Most junctions between freeways and surface streets in urban/suburban areas are handled by stoplights.
However, I-490 and NY-31 is one of the busiest interchanges (besides freeway-freeway) in my area, and there are no stoplights at the junction. It functions as a set of T-intersections, with right turn modifications. I would not be surprised if this is the busiest surface street in the nation to cross a freeway without a single stoplight.
Are there any others out there?
(EDIT: cloverleafs and parclos don't count here. Let's say four ramps maximum while allowing all possible turn movements.)
ADDED: Roundabouts have neither left turns nor cross traffic. So they are not at-grade intersections for the purpose of this discussion.
interstate 10 and Rosemead Blvd in Socal.
LGMS210
Are roundabouts acceptable or not? Your post isn't clear. On one hand you seem like you want just stop signs. On the other it seems you just don't want stop lights. So I'm confused. Because for MD, MD 216 @ US 29 comes to mind.
https://www.google.com/maps/@39.1458431,-76.8999922,16.92z
US 301 & I-75 Parclo B4 interchange near Tampa. US301 is a major 6-lane boulevard and according to FDOT has a link volume of 74,000 just south of the interchange.
https://www.google.com/maps/@27.9028527,-82.3437491,484m/data=!3m1!1e3
^Here is the intersection just south of the US301 & I-75 interchange. Going SB it has 3 thru lanes, 3 left turn lanes, and a dedicated right turn lane. It carries a massive amount of traffic.
https://www.google.com/maps/@27.8939873,-82.3380387,121m/data=!3m1!1e3
Quote from: ParrDa on October 10, 2017, 08:55:31 PM
Quote from: BrianP on October 10, 2017, 06:30:59 PM
Are roundabouts acceptable or not? Your post isn't clear. On one hand you seem like you want just stop signs. On the other it seems you just don't want stop lights. So I'm confused. Because for MD, MD 216 @ US 29 comes to mind.
https://www.google.com/maps/@39.1458431,-76.8999922,16.92z
Seems pretty clear to me:
Quote from: ParrDa on October 10, 2017, 05:49:06 PM(Obviously cloverleafs don't count - let's say six ramps maximum and at least one at-grade intersection to qualify.)
So a roundabout could be included, but there still has to be an at-grade intersection. Keep in mind the +20K criteria as well.
Well, all roundabouts are at-grade intersections, so any roundabout could be included?
No left turns in roundabouts? I must be breaking the law somehow, then when I go counter-clockwise around the circle and out. :D
Quote from: ParrDa on October 11, 2017, 12:21:00 PM
Roundabouts have neither left turns nor cross traffic. So they are not at-grade intersections for the purpose of this discussion.
OK, I get that. I tend to think of a roundabout as a series of T intersections, but I understand you now.
Quote from: ParrDa on October 10, 2017, 05:49:06 PM
However, I-490 and NY-31 is one of the busiest interchanges (besides freeway-freeway) in my area, and there are no stoplights at the junction. It functions as a set of T-intersections, with right turn modifications. I would not be surprised if this is the busiest surface street in the nation to cross a freeway without a single stoplight.
This is the I-490 and NY-31 interchange in question right?
https://www.google.com/maps/@43.0788922,-77.4853303,326m/data=!3m1!1e3
NY-31 is a 2-lane road west of the interchange and it's not super surprising that the interchange doesn't have stoplights. There are plenty of busier interchanges out there without traffic signals (i know of 36 unsignalized Parclo interchanges along 4-lane or 6-lane surface streets that carry much more traffic than NY-31).
Quote from: tradephoric on October 11, 2017, 03:15:38 PM
Quote from: ParrDa on October 10, 2017, 05:49:06 PM
However, I-490 and NY-31 is one of the busiest interchanges (besides freeway-freeway) in my area, and there are no stoplights at the junction. It functions as a set of T-intersections, with right turn modifications. I would not be surprised if this is the busiest surface street in the nation to cross a freeway without a single stoplight.
This is the I-490 and NY-31 interchange in question right?
https://www.google.com/maps/@43.0788922,-77.4853303,326m/data=!3m1!1e3
NY-31 is a 2-lane road west of the interchange and it's not super surprising that the interchange doesn't have stoplights. There are plenty of busier interchanges out there without traffic signals (i know of 36 unsignalized Parclo interchanges along 4-lane or 6-lane surface streets that carry much more traffic than NY-31).
Thanks for posting this. I was about to comment likewise, but I just figured I wasn't familiar with the area so I didn't know the scoop.
The full access question was another that I assumed. I figured partial interchanges wouldn't be included.
Here is an unsignalized SPUI in Illinois...
https://www.google.com/maps/@42.3639101,-87.8287867,101m/data=!3m1!1e3
Quote from: ParrDa on October 11, 2017, 05:39:35 PM
Are you sure there's 36? Care to tell us where they are?
Here is a KMZ file of unsignalized Parclos...
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
Here is a unsignalized Parclo that has dual left-turn lanes entering the freeway which adds some complexity...
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
Quote from: tradephoric on October 11, 2017, 08:36:11 PM
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
Aren't those two the exact same link?
Quote from: kphoger on October 12, 2017, 09:59:03 AM
Quote from: tradephoric on October 11, 2017, 08:36:11 PM
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
Aren't those two the exact same link?
Woops! Here is the correct link to the unsignalized Parclo that has dual left-turn lanes...
https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3
The Andytown interchange with the Alligator Alley section of I-75 and US 27 has no traffic signals nor stop lights:
https://www.google.com/maps/@26.1435766,-80.4412922,15z
Quote from: tradephoric on October 12, 2017, 10:05:52 AM
Quote from: kphoger on October 12, 2017, 09:59:03 AM
Quote from: tradephoric on October 11, 2017, 08:36:11 PM
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
Aren't those two the exact same link?
Woops! Here is the correct link to the unsignalized Parclo that has dual left-turn lanes...
https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3
That's the best thing I've ever seen. I didn't think an unsignalized dual left existed anywhere in the US. I know of many double lefts that yield, but they're all signalized.
Quote from: Max Rockatansky on October 12, 2017, 10:35:16 AM
The Andytown interchange with the Alligator Alley section of I-75 and US 27 has no traffic signals nor stop lights:
https://www.google.com/maps/@26.1435766,-80.4412922,15z
But it has more than six ramps. And it has no at-grade intersections.
Quote from: BrianP on October 12, 2017, 11:49:06 AM
Quote from: Max Rockatansky on October 12, 2017, 10:35:16 AM
The Andytown interchange with the Alligator Alley section of I-75 and US 27 has no traffic signals nor stop lights:
https://www.google.com/maps/@26.1435766,-80.4412922,15z
But it has more than six ramps. And it has no at-grade intersections.
On the other hand, it has roads. That's something.
I-75 at College Ave is another Florida interchange without any traffic lights. NB I-75 traffic exiting the freeway turning left onto College Avenue must cross 3-lanes of traffic without the assistance of a traffic signal.
https://www.google.com/maps/@27.7125666,-82.383995,654m/data=!3m1!1e3
Personally i love interchanges without traffic lights. The I-75/College Ave interchange has been unsignalized for over 20 years and throughout that time it has been a relatively built up area. If this heavily traveled interchange doesn't require traffic signals to regulate traffic, surely there are interchanges that have traffic signals that don't really need them.
Quote from: jakeroot on October 12, 2017, 10:41:11 AM
Quote from: tradephoric on October 12, 2017, 10:05:52 AM
Quote from: kphoger on October 12, 2017, 09:59:03 AM
Quote from: tradephoric on October 11, 2017, 08:36:11 PM
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
Aren't those two the exact same link?
Woops! Here is the correct link to the unsignalized Parclo that has dual left-turn lanes...
https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3
That's the best thing I've ever seen. I didn't think an unsignalized dual left existed anywhere in the US. I know of many double lefts that yield, but they're all signalized.
There is an unsignalized double left turn in Hampton roads, va.
https://goo.gl/maps/7zXiAd5By6K2
Closest one to me is I-691 Exit 7 in Meriden. The ramps eastbound and westbound lead to different streets. Eastbound meets the street at an angle where both have stop signs, while the westbound exit splits at the end with the southbound traffic meeting a stop sign and the northbound stub has no stop sign whatsoever.
https://goo.gl/maps/GX91gHeYGq32
https://goo.gl/maps/R6v8RroTfGU2
In Kissimmee, FL the FL 417 and Osceola Parkway have a stop light, but has not been used in over 20 years. The signal was installed when FL 417 opened there, and was used briefly after it opened, but Osceola County found them to be unwarranted and turned them into flashers, placed STOP signs on the 417 ramps and left the signals in tact all these years.
Now it may not count as being unsignalized for sake of the OP, but in fact acts as one as it has gotten busy around the area of the interchange, but Osceola County has not decided to reactivate these two signals that are at the ends of both the NB and SB ramps of 417. Being that the STOP signs are in place it is legally considered to be a normal unsignalized intersection as the MUTCD requires the signs to be in place on even signals in the shore regions of the northern states where local towns after Labor Day turn the signals to flash mode until Memorial Day as the beaches are not crowded with Summer tourists those months where they still technically operate. Apparently the FHWA does not allow a red beacon to solely be a traffic control device. Short flashes at night or for just a few days are okay, but indefinitely is not okay. Though I did hear of one such intersection in a place from Alex that has just the beacon and no Stop signs, but someone in Osceola County Roads in FL told me that the MUTCD (at the time, if it changed NE 2 will be on me here like Maple Syrup to Pancakes) does stress a rule.
^^Don't know where they are getting that from: 2009 MUTCD
Section 2B.05 STOP Sign (R1-1) and ALL WAY Plaque (R1-3P)
Standard:
01 When it is determined that a full stop is always required on an approach to an intersection, a STOP (R1-1) sign (see Figure 2B-1) shall be used.
Quote from: MCRoads on October 12, 2017, 04:30:51 PM
There is an unsignalized double left turn in Hampton roads, va.
https://goo.gl/maps/7zXiAd5By6K2
Why does that street exist?
Quote from: CtrlAltDel on October 12, 2017, 07:56:07 PM
Quote from: MCRoads on October 12, 2017, 04:30:51 PM
There is an unsignalized double left turn in Hampton roads, va.
https://goo.gl/maps/7zXiAd5By6K2
Why does that street exist?
HEY!! that's what i thought! why does it have a double turn, anyway? couldn't they just paint a yellow line and crosshatches and call it a day? or, just remove it altogether. there is a perfectly good parclo right up the street, which is what they use anyway!
Quote from: MCRoads on October 13, 2017, 10:13:00 AM
Quote from: CtrlAltDel on October 12, 2017, 07:56:07 PM
Quote from: MCRoads on October 12, 2017, 04:30:51 PM
There is an unsignalized double left turn in Hampton roads, va.
https://goo.gl/maps/7zXiAd5By6K2
Why does that street exist?
HEY!! that's what i thought! why does it have a double turn, anyway? couldn't they just paint a yellow line and crosshatches and call it a day? or, just remove it altogether. there is a perfectly good parclo right up the street, which is what they use anyway!
I was thinking it could've been built for future development. Either that, or it could be an attempt at a quadrant roadway intersection (https://en.wikipedia.org/wiki/Quadrant_roadway_intersection).
Quote from: MCRoads on October 12, 2017, 04:30:51 PM
Quote from: jakeroot on October 12, 2017, 10:41:11 AM
Quote from: tradephoric on October 12, 2017, 10:05:52 AM
Quote from: kphoger on October 12, 2017, 09:59:03 AM
Quote from: tradephoric on October 11, 2017, 08:36:11 PM
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
https://www.mediafire.com/file/6vpo98f63r3z5w0/Unsignalized%20Parclos.kmz
Aren't those two the exact same link?
Woops! Here is the correct link to the unsignalized Parclo that has dual left-turn lanes...
https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3
That's the best thing I've ever seen. I didn't think an unsignalized dual left existed anywhere in the US. I know of many double lefts that yield, but they're all signalized.
There is an unsignalized double left turn in Hampton roads, va.
https://goo.gl/maps/7zXiAd5By6K2
How very Un-Virginia of Virginia.
As others above have suggested, the double left turn doesn't seem necessary. But, I guess it doesn't hurt!
QuoteHow very Un-Virginia of Virginia
Note this is within an Independent City (Hampton in this case). Independent cities in Virginia have a little more leeway than VDOT-standard in terms of their non-Interstate roadways.
It's for a similar reason why most Hampton Roads cities had red left arrows for years before VDOT finally made the jump.
EB I-96 off ramp @ State Road you gotta turn right and then take a turnaround to continue North on State Street. WB I-96 off ramp you can make a direct left turn onto State. Both off-ramps are unsignalized. While Michigan has a lot of Michigan left setups, this is relatively uncommon at interchanges (especially ones that are unsignalized).
https://www.google.com/maps/@42.8783279,-85.073429,1082m/data=!3m1!1e3
Quote from: roadman65 on October 12, 2017, 05:28:17 PM
In Kissimmee, FL the FL 417 and Osceola Parkway have a stop light, but has not been used in over 20 years. The signal was installed when FL 417 opened there, and was used briefly after it opened, but Osceola County found them to be unwarranted and turned them into flashers, placed STOP signs on the 417 ramps and left the signals in tact all these years.
Now it may not count as being unsignalized for sake of the OP, but in fact acts as one as it has gotten busy around the area of the interchange, but Osceola County has not decided to reactivate these two signals that are at the ends of both the NB and SB ramps of 417. Being that the STOP signs are in place it is legally considered to be a normal unsignalized intersection as the MUTCD requires the signs to be in place on even signals in the shore regions of the northern states where local towns after Labor Day turn the signals to flash mode until Memorial Day as the beaches are not crowded with Summer tourists those months where they still technically operate. Apparently the FHWA does not allow a red beacon to solely be a traffic control device. Short flashes at night or for just a few days are okay, but indefinitely is not okay. Though I did hear of one such intersection in a place from Alex that has just the beacon and no Stop signs, but someone in Osceola County Roads in FL told me that the MUTCD (at the time, if it changed NE 2 will be on me here like Maple Syrup to Pancakes) does stress a rule.
That does seem like an odd setup. Exiting FL 417 you approach a flashing red traffic signal and a stop sign. Some drivers may assume that the near side of the intersection is stop controlled (since there is no near side traffic signal and they are facing a stop sign) and the far side is controlled by the signal. Also a clearly visible stop bar can be seen on Osceola Parkway. If drivers are assuming that the near side is stop controlled, the existence of the stop bar on Osceola Parkway could have drivers believing that it's an all-way stop.
https://www.google.com/maps/@28.3403946,-81.5157538,3a,75y,12.17h,82.45t/data=!3m6!1e1!3m4!1sudbppdw5Y-ltvaEhVrkkog!2e0!7i13312!8i6656
Quote from: froggie on October 16, 2017, 09:24:00 AM
QuoteHow very Un-Virginia of Virginia
Note this is within an Independent City (Hampton in this case). Independent cities in Virginia have a little more leeway than VDOT-standard in terms of their non-Interstate roadways.
It's for a similar reason why most Hampton Roads cities had red left arrows for years before VDOT finally made the jump.
I see. Thanks for the update. I saw that Magruder Blvd was part of VA-134, so I assumed the state was in charge. But there's plenty of cases here in Washington where local municipalities will maintain state highways, so I should know better than to assume!
The I-95 and Okeechobee Road interchange in Florida has traffic signals but what makes it unique is that all traffic entering the freeway bypasses them (which increases capacity and prevents backups onto Okeechobee Road). Not exactly what the OP is looking for, but still a pretty awesome design.
https://www.google.com/maps/@27.4158365,-80.3883898,446m/data=!3m1!1e3
Quote from: tradephoric on October 16, 2017, 05:42:33 PM
The I-95 and Okeechobee Road interchange in Florida has traffic signals but what makes it unique is that all traffic entering the freeway bypasses them (which increases capacity and prevents backups onto Okeechobee Road). Not exactly what the OP is looking for, but still a pretty awesome design.
https://www.google.com/maps/@27.4158365,-80.3883898,446m/data=!3m1!1e3
I've seen this setup very rarely, and it's one of a few layout advantages that an A4 Parclo has over a B4. While an A4 requires two signals, the entering traffic can bypass both using a setup like what Florida has done here. While the B4 can operate completely without signals, and can have more even distribution of traffic along the arterial, it's not possible for traffic to go left onto the freeway from a B4 without first conflicting with two directions of traffic: vehicles coming towards you attempting to turn left, and then oncoming traffic again when attempting to turn left ourselves. Because these conflict points often have signals, left and through traffic often must stop once to allow drivers to turn left, and then left turning traffic must often stop again to wait for a left-green arrow. Still, easier to coordinate a B4 than an A4 (directions of an arterial can run independently, as you know).
Quote from: jakeroot on October 16, 2017, 06:43:43 PM
Quote from: tradephoric on October 16, 2017, 05:42:33 PM
The I-95 and Okeechobee Road interchange in Florida has traffic signals but what makes it unique is that all traffic entering the freeway bypasses them (which increases capacity and prevents backups onto Okeechobee Road). Not exactly what the OP is looking for, but still a pretty awesome design.
https://www.google.com/maps/@27.4158365,-80.3883898,446m/data=!3m1!1e3
I've seen this setup very rarely, and it's one of a few layout advantages that an A4 Parclo has over a B4. While an A4 requires two signals, the entering traffic can bypass both using a setup like what Florida has done here. While the B4 can operate completely without signals, and can have more even distribution of traffic along the arterial, it's not possible for traffic to go left onto the freeway from a B4 without first conflicting with two directions of traffic: vehicles coming towards you attempting to turn left, and then oncoming traffic again when attempting to turn left ourselves. Because these conflict points often have signals, left and through traffic often must stop once to allow drivers to turn left, and then left turning traffic must often stop again to wait for a left-green arrow. Still, easier to coordinate a B4 than an A4 (directions of an arterial can run independently, as you know).
Here is an equivalent design when applied to a B4. Traffic turning left onto the freeway only conflicts with opposing thru traffic (conflicting left turners onto the freeway criss-cross each other similar to a DDI). This design is only conceptual and i don't know of any real world examples. One downside of this design is that it requires a wide ROW along the arterial to allow enough room for the left-turns to criss-cross (of course the I-95 and Okeechobee A4 interchange also requires a wide ROW to fit the bypass lanes but that didn't stop FDOT).
https://www.youtube.com/watch?v=ZZZOBPyHuCM
Here is another interesting design where there are traffic signals on the ramps themselves. They call it a PFI Folded Diamond. The benefit is it eliminates a phase along the main on/off ramp signals turning a 3-phase signal into a 2-phase signal. The disadvantage is it adds 2 additional traffic signals to the interchange. Since the OP is looking for interchanges without traffic signals, this is the opposite of that! There are operational benefits to this design but is it worth it?
https://www.youtube.com/watch?v=7F-RvFyXWlA
Quote from: tradephoric on October 16, 2017, 11:49:53 AM
Quote from: roadman65 on October 12, 2017, 05:28:17 PM
In Kissimmee, FL the FL 417 and Osceola Parkway have a stop light, but has not been used in over 20 years. The signal was installed when FL 417 opened there, and was used briefly after it opened, but Osceola County found them to be unwarranted and turned them into flashers, placed STOP signs on the 417 ramps and left the signals in tact all these years.
Now it may not count as being unsignalized for sake of the OP, but in fact acts as one as it has gotten busy around the area of the interchange, but Osceola County has not decided to reactivate these two signals that are at the ends of both the NB and SB ramps of 417. Being that the STOP signs are in place it is legally considered to be a normal unsignalized intersection as the MUTCD requires the signs to be in place on even signals in the shore regions of the northern states where local towns after Labor Day turn the signals to flash mode until Memorial Day as the beaches are not crowded with Summer tourists those months where they still technically operate. Apparently the FHWA does not allow a red beacon to solely be a traffic control device. Short flashes at night or for just a few days are okay, but indefinitely is not okay. Though I did hear of one such intersection in a place from Alex that has just the beacon and no Stop signs, but someone in Osceola County Roads in FL told me that the MUTCD (at the time, if it changed NE 2 will be on me here like Maple Syrup to Pancakes) does stress a rule.
That does seem like an odd setup. Exiting FL 417 you approach a flashing red traffic signal and a stop sign. Some drivers may assume that the near side of the intersection is stop controlled (since there is no near side traffic signal and they are facing a stop sign) and the far side is controlled by the signal. Also a clearly visible stop bar can be seen on Osceola Parkway. If drivers are assuming that the near side is stop controlled, the existence of the stop bar on Osceola Parkway could have drivers believing that it's an all-way stop.
https://www.google.com/maps/@28.3403946,-81.5157538,3a,75y,12.17h,82.45t/data=!3m6!1e1!3m4!1sudbppdw5Y-ltvaEhVrkkog!2e0!7i13312!8i6656
Not a fan of this. Seeems confusing. IF they don't want to operate the signal, then don't operate the signal and put up cardboard to cover the signal faces.
Wow, the rare case where the forum search function was more effective than a Google search.
Quote from: webny99 on October 10, 2017, 05:49:06 PMI-490 and NY-31 is one of the busiest interchanges (besides freeway-freeway) in my area, and there are no stoplights at the junction. It functions as a set of T-intersections, with right turn modifications. I would not be surprised if this is the busiest surface street in the nation to cross a freeway without a single stoplight.
I thought of this thread the other day and wanted to refresh my memory on if there was any definitive "winner". It doesn't look like there was, but there also wasn't much discussion of AADT counts for any of the interchanges mentioned.
I still think I-490/NY 31 wins, but I'm clarifying the guidelines since the OP was too vague and didn't accurately encompass what I was looking for. The interchange must have exactly 4 ramps, and all 8 possible turn movements to/from the freeway ramps must be allowed. That eliminates parclos and the like, but still includes a large majority of freeway-to-non-freeway interchanges nationwide.
With those criteria, what interchange with no traffic signals has the highest combined AADT between the four ramps and the surface street? (For the purposes of this question, the AADT of the freeway can be ignored.)
For I-490 Exit 26 (NY 31), AADT counts are as follows:
NY 31 east of Exit 26: 30,418
NY 31 west of Exit 26: 19,549
NY 31 thru traffic (estimate): 13,100
I-490 EB to NY 31: 8,930
NY 31 to I-490 EB: 3,150
I-490 WB to NY 31: 2,366
NY 31 to I-490 WB: 9,293
TOTAL (ramps plus estimated NY 31 thru traffic): 36,839
Jalisco State Highways 404 and 406 are stoplight free at their interchanges with Federal Highway 54D. In fact both interchanges prohibit left hand turns off the Autopista. You have to utilize roundabouts on both sides of the interchange if you want to turn around.
Honorable mention from Mexico:
This busy modified DDI (https://maps.app.goo.gl/5TGRcxYykq8vsFp27) in the suburban outskirts of Mexico City has zero signage on either side instructing drivers to switch sides at the crossover (including the SB off-ramp (https://maps.app.goo.gl/9FgLgU3PAnLYMro77), which does not force traffic onto the correct side because it also has a straight-through movement). But more to the point, only one of the crossovers (https://maps.app.goo.gl/h5LtnUwfkZ3hu8pQ8) has a stoplight. The other crossover (https://maps.app.goo.gl/oGEzkbab9D3Nzsi3A) is an uncontrolled intersection. This is my all-time favorite WTF interchange.
ETA: By the way, that off-ramp has a yellow plaque on the overhead directional sign that says "MATUTINO DE 5:00 A 12:00 h". This translates to "MORNINGS FROM 5:00 TO 12:00". I have no idea what that's supposed to mean.
Quote from: kphoger on March 05, 2025, 01:51:11 PMonly one of the crossovers (https://maps.app.goo.gl/h5LtnUwfkZ3hu8pQ8) has a stoplight. The other crossover (https://maps.app.goo.gl/oGEzkbab9D3Nzsi3A) is an uncontrolled intersection.
Wow. Who has the right of way at the uncontrolled crossover?
Quote from: kphoger on March 05, 2025, 01:51:11 PMETA: By the way, that off-ramp has a yellow plaque on the overhead directional sign that says "MATUTINO DE 5:00 A 12:00 h". This translates to "MORNINGS FROM 5:00 TO 12:00". I have no idea what that's supposed to mean.
Probably that something is either expressly allowed or expressly prohibited during that time period. What, I have no idea.
Highway signage in Mexico is mainly just for window dressing. A lot of it is factually incorrect and tends to be universally ignored.
Quote from: webny99 on March 05, 2025, 03:08:14 PMWow. Who has the right of way at the uncontrolled crossover?
There's a general rule of taking turns at intersections. That may or may not be actual law, but it's common practice.
That area has some good uncontrolled interchanges. For example, the diamond interchange on Carr. Fed. 57(D) at Carr. Fed. 85 (https://maps.app.goo.gl/pg56V5pgVUrXfvnN9) only has a single stop sign (https://maps.app.goo.gl/9rWw63xh3L4WBeYg9).
Quote from: jakeroot on October 12, 2017, 10:41:11 AMQuoteWoops! Here is the correct link to the unsignalized Parclo that has dual left-turn lanes...
https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3 (https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3)
That's the best thing I've ever seen.
It seems that ALDOT or whatever DOT is responsible for Bradford Drive did not agree with you, because as of
the most recent Street View (https://maps.app.goo.gl/DA1DSE6xhV7Xm5o7A) and satellite view, the dual left turn lanes have been changed to single left turn lanes, with painted chevrons in the former left turn lane adjacent to the thru lanes.
Quote from: webny99 on March 06, 2025, 09:25:08 AMQuote from: jakeroot on October 12, 2017, 10:41:11 AMQuoteWoops! Here is the correct link to the unsignalized Parclo that has dual left-turn lanes...
https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3 (https://www.google.com/maps/@34.72793,-86.66928,361m/data=!3m1!1e3)
That's the best thing I've ever seen.
It seems that ALDOT or whatever DOT is responsible for Bradford Drive did not agree with you, because as of the most recent Street View (https://maps.app.goo.gl/DA1DSE6xhV7Xm5o7A) and satellite view, the dual left turn lanes have been changed to single left turn lanes, with painted chevrons in the former left turn lane adjacent to the thru lanes.
Yeah, this was changed a few years ago when ALDOT added the ramp to Research Drive. They removed the outside turn lane, made the slip lane into an add-lane, and then added the split just downstream.
Personally, I don't think the change makes any sense, because now there is a weave between the two lanes. If the double left had been maintained, there would be no need for a weave since cars could turn left from the lane they needed (either towards 255 [left lane] or Research Drive [right lane]). Traffic entering via the right turn slip lane could have easily turned into either lane depending on where they wanted to go.
Quote from: jakeroot on March 07, 2025, 04:39:21 AMPersonally, I don't think the change makes any sense, because now there is a weave between the two lanes. If the double left had been maintained, there would be no need for a weave since cars could turn left from the lane they needed (either towards 255 [left lane] or Research Drive [right lane]). Traffic entering via the right turn slip lane could have easily turned into either lane depending on where they wanted to go.
I tend to agree with you overall, but it is worth noting that yielding to an unsignalized double-left could be potentially confusing/problematic for those turning right. The flow of left turning traffic would have been fairly jolty and unpredictable, and if it was busy, you'd have to rely on guessing when they would turn and verifying that they were turning into the appropriate lane to accurately judge whether it was safe to proceed.
How about this thing in the City of Alexandria between I-95/495 and US-1? (https://www.google.com/maps/@38.7938783,-77.0574582,1371m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI1MDMwNC4wIKXMDSoASAFQAw%3D%3D) There are traffic lights to the south at Fort Hunt Road and to the north at Franklin Street, but neither are part of the interchange. (I-495 in Virginia has two other interchanges with no traffic lights that link to arterials, but they're just ordinary old cloverleaf designs.)
Edited to add: Ah, I missed the reference to an "at-grade intersection" in the original post. Carry on.
I just went through the entire thread and ended up with just one example that meets the new criteria:
Quote from: tradephoric on October 11, 2017, 08:27:00 PMHere is an unsignalized SPUI in Illinois...
https://www.google.com/maps/@42.3639101,-87.8287867,101m/data=!3m1!1e3 (https://www.google.com/maps/@42.3639101,-87.8287867,101m/data=!3m1!1e3)
AADT counts for this one per IDOT: 4600 (ramps) + 5300 (Mathon Dr estimated thru traffic) = ~9900
I've also been questioning the logic of the "no roundabouts" rule and open to any input on whether they should count. If they do count, we can add this entry:
Quote from: BrianP on October 10, 2017, 06:30:59 PMMD 216 @ US 29 comes to mind.
https://www.google.com/maps/@39.1458431,-76.8999922,16.92z (https://www.google.com/maps/@39.1458431,-76.8999922,16.92z)
Either way, there just doesn't seem to be much out there that directly compares to I-490/NY 31. I guess that kind of proves my point, but I'm still hoping that more comparable examples can be found.
Quote from: 1995hoo on March 07, 2025, 09:23:14 AMHow about this thing in the City of Alexandria between I-95/495 and US-1? (https://www.google.com/maps/@38.7938783,-77.0574582,1371m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI1MDMwNC4wIKXMDSoASAFQAw%3D%3D) There are traffic lights to the south at Fort Hunt Road and to the north at Franklin Street, but neither are part of the interchange. (I-495 in Virginia has two other interchanges with no traffic lights that link to arterials, but they're just ordinary old cloverleaf designs.)
There's a lot going on here. This is a pretty cool design considering the space constraints, but it definitely has more than four ramps (and no at grades, as I see you have noted).
I-81 @ US/VA-211 in New Market. Controlled with Stop Signs on the ramps.
US 250 @ Rugby Avenue in Charlottesville. Controlled with Stops on ramps + one Yield (US 250 WB to Rugby Ave WB)
VA-7 @ VA-7 BUS in Round Hill. Controlled with Stops + Yields on the ramps.
Quote from: webny99 on March 07, 2025, 09:37:52 AMQuote from: 1995hoo on March 07, 2025, 09:23:14 AMHow about this thing in the City of Alexandria between I-95/495 and US-1? (https://www.google.com/maps/@38.7938783,-77.0574582,1371m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI1MDMwNC4wIKXMDSoASAFQAw%3D%3D) There are traffic lights to the south at Fort Hunt Road and to the north at Franklin Street, but neither are part of the interchange. (I-495 in Virginia has two other interchanges with no traffic lights that link to arterials, but they're just ordinary old cloverleaf designs.)
There's a lot going on here. This is a pretty cool design considering the space constraints, but it definitely has more than four ramps (and no at grades, as I see you have noted).
Depending on one's point of view, one could argue that it has only five ramps because most of those start out as single ramps and then split, some of them multiple times. Once you learn what goes where and how to read the signs, it becomes a fairly simple and effective design because one of the main goals was to eliminate weave areas on both roads.
—One from SB US-1 that splits to serve both directions of the Beltway (this one splits three times and serves both the "Local" and "Thru" carriageways in both directions)
—One from the Beltway's outer loop that splits to serve both directions of US-1
—One from NB US-1 that splits to serve both directions of the Beltway (this one splits twice; it serves both carriageways on the Inner Loop but only the "Local" one on the Outer Loop)
—One from the Beltway's Inner Loop that splits to serve NB US-1 and Church Street (connecting to Washington Street, which becomes the GW Parkway to the south)
—One from the Beltway's Inner Loop that serves SB US-1 (perhaps the most conventional ramp there, a simple loop-around)
Quote from: 1995hoo on March 07, 2025, 10:02:47 AMQuoteQuoteHow about this thing in the City of Alexandria between I-95/495 and US-1? (https://www.google.com/maps/@38.7938783,-77.0574582,1371m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI1MDMwNC4wIKXMDSoASAFQAw%3D%3D) There are traffic lights to the south at Fort Hunt Road and to the north at Franklin Street, but neither are part of the interchange. (I-495 in Virginia has two other interchanges with no traffic lights that link to arterials, but they're just ordinary old cloverleaf designs.)
There's a lot going on here. This is a pretty cool design considering the space constraints, but it definitely has more than four ramps (and no at grades, as I see you have noted).
Depending on one's point of view, one could argue that it has only five ramps because most of those start out as single ramps and then split, some of them multiple times. Once you learn what goes where and how to read the signs, it becomes a fairly simple and effective design because one of the main goals was to eliminate weave areas on both roads.
I would probably consider the splits to be separate ramps, but still, only five mainline exit ramps for the entire complex is impressive.
There's also the pair of ramps to/from Eisenhower Avenue that appear to be unnumbered and considered separately, but they do overlap with the US 1 interchange.
Quote from: webny99 on March 07, 2025, 10:15:01 AM....
There's also the pair of ramps to/from Eisenhower Avenue that appear to be unnumbered and considered separately, but they do overlap with the US 1 interchange.
I wasn't counting those because they tie in to a completely separate road (they connect to Mill Road in front of the police station/jail and Mill then connects to Eisenhower, but the latter doesn't connect directly to Route 1). They're also a partial interchange.
I don't know what rule, inclusion or exclusion this would fall under, but NJ 42 South at CR 534 (https://maps.app.goo.gl/vy9P7bYjmGsN6kvd7, E Church Street/Blackwood-Clementon Rd), stop and yield sign controlled, has a 12 hour traffic count from 2009 of 19,600 vehicles, with 2,400 vehicles at the PM Peak ( https://www.njtms.org/map/tms_reports/reports/9t2-313-wrpt-09_02_26_10.pdf ), and I'm sure traffic hasn't gotten lighter in the 15 years since.
CA 41 at Excelsior Avenue just has stop signs at the end the off ramps.
Quote from: jeffandnicole on March 07, 2025, 01:01:38 PMI don't know what rule, inclusion or exclusion this would fall under, but NJ 42 South at CR 534 (https://maps.app.goo.gl/vy9P7bYjmGsN6kvd7, E Church Street/Blackwood-Clementon Rd), stop and yield sign controlled, has a 12 hour traffic count from 2009 of 19,600 vehicles, with 2,400 vehicles at the PM Peak ( https://www.njtms.org/map/tms_reports/reports/9t2-313-wrpt-09_02_26_10.pdf ), and I'm sure traffic hasn't gotten lighter in the 15 years since.
This works without a signal since most people using this interchange are coming from/going to the east which just involve right turns. People in Blackwood would most likely use the NJ 168 interchange instead. Thus why there's no dedicated left turn lane to the ramp onto 42 north.
I-10 at I-20
Quote from: webny99 on March 07, 2025, 08:44:45 AMQuote from: jakeroot on March 07, 2025, 04:39:21 AMPersonally, I don't think the change makes any sense, because now there is a weave between the two lanes. If the double left had been maintained, there would be no need for a weave since cars could turn left from the lane they needed (either towards 255 [left lane] or Research Drive [right lane]). Traffic entering via the right turn slip lane could have easily turned into either lane depending on where they wanted to go.
I tend to agree with you overall, but it is worth noting that yielding to an unsignalized double-left could be potentially confusing/problematic for those turning right. The flow of left turning traffic would have been fairly jolty and unpredictable, and if it was busy, you'd have to rely on guessing when they would turn and verifying that they were turning into the appropriate lane to accurately judge whether it was safe to proceed.
Point taken. But it operated exactly the way you've described it for over 30 years with no apparent changes to the configuration. That alone doesn't mean it was safe, but I think we can assume it operated with a good safety record if nothing ever changed.
Also, while traffic would have to yield to two oncoming turn lanes, slip lanes almost never have right-of-way. I would argue that yielding to an oncoming double left turn is barely different than yielding to two through lanes from the left. In both cases, you look around as you approach and determine if there is a gap. In both cases, there is a chance that drivers can change lanes, fail to stay in their lane, or whatever. Though with an oncoming double left, you just have much better visibility of the traffic you might have to yield to.
They could have also fixed the issue by just removing the slip lane and making the double left yield to all lanes. In any case, I don't see how the new weave is better or safer; weave locations are notorious danger hot spots.
I-35 at Central Avenue in Duluth, which abuts a busy commercial district on the north side of the freeway. Also at 21st Ave E, where during college move-in weekend traffic backs up onto the freeway.
In downtown Minneapolis, the ramp from I-35W to 11th Ave ends at a stop sign.
Hamilton Street @ US 75 in Omaha on the North Freeway.
Quote from: TheHighwayMan3561 on March 07, 2025, 11:22:13 PMI-35 at Central Avenue in Duluth, which abuts a busy commercial district on the north side of the freeway.
Heh. "Busy" is quite a relative term. Super One and the Jade Fountain (heard the latter was having a hard time staying open).
Quote from: jakeroot on March 07, 2025, 10:59:50 PMI would argue that yielding to an oncoming double left turn is barely different than yielding to two through lanes from the left. In both cases, you look around as you approach and determine if there is a gap. In both cases, there is a chance that drivers can change lanes, fail to stay in their lane, or whatever. Though with an oncoming double left, you just have much better visibility of the traffic you might have to yield to.
Regarding the bolded phrase, the biggest difference at this location specifically is predictability. Because the left turn is unsignalized, right turning traffic can only guess when left turners might actually complete their turn. Sure, they can *try* to intuit based on the gaps in thru traffic, but it's difficult to keep an eye on traffic behind you from a turning position, and each left turner has a different tolerance for when it's safe to complete the turn, so it's much more of a guessing game than two thru lanes, even despite better visibility.
Also previously, both directions of turning traffic could choose either lane to turn into, since they ended up merging downstream. Now, their lane choice depends on whether they're headed to 255 North or Research Dr. If there's two left turn lanes, now you're asking drivers to pre-select their destination, requiring additional signage, or surprising them into a quick weave after they complete their turn. And it could add delays for right turners, since they now have to make sure
both lanes are clear if they're heading to 255 North.
In short: a weave obviously isn't ideal, but I can see how it's the simpler and more effective solution here.
Quote from: jakeroot on March 07, 2025, 10:59:50 PMIn any case, I don't see how the new weave is better or safer; weave locations are notorious danger hot spots.
Aside from my thoughts above, it seems likely that the responsible DOT identified either a problem with the double left or a benefit to the weave, or they wouldn't have bothered with changing it. Or perhaps more likely, the volumes just didn't warrant two left turn lanes anyways.
Quote from: jeffandnicole on March 07, 2025, 01:01:38 PMI don't know what rule, inclusion or exclusion this would fall under, but NJ 42 South at CR 534 (https://maps.app.goo.gl/vy9P7bYjmGsN6kvd7 (https://maps.app.goo.gl/vy9P7bYjmGsN6kvd7), E Church Street/Blackwood-Clementon Rd), stop and yield sign controlled, has a 12 hour traffic count from 2009 of 19,600 vehicles, with 2,400 vehicles at the PM Peak ( https://www.njtms.org/map/tms_reports/reports/9t2-313-wrpt-09_02_26_10.pdf (https://www.njtms.org/map/tms_reports/reports/9t2-313-wrpt-09_02_26_10.pdf) ), and I'm sure traffic hasn't gotten lighter in the 15 years since.
Quote from: BrianP on March 07, 2025, 02:08:59 PMThis works without a signal since most people using this interchange are coming from/going to the east which just involve right turns. People in Blackwood would most likely use the NJ 168 interchange instead. Thus why there's no dedicated left turn lane to the ramp onto 42 north.
Aside from being a partial interchange, this works very similarly to the example in the OP: It's able to sustain high volumes without a traffic signal because the high volume movements are all right turns. Essentially add the missing ramps and it probably ends up pretty similar to the I-490/NY 31 volume and capacity-wise.
I-75 at US-33 Ohio (https://maps.app.goo.gl/DbbZBKiso6M3Dy8K7)
You have to stop at a stop sign to turn left to get on the US-33 freeway
(https://i.imgur.com/bKdbEtZ.png)
I-96 at 3 Mile RD/Alpine Ave Michigan
(https://maps.app.goo.gl/FgseVmMmNCinUgtf7)You have to stop at a stop sign and turn left on a 5 lane road to get to the busy Alpine Ave shopping area
(https://i.imgur.com/lV1Nciq.png)
As for mainly right turn stops I don't think they should count.
Quote from: michiganguy123 on March 08, 2025, 06:19:10 PMI-75 at US-33 Ohio (https://maps.app.goo.gl/DbbZBKiso6M3Dy8K7)
You have to stop at a stop sign to turn left to get on the US-33 freeway
I-71 at US 30 (https://www.google.com/maps/@40.7824244,-82.4111923,528m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI1MDMwNC4wIKXMDSoASAFQAw%3D%3D) near Mansfield, OH is also like this.. but the movements between east and north aren't allowed there and are instead serviced by a separate interchange. This one is a better example because all turn movements are allowed.
Quote from: michiganguy123 on March 08, 2025, 06:19:10 PMI-96 at 3 Mile RD/Alpine Ave Michigan
(https://maps.app.goo.gl/FgseVmMmNCinUgtf7)You have to stop at a stop sign and turn left on a 5 lane road to get to the busy Alpine Ave shopping area
Wow, it is surprising that the left turn here is unsignalized. This is also just a cool interchange design in general, but there is also a stoplight on Alpine Ave in the median of I-96.
Quote from: michiganguy123 on March 08, 2025, 06:19:10 PMAs for mainly right turn stops I don't think they should count.
Examples with heavy right turning traffic may be discounted or excluded if you're looking specifically for the *worst* interchange with no stoplights, but that isn't the premise of the thread.
Simply the busier the better is what's being looked for here.
Plenty of diamonds and other styles of interchange across the rural parts of Alabama only have stop signs for the ramps.
Quote from: freebrickproductions on March 11, 2025, 12:51:40 AMPlenty of diamonds and other styles of interchange across the rural parts of Alabama only have stop signs for the ramps.
Of course, and that's true nation-wide, but how busy they are is the key question here.
EDIT: the quick formula for calculating the approximate AADT of an interchange is:
- Add the surface street counts from either side of the interchange. Divide by 2.
- Add all of the ramp counts.
- Add your answers from 1. and 2.