Interchanges with no stoplights

[MCRoads]

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!

[Ian]

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.

[jakeroot]

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!

[froggie]

How 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.

[tradephoric]

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

[tradephoric]

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

[jakeroot]

How 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!

[tradephoric]

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

[jakeroot]

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).

[tradephoric]

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

[tradephoric]

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

[mrsman]

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.

[webny99]

Wow, the rare case where the forum search function was more effective than a Google search.

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.

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

[Max Rockatansky]

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.

[kphoger]

Honorable mention from Mexico:

This busy modified DDI 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, 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 has a stoplight.  The other crossover 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.

[webny99]

only one of the crossovers has a stoplight.  The other crossover is an uncontrolled intersection. 

Wow. Who has the right of way at the uncontrolled crossover?

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.

Probably that something is either expressly allowed or expressly prohibited during that time period. What, I have no idea.

[Max Rockatansky]

Highway signage in Mexico is mainly just for window dressing.  A lot of it is factually incorrect and tends to be universally ignored. 

[kphoger]

Wow. 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.

[kphoger]

That area has some good uncontrolled interchanges.  For example, the diamond interchange on Carr. Fed. 57(D) at Carr. Fed. 85 only has a single stop sign.

[webny99]

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.

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 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.

[jakeroot]

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.

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 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.

[webny99]

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.

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.

[1995hoo]

How about this thing in the City of Alexandria between I-95/495 and US-1? 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.

[webny99]

I just went through the entire thread and ended up with just one example that meets the new criteria:

Here is an unsignalized SPUI in Illinois...

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:

MD 216 @ US 29 comes to mind.
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.

[webny99]

How about this thing in the City of Alexandria between I-95/495 and US-1? 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).