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Interchanges with no stoplights

Started by ParrDa, October 10, 2017, 05:49:06 PM

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CtrlAltDel

#25
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?
Interstates clinched: 4, 57, 275 (IN-KY-OH), 465 (IN), 640 (TN), 985
State Interstates clinched: I-26 (TN), I-75 (GA), I-75 (KY), I-75 (TN), I-81 (WV), I-95 (NH)


MCRoads

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 build roads on Minecraft. Like, really good roads.
Interstates traveled:
4/5/10*/11**/12**/15/25*/29*/35(E/W[TX])/40*/44**/49(LA**)/55*/64**/65/66*/70°/71*76(PA*,CO*)/78*°/80*/95°/99(PA**,NY**)

*/** indicates a terminus/termini being traveled
° Indicates a gap (I.E Breezwood, PA.)

more room plz

Ian

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.
UMaine graduate, former PennDOT employee, new SoCal resident.
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jakeroot

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!

froggie

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.

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

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

jakeroot

#32
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!

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

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).

tradephoric

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

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

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.



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