer on August 24, 2015, 10:07:08 PM
Quote from: cl94 on August 24, 2015, 11:34:41 AM
#1 and #5 are basically the same thing. 1 just extends the line a little further. People probably treat 1 and 5 the same way.
I think the main difference between #1 and #5 is that two exiting cars would technically have to cross into the single exit lane one after another before the exit is marked as two lanes. With #1, two cars can decide to exit and cross the dashed exit line at the same exact time into the two separate lanes, and legally do it without crossing a gore or cutting into a lane only marked for one vehicle. For #5, depending on the distance between the exit and when the lane line begins, if drivers treated it like #1, two cars could be in an area technically marked for one vehicle.
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Quote from: cl94 on August 24, 2015, 10:22:29 PM
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Interesting. Would you consider these to be examples of four-lanes without cars, two-lanes with? I use these roads on a regular basis, and I will occasionally pass on the right, but I get a lot of dirty looks.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FbwGFD8L.png&hash=8b686f3754609f7933356e6a4eee0b18b1e80ccc)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FR33bhnp.png&hash=4004f6f1f8c545824a1141b7a6ec04f4b4461f04)
I-5 northbound's exit to I-605. Slightly justified in that the two lanes are marked for different directions on 605.
https://www.google.com/maps/@33.9359312,-118.0927044,284m/data=!3m1!1e3
Quote from: jakeroot on August 25, 2015, 12:55:25 AM
Quote from: cl94 on August 24, 2015, 10:22:29 PM
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Interesting. Would you consider these to be examples of four-lanes without cars, two-lanes with? I use these roads on a regular basis, and I will occasionally pass on the right, but I get a lot of dirty looks.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FbwGFD8L.png&hash=8b686f3754609f7933356e6a4eee0b18b1e80ccc)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FR33bhnp.png&hash=4004f6f1f8c545824a1141b7a6ec04f4b4461f04)
If you truly do that, that is clearly a 2 lane road. But I would hope you're just saying you pass on the right as an example.
Quote from: jeffandnicole on August 25, 2015, 06:20:29 AM
Quote from: jakeroot on August 25, 2015, 12:55:25 AM
Quote from: cl94 on August 24, 2015, 10:22:29 PM
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Interesting. Would you consider these to be examples of four-lanes without cars, two-lanes with? I use these roads on a regular basis, and I will occasionally pass on the right, but I get a lot of dirty looks.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FbwGFD8L.png&hash=8b686f3754609f7933356e6a4eee0b18b1e80ccc)
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FR33bhnp.png&hash=4004f6f1f8c545824a1141b7a6ec04f4b4461f04)
If you truly do that, that is clearly a 2 lane road. But I would hope you're just saying you pass on the right as an example.
Those are 2 lanes. Some of the streets I'm talking about have 20 foot lanes as they are striped.
Quote from: jakeroot on August 25, 2015, 12:55:25 AM
Quote from: cl94 on August 24, 2015, 10:22:29 PM
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Interesting. Would you consider these to be examples of four-lanes without cars, two-lanes with? I use these roads on a regular basis, and I will occasionally pass on the right, but I get a lot of dirty looks.
I would never consider passing on the right along that street, and am not surprised that doing so generates dirty looks. Exception: a car is turning left into a side street/driveway (either stopped, or slowing with turn signal on)-I would definitely pass them on the right.
Quote from: cl94 on August 25, 2015, 07:57:14 AM
Quote from: jeffandnicole on August 25, 2015, 06:20:29 AM
Quote from: jakeroot on August 25, 2015, 12:55:25 AM
Quote from: cl94 on August 24, 2015, 10:22:29 PM
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Interesting. Would you consider these to be examples of four-lanes without cars, two-lanes with? I use these roads on a regular basis, and I will occasionally pass on the right, but I get a lot of dirty looks.
If you truly do that, that is clearly a 2 lane road. But I would hope you're just saying you pass on the right as an example.
Those are 2 lanes. Some of the streets I'm talking about have 20 foot lanes as they are striped.
Here's some Chicago examples, and yes, they do act as though they are four lanes.
Fullerton Avenue (https://www.google.com/maps/@41.9249208,-87.6855683,3a,49.8y,91.88h,90.13t/data=!3m7!1e1!3m5!1sKjdGeSQ34MFopExXU8jQng!2e0!6s%2F%2Fgeo0.ggpht.com%2Fcbk%3Fpanoid%3DKjdGeSQ34MFopExXU8jQng%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D100%26h%3D80%26yaw%3D293.71%26pitch%3D0!7i13312!8i6656)
63rd Street (https://www.google.com/maps/@41.7798945,-87.6364348,3a,66.4y,275.05h,85.84t/data=!3m7!1e1!3m5!1s4TfUVWYfRL6gGczGlpZJlA!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3D4TfUVWYfRL6gGczGlpZJlA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D100%26h%3D80%26yaw%3D72.295013%26pitch%3D0!7i13312!8i6656) Note the truck passing the bus.
And in the other direction on 63rd Street (https://www.google.com/maps/@41.7798945,-87.6364348,3a,33.9y,91.87h,82.48t/data=!3m7!1e1!3m5!1s4TfUVWYfRL6gGczGlpZJlA!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3D4TfUVWYfRL6gGczGlpZJlA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D100%26h%3D80%26yaw%3D72.295013%26pitch%3D0!7i13312!8i6656)
87th Street (https://www.google.com/maps/@41.7365353,-87.6117232,3a,18y,270.44h,87.9t/data=!3m6!1e1!3m4!1s6NghevUAC0XvUTl6B-D3Ew!2e0!7i13312!8i6656) Note the vehicle having to move left to avoid a parked car. That's fairly common.
Quote from: jeffandnicole on August 25, 2015, 06:20:29 AM
If you truly do that, that is clearly a 2 lane road. But I would hope you're just saying you pass on the right as an example.
I used to understand the law as saying that you could pass on the right as long as there was sufficient pavement on the right, but, since I've reread the law, I realize that it only allows passing on the right of a car is turning left. So I have passed slow-moving vehicles on the right, but I don't anymore.
EDIT: RCW 46.61.115
Quote from: Brandon on August 25, 2015, 09:47:35 AM
Quote from: cl94 on August 25, 2015, 07:57:14 AM
Quote from: jeffandnicole on August 25, 2015, 06:20:29 AM
Quote from: jakeroot on August 25, 2015, 12:55:25 AM
Quote from: cl94 on August 24, 2015, 10:22:29 PM
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Interesting. Would you consider these to be examples of four-lanes without cars, two-lanes with? I use these roads on a regular basis, and I will occasionally pass on the right, but I get a lot of dirty looks.
If you truly do that, that is clearly a 2 lane road. But I would hope you're just saying you pass on the right as an example.
Those are 2 lanes. Some of the streets I'm talking about have 20 foot lanes as they are striped.
Here's some Chicago examples, and yes, they do act as though they are four lanes.
Fullerton Avenue (https://www.google.com/maps/@41.9249208,-87.6855683,3a,49.8y,91.88h,90.13t/data=!3m7!1e1!3m5!1sKjdGeSQ34MFopExXU8jQng!2e0!6s%2F%2Fgeo0.ggpht.com%2Fcbk%3Fpanoid%3DKjdGeSQ34MFopExXU8jQng%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D100%26h%3D80%26yaw%3D293.71%26pitch%3D0!7i13312!8i6656)
63rd Street (https://www.google.com/maps/@41.7798945,-87.6364348,3a,66.4y,275.05h,85.84t/data=!3m7!1e1!3m5!1s4TfUVWYfRL6gGczGlpZJlA!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3D4TfUVWYfRL6gGczGlpZJlA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D100%26h%3D80%26yaw%3D72.295013%26pitch%3D0!7i13312!8i6656) Note the truck passing the bus.
And in the other direction on 63rd Street (https://www.google.com/maps/@41.7798945,-87.6364348,3a,33.9y,91.87h,82.48t/data=!3m7!1e1!3m5!1s4TfUVWYfRL6gGczGlpZJlA!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3D4TfUVWYfRL6gGczGlpZJlA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D100%26h%3D80%26yaw%3D72.295013%26pitch%3D0!7i13312!8i6656)
87th Street (https://www.google.com/maps/@41.7365353,-87.6117232,3a,18y,270.44h,87.9t/data=!3m6!1e1!3m4!1s6NghevUAC0XvUTl6B-D3Ew!2e0!7i13312!8i6656) Note the vehicle having to move left to avoid a parked car. That's fairly common.
I would post a Buffalo example, but they look exactly like these down to the broken yellow centerline.
Passing on the right on Trent Road in New Bern had gotten so bad that DOT felt the need to post a sign reminding drivers that it's illegal to do so. (https://www.google.com/maps/@35.1040746,-77.0729748,3a,30y,79.34h,81.55t/data=!3m6!1e1!3m4!1sD2nQwZFRzzS-kjvbcOQLtg!2e0!7i13312!8i6656?hl=en)
See we have a buttload of retirees here that like to do 20-25 in a 35 and hug the center line that people were just blowing their doors off to the right, and then wrecks would happen when said retiree decided to turn right at one of the side streets. Back in my pizza delivery days I had witnessed a bunch of these wrecks first hand.
Quote from: cl94 on August 24, 2015, 10:22:29 PM
I mean that, if a lane is wide enough for 2 cars, 2 cars will use it regardless of legality. Don't know about the rest of the country, but many 2-lane streets with on-street parking around here are treated as 4 lanes if there are no parked cars. Same logic applies. I'm referring to practice, not theory.
Sure, a wide city street might be different. In the case of a freeway exit, I would be more inclined to follow the pavement markings indicating a single, albeit very wide, lane. I think using #5 the same way as #1 is dangerous and confusing to drivers. #1 is marked in a way to remove the confusion from this movement and actually delineate the paths drivers should take to complete it.
Quote from: blanketcomputer on August 25, 2015, 09:02:39 PM
I think using #5 the same way as #1 is dangerous and confusing to drivers. #1 is marked in a way to remove the confusion from this movement and actually delineate the paths drivers should take to complete it.
If we're talking about situations that are confusing to drivers, what do other people here think of a situation where a single, unstriped right lane on a freeway becomes a two-lane exit? The lack of striping makes it impossible to determine whether it is a #2 or a #3 (numbers of course referring to this diagram: https://www.aaroads.com/forum/index.php?topic=15440.msg2062903#msg2062903). My assumption is that this defaults to a #3, but is that correct? I've already posted about the one occurrence of this situation that I've seen, and I don't want to make this a duplicate post, so I'll just leave this as questions for anyone who's interested.
(Edited for word choice.)
I found this example yesterday evening. US 277 exits off a concurrency with TX 70. Two lanes divide directly into four lanes. I'm not sure why, as one lane ends and US 277 becomes a two-lane road. I suppose it's a short passing zone in case a top-heavy truck slows down a lot on the curve.
https://www.google.com/maps/@32.0104036,-100.2770044,3a,75y,338.31h,90t/data=!3m6!1e1!3m4!1sVuC73_7I1aH3XZVk36eeQA!2e0!7i13312!8i6656?hl=en (https://www.google.com/maps/@32.0104036,-100.2770044,3a,75y,338.31h,90t/data=!3m6!1e1!3m4!1sVuC73_7I1aH3XZVk36eeQA!2e0!7i13312!8i6656?hl=en)
Quote from: wxfree on September 13, 2015, 03:11:48 AM
I found this example yesterday evening. US 277 exits off a concurrency with TX 70. Two lanes divide directly into four lanes. I'm not sure why, as one lane ends and US 277 becomes a two-lane road. I suppose it's a short passing zone in case a top-heavy truck slows down a lot on the curve.
https://www.google.com/maps/@32.0104036,-100.2770044,3a,75y,338.31h,90t/data=!3m6!1e1!3m4!1sVuC73_7I1aH3XZVk36eeQA!2e0!7i13312!8i6656?hl=en (https://www.google.com/maps/@32.0104036,-100.2770044,3a,75y,338.31h,90t/data=!3m6!1e1!3m4!1sVuC73_7I1aH3XZVk36eeQA!2e0!7i13312!8i6656?hl=en)
I just remembered this specific interchange, got all excited, dug through three pages of threads, posted a GSV shot, then realized the last post on the thread was the EXACT SAME LOCATION. Grrrrr.....
Anyway, I just wanted to point out that the crossover for southbound TX-70 traffic heading north on US-277 is also inexplicably two lanes. This leads to the following weird progression. It really is insanity.
1. A two-lane left exit with no dropped or option lane(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2F277_1_zpsi6cxsqsy.png&hash=26faba5d935d9543a4b9ff2015105f873cfea701)
2. 460 feet later, two lanes merging into the single left lane of US-277 with no taper(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2F277_2_zpsvxsqcxkl.png&hash=1a07b597884da1c0560fda7282a89c843055a908)
3. A diagrammatic sign suggesting you're now on a three-lane roadway with an option lane (LIES!)(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2F277_3_zpsluuyikpl.png&hash=a6de9c9a83291b17d6d31002f74c7b57da4f4891)
4. A two-lane right exit with no dropped or option lane(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2F277_4_zpsksyvt5tp.png&hash=9f5c3a316ceee83f3f02c0a745a4975daacf7bfb)
I can't post a link on my phone, but there are a couple at Jones Beach on Long Island. One of them is even 3 lanes.
Now that I'm thinking about 277 in Texas, I realize it's more common than I thought. Where US-277 meets US-67 on the northeast side of San Angelo, there is this type of situation as well. This interchange recently underwent some construction (an active project when I drove through last summer), so it may be that some of these examples are no longer apparent.
Approaching on SB US-277: 2-lane left exit with no option or dropped lane (http://2-lane%20left%20exit%20with%20no%20option%20or%20dropped%20lane)
Merging from SB US-277 onto NB US-67: 2-lanes merge into a single lane with no taper (https://goo.gl/maps/45cJn1EZEMs)
There are a couple of others visible in GSV at this junction, but the approach tapers are longer, so I figure they're iffy examples.
Quote from: cl94 on July 16, 2016, 01:30:47 PM
I can't post a link on my phone, but there are a couple at Jones Beach on Long Island. One of them is even 3 lanes.
Indeed. Here's an example there (https://goo.gl/maps/9sSKGkgXP7R2), where the option lane splits in two. Basically, two lanes become three lanes at the point of exit.
Quote from: kphoger on July 16, 2016, 01:36:37 PM
Quote from: cl94 on July 16, 2016, 01:30:47 PM
I can't post a link on my phone, but there are a couple at Jones Beach on Long Island. One of them is even 3 lanes.
Indeed. Here's an example there (https://goo.gl/maps/9sSKGkgXP7R2), where the option lane splits in two. Basically, two lanes become three lanes at the point of exit.
I was actually thinking of this one at the end of the Meadowbrook (https://www.google.com/maps/@40.5933601,-73.5367613,3a,60y,100.59h,79.7t/data=!3m6!1e1!3m4!1s1jCcc6lCplDAk-gYydT4Xg!2e0!7i13312!8i6656?hl=en).
Quote from: cl94 on July 16, 2016, 02:07:33 PM
Quote from: kphoger on July 16, 2016, 01:36:37 PM
Quote from: cl94 on July 16, 2016, 01:30:47 PM
I can't post a link on my phone, but there are a couple at Jones Beach on Long Island. One of them is even 3 lanes.
Indeed. Here's an example there (https://goo.gl/maps/9sSKGkgXP7R2), where the option lane splits in two. Basically, two lanes become three lanes at the point of exit.
I was actually thinking of this one at the end of the Meadowbrook (https://www.google.com/maps/@40.5933601,-73.5367613,3a,60y,100.59h,79.7t/data=!3m6!1e1!3m4!1s1jCcc6lCplDAk-gYydT4Xg!2e0!7i13312!8i6656?hl=en).
That's a dropped lane (#3 in the image below), so it does not fit the thread.
Quote from: briantroutman on May 08, 2015, 03:58:47 PM
There seems to be some misunderstanding as to what I'm talking about, so maybe a simplified diagram would be clearer.
(https://farm8.staticflickr.com/7738/17430516692_9edb7a41c8_o.png)
The two key characteristics are: 1.) No lane drop, and 2.) Two theoretical gore points (one for each exit lane) touching the edge line of the through lane.
There's a bit of a gray area between #1 and #5, but I think the distinction is relevant. With the striping in #1, two cars riding nose-to-tail in the right lane could exit simultaneously–easily and neatly. Even though the pavement surface is essentially identical in #5, the striping forces it to act more like #4, where vehicles would exit single file and then fan out to fill both lanes where the divider striping appears.
There's a thread for this!? Awesome!! This annoys the hell out of me too.
And I am very very grateful to briantroutman for that diagram. It drives me nuts. It's not that the other configurations are unsafe-it's that they're inefficient. If you can get twice the flow into the exit ramp, why wouldn't you configure the striping to allow that--especially if it's a heavily-traveled ramp?
If you're looking for more examples, I-465 southbound at 86th St is one that gets me every time. One lane gets to exit and immediately opens into two lanes, instead of allowing for an optional exit out of the second lane of I-465. https://goo.gl/maps/U5XGQ98oH9D2
Quote from: paulthemapguy on November 09, 2016, 10:06:33 AM
There's a thread for this!? Awesome!! This annoys the hell out of me too.
And I am very very grateful to briantroutman for that diagram. It drives me nuts. It's not that the other configurations are unsafe-it's that they're inefficient. If you can get twice the flow into the exit ramp, why wouldn't you configure the striping to allow that--especially if it's a heavily-traveled ramp?
If you're looking for more examples, I-465 southbound at 86th St is one that gets me every time. One lane gets to exit and immediately opens into two lanes, instead of allowing for an optional exit out of the second lane of I-465. https://goo.gl/maps/U5XGQ98oH9D2
Isn't that one a #3?
Quote from: kphoger on November 10, 2016, 05:33:57 PM
Quote from: paulthemapguy on November 09, 2016, 10:06:33 AM
There's a thread for this!? Awesome!! This annoys the hell out of me too.
And I am very very grateful to briantroutman for that diagram. It drives me nuts. It's not that the other configurations are unsafe-it's that they're inefficient. If you can get twice the flow into the exit ramp, why wouldn't you configure the striping to allow that--especially if it's a heavily-traveled ramp?
If you're looking for more examples, I-465 southbound at 86th St is one that gets me every time. One lane gets to exit and immediately opens into two lanes, instead of allowing for an optional exit out of the second lane of I-465. https://goo.gl/maps/U5XGQ98oH9D2
Isn't that one a #3?
Yeah but it's the same situation, just with an exit only lane. (I'm not starting a new thread when the situations are nearly the same.)
I hope this one on Holmes Avenue here in Huntsville counts, even though it isn't signed as an exit:
https://www.google.com/maps/@34.7276361,-86.6404949,3a,46y,251.54h,80.27t/data=!3m6!1e1!3m4!1sHrBkYHKVDCrqqrcUwWanjg!2e0!7i13312!8i6656?hl=en&authuser=0
Also, a bit of a fun fact: the one-way road the peels off of Holmes Avenue and onto UAH's campus is actually the original routing of Holmes Avenue.
You know, it occurs to me that all the exits from the Bear Mountain Circle qualify:
https://goo.gl/maps/zvXdz5scmLm
This probably applies to a lot of older-style traffic circles elsewhere, too.
Eastbound I-94 at I-75 in downtown Detroit.
https://goo.gl/maps/ZNJEpHNbaZA2
Quote from: empirestate on November 11, 2016, 08:45:41 AM
You know, it occurs to me that all the exits from the Bear Mountain Circle qualify:
https://goo.gl/maps/zvXdz5scmLm
This probably applies to a lot of older-style traffic circles elsewhere, too.
Two exits at the one a few miles west of there (https://www.google.com/maps/@41.3049619,-74.0347515,191m/data=!3m1!1e3?hl=en) qualify.
The old Kingston traffic circle at the west end of I-587 qualified until they got rid of it. Latham Circle also qualified until they channelized the lanes.
Here's one in Niskayuna (https://www.google.com/maps/@42.8252083,-73.8787342,3a,60y,71.31h,64.48t/data=!3m6!1e1!3m4!1s_sMtXKcoj7JVpEoGOzoD-w!2e0!7i13312!8i6656?hl=en) outside of GE's research complex.
Quote from: cl94 on November 13, 2016, 08:36:43 PM
Quote from: empirestate on November 11, 2016, 08:45:41 AM
You know, it occurs to me that all the exits from the Bear Mountain Circle qualify:
https://goo.gl/maps/zvXdz5scmLm
This probably applies to a lot of older-style traffic circles elsewhere, too.
Two exits at the one a few miles west of there (https://www.google.com/maps/@41.3049619,-74.0347515,191m/data=!3m1!1e3?hl=en) qualify.
The old Kingston traffic circle at the west end of I-587 qualified until they got rid of it. Latham Circle also qualified until they channelized the lanes.
Here's one in Niskayuna (https://www.google.com/maps/@42.8252083,-73.8787342,3a,60y,71.31h,64.48t/data=!3m6!1e1!3m4!1s_sMtXKcoj7JVpEoGOzoD-w!2e0!7i13312!8i6656?hl=en) outside of GE's research complex.
I'm not totally sure I agree with this assessment. At least by European standards (assuming the US has none for
traffic circles), the right-most lane of a circle is an "exit only" at each leg (inside lane being an optional turn-off-or-stay-on lane). The inside lane has the option of exiting, or continuing around. The lane lines don't agree with this, but this is typically how traffic circles operate in the rest of the world (to the best of my knowledge).
Then again, I don't live in the Northeast. The only experience I have driving traffic circles are driving around the various traffic circles in Edmonton, Alberta, where they operate as I describe above.
Quote from: jakeroot on November 14, 2016, 01:41:56 AM
Quote from: cl94 on November 13, 2016, 08:36:43 PM
Quote from: empirestate on November 11, 2016, 08:45:41 AM
You know, it occurs to me that all the exits from the Bear Mountain Circle qualify:
https://goo.gl/maps/zvXdz5scmLm
This probably applies to a lot of older-style traffic circles elsewhere, too.
Two exits at the one a few miles west of there (https://www.google.com/maps/@41.3049619,-74.0347515,191m/data=!3m1!1e3?hl=en) qualify.
The old Kingston traffic circle at the west end of I-587 qualified until they got rid of it. Latham Circle also qualified until they channelized the lanes.
Here's one in Niskayuna (https://www.google.com/maps/@42.8252083,-73.8787342,3a,60y,71.31h,64.48t/data=!3m6!1e1!3m4!1s_sMtXKcoj7JVpEoGOzoD-w!2e0!7i13312!8i6656?hl=en) outside of GE's research complex.
I'm not totally sure I agree with this assessment. At least by European standards (assuming the US has none for traffic circles), the right-most lane of a circle is an "exit only" at each leg (inside lane being an optional turn-off-or-stay-on lane). The inside lane has the option of exiting, or continuing around. The lane lines don't agree with this, but this is typically how traffic circles operate in the rest of the world (to the best of my knowledge).
Then again, I don't live in the Northeast. The only experience I have driving traffic circles are driving around the various traffic circles in Edmonton, Alberta, where they operate as I describe above.
At least around here, both lanes could operate as option lanes.
Now, how about the other side of the interchange -- two entrance lanes merging into a single existing thru lane with no extended acceleration lane?
Entrance ramp to westbound I-696 west of M-1 (Woodward Avenue):
https://goo.gl/maps/TTSD5eaxbHK2
Quote from: cl94 on November 14, 2016, 10:05:17 AM
Quote from: jakeroot on November 14, 2016, 01:41:56 AM
Quote from: cl94 on November 13, 2016, 08:36:43 PM
Quote from: empirestate on November 11, 2016, 08:45:41 AM
You know, it occurs to me that all the exits from the Bear Mountain Circle qualify:
https://goo.gl/maps/zvXdz5scmLm
This probably applies to a lot of older-style traffic circles elsewhere, too.
Two exits at the one a few miles west of there (https://www.google.com/maps/@41.3049619,-74.0347515,191m/data=!3m1!1e3?hl=en) qualify.
The old Kingston traffic circle at the west end of I-587 qualified until they got rid of it. Latham Circle also qualified until they channelized the lanes.
Here's one in Niskayuna (https://www.google.com/maps/@42.8252083,-73.8787342,3a,60y,71.31h,64.48t/data=!3m6!1e1!3m4!1s_sMtXKcoj7JVpEoGOzoD-w!2e0!7i13312!8i6656?hl=en) outside of GE's research complex.
I'm not totally sure I agree with this assessment. At least by European standards (assuming the US has none for traffic circles), the right-most lane of a circle is an "exit only" at each leg (inside lane being an optional turn-off-or-stay-on lane). The inside lane has the option of exiting, or continuing around. The lane lines don't agree with this, but this is typically how traffic circles operate in the rest of the world (to the best of my knowledge).
Then again, I don't live in the Northeast. The only experience I have driving traffic circles are driving around the various traffic circles in Edmonton, Alberta, where they operate as I describe above.
At least around here, both lanes could operate as option lanes.
That's just it; there's no apparent standard for how striping like this is supposed to work. You can't count on a motorist entering the right lane not to continue 180 degrees through the circle, rather than existing immediately.
We must also assume that, if these older traffic circles were meant to function as modern roundabout, they'd be re-striped as such. But then, what purpose does the left lane have, if exits are only ever allowed from the right lane?
iPhone
Quote from: empirestate on November 15, 2016, 05:35:02 PM
Quote from: cl94 on November 14, 2016, 10:05:17 AM
Quote from: jakeroot on November 14, 2016, 01:41:56 AM
At least by European standards (assuming the US has none for traffic circles), the right-most lane of a circle is an "exit only" at each leg (inside lane being an optional turn-off-or-stay-on lane). The inside lane has the option of exiting, or continuing around. The lane lines don't agree with this, but this is typically how traffic circles operate in the rest of the world (to the best of my knowledge).
Then again, I don't live in the Northeast. The only experience I have driving traffic circles are driving around the various traffic circles in Edmonton, Alberta, where they operate as I describe above.
At least around here, both lanes could operate as option lanes.
That's just it; there's no apparent standard for how striping like this is supposed to work. You can't count on a motorist entering the right lane not to continue 180 degrees through the circle, rather than exiting immediately.
We must also assume that, if these older traffic circles were meant to function as modern roundabout, they'd be re-striped as such.
The European rules generally discount the first exit (most often, a right turn). Both lanes can proceed past this exit, but at the next exit, the right lane becomes an exit only.
Why more circles aren't re-striped as roundabouts, I couldn't say. It genuinely boggles my mind. There are obviously many that have been re-striped, but the fact that there are circles with concentric markings still out there, really surprises me. We've been building modern roundabouts for over 20 years at this point.
Quote from: empirestate on November 15, 2016, 05:35:02 PM
But then, what purpose does the left lane have, if exits are only ever allowed from the right lane?
Seemingly none, by American standards. If the right lane was an exit-only at each leg, a la Europe, these traffic circles would have much higher capacities.
Quote from: jakeroot on November 15, 2016, 06:07:15 PM
The European rules generally discount the first exit (most often, a right turn). Both lanes can proceed past this exit, but at the next exit, the right lane becomes an exit only.
Thing is, exit only
to which lane? You'll often have conflicts here between motorists exiting from the right lane of the circle and from the left lane of the circle, both into the left lane of the exit. Given the way it's striped, why shouldn't someone in the right lane of the circle expect to have both exiting lanes available to him?
(There's a lot more at play here, too, such as the toll booth to the bridge requiring a choice between staffed (right) and E-ZPass (left) lanes. Plus the fact that the circle is often just plain jammed up with traffic, such that any roundabout functionality goes out the window...)
Quote from: jakeroot on November 15, 2016, 06:07:15 PM
Why more circles aren't re-striped as roundabouts, I couldn't say. It genuinely boggles my mind. There are obviously many that have been re-striped, but the fact that there are circles with concentric markings still out there, really surprises me. We've been building modern roundabouts for over 20 years at this point.
Markings? We don't need no stinkin markings.
This is a 2 lane circle throughout: https://goo.gl/maps/eWrSDzh3DJs It's only marked in two spots, and that's only to show where traffic is supposed to yield within the circle.
Quote from: empirestate on November 16, 2016, 10:53:02 AM
Quote from: jakeroot on November 15, 2016, 06:07:15 PM
The European rules generally discount the first exit (most often, a right turn). Both lanes can proceed past this exit, but at the next exit, the right lane becomes an exit only.
Thing is, exit only to which lane? You'll often have conflicts here between motorists exiting from the right lane of the circle and from the left lane of the circle, both into the left lane of the exit. Given the way it's striped, why shouldn't someone in the right lane of the circle expect to have both exiting lanes available to him?
You exit into the lane that you're in within the circle. For example, if you're in the right lane, you exit into the right lane. If you're in the left lane, you exit into the left lane (or continue around the circle). The way it's striped is definitely misleading. But the markings are only meant to delineate lanes within the circle (i.e. to prevent side-swipes), not to help traffic exit the circle.
Quote from: empirestate on November 16, 2016, 10:53:02 AM
(There's a lot more at play here, too, such as the toll booth to the bridge requiring a choice between staffed (right) and E-ZPass (left) lanes. Plus the fact that the circle is often just plain jammed up with traffic, such that any roundabout functionality goes out the window...)
They wouldn't jam up as much, if there were more rules. Higher lane utilization = higher throughput = less jams.
Quote from: jeffandnicole on November 16, 2016, 11:12:49 AM
Quote from: jakeroot on November 15, 2016, 06:07:15 PM
Why more circles aren't re-striped as roundabouts, I couldn't say. It genuinely boggles my mind. There are obviously many that have been re-striped, but the fact that there are circles with concentric markings still out there, really surprises me. We've been building modern roundabouts for over 20 years at this point.
Markings? We don't need no stinkin markings.
This is a 2 lane circle throughout: https://goo.gl/maps/eWrSDzh3DJs It's only marked in two spots, and that's only to show where traffic is supposed to yield within the circle.
They should at least put some left/right/straight arrows at the entry legs, so each lane knows what it can do. And maybe move the yield lines to the entry legs.
Quote from: jakeroot on November 16, 2016, 12:37:02 PM
Quote from: empirestate on November 16, 2016, 10:53:02 AM
Quote from: jakeroot on November 15, 2016, 06:07:15 PM
The European rules generally discount the first exit (most often, a right turn). Both lanes can proceed past this exit, but at the next exit, the right lane becomes an exit only.
Thing is, exit only to which lane? You'll often have conflicts here between motorists exiting from the right lane of the circle and from the left lane of the circle, both into the left lane of the exit. Given the way it's striped, why shouldn't someone in the right lane of the circle expect to have both exiting lanes available to him?
You exit into the lane that you're in within the circle. For example, if you're in the right lane, you exit into the right lane. If you're in the left lane, you exit into the left lane (or continue around the circle). The way it's striped is definitely misleading. But the markings are only meant to delineate lanes within the circle (i.e. to prevent side-swipes), not to help traffic exit the circle.
So if you're exiting from left lane to left lane, how do you avoid conflict with someone in the right lane not exiting?
iPhone
Quote from: jakeroot on November 16, 2016, 12:37:02 PM
They should at least put some left/right/straight arrows at the entry legs, so each lane knows what it can do. And maybe move the yield lines to the entry legs.
Ah, then it wouldn't be a Jersey traffic circle!
Most of them have functioned in this nature...sometimes the entry yields, sometimes those within the circle yields, and sometimes there is no control. Generally, the movements with the heaviest traffic flow have the right of way. It's been like this for decades...it's not going to change. Compared to some of them, this one actually has a fair amount of lane control.
That all said, the circle is undergoing some reconstruction: There's a small, heavily used side road (Creek Road) just south of the circle. They're eliminating most movements to/from this road from the circle as turning vehicles from the circle have a habit of blocking the entire road. They'll reconstruct other portions of the circle to provide more room. But it will still be a Jersey traffic circle with Jersey traffic circle features when construction is completed.
Quote from: empirestate on November 16, 2016, 02:02:24 PM
Quote from: jakeroot on November 16, 2016, 12:37:02 PM
Quote from: empirestate on November 16, 2016, 10:53:02 AM
Quote from: jakeroot on November 15, 2016, 06:07:15 PM
The European rules generally discount the first exit (most often, a right turn). Both lanes can proceed past this exit, but at the next exit, the right lane becomes an exit only.
Thing is, exit only to which lane? You'll often have conflicts here between motorists exiting from the right lane of the circle and from the left lane of the circle, both into the left lane of the exit. Given the way it's striped, why shouldn't someone in the right lane of the circle expect to have both exiting lanes available to him?
You exit into the lane that you're in within the circle. For example, if you're in the right lane, you exit into the right lane. If you're in the left lane, you exit into the left lane (or continue around the circle). The way it's striped is definitely misleading. But the markings are only meant to delineate lanes within the circle (i.e. to prevent side-swipes), not to help traffic exit the circle.
So if you're exiting from left lane to left lane, how do you avoid conflict with someone in the right lane not exiting?
The person in the right lane
must exit. If there's a conflict, it's because the person in the right lane incorrectly continued around the circle.
To make it clearer (hopefully), the right lane cannot go more than 180-degrees around the circle. If you plan on going more than 180 degrees around the circle, use the left lane. If you plan on going less than 180 degrees around the circle, use the right lane. If you plan on going exactly 180 degrees through the circle, use either lane (if applicable), but exit into the lane that you were in while within the circle.
Here's a diagram. You can see that, in no scenario, does the right lane ever continue more than 180 degrees around the circle. What you do at each "node" is dependent on where you entered.
I can do more of these diagrams if you want. They don't take me long.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FBEnSScs.png&hash=c84094b8d24a50a12c6cccf1513f9f182151d911)
Quote from: jakeroot on November 16, 2016, 02:51:57 PM
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FBEnSScs.png&hash=c84094b8d24a50a12c6cccf1513f9f182151d911)
OK, so if I'm in the left pink entrance lane destined for the left blue exit lane, I'm in conflict with the right yellow entrance lane if he's going 180 around the circle. In a properly-striped roundabout, my path would shunt over and merge with his entrance path. But in this case it doesn't; I'm still in the left lane and cutting across his right lane.
iPhone
Around here, our multilane roundabouts say "yield to all lanes in circle" for that reason. Multilane modern roundabouts use the European rules, but traffic circles are ambiguous, so you could have the situation where the left lane is in conflict with the right there.
Quote from: jakeroot on November 15, 2016, 06:07:15 PM
Both lanes can proceed past this exit, but at the next exit, the right lane becomes an exit only.
Quote from: jakeroot on November 16, 2016, 02:51:57 PM
The person in the right lane must exit. If there's a conflict, it's because the person in the right lane incorrectly continued around the circle.
These two statements are contradictory. If I am in the left lane, intending to proceed straight through the roundabout, then my path conflicts with a driver entering from my right using the right lane and intending to proceed straight through the roundabout. Photobucket is being stupid right now, so I can't post the illustration I made.
Quote from: empirestate on November 16, 2016, 03:23:03 PM
OK, so if I'm in the left pink entrance lane destined for the left blue exit lane, I'm in conflict with the right yellow entrance lane if he's going 180 around the circle. In a properly-striped roundabout, my path would shunt over and merge with his entrance path. But in this case it doesn't; I'm still in the left lane and cutting across his right lane.
See my response below. It may answer this concern.
Quote from: kphoger on November 16, 2016, 05:46:52 PM
[click link above for original quote]
These two statements are contradictory. If I am in the left lane, intending to proceed straight through the roundabout, then my path conflicts with a driver entering from my right using the right lane and intending to proceed straight through the roundabout. Photobucket is being stupid right now, so I can't post the illustration I made.
What you do at each node is dependent on where you entered, and is the reason why spiral markings are now preferred. Ideally, avoid driving next to someone who merged from an entry leg other than your own, because at each node, there'd be a conflict between drivers who are, in their head, going straight, and other drivers who are, in their head, going left.
To say this is hard to explain would be an understatement.
Let's see if I can summarize the four pages of this thread: Every diverge should be striped to allow, at max, one driver to make a choice. :D
Quote from: jakeroot on November 16, 2016, 06:23:51 PM
Quote from: empirestate on November 16, 2016, 03:23:03 PM
OK, so if I'm in the left pink entrance lane destined for the left blue exit lane, I'm in conflict with the right yellow entrance lane if he's going 180 around the circle. In a properly-striped roundabout, my path would shunt over and merge with his entrance path. But in this case it doesn't; I'm still in the left lane and cutting across his right lane.
See my response below. It may answer this concern.
Quote from: kphoger on November 16, 2016, 05:46:52 PM
[click link above for original quote]
These two statements are contradictory. If I am in the left lane, intending to proceed straight through the roundabout, then my path conflicts with a driver entering from my right using the right lane and intending to proceed straight through the roundabout. Photobucket is being stupid right now, so I can't post the illustration I made.
What you do at each node is dependent on where you entered, and is the reason why spiral markings are now preferred. Ideally, avoid driving next to someone who merged from an entry leg other than your own, because at each node, there'd be a conflict between drivers who are, in their head, going straight, and other drivers who are, in their head, going left.
To say this is hard to explain would be an understatement.
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2Frbt_conflict_zpshidjw3o4.png&hash=79615e73f4d3820a1bc0350943561c63c21ab4e0)
This thread has gotten off topic by now, but it has somehow managed to fit quite nicely into the 'crash-prone modern roundabouts' discussion–i.e., what it is about multi-lane roundabouts that can lead to accidents.
Quote from: kphoger on November 16, 2016, 09:50:54 PM
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2Frbt_conflict_zpshidjw3o4.png&hash=79615e73f4d3820a1bc0350943561c63c21ab4e0)
If it's a standard roundabout, then everyone is required to yield upon entry to the roundabout. This means the blue car was required to yield to all traffic already in the roundabout, meaning the blue car was required to yield to the red car.
Quote from: stridentweasel on November 17, 2016, 12:33:46 AM
Quote from: kphoger on November 16, 2016, 09:50:54 PM
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2Frbt_conflict_zpshidjw3o4.png&hash=79615e73f4d3820a1bc0350943561c63c21ab4e0)
If it's a standard roundabout, then everyone is required to yield upon entry to the roundabout. This means the blue car was required to yield to all traffic already in the roundabout, meaning the blue car was required to yield to the red car.
Ah, well that's the whole issue–it isn't a standard roundabout. (Here again is a link (https://goo.gl/maps/NFRfXYM7WxJ2) to the one in question.)
In our case, the red car is in the left lane of the circle, which is just striped to be concentric to the central island. Cars can change lanes into and out of it, but there's no visual indication that the left lane offers an exit to the left lane of the leg of the intersection. However, when I pondered what the left lane's purpose was, it was suggested that it is indeed intended to function this way. This leads to conflicts between exiting traffic in the left lane of the circle, and traffic entering its right lane.
(Also, the blue car doesn't have to be traveling through the circle to pose a conflict. It could also be entering from the right lane but taking the left lane of the first exit.)
Quote from: stridentweasel on November 17, 2016, 12:33:46 AM
Quote from: kphoger on November 16, 2016, 09:50:54 PM
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
If it's a standard roundabout, then everyone is required to yield upon entry to the roundabout. This means the blue car was required to yield to all traffic already in the roundabout, meaning the blue car was required to yield to the red car.
That statement would mean that only one car would be permitted in a roundabout at one time, which is by far not the objective of a roundabout, and would lead to significant congestion.
A car in the right lane, pulling into the right lane, only should need to worry about the right lane.
Quote from: jeffandnicole on November 17, 2016, 10:43:21 AM
Quote from: stridentweasel on November 17, 2016, 12:33:46 AM
Quote from: kphoger on November 16, 2016, 09:50:54 PM
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
If it's a standard roundabout, then everyone is required to yield upon entry to the roundabout. This means the blue car was required to yield to all traffic already in the roundabout, meaning the blue car was required to yield to the red car.
That statement would mean that only one car would be permitted in a roundabout at one time, which is by far not the objective of a roundabout, and would lead to significant congestion.
A car in the right lane, pulling into the right lane, only should need to worry about the right lane.
That's true in theory. But in practice, there's lots of spiralling that occurs within roundabouts. It's not always a safe to merge into a roundabout right next to someone else.
empirestate
To me, the question of how striping should be done is a different (though related) topic from what people should and shouldn't do from a given lane. After all, I don't know how the circulating roadway of a multi-lane roundabout is striped upon approach; I choose my lane before I ever get to that point, based on my intended path.
jeffandnicle
That may be overstating things. There's a big difference between saying an approaching driver must yield to everyone in the roundabout and saying an approaching driver must wait for all traffic to completely clear the roundabout before entering. It might be fair to say the blue driver must yield to the red driver if their paths might conflict, or it might be fair to say there's an inherent problem in the design.
Quote from: kphoger on November 17, 2016, 12:46:40 PM
jeffandnicle
That may be overstating things. There's a big difference between saying an approaching driver must yield to everyone in the roundabout and saying an approaching driver must wait for all traffic to completely clear the roundabout before entering. It might be fair to say the blue driver must yield to the red driver if their paths might conflict, or it might be fair to say there's an inherent problem in the design.
I simply responded to the message above mine: "This means the blue car was required to yield to all traffic already in the roundabout"
Quote from: jeffandnicole on November 17, 2016, 12:53:18 PM
I simply responded to the message above mine: "This means the blue car was required to yield to all traffic already in the roundabout"
I meant "yield" as in giving the other cars precedence at conflict points, not waiting for all traffic inside the roundabout to go away. My understanding of roundabout rules has always been that traffic entering a roundabout yields to traffic inside the roundabout when their paths conflict.
Quote from: empirestate on November 17, 2016, 10:16:54 AM
Ah, well that's the whole issue–it isn't a standard roundabout. (Here again is a link (https://goo.gl/maps/NFRfXYM7WxJ2) to the one in question.)
In our case, the red car is in the left lane of the circle, which is just striped to be concentric to the central island. Cars can change lanes into and out of it, but there's no visual indication that the left lane offers an exit to the left lane of the leg of the intersection. However, when I pondered what the left lane's purpose was, it was suggested that it is indeed intended to function this way. This leads to conflicts between exiting traffic in the left lane of the circle, and traffic entering its right lane.
(Also, the blue car doesn't have to be traveling through the circle to pose a conflict. It could also be entering from the right lane but taking the left lane of the first exit.)
Judging solely by the rule of who yields to whom, it's a standard roundabout. Judging by striping, suffice it to say that I'd agree that the striping in that example is confusing, and I believe the striping in kphoger's diagram is preferable.
Quote from: kphoger on November 17, 2016, 12:46:40 PM
empirestate
To me, the question of how striping should be done is a different (though related) topic from what people should and shouldn't do from a given lane. After all, I don't know how the circulating roadway of a multi-lane roundabout is striped upon approach; I choose my lane before I ever get to that point, based on my intended path.
To me as well. To be sure, better signage of the options approaching this roundabout would help, particularly as it pertains to which exit lane at the tollboth is E-ZPass only, and which is staffed. But my ponderance was based solely on the way it is actually striped, and how that suggests the inner lane of the circle is meant to be used. Or, for that matter, the outer lane, since the way it's striped suggests that someone in that lane could continue around the circle indefinitely; it never guides you to either (and only) the first or second exit, as a proper roundabout would.
Well, I think the only thing I now understand about roundabouts after this last page or so is the reason why so many people despise them so much.
At least at an admittedly less efficient 4 way intersection with traffic control devices in place its not hard to tell who should be doing what in each lane of the intersection. Fool Proof? No, and the thousands of intersection crashes every year attest to that, but at least when the dust settles, it's pretty easy to figure out who screwed up.
I have always been ambivalent about roundabouts. I like them for their efficiency but hate them for the fact that if the members of a road related forum can't agree on how to use them, how in the hell can we expect little Ms Soccermom who is barely able to pay attention to the road with a van full of screaming kids to figure out how to use them? Which lane to be in, who has the right of away, oh GOD why is this idiot in front of me slamming on the brakes we don't have to stop?!?!
Quote from: jeffandnicole on November 17, 2016, 10:43:21 AM
Quote from: stridentweasel on November 17, 2016, 12:33:46 AM
Quote from: kphoger on November 16, 2016, 09:50:54 PM
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
If it's a standard roundabout, then everyone is required to yield upon entry to the roundabout. This means the blue car was required to yield to all traffic already in the roundabout, meaning the blue car was required to yield to the red car.
That statement would mean that only one car would be permitted in a roundabout at one time, which is by far not the objective of a roundabout, and would lead to significant congestion.
A car in the right lane, pulling into the right lane, only should need to worry about the right lane.
That kind of activity should get you the horn. You pull out only when
ALL lanes are clear. Otherwise, you are at fault for that crash, and will get the ticket assigned to you.
Quote from: Brandon on December 06, 2016, 10:13:50 AM
Quote from: jeffandnicole on November 17, 2016, 10:43:21 AM
Quote from: stridentweasel on November 17, 2016, 12:33:46 AM
Quote from: kphoger on November 16, 2016, 09:50:54 PM
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
If it's a standard roundabout, then everyone is required to yield upon entry to the roundabout. This means the blue car was required to yield to all traffic already in the roundabout, meaning the blue car was required to yield to the red car.
That statement would mean that only one car would be permitted in a roundabout at one time, which is by far not the objective of a roundabout, and would lead to significant congestion.
A car in the right lane, pulling into the right lane, only should need to worry about the right lane.
That kind of activity should get you the horn. You pull out only when ALL lanes are clear. Otherwise, you are at fault for that crash, and will get the ticket assigned to you.
How come? I'm pulling out from the right lane to the right lane. I'm not impacting the vehicle in the left lane.
Please state the statute number that I have violated by doing the above.
Quote from: slorydn1 on December 06, 2016, 07:59:01 AM
Well, I think the only thing I now understand about roundabouts after this last page or so is the reason why so many people despise them so much.
Meaning, people despise modern roundabouts because of the uncertainty surrounding old-fashioned traffic circles?
Quote from: slorydn1 on December 06, 2016, 07:59:01 AM
I have always been ambivalent about roundabouts. I like them for their efficiency but hate them for the fact that if the members of a road related forum can't agree on how to use them, how in the hell can we expect little Ms Soccermom who is barely able to pay attention to the road with a van full of screaming kids to figure out how to use them? Which lane to be in, who has the right of away, oh GOD why is this idiot in front of me slamming on the brakes we don't have to stop?!?!
I don't think we (forum members) have any trouble figuring out how to use roundabouts; the confusion in recent posts has been about whether and how to apply the lane assignment conventions of modern roundabouts to an older installation whose lane markings don't match that usage.
You're quite right, though, that the average motorist tends to find them confusing. The biggest hang-up I normally see is that people stop on the approach when there is no traffic in the circle, which reduces the efficiency of the design. Honestly, in my area it's not a major delay at all, but being this close to NYC/NJ/CT, it's just frustrating that the one and only time you can always count on people to observe a stop or yield sign is when they don't even need to! :-D
Quote from: jeffandnicole on December 06, 2016, 10:25:42 AM
Quote from: Brandon on December 06, 2016, 10:13:50 AM
Quote from: jeffandnicole on November 17, 2016, 10:43:21 AM
Quote from: stridentweasel on November 17, 2016, 12:33:46 AM
Quote from: kphoger on November 16, 2016, 09:50:54 PM
OK, I'm back home again and Photobucket is cooperating. Here is my illustration. If I am following the red path, then I conflict with a car following the blue path at my point of exit. To say that I should avoid driving next to that blue-path car doesn't help at all, because that car doesn't enter the roundabout until I'm already committed to exiting.
If it's a standard roundabout, then everyone is required to yield upon entry to the roundabout. This means the blue car was required to yield to all traffic already in the roundabout, meaning the blue car was required to yield to the red car.
That statement would mean that only one car would be permitted in a roundabout at one time, which is by far not the objective of a roundabout, and would lead to significant congestion.
A car in the right lane, pulling into the right lane, only should need to worry about the right lane.
That kind of activity should get you the horn. You pull out only when ALL lanes are clear. Otherwise, you are at fault for that crash, and will get the ticket assigned to you.
How come? I'm pulling out from the right lane to the right lane. I'm not impacting the vehicle in the left lane.
Please state the statute number that I have violated by doing the above.
And should that vehicle in the left lane decides to change lanes, you're the one who will get hit.
Plus, in a modern roundabout, vehicles don't necessarily STAY in the same lane. In a properly striped roundabout, the right lane exits off, and the left becomes the right, with a new one forming on the left, often with traffic exiting from the left as well! If you didn't yield to all lanes, you'd cause an accident.
https://goo.gl/maps/hSLpBVfwNBr
Quote from: vdeane on December 06, 2016, 12:42:47 PM
Plus, in a modern roundabout, vehicles don't necessarily STAY in the same lane. In a properly striped roundabout, the right lane exits off, and the left becomes the right, with a new one forming on the left, often with traffic exiting from the left as well! If you didn't yield to all lanes, you'd cause an accident.
https://goo.gl/maps/hSLpBVfwNBr
Is this improperly striped then?
https://www.google.com/maps/@34.7576915,-86.6879507,3a,75y,168.38h,72.48t/data=!3m6!1e1!3m4!1sDGhm0lMg2mQ_jBvVO4wC2g!2e0!7i13312!8i6656
Not sure what they're going for there; half the roundabout is a single lane, but the other half is hard to say since there are no markings in the circle there. One of those yield lines is definitely in an odd place, though.
Quote from: briantroutman on May 08, 2015, 03:58:47 PM
There seems to be some misunderstanding as to what I’m talking about, so maybe a simplified diagram would be clearer.
(https://farm8.staticflickr.com/7738/17430516692_9edb7a41c8_o.png)
The exit ramp for CA-13 from I-580 in Oakland is a good example, albeit somewhat stretched out, of version #1. There is no dotted line, but the concrete/asphalt separation serves the same purpose:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FE75Pf0Q.png&hash=b46cfe18a8bfda76f109bcfa7a0c329eb41fbe94)
Quote from: vdeane on December 06, 2016, 12:42:47 PM
Plus, in a modern roundabout, vehicles don't necessarily STAY in the same lane. In a properly striped roundabout, the right lane exits off, and the left becomes the right, with a new one forming on the left, often with traffic exiting from the left as well! If you didn't yield to all lanes, you'd cause an accident.
https://goo.gl/maps/hSLpBVfwNBr
A properly striped roundabout doesn't necessarily have the right lane exit off right away though. Depends on the turning geometry desired. For example, for a double left turn northbound, that right lane circles around and exits off at the third exit (westbound).
Entering traffic must yield in part because of these types of cases.
So, Brandon and vdeane...I now see your points. And I almost begrudgingly agree with tradephoric...I can see why these 2 lane roundabouts can have a fairly high accident rate. If I'm approaching a roundabout, while it's signed to tell me what I need to do to get to any of the outputs, I don't know what those within the roundabout will be doing. Yeah, I guess that's where turn signals can come into play, but the movements are so short that the signal, even when properly used, will give a very short moment's notice as to the driver's intention.
I realize this might qualify as "NOT THIS #3", but I certainly think it's worthy of honorable mention. At this location on the north side of Monterrey (https://goo.gl/maps/T1aMHDWdD1h5H6g29), it appears that two dropped southbound lanes become seven exit lanes, which are divided into three channelizations.
In the image below, the orange line is the only true through lane. The two green lines are the two dropped lanes, which split into seven. Signage visible in GSV indicates that only the right lane is considered to be an actual dropped lane, but the second lane ends immediately after the exit(s). So I guess, if you want to follow signage, then it truly is a seven-lane exit from a single lane.
(https://i.imgur.com/LYmYZ9i.png)