In situations where one multi-lane road or ramp joins another, which states allow the center lanes to merge together while retaining the outside lanes?
Here's an example (https://www.google.com/maps/@42.8831534,-112.4284246,3a,37.5y,161.39h,77.71t/data=!3m6!1e1!3m4!1s9VIKtwOansYcStnpwL5SGA!2e0!7i16384!8i8192) I found while browsing Street View for another thread. I think I've seen a similar situation in Ohio, but it strikes me as potentially unsafe, and I'm pretty sure that type of striping is not allowed here in New York.
Quote from: webny99 on February 21, 2021, 10:37:10 PM
In situations where one multi-lane road or ramp joins another, which states allow the center lanes to merge together while retaining the outside lanes?
Here's an example (https://www.google.com/maps/@42.8831534,-112.4284246,3a,37.5y,161.39h,77.71t/data=!3m6!1e1!3m4!1s9VIKtwOansYcStnpwL5SGA!2e0!7i16384!8i8192) I found while browsing Street View for another thread. I think I've seen a similar situation in Ohio, but it strikes me as potentially unsafe, and I'm pretty sure that type of striping is not allowed here in New York.
We have some here in North Carolina (practically at dated interchanges).
I-494 NB to I-94 WB in Maple Grove, MN, though I'm assuming this will go away as part of the rebuild. All three movements in the Fish Lake interchange used to feature this, but the NB 494-EB 94/694 merge was fixed in 2004 and the EB 94-SB 494 in 2018.
Does the 90/94 EB merge into the Dan Ryan still have this?
There is one on eastbound I-20 at I-520 (https://www.google.com/maps/@33.4971558,-82.0740726,45m/data=!3m1!1e3) in Augusta, GA. It very much caught me off guard - especially with the extra ramp coming in from Walton Way Ext - and I would be in favor of removing all instances of this type of merge.
Here's a dangerous example (https://goo.gl/maps/aPf8QRoT6FDNjLZp6) where northbound I-75 merges to itself at I-375 in downtown Detroit. Spin the view around 180 degrees and you'll see where the barrier wall of the onramp blocks the view to the thru lanes from I-375.
Westbound I-696 onramp from M-1 (https://goo.gl/maps/ovsaxwsFUaxW17MX9) in Pleasant Ridge, Michigan.
Reagan Highway and I-275 in Cincinnati (https://www.google.com/maps/@39.229229,-84.638422,3a,75y,251.29h,79.1t/data=!3m6!1e1!3m4!1s91A1Yn4mCtUqTpYTHY6x3A!2e0!7i16384!8i8192)
NB I-93/I-293 north of Manchester, NH. A tad troublesome if you're on NB 93 and trying to get left for the Express Lanes at the Hooksett toll booth.
Quote from: TheHighwayMan394 on February 21, 2021, 10:47:37 PM
Does the 90/94 EB merge into the Dan Ryan still have this?
I am thinking that you've meant this: https://www.google.com/maps/@41.9611756,-87.7440334,3a,75y,165.2h,80.24t/data=!3m6!1e1!3m4!1svNLE8VnMbXOEND1JKx1yFQ!2e0!7i16384!8i8192
94 EB (SB) merge into the Kennedy (90) from the Edens
Another one in the Chicagoland region:
https://www.google.com/maps/@41.5774109,-87.5699597,3a,30y,76.93h,89.53t/data=!3m6!1e1!3m4!1sw1QuWdAqsTLK1_R6lBXA2Q!2e0!7i16384!8i8192
94 EB merging onto 80 from the Bishop Ford towards Indiana
In NJ the AC Expressway has 5 examples.
First and most common example: AC Expressway WB at 42 NB:
https://maps.app.goo.gl/a1YC9nPh4VDSb4om8
The other 4 examples would be both directions at each mainline toll plaza on the Expressway, where the right lane of the Express EZ Pass lane merges into what becomes the left lane from the traditional toll plaza lanes, such as:
https://maps.app.goo.gl/sHFZtbQGyMZuwbtH8
This one is on I-280 in Kearny, NJ.
https://www.google.com/maps/@40.7458253,-74.1337237,3a,25.2y,49.57h,86t/data=!3m6!1e1!3m4!1s3w1ls8DDM0YIea6oZKcc8Q!2e0!7i16384!8i8192
It's pretty terrible. No warning and the geometry makes it difficult to expect. Out of all the states NJ seems to be the one that will never tell you in advance of a lane ending, beginning, exiting, etc.
I-205 south to I-5 north https://goo.gl/maps/cFDtSLyiEX4nbU9QA
Formally: OR 99W north to I-5 north via I-5 trucklanes at exit 294. It used to be a 3+3 merge, with the center lanes merging as to allow the trucks climbing the grade an uninterrupted lane.
Quote from: Great Lakes Roads on February 22, 2021, 12:35:42 AM
Quote from: TheHighwayMan394 on February 21, 2021, 10:47:37 PM
Does the 90/94 EB merge into the Dan Ryan still have this?
I am thinking that you've meant this: https://www.google.com/maps/@41.9611756,-87.7440334,3a,75y,165.2h,80.24t/data=!3m6!1e1!3m4!1svNLE8VnMbXOEND1JKx1yFQ!2e0!7i16384!8i8192
94 EB (SB) merge into the Kennedy (90) from the Edens
Another one in the Chicagoland region:
https://www.google.com/maps/@41.5774109,-87.5699597,3a,30y,76.93h,89.53t/data=!3m6!1e1!3m4!1sw1QuWdAqsTLK1_R6lBXA2Q!2e0!7i16384!8i8192
94 EB merging onto 80 from the Bishop Ford towards Indiana
The Illinois tollways also have a number of these. Both the ramp from I-88 W to I-355 S and from I-355 N to I-88 E have it. Also, both the ramp from I-57 N to I-294 N and from I-294 S to I-57 S. Also, I-88 E to I-294 S has it, or at least used to, and so do the combined ramps from I-355 N and I-355 S to I-55 N. There might be more.
South Carolina had at least two of these:
I-385 SB merge with I-26 EB which was restriped to eliminate
US 52 CONN merge with I-26 EB at Exit 209. This was completely reconstructed to a new configuration.
The last one I remember driving through was I-55/72 merge in Springfield IL which GMSV shows is still there.
These are dangerous if you don't know this is the configuration when you get there. I almost got in a wreck in Dallas once because of one of these after sunset and there was no warning.
Yes. IH 69/US 59 and SH 288 in Houston. They meet up in a dual freeway system after leaving IH 45. The way it works, if you're trying to get into IH 69 south from 45, you first exit onto what is the beginning of SH 288 for a about a quarter of a mile before the right lane merged into the center of the whole complex. I may not have described it the best but check out a video or a picture online sometime and you'll see what I mean.
How common is the reverse? Because that happens at the Express-Local split on I-78.
Quote from: TheGrassGuy on February 22, 2021, 07:20:25 AM
How common is the reverse? Because that happens at the Express-Local split on I-78.
What do you mean by reverse, outside lanes merging or inside lanes splitting to exit? They're both common.
Quote from: webny99 on February 21, 2021, 10:37:10 PM
.... I'm pretty sure that type of striping is not allowed here in New York.
Here's one in Brooklyn: The Belt Parkway's right lane and the left lane of the ramp from the Verrazzano merge. (Link from Google Maps app, pan around as needed. I'll try to replace it with a link from my PC later this morning.)
https://goo.gl/maps/qBvTtHz6FmB8QvcDAEdited to use a link from the website on my PC: https://goo.gl/maps/GauNLQoaYqHpTwV78 Funny thing is, when I view the other link on my PC, it doesn't require me to pan. Strange.
If you click that back to 2013, you'll see the lane configuration more clearly due to lighter traffic.
Quote from: jeffandnicole on February 22, 2021, 12:46:51 AM
The other 4 examples would be both directions at each mainline toll plaza on the Expressway, where the right lane of the Express EZ Pass lane merges into what becomes the left lane from the traditional toll plaza lanes, such as:
https://maps.app.goo.gl/sHFZtbQGyMZuwbtH8
I don't like that, but I don't mind it so much as the other examples just because speeds are lower, and merges are often weird coming out of toll booths.
The other well-known example from New Jersey is on the southbound Turnpike where the "dual-dual" configuration ends:
https://goo.gl/maps/ktvmjMUkHg6LquBx8
Quote from: 1995hoo on February 22, 2021, 07:42:03 AM
Here's one in Brooklyn: The Belt Parkway's right lane and the left lane of the ramp from the Verrazzano merge.
...
Edited to use a link from the website on my PC: https://goo.gl/maps/GauNLQoaYqHpTwV78
Well, at least they've got good signage for it - best I've seen so far. I wouldn't be surprised if that's the only example in the state.
To a certain extent, this actually makes
more sense in high-traffic, space-constrained place like NYC. Then, not only are people going slow enough to get a better view of the merge, they can just take turns merging and traffic should keep flowing more evenly rather than the side with the lane ending getting significantly more jammed up.
Quote from: 1995hoo on February 22, 2021, 08:06:33 AM
The other well-known example from New Jersey is on the southbound Turnpike where the "dual-dual" configuration ends:
https://goo.gl/maps/ktvmjMUkHg6LquBx8
I've driven that stretch and had forgotten about that configuration. I don't hate it there, either. It's not perfect, but I understand why they don't want two lanes ending on a single side, and the signage and striping are well done.
Quote from: webny99 on February 22, 2021, 08:11:13 AM
Quote from: 1995hoo on February 22, 2021, 07:42:03 AM
Here's one in Brooklyn: The Belt Parkway's right lane and the left lane of the ramp from the Verrazzano merge.
...
Edited to use a link from the website on my PC: https://goo.gl/maps/GauNLQoaYqHpTwV78
Well, at least they've got good signage for it - best I've seen so far. I wouldn't be surprised if that's the only example in the state.
To a certain extent, this actually makes more sense in high-traffic, space-constrained place like NYC. Then, not only are people going slow enough to get a better view of the merge, they can just take turns merging and traffic should keep flowing more evenly rather than the side with the lane ending getting significantly more jammed up.
Some years back we were discussing the Jersey Turnpike's use of this configuration at the southern end of the "dual-dual" setup, which at the time was near Exit 8A and of course is now near Exit 6. Forum member jeffandnicole gave this explanation:
Quote from: jeffandnicole on August 02, 2011, 08:00:18 PM
Jumping on this thread rather late, but at one of the local meetings prior to the start of any construction, I asked the very question about the merge at the car/truck lanes (the turnpike actually knows them as SNI, SNO (South to North Inner & Outer Drives), NSI and NSO (North to South Inner & Outer Drives). A representive of the turnpike stated that their studies showed that a merging of two lanes at once produced fewer lane merges and allowed traffic to flow at a more steady pace than trying to merge one lane into another, then that lane again into another - regardless if it was a right lane end or left lane end. Again, as mentioned before, only the turnpike powers-to-be know the real reason.
For the 3x3 drives, in most cases car/trucks/buses will only be in the 2 right lanes of the outer drive, so they will merge into one lane, and cars will exclusively use the Left and center lanes of the inner drive, and the right lane of the inner drive and the left lane of the outer drive. And having said all of that, traffic volumes drop dramatically below interchange 6. The merge will be 2 miles below the interchange, so except for the heaviest travel weekends and holidays, it shouldn't be a problem.
I also inquired about the lack of acceleration lanes (the turnpike typically has long decel lanes, but non-existent accel lanes). Part of the widening project will include longer accel lanes. Actually, many of the onramps in the construction zone have temporary lengthened accel lanes already...the exact opposite of many construction zones where there are stop signs at the end of the ramps!
One final note for now: One reason the turnpike doesn't know the lanes as car and car/truck/bus lanes is that at any time a ramp is closed from an interchange or service plaza to the outer drive, trucks are permitted from the interchange onto the inner drive, and are not forced to exit that carriageway. After the widening project, that would mean any of 14 interchanges and 3 service plazas along the dual-dual section could have a ramp closure that would lead to trucks using the 'car' lanes.
I suppose there might be something to the idea of the center two lanes merging at a given point being a potential reason to do a proper zipper merge in those two lanes because there is no advantage to "merging early."
Quote from: tolbs17 on February 21, 2021, 10:41:54 PM
We have some here in North Carolina (practically at dated interchanges).
The one on [By-Pass] US-15/501 southbound merging with Durham-Chapel Hill Boulevard (Bus US-15/501) near South Square was changed a few years ago. Before then, Durham-Chapel Hill Boulevard was three lanes southbound with a right lane drop before merging into 15/501 two lanes southbound. The middle lanes merged there. After the change, the original concept had the second right lane drop before a merge into the far left lane of 15/501. About a year later, that was changed to have the left lane drop and the remaining middle lane shift over to left hand merge.
The merge worked well prior to the change, balancing traffic weaving patterns for right and left turns before the AMF Bowling Alley crossover and Garrett Road intersection. However, this is a poor drainage area on 15/501 and there had been numerous accidents during flooding conditions blocking the two lanes of 15/501 (with bypass traffic pushing over into the both lanes of Durham-Chapel Hill Boulevard before the merge point). Worse, I've seen a number of accidents when this area was iced over and cars spun out into the merge lanes. Speeds on 15/501 drop from 60MPH to 45MPH just before the merge and nobody pays attention (most cars going over 70MPH) until closing in on the traffic signal at Garrett Road.
Quote from: CtrlAltDel on February 22, 2021, 03:27:39 AM
Quote from: Great Lakes Roads on February 22, 2021, 12:35:42 AM
Quote from: TheHighwayMan394 on February 21, 2021, 10:47:37 PM
Does the 90/94 EB merge into the Dan Ryan still have this?
I am thinking that you've meant this: https://www.google.com/maps/@41.9611756,-87.7440334,3a,75y,165.2h,80.24t/data=!3m6!1e1!3m4!1svNLE8VnMbXOEND1JKx1yFQ!2e0!7i16384!8i8192
94 EB (SB) merge into the Kennedy (90) from the Edens
Another one in the Chicagoland region:
https://www.google.com/maps/@41.5774109,-87.5699597,3a,30y,76.93h,89.53t/data=!3m6!1e1!3m4!1sw1QuWdAqsTLK1_R6lBXA2Q!2e0!7i16384!8i8192
94 EB merging onto 80 from the Bishop Ford towards Indiana
The Illinois tollways also have a number of these. Both the ramp from I-88 W to I-355 S and from I-355 N to I-88 E have it. Also, both the ramp from I-57 N to I-294 N and from I-294 S to I-57 S. Also, I-88 E to I-294 S has it, or at least used to, and so do the combined ramps from I-355 N and I-355 S to I-55 N. There might be more.
I-294 north/south to I-90 westbound
Quote from: webny99 on February 21, 2021, 10:37:10 PM
In situations where one multi-lane road or ramp joins another, which states allow the center lanes to merge together while retaining the outside lanes?
Here's an example (https://www.google.com/maps/@42.8831534,-112.4284246,3a,37.5y,161.39h,77.71t/data=!3m6!1e1!3m4!1s9VIKtwOansYcStnpwL5SGA!2e0!7i16384!8i8192) I found while browsing Street View for another thread. I think I've seen a similar situation in Ohio, but it strikes me as potentially unsafe, and I'm pretty sure that type of striping is not allowed here in New York.
You might need to get to Binghamton (https://www.google.com/maps/@42.1353552,-75.9032161,3a,75y,1.23h,67.69t/data=!3m6!1e1!3m4!1sDK1gipMFRfiIc7rZyZ8BvQ!2e0!7i16384!8i8192) more often.
Quote from: vdeane on February 22, 2021, 12:51:16 PM
Quote from: webny99 on February 21, 2021, 10:37:10 PM
... it strikes me as potentially unsafe, and I'm pretty sure that type of striping is not allowed here in New York.
You might need to get to Binghamton (https://www.google.com/maps/@42.1353552,-75.9032161,3a,75y,1.23h,67.69t/data=!3m6!1e1!3m4!1sDK1gipMFRfiIc7rZyZ8BvQ!2e0!7i16384!8i8192) more often.
Slightly different because there are a few dashes before the merge... but for how many times I've been by there, it is surprising that I had no idea that was there. It should be striped so that the right lane ends and the second lane become the exit only lane. That's clearly how I
thought it was striped, or I would have noticed and remembered it.
Quote from: webny99 on February 21, 2021, 10:37:10 PM
In situations where one multi-lane road or ramp joins another, which states allow the center lanes to merge together while retaining the outside lanes?
Here's an example (https://www.google.com/maps/@42.8831534,-112.4284246,3a,37.5y,161.39h,77.71t/data=!3m6!1e1!3m4!1s9VIKtwOansYcStnpwL5SGA!2e0!7i16384!8i8192) I found while browsing Street View for another thread. I think I've seen a similar situation in Ohio, but it strikes me as potentially unsafe, and I'm pretty sure that type of striping is not allowed here in New York.
There are a few places where this happens here in the SF Bay Area, often enough that I don't even consider it all that unusual...
The first one to come to mind, which is also fairly unpleasant to navigate at most times is where westbound CA-24 traffic has to merge with westbound I-580 traffic, in an area locally known as the MacArthur Maze.
https://www.google.com/maps/@37.8263458,-122.2762389,3a,75y,288.48h,84.63t/data=!3m7!1e1!3m5!1si7wS97c2f6hcIbskopMFaQ!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3Di7wS97c2f6hcIbskopMFaQ%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D355.29285%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192
There is another one not far from where I live where the I-680 North merges with I-80 East:
https://www.google.com/maps/@38.2189487,-122.1341968,3a,75y,61.73h,78.16t/data=!3m7!1e1!3m5!1sXqB9NOiFDUlRMLzOH6oPyA!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DXqB9NOiFDUlRMLzOH6oPyA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D158.89418%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192
I am sure there are several others around here.
I think we need a poll on whether this should be banned or not. Overall, I still think so, but this thread has been enlightening as to how/why it can be useful in certain contexts.
I think it should be banned, in favor of either the left or right lane merging.
Another NY example: https://goo.gl/maps/tDchZpL9QMRkD7Ns5
Personally, I think it should be banned. Much safer to do an added lane for the two center lanes and then right/left lane ends
Quote from: interstatefan990 on February 23, 2021, 09:49:19 PM
Personally, I think it should be banned. Much safer to do an added lane for the two center lanes and then right/left lane ends
Do we know this, though? It could be that they're fairly common where I'm from, but to me they don't seem more dangerous than anything else.
Quote from: CtrlAltDel on February 23, 2021, 10:54:23 PM
Quote from: interstatefan990 on February 23, 2021, 09:49:19 PM
Personally, I think it should be banned. Much safer to do an added lane for the two center lanes and then right/left lane ends
Do we know this, though? It could be that they're fairly common where I'm from, but to me they don't seem more dangerous than anything else.
Center-lane merging situations are usually difficult to post advance warning of since it seems to me they are often found on wide highways and drivers may miss a sign on the side of the road. When drivers reach the actual merging point and finally realize what's happening, they have to focus on three things at once: looking out for traffic merging from the through lane beside them, safely merging with the traffic from the merging lane, and keeping a safe distance from the traffic ahead of them. I'd err on the side of caution and say this is too much happening at once to be considered safe. However, I would make an exception for low-speed urban roads where there's less pressure, but only if there's a clearly visible merge sign providing advance warning.
I was almost in a collision near Montreal when driving there for the first time with a merge like this. Anyone know if it's more common up there?
I've heard a reference to this type of merge as a "suicide squeeze". There is one on the four-level in downtown L.A. at the northbound U.S. 101 merge from CA 110:
https://goo.gl/maps/e5x9zi2hb9SeTLdS6
and another at the East L.A Interchange on WB Interstate 10 where it connects with the ramp from SB Interstate 5:
https://goo.gl/maps/URo4KLSrw4KobCdj8
I really don't see why it's a big deal, besides being unusual. Merging occurs no matter which lane ends.
I think I've seen this somewhere in WA. But the actual last time I saw this, with certainty, was merging from southbound I-69 to I-465 (https://goo.gl/maps/Av94iF2TvjudbMyR9) northeast of Indianapolis.
I'm fine with them on low-speed roads, but I'm a bit uncomfortable with them on high-speed roads. With adequate signage, not such a huge deal, I suppose, but I'd still prefer a different design.
Quote from: interstatefan990 on February 23, 2021, 11:25:05 PM
Quote from: CtrlAltDel on February 23, 2021, 10:54:23 PM
Quote from: interstatefan990 on February 23, 2021, 09:49:19 PM
Personally, I think it should be banned. Much safer to do an added lane for the two center lanes and then right/left lane ends
Do we know this, though? It could be that they're fairly common where I'm from, but to me they don't seem more dangerous than anything else.
Center-lane merging situations are usually difficult to post advance warning of since it seems to me they are often found on wide highways and drivers may miss a sign on the side of the road. When drivers reach the actual merging point and finally realize what's happening, they have to focus on three things at once: looking out for traffic merging from the through lane beside them, safely merging with the traffic from the merging lane, and keeping a safe distance from the traffic ahead of them. I'd err on the side of caution and say this is too much happening at once to be considered safe. However, I would make an exception for low-speed urban roads where there's less pressure, but only if there's a clearly visible merge sign providing advance warning.
All that makes sense, of course, but so does the idea that inside lanes merging allows for smoother flow. So, the question is, what do the numbers say? I wouldn't be surprised either way, so I'm genuinely curious here.
ETA: I've been looking around here and there, but so far I haven't found anything addressing this issue.
Quote from: kphoger on February 24, 2021, 10:14:27 AM
I'm fine with them on low-speed roads, but I'm a bit uncomfortable with them on high-speed roads. With adequate signage, not such a huge deal, I suppose, but I'd still prefer a different design.
The main advantage seems to be higher capacity. I've noticed multi-lane ramps, where the outside lane ends after the merge, have lower usage of the ending lane (sometimes significantly so). In the inside-lane-merging style, there seems to be better distribution. Likely because (A) some drivers want to immediately merge left into 'faster' traffic, so they'll use the inside lane, but you also have (B) drivers using the outside, non-merging lane to avoid having to merge.
From using the one in Indianapolis that I linked earlier, the key seems to be a longer merge area/neutral zone.
Quote from: CtrlAltDel on February 24, 2021, 01:49:12 PM
Quote from: interstatefan990 on February 23, 2021, 11:25:05 PM
Quote from: CtrlAltDel on February 23, 2021, 10:54:23 PM
Quote from: interstatefan990 on February 23, 2021, 09:49:19 PM
Personally, I think it should be banned. Much safer to do an added lane for the two center lanes and then right/left lane ends
Do we know this, though? It could be that they're fairly common where I'm from, but to me they don't seem more dangerous than anything else.
Center-lane merging situations are usually difficult to post advance warning of since it seems to me they are often found on wide highways and drivers may miss a sign on the side of the road. When drivers reach the actual merging point and finally realize what's happening, they have to focus on three things at once: looking out for traffic merging from the through lane beside them, safely merging with the traffic from the merging lane, and keeping a safe distance from the traffic ahead of them. I'd err on the side of caution and say this is too much happening at once to be considered safe. However, I would make an exception for low-speed urban roads where there's less pressure, but only if there's a clearly visible merge sign providing advance warning.
All that makes sense, of course, but so does the idea that inside lanes merging allows for smoother flow. So, the question is, what do the numbers say? I wouldn't be surprised either way, so I'm genuinely curious here.
ETA: I've been looking around here and there, but so far I haven't found anything addressing this issue.
See Reply #20 quoting jeffandnicole's explanation of why the Jersey Turnpike uses center-lane merges.
Quote from: jakeroot on February 24, 2021, 01:59:05 PM
Quote from: kphoger on February 24, 2021, 10:14:27 AM
I'm fine with them on low-speed roads, but I'm a bit uncomfortable with them on high-speed roads. With adequate signage, not such a huge deal, I suppose, but I'd still prefer a different design.
The main advantage seems to be higher capacity. I've noticed multi-lane ramps, where the outside lane ends after the merge, have lower usage of the ending lane (sometimes significantly so). In the inside-lane-merging style, there seems to be better distribution. Likely because (A) some drivers want to immediately merge left into 'faster' traffic, so they'll use the inside lane, but you also have (B) drivers using the outside, non-merging lane to avoid having to merge.
From using the one in Indianapolis that I linked earlier, the key seems to be a longer merge area/neutral zone.
Another possible advantage is the merging vehicles have a second option with the center merge. If the right lane ends. You have one choice which is merge left. (Not counting the emergency use the shoulder option. Should it be counted? The shoulder is usually empty.) While with the center merge, merging vehicles can merge into the center lane or change lanes to the outer lane to which they are adjacent. Though I'm not sure if this is a true advantage.
Quote from: BrianP on February 24, 2021, 02:21:24 PM
Quote from: jakeroot on February 24, 2021, 01:59:05 PM
Quote from: kphoger on February 24, 2021, 10:14:27 AM
I'm fine with them on low-speed roads, but I'm a bit uncomfortable with them on high-speed roads. With adequate signage, not such a huge deal, I suppose, but I'd still prefer a different design.
The main advantage seems to be higher capacity. I've noticed multi-lane ramps, where the outside lane ends after the merge, have lower usage of the ending lane (sometimes significantly so). In the inside-lane-merging style, there seems to be better distribution. Likely because (A) some drivers want to immediately merge left into 'faster' traffic, so they'll use the inside lane, but you also have (B) drivers using the outside, non-merging lane to avoid having to merge.
From using the one in Indianapolis that I linked earlier, the key seems to be a longer merge area/neutral zone.
Another possible advantage is the merging vehicles have a second option with the center merge. If the right lane ends. You have one choice which is merge left. (Not counting the emergency use the shoulder option. Should it be counted? The shoulder is usually empty.) While with the center merge, merging vehicles can merge into the center lane or change lanes to the outer lane to which they are adjacent. Though I'm not sure if this is a true advantage.
I was going to mention that in my post but couldn't figure out how to word it. Indeed, you do have two options: left, as would be intended, but you can bail right as well if totally necessary. Seems like it might be safer.
No doubt these would always be unusual, but I still don't see how unusual is bad. Or even how going above and beyond with signage would be necessary. I think arrows and "left lane merges" signage would be perfectly adequate.
Quote from: jakeroot on February 24, 2021, 03:02:56 PM
Quote from: BrianP on February 24, 2021, 02:21:24 PM
Quote from: jakeroot on February 24, 2021, 01:59:05 PM
Quote from: kphoger on February 24, 2021, 10:14:27 AM
I'm fine with them on low-speed roads, but I'm a bit uncomfortable with them on high-speed roads. With adequate signage, not such a huge deal, I suppose, but I'd still prefer a different design.
The main advantage seems to be higher capacity. I've noticed multi-lane ramps, where the outside lane ends after the merge, have lower usage of the ending lane (sometimes significantly so). In the inside-lane-merging style, there seems to be better distribution. Likely because (A) some drivers want to immediately merge left into 'faster' traffic, so they'll use the inside lane, but you also have (B) drivers using the outside, non-merging lane to avoid having to merge.
From using the one in Indianapolis that I linked earlier, the key seems to be a longer merge area/neutral zone.
Another possible advantage is the merging vehicles have a second option with the center merge. If the right lane ends. You have one choice which is merge left. (Not counting the emergency use the shoulder option. Should it be counted? The shoulder is usually empty.) While with the center merge, merging vehicles can merge into the center lane or change lanes to the outer lane to which they are adjacent. Though I'm not sure if this is a true advantage.
I was going to mention that in my post but couldn't figure out how to word it. Indeed, you do have two options: left, as would be intended, but you can bail right as well if totally necessary. Seems like it might be safer.
No doubt these would always be unusual, but I still don't see how unusual is bad. Or even how going above and beyond with signage would be necessary. I think arrows and "left lane merges" signage would be perfectly adequate.
https://goo.gl/maps/muvEURUujBgNj2W19
https://goo.gl/maps/8mHVeAhcE7Nweh7S9 <---click just beyond the overpass to see the actual merge point
Quote from: 1995hoo on February 24, 2021, 03:23:27 PM
Quote from: jakeroot on February 24, 2021, 03:02:56 PM
Quote from: BrianP on February 24, 2021, 02:21:24 PM
Quote from: jakeroot on February 24, 2021, 01:59:05 PM
Quote from: kphoger on February 24, 2021, 10:14:27 AM
I'm fine with them on low-speed roads, but I'm a bit uncomfortable with them on high-speed roads. With adequate signage, not such a huge deal, I suppose, but I'd still prefer a different design.
The main advantage seems to be higher capacity. I've noticed multi-lane ramps, where the outside lane ends after the merge, have lower usage of the ending lane (sometimes significantly so). In the inside-lane-merging style, there seems to be better distribution. Likely because (A) some drivers want to immediately merge left into 'faster' traffic, so they'll use the inside lane, but you also have (B) drivers using the outside, non-merging lane to avoid having to merge.
From using the one in Indianapolis that I linked earlier, the key seems to be a longer merge area/neutral zone.
Another possible advantage is the merging vehicles have a second option with the center merge. If the right lane ends. You have one choice which is merge left. (Not counting the emergency use the shoulder option. Should it be counted? The shoulder is usually empty.) While with the center merge, merging vehicles can merge into the center lane or change lanes to the outer lane to which they are adjacent. Though I'm not sure if this is a true advantage.
I was going to mention that in my post but couldn't figure out how to word it. Indeed, you do have two options: left, as would be intended, but you can bail right as well if totally necessary. Seems like it might be safer.
No doubt these would always be unusual, but I still don't see how unusual is bad. Or even how going above and beyond with signage would be necessary. I think arrows and "left lane merges" signage would be perfectly adequate.
https://goo.gl/maps/muvEURUujBgNj2W19
https://goo.gl/maps/8mHVeAhcE7Nweh7S9 <---click just beyond the overpass to see the actual merge point
These must be examples related to
jeffandnicole's post about the NJ Turnpike on the last page.
I must say that a merging setup
exactly like this is not something I've seen before (and based on the comments, it seems this is unique to the NJ Turnpike), but I'll be damned if it doesn't look like it works really well. Bit more signage than maybe I was thinking necessary, but then I have virtually zero first-hand experience with this setup.
I would hate to see the lane usage on the outside carriageway of the NJ Turnpike if all of those lanes merged into the #3 lane of the inner southbound carriageway. Current distribution of traffic looks very good from Street View imagery.
The New Jersey Turnpike is a special case though. Their arrangement is an attempt to compromise among 3 possibilities: both roadways open, left roadway closed, or right roadway closed. A configuration that avoids inside merging would result in some amount of thru traffic having to change lanes twice.
(I think that instead of such a merge, one lane could be dropped from each of the roadways at Exit 6 so that only 4 lanes instead of 6 lanes reach the merge point)
In the cases of a merge between different roads, having "thru traffic" from the minor route (i.e. not thru traffic from the perspective of the dominant route) change lanes twice would be safer than inside lane traffic not having any escape room if unable to merge.
Quote from: ran4sh on February 24, 2021, 05:28:15 PM
In the cases of a merge between different roads, having "thru traffic" from the minor route (i.e. not thru traffic from the perspective of the dominant route) change lanes twice would be safer than inside lane traffic not having any escape room if unable to merge.
Would it though? I've not seen anyone here mention, with absolute certainty, that inside-lane merging is definitively less safe. I don't believe inside-lane merging is used to improve safety, granted, but the potential for danger seems mostly theoretical. Primarily, unfamiliarity with the setup could lead to dangerous situations. But the NJ Turnpike example is proof that even unfamiliar merging situations can be adequately marked and signed to the point of being perfectly manageable by drivers.
It's true that inside lane merging does not have that shoulder escape option** that an outside lane merge might have, but that's likely why most examples in this thread are exceptionally long. Long enough that not finding a merge point seems almost impossibly unlikely. And you'd still have the option of merging into the other lane; simply because it's another lane doesn't mean it will absolutely have cars in it.
** I've personally noticed that drivers are not necessarily keen to escape into shoulders, even when they should; I personally just witnessed a driver fail to find a gap on an on-ramp a couple days ago
stop and wait for a gap, despite the availability of a shoulder that he could have used to merge. Why exactly a driver would rather stop in an active lane of traffic than drive a couple hundred feet in a shoulder is beyond me (I was waiting for him to get rear-ended), but drivers really don't seem keen on driving in shoulders. Apart from passing left-turning traffic, I suppose. Point being that having an escape option be another lane might actually be safer. But that's no more hypothetical than inside-lane merging being dangerous, so...yeah.
^^ This is why I have a love-hate relationship with combined entry-exit ramps/weave lanes. They provide an escape for traffic that can't merge in time, allowing them to just continue to the exit and try again. But at the same time, they can be chaotic during periods of even slightly increased traffic levels, with several vehicles literally competing to merge into each other's spot all at once. I think traffic already on the freeway trying to take the exit technically has the right of way, but I'd be damned if I could find an everyday driver that actually knew that. Whenever I encounter this type of ramp, I always cross my fingers and hope no one is trying to enter while I exit or vice versa.
What is the best way to sign an inside lane merge? This is how my example of Reagan Hwy onto I-275 SB earlier in this thread is signed, and I find it to be pretty good in terms of signage.
(https://i.imgur.com/MP6bGea.png)
Quote from: jakeroot on February 24, 2021, 05:52:49 PM
... most examples in this thread are exceptionally long. Long enough that not finding a merge point seems almost impossibly unlikely.
On the other hand, the fact that they're usually so long (presumably to allow more merging space) is another reason why I dislike them: they create ambiguity, and drivers tend not to react well to ambiguity especially on a fast-moving freeway.
Quote from: SkyPesos on February 24, 2021, 07:09:59 PM
What is the best way to sign an inside lane merge?
I think that sign could be too easily mistaken as a triple added-lane with no merging necessary. This is my idea:
(https://i.ibb.co/bshFYHR/293-C2-EC5-4282-4643-866-E-34197-A65293-E.jpg)
Quote from: interstatefan990 on February 24, 2021, 07:06:30 PM
I think traffic already on the freeway trying to take the exit technically has the right of way, but I'd be damned if I could find an everyday driver that actually knew that.
This is the sort of thing that would depend greatly on each state's vehicle code. For example, in Illinois,
both drivers are required to accommodate
each other. See below.
Quote from: kphoger on April 12, 2019, 01:51:46 PM
Quote from: Paulinator66 on April 12, 2019, 09:46:39 AM
Quote from: jeffandnicole on April 03, 2019, 08:21:28 AM
. . .Those on the highway have the right-of-way. . .
Not in Illinois. Traffic in the on-ramp has the ROW and traffic on the Interstate must move over or slow down to accommodate. Yup, I know, I was floored when I found out too. No one here knows this so it's not really an issue until there's an accident and YOU end up with the ticket when you were just minding your own business in the right lane.
Who told you that? What I see in the Illinois vehicle code is as follows:
Quote from: 625 ILCS 5/ Illinois Vehicle Code, Sec. 11-901: Vehicles approaching or entering intersection
(a) When 2 vehicles approach or enter an intersection from different roadways at approximately the same time, the driver of the vehicle on the left must yield the right-of-way to the vehicle on the right.
(b) The right-of-way rule declared in paragraph (a) of this Section is modified at through highways and otherwise as stated in this Chapter.
Quote from: 625 ILCS 5/ Illinois Vehicle Code, Sec. 11-905: Merging traffic
Notwithstanding the right-of-way provision in Section 11-901 of this Act, at an intersection where traffic lanes are provided for merging traffic the driver of each vehicle on the converging roadways is required to adjust his vehicular speed and lateral position so as to avoid a collision with another vehicle.
Basically, it is equally the responsibility of both drivers to make accommodation.
I was driving in a rented prius merging into 80 from the bishop ford 2 years ago. not being from illinois i was unaware of the merging area as well as the law that I had ROW in that situation. I nearly got run off the road by a semi in stop and go traffic. center merge lanes are dangerous especially since they are not a universal thing. its probably safer to merge the lanes of the incoming road than center merge.
Quote from: ctkatz on February 25, 2021, 01:19:17 PM
not being from illinois i was unaware ... that I had ROW in that situation.
You didn't. See what I posted right before you. Both drivers are required to accommodate each other. Neither one is granted the "right of way" at merge situations in Illinois.
The East LA interchange and Golden State/San Bernardino interchange have a couple of inside lanes merge at the transitions. The 60 east has one and the 5 south at the 5/10 merge has another.
The Bellflower Blvd on ramp to the 405 north in Long Beach has two lanes entering the freeway where the inside lane merges with the mainline and the outside lane continues on as an auxiliary lane for the upcoming Lakewood Blvd exit.
The NJ Turnpike example could also be noted for its use of lane striping. They don't maintain a full passing zone between all lanes as the roadways merge, but rather use a single line to encourage traffic to stay in their group. But, by not using the double white line, it's not technically illegal to merge out of the 2 lanes that are merging.
It's also notable that this merging area is a mile south of Interchange 6. Quite a bit of traffic will exit at Exit 6, and that leaves traffic time to adjust to lighter traffic conditions before needing to merge. The Turnpike maintains its 65 mph speed limit thru this area. Traffic can be noticeably heavier in the 3 lane area just south of the 6 lane area, but rarely does traffic slow down below the speed limit, much less congest, except on the busiest of travel days.
Quote from: ran4sh on February 24, 2021, 05:28:15 PM
The New Jersey Turnpike is a special case though. Their arrangement is an attempt to compromise among 3 possibilities: both roadways open, left roadway closed, or right roadway closed. A configuration that avoids inside merging would result in some amount of thru traffic having to change lanes twice.
It's minor, but generally speaking there may always be traffic on the outer roadway at this point. There is only 1 ramp from the NJ/PA Turnpike Extension East (technically I-95 North) onto the NJ Turnpike South, which takes traffic to the outer roadway.
Quote
(I think that instead of such a merge, one lane could be dropped from each of the roadways at Exit 6 so that only 4 lanes instead of 6 lanes reach the merge point)
I believe this was considered, but the NJ Turnpike prefers to keep the mainline traffic flowing in continuous lanes, rather than use an 'Exit Only' lane setup. At Exit 4 SB where the Turnpike goes from 3 lanes to 2, and Exit 13 NB where the turnpike goes from 4 lanes to 3, the right lane ends just after the gore point of the ramp, rather than forcing traffic off via 'Exit Only' signage.
QuoteIn the cases of a merge between different roads, having "thru traffic" from the minor route (i.e. not thru traffic from the perspective of the dominant route) change lanes twice would be safer than inside lane traffic not having any escape room if unable to merge.
And what's a little peculiar about all of this: The NJ Turnpike is noted for their calm merging pattern south of Interchange 6. Yet, if you're coming from PA on the Extension and continue North on 95 & the Turnpike, the 2 lane ramps from the extension immediately ends and both lanes must quickly merge over into the mainline travel lanes. There's about an 800 foot distance for this to occur
As my reply from 10 years ago was noted in #20, at the time I clearly remember at a public open-house meeting that longer acceleration lanes were going to be used. 800 feet would barely acceptable for a single ramp lane; we have 2 lanes ending in that distance here!
Quote from: jeffandnicole on February 25, 2021, 03:49:53 PM
Quote from: ran4sh on February 24, 2021, 05:28:15 PM
In the cases of a merge between different roads, having "thru traffic" from the minor route (i.e. not thru traffic from the perspective of the dominant route) change lanes twice would be safer than inside lane traffic not having any escape room if unable to merge.
I believe this was considered, but the NJ Turnpike prefers to keep the mainline traffic flowing in continuous lanes, rather than use an 'Exit Only' lane setup. At Exit 4 SB where the Turnpike goes from 3 lanes to 2, and Exit 13 NB where the turnpike goes from 4 lanes to 3, the right lane ends just after the gore point of the ramp, rather than forcing traffic off via 'Exit Only' signage.
I've noticed this preference also exists in Washington State. Seems to be better for capacity (in some situations) and safety (again, in some situations). Unless an exit is tremendously busy, you'll have higher capacity with all lanes continuing, as you don't have through traffic avoiding the exit-only lane needlessly early, as can sometimes be the case. It can also be safer, as traffic merging into the through lanes can use the defined merge point at the end, rather than trying to find a place randomly along the length of the lane (especially dangerous if the through traffic is moving slower than the exit-only lane).
Places with heavy usage of auxiliary lanes between exits must have a lot of free-for-all situations when traffic is heavy; where do drivers merge? This is one of the few situations where I see people drive through shoulders, to pass someone who had to stop to merge because there is no defined merge point.
Quote from: jakeroot on February 25, 2021, 05:07:37 PM
Quote from: jeffandnicole on February 25, 2021, 03:49:53 PM
Quote from: ran4sh on February 24, 2021, 05:28:15 PM
In the cases of a merge between different roads, having "thru traffic" from the minor route (i.e. not thru traffic from the perspective of the dominant route) change lanes twice would be safer than inside lane traffic not having any escape room if unable to merge.
I believe this was considered, but the NJ Turnpike prefers to keep the mainline traffic flowing in continuous lanes, rather than use an 'Exit Only' lane setup. At Exit 4 SB where the Turnpike goes from 3 lanes to 2, and Exit 13 NB where the turnpike goes from 4 lanes to 3, the right lane ends just after the gore point of the ramp, rather than forcing traffic off via 'Exit Only' signage.
I've noticed this preference also exists in Washington State. Seems to be better for capacity (in some situations) and safety (again, in some situations). Unless an exit is tremendously busy, you'll have higher capacity with all lanes continuing, as you don't have through traffic avoiding the exit-only lane needlessly early, as can sometimes be the case. It can also be safer, as traffic merging into the through lanes can use the defined merge point at the end, rather than trying to find a place randomly along the length of the lane (especially dangerous if the through traffic is moving slower than the exit-only lane).
Places with heavy usage of auxiliary lanes between exits must have a lot of free-for-all situations when traffic is heavy; where do drivers merge? This is one of the few situations where I see people drive through shoulders, to pass someone who had to stop to merge because there is no defined merge point.
"Places with heavy usage of auxiliary lanes between exits must have a lot of free-for-all situations when traffic is heavy; where do drivers merge?"
Drivers merge when they have accelerated to the speed of the mainline. Exiting drivers change to the auxiliary lane early on and then slow to exit speed only after getting out of the thru lane.
Or at least that is the safest way to do it, based on my experience when driving Atlanta-area freeways that have 8, 10, or 12 lanes often with auxiliary lanes between exits.
Quote from: ran4sh on February 26, 2021, 09:18:37 PM
Quote from: jakeroot on February 25, 2021, 05:07:37 PM
Quote from: jeffandnicole on February 25, 2021, 03:49:53 PM
Quote from: ran4sh on February 24, 2021, 05:28:15 PM
In the cases of a merge between different roads, having "thru traffic" from the minor route (i.e. not thru traffic from the perspective of the dominant route) change lanes twice would be safer than inside lane traffic not having any escape room if unable to merge.
I believe this was considered, but the NJ Turnpike prefers to keep the mainline traffic flowing in continuous lanes, rather than use an 'Exit Only' lane setup. At Exit 4 SB where the Turnpike goes from 3 lanes to 2, and Exit 13 NB where the turnpike goes from 4 lanes to 3, the right lane ends just after the gore point of the ramp, rather than forcing traffic off via 'Exit Only' signage.
I've noticed this preference also exists in Washington State. Seems to be better for capacity (in some situations) and safety (again, in some situations). Unless an exit is tremendously busy, you'll have higher capacity with all lanes continuing, as you don't have through traffic avoiding the exit-only lane needlessly early, as can sometimes be the case. It can also be safer, as traffic merging into the through lanes can use the defined merge point at the end, rather than trying to find a place randomly along the length of the lane (especially dangerous if the through traffic is moving slower than the exit-only lane).
Places with heavy usage of auxiliary lanes between exits must have a lot of free-for-all situations when traffic is heavy; where do drivers merge? This is one of the few situations where I see people drive through shoulders, to pass someone who had to stop to merge because there is no defined merge point.
"Places with heavy usage of auxiliary lanes between exits must have a lot of free-for-all situations when traffic is heavy; where do drivers merge?"
Drivers merge when they have accelerated to the speed of the mainline. Exiting drivers change to the auxiliary lane early on and then slow to exit speed only after getting out of the thru lane.
Or at least that is the safest way to do it, based on my experience when driving Atlanta-area freeways that have 8, 10, or 12 lanes often with auxiliary lanes between exits.
But what about when mainline traffic is flowing
slower than the auxiliary lane (
example here (https://goo.gl/maps/R5qPLAZfX6TiYkGA8))? Where do you merge?
Obviously the answer is "wherever you find a gap", but what about those cars not looking to enter the mainline? Or those cars behind you who left the mainline who you are now blocking? That's when you start getting shoulder-driving and annoyed drivers.
This was my point when I said "when traffic is heavy". Somehow you quoted this verbatim yet seemed to miss my point.
The auxiliary lane is not a thru lane, so anyone that is using it to pass slow mainline traffic is an asshole.
The auxiliary lane is for both entering and exiting traffic, so although an entering vehicle that is using a long length of the lane to enter the mainline may annoy exiting traffic behind, there's nothing exiting traffic can do about it.
Quote from: ran4sh on February 26, 2021, 10:24:34 PM
The auxiliary lane is not a thru lane, so anyone that is using it to pass slow mainline traffic is an asshole.
The auxiliary lane is for both entering and exiting traffic, so although an entering vehicle that is using a long length of the lane to enter the mainline may annoy exiting traffic behind, there's nothing exiting traffic can do about it.
The fact that it
isn't a through lane is what I'm getting at: by forcing the lane off at the next exit, you're not providing a clear point for traffic to merge at. This is a serious problem if the auxiliary lanes are moving faster than mainline traffic, and you block traffic using the auxiliary lane trying to exit. There's clearly a safety issue by requiring drivers to come to a near-stop just to merge, while their tail end is still parked in the auxiliary lane. You may not see this much in Georgia, but it's something I see here in WA often enough. Primarily along that stretch I linked to before.
What can be done about it is: not forcing the lane off at the next exit. Instead, have it continue past the exit for a few hundred feet, and then merge in.
That doesn't really work if the next exit has more than one lane. (Or even just 1 exit-only lane [the auxiliary lane] and 1 option lane [right mainline lane has the option to exit or stay on].)
Quote from: ran4sh on February 26, 2021, 11:48:05 PM
That doesn't really work if the next exit has more than one lane. (Or even just 1 exit-only lane [the auxiliary lane] and 1 option lane [right mainline lane has the option to exit or stay on].)
In those situations, yes, there's not much that can be done. I find the issue is most prevalent between two "quieter" ramps with just a single lane coming in, and a single lane departing.
US-35 in Ohio is pretty good at this:
- Both ends of the US-23 concurrency
- Westbound entering the state at OH-735 the lanes basically feed right into 735's alignment.
Quote from: jakeroot on February 26, 2021, 11:33:52 PM
Quote from: ran4sh on February 26, 2021, 10:24:34 PM
The auxiliary lane is not a thru lane, so anyone that is using it to pass slow mainline traffic is an asshole.
The auxiliary lane is for both entering and exiting traffic, so although an entering vehicle that is using a long length of the lane to enter the mainline may annoy exiting traffic behind, there's nothing exiting traffic can do about it.
The fact that it isn't a through lane is what I'm getting at: by forcing the lane off at the next exit, you're not providing a clear point for traffic to merge at. This is a serious problem if the auxiliary lanes are moving faster than mainline traffic, and you block traffic using the auxiliary lane trying to exit. There's clearly a safety issue by requiring drivers to come to a near-stop just to merge, while their tail end is still parked in the auxiliary lane. You may not see this much in Georgia, but it's something I see here in WA often enough. Primarily along that stretch I linked to before.
What can be done about it is: not forcing the lane off at the next exit. Instead, have it continue past the exit for a few hundred feet, and then merge in.
And then have to reconstruct
this bridge (https://goo.gl/maps/obmrcp7LTTYMih6q7), while you're at it. Seriously, the afternoon rush-hour traffic jam here could be improved so much, if only the K-254 exit-only ramp continued and became an I-235 exit-only ramp instead.
Wait a minute, though, isn't this interchange finally on the books to be redone?
Quote from: kphoger on February 27, 2021, 08:31:47 AM
Quote from: jakeroot on February 26, 2021, 11:33:52 PM
Quote from: ran4sh on February 26, 2021, 10:24:34 PM
The auxiliary lane is not a thru lane, so anyone that is using it to pass slow mainline traffic is an asshole.
The auxiliary lane is for both entering and exiting traffic, so although an entering vehicle that is using a long length of the lane to enter the mainline may annoy exiting traffic behind, there's nothing exiting traffic can do about it.
The fact that it isn't a through lane is what I'm getting at: by forcing the lane off at the next exit, you're not providing a clear point for traffic to merge at. This is a serious problem if the auxiliary lanes are moving faster than mainline traffic, and you block traffic using the auxiliary lane trying to exit. There's clearly a safety issue by requiring drivers to come to a near-stop just to merge, while their tail end is still parked in the auxiliary lane. You may not see this much in Georgia, but it's something I see here in WA often enough. Primarily along that stretch I linked to before.
What can be done about it is: not forcing the lane off at the next exit. Instead, have it continue past the exit for a few hundred feet, and then merge in.
And then have to reconstruct this bridge (https://goo.gl/maps/obmrcp7LTTYMih6q7), while you're at it. Seriously, the afternoon rush-hour traffic jam here could be improved so much, if only the K-254 exit-only ramp continued and became an I-235 exit-only ramp instead.
Wait a minute, though, isn't this interchange finally on the books to be redone?
At that interchange, yes, I think it would make much more sense for the exit-only to continue past the first exit. It would require replacing the bridge, clearly. But I don't think continuing that lane past the second exit would be necessary.
Continuing the auxiliary lane past the exit ramp is clearly not something that needs to be done under all circumstances. Especially when the exit is either nearly as busy, or as busy, as the mainline maneuver. But I can appreciate them in high-traffic areas. I suspect the I-135/I-235/K-254 interchange isn't a place where it would be necessary.
ODOT loved doing inside lane merges.
Signs like this below were common around Columbus:
http://www.roadfan.com/sqdia.jpg
(I-71 SB - I-670 EB merge near Broad St. exit, back in 2000)
I-76/77 in Akron had a sign similar to what Skypesos showed for Cincy
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.roadfan.com%2F2merge.jpg&hash=c696718b4daf0f4c5d9b26cea86ab619fa72c7ed)
One of the few inside merges still existing in Columbus, I-270 NB between US 40 & Oh 16
https://goo.gl/maps/HeaMCYUt9mqyyFHJA
Quote from: interstatefan990 on February 24, 2021, 07:51:26 PM
Quote from: SkyPesos on February 24, 2021, 07:09:59 PM
What is the best way to sign an inside lane merge?
I think that sign could be too easily mistaken as a triple added-lane with no merging necessary. This is my idea:
(https://i.ibb.co/bshFYHR/293-C2-EC5-4282-4643-866-E-34197-A65293-E.jpg)
You'd need to show both of the outside arrows with curved stems, to make it more clear that is a merge. I also like the first example that shows the lane lines (similar to the added lane sign) to make it even more obvious
Here's an inside-merge sign in use (Pasadena, CA):
https://goo.gl/maps/moY9a9E1UwRhskeB6
It replaced a normal merge-from-right between 2011 and 2014, according to the GSV dating.
Note that this is actually at a merge of two surface streets (NB Sierra Madre Blvd and NB San Gabriel Blvd), and the intersection is signal-controlled so that (I believe) there are no times when traffic from both streets actually needs to merge. It's actually somewhat of an interesting intersection, with a WB I-210 frontage road making it a five-way.
Quote from: interstatefan990 on February 24, 2021, 07:51:26 PM
Quote from: SkyPesos on February 24, 2021, 07:09:59 PM
What is the best way to sign an inside lane merge?
I think that sign could be too easily mistaken as a triple added-lane with no merging necessary. This is my idea:
Maybe something like this?
(https://i.imgur.com/UXUR9rj.png)
I might argue that anything left of the merge lane may not be necessary. This is my concept:
(https://live.staticflickr.com/65535/51001658041_058427e77d_o.png)
Quote from: jakeroot on March 03, 2021, 08:32:39 PM
I might argue that anything left of the merge lane may not be necessary. This is my concept:
(https://live.staticflickr.com/65535/51001658041_058427e77d_o.png)
That looks similar to what was posted above for Akron (image didn't show for some reason, here (http://www.roadfan.com/2merge.jpg)'s the link for it).
(https://live.staticflickr.com/65535/51001658041_058427e77d_o.png) (https://i.imgur.com/UXUR9rj.png)
It's a question, I think, of whether you add in the third arrow or the lane lines. The design I borrowed seems a bit less busy than yours, but that might also give rise to a lack of clarity. Also, for the record, the arrows in my attempt are yours. I took them from one of your APL designs.
Quote from: SkyPesos on March 03, 2021, 08:45:32 PM
Quote from: jakeroot on March 03, 2021, 08:32:39 PM
I might argue that anything left of the merge lane may not be necessary. This is my concept:
https://live.staticflickr.com/65535/51001658041_058427e77d_o.png
That looks similar to what was posted above for Akron (image didn't show for some reason, here (http://www.roadfan.com/2merge.jpg)'s the link for it).
Ahhh, because it's damn near the same. The image also didn't show for me, which may be why I missed it.
Quote from: CtrlAltDel on March 03, 2021, 08:52:23 PM
It's a question, I think, of whether you add in the third arrow or the lane lines. The design I borrowed seems a bit less busy than yours, but that might also give rise to a lack of clarity. Also, for the record, the arrows in my attempt are yours. I took them from one of your APL designs.
Glad my arrows are getting use! The arrowheads themselves I installed myself into the arrowheads library in Illustrator.
I added the lane lines but I suppose those are fairly dispensable.
Quote from: jakeroot on March 03, 2021, 08:32:39 PM
I might argue that anything left of the merge lane may not be necessary. This is my concept:
(https://live.staticflickr.com/65535/51001658041_058427e77d_o.png)
Iowa has a similar sign (https://goo.gl/maps/YDqWrsAsdQ63YV2F9)
Then's there this version in Chicagoland (https://goo.gl/maps/QZbqDR3oN6MBWhc26)
Quote from: jakeroot on March 03, 2021, 08:32:39 PM
I might argue that anything left of the merge lane may not be necessary. This is my concept:
(https://live.staticflickr.com/65535/51001658041_058427e77d_o.png)
I like this a lot. If there has to be an inside lane merge, this is what I'd go with out of everything posted so far.
I would also add that it would be important to keep the "Center Lanes Merge" plaque along with the sign. It's better to have symbol/word ambiguity for redundancy, since the sign might confuse drivers.
Quote from: jakeroot on March 03, 2021, 09:01:17 PM
I added the lane lines but I suppose those are fairly dispensable.
(https://i.imgur.com/nx3PXac.png)
Quote from: interstatefan990 on March 04, 2021, 10:43:27 AM
I would also add that it would be important to keep the "Center Lanes Merge" plaque along with the sign. It's better to have symbol/word ambiguity for redundancy, since the sign might confuse drivers.
One could argue that there *has* to be a word message on the sign (whether it's on the main sign or a plaque), because there is no standard symbol in the MUTCD for center lane merging.