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Leading Green/Delayed Green signs still in use

Started by Takumi, September 26, 2022, 07:21:22 PM

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Takumi

https://maps.app.goo.gl/NiGLFpvagNSPyFke8

US 301 southbound at I-95 in Petersburg, VA has a "delayed green"  sign, a thing that used to be common in the area until the 1990s. On intersections with a protected/permissive phase, the side with the doghouse signal would have a sign saying "leading green" , while the side that didn't would have one saying "delayed green" , as seen here. How common was this, and how often is it still seen? I'm sure with the changes in signals over the past few decades, it's rare to see.
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roadman65

NJ was big on them. Plus OPPOSING TRAFFIC HAS EXTENDED GREEN if the other side has its permissive or protected left at the end of the cycle.
Every day is a winding road, you just got to get used to it.

Sheryl Crowe

kphoger

Are you also wanting examples of "yellow trap" signage?  Like this:

Wheaton, IL
ON COMING TRAFFIC HAS LONGER GREEN
https://goo.gl/maps/MNkusWpYwjcfErYo7
Keep right except to pass.  Yes.  You.
Visit scenic Orleans County, NY!
Male pronouns, please.

Quote from: Philip K. DickIf you can control the meaning of words, you can control the people who must use them.

Dirt Roads

Quote from: kphoger on September 26, 2022, 07:36:26 PM
Are you also wanting examples of "yellow trap" signage?  Like this:

Wheaton, IL
ON COMING TRAFFIC HAS LONGER GREEN
https://goo.gl/maps/MNkusWpYwjcfErYo7

You would need to watch the normal cycle here to verify whether this is to prevent a traditional "yellow trap".  This signal should be equipped with a railroad preemption cycle, and it looks to me like this sign is intended to address the "clear-out phase" when the gates have been activated.  The southbound traffic would then get say 5 more seconds of green phase (after the protected left turn phase is reactivated) in order to pull traffic away from the crossing before the train arrives.  Indeed, a "yellow trap" would make a mess of that (but it's not considered a traditional "yellow trap" unless the extended green phase occurs at times other than railroad preemption).

By the way, this situation happens all over the place but it is the first time I've seen the ON COMING TRAFFIC HAS LONGER GREEN sign at a railroad crossing.

AppleMaps is currently showing an aerial photo that has all of the northbound lanes of West Street between Liberty Street and the crossing painted with XXXX to discourage vehicles from stacking up between the traffic signal and the crossing gates (probably for when the traffic signal at Front Street gets stacked up).  I'm wondering if the traditional striping and the ON COMING TRAFFIC HAS LONGER GREEN signage is new.  If so, that would indicate to me that the traffic signal at West and Front has been tied into the controller for West and Liberty, and the crossing preemption cycle might be way more complex than usual.  (It's already more complex on the railroad side, given that the crossing has pedestrian gates on both sides).

1995hoo

Quote from: Takumi on September 26, 2022, 07:21:22 PM
https://maps.app.goo.gl/NiGLFpvagNSPyFke8

US 301 southbound at I-95 in Petersburg, VA has a "delayed green"  sign, a thing that used to be common in the area until the 1990s. On intersections with a protected/permissive phase, the side with the doghouse signal would have a sign saying "leading green" , while the side that didn't would have one saying "delayed green" , as seen here. How common was this, and how often is it still seen? I'm sure with the changes in signals over the past few decades, it's rare to see.

There used to be an "Oncoming Traffic Has Extended Green" sign in Alexandria, Virginia, on westbound Duke Street at Cameron Station Boulevard: https://goo.gl/maps/53goYqPez6YF6dM29 (link should show the August 2009 image). That sign is gone now. The light has a flashing yellow arrow and, oddly, there is no sign saying to yield on flashing yellow, which is routine in Virginia. Of course it's an independent city, meaning it's not a VDOT installation, but elsewhere Alexandria has normally used a sign of that sort.
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

7/8

For some reason Parry Sound, ON has multiple examples (I can't think of any other Ontario towns/cities that do this).

- James and Segiun has "delayed green" signs for the northbound and eastbound directions.
- At River and Bowes, the eastbound direction has a "delayed green" sign, while the westbound direction has an "advance green" sign.
-At Bowes and Louisa/Oastler Park, the westbound direction has a "delayed green" sign while the eastbound direction has an "advance green" sign.

jeffandnicole

Quote from: Takumi on September 26, 2022, 07:21:22 PM
https://maps.app.goo.gl/NiGLFpvagNSPyFke8

US 301 southbound at I-95 in Petersburg, VA has a "delayed green"  sign, a thing that used to be common in the area until the 1990s. On intersections with a protected/permissive phase, the side with the doghouse signal would have a sign saying "leading green" , while the side that didn't would have one saying "delayed green" , as seen here. How common was this, and how often is it still seen? I'm sure with the changes in signals over the past few decades, it's rare to see.

Still in use in NJ whenever one direction has a leading arrow and the opposing direction does not.

roadman65

I remember also when NJ used WAIT FOR GREEN to inform traffic of the sudden change on the other side for permissive lefts.
Every day is a winding road, you just got to get used to it.

Sheryl Crowe

JoePCool14

I can't think of any I've seen around me. There's not many intersections I can think of with this pattern.

Also, could someone explain what the "yellow trap" is, please? Is it the case of when you want to turn left and your direction turns yellow while oncoming traffic gets an extended green, confusing you as to whether oncoming traffic will stop or not? Or is it when you get the yellow arrow of a 5-light tower/doghouse where in theory you could make the turn because oncoming traffic hasn't started moving yet but you should stop because your phase is turning "red"? Based on my observations, I feel like it's the latter. FYA signals eliminate this problem.

:) Needs more... :sombrero: Not quite... :bigass: Perfect.
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kphoger

Quote from: Dirt Roads on September 27, 2022, 10:46:11 AM

Quote from: kphoger on September 26, 2022, 07:36:26 PM
Are you also wanting examples of "yellow trap" signage?  Like this:

Wheaton, IL
ON COMING TRAFFIC HAS LONGER GREEN
https://goo.gl/maps/MNkusWpYwjcfErYo7

You would need to watch the normal cycle here to verify whether this is to prevent a traditional "yellow trap".  This signal should be equipped with a railroad preemption cycle, and it looks to me like this sign is intended to address the "clear-out phase" when the gates have been activated.  The southbound traffic would then get say 5 more seconds of green phase (after the protected left turn phase is reactivated) in order to pull traffic away from the crossing before the train arrives.  Indeed, a "yellow trap" would make a mess of that (but it's not considered a traditional "yellow trap" unless the extended green phase occurs at times other than railroad preemption).

By the way, this situation happens all over the place but it is the first time I've seen the ON COMING TRAFFIC HAS LONGER GREEN sign at a railroad crossing.

AppleMaps is currently showing an aerial photo that has all of the northbound lanes of West Street between Liberty Street and the crossing painted with XXXX to discourage vehicles from stacking up between the traffic signal and the crossing gates (probably for when the traffic signal at Front Street gets stacked up).  I'm wondering if the traditional striping and the ON COMING TRAFFIC HAS LONGER GREEN signage is new.  If so, that would indicate to me that the traffic signal at West and Front has been tied into the controller for West and Liberty, and the crossing preemption cycle might be way more complex than usual.  (It's already more complex on the railroad side, given that the crossing has pedestrian gates on both sides).

I have watched the normal cycle.  I used to live less than ¾ mile from that intersection back in 2000.  Southbound traffic got a lagging left arrow, even with no train approaching.
Keep right except to pass.  Yes.  You.
Visit scenic Orleans County, NY!
Male pronouns, please.

Quote from: Philip K. DickIf you can control the meaning of words, you can control the people who must use them.

1995hoo

Quote from: JoePCool14 on September 27, 2022, 11:34:27 AM
I can't think of any I've seen around me. There's not many intersections I can think of with this pattern.

Also, could someone explain what the "yellow trap" is, please? Is it the case of when you want to turn left and your direction turns yellow while oncoming traffic gets an extended green, confusing you as to whether oncoming traffic will stop or not? Or is it when you get the yellow arrow of a 5-light tower/doghouse where in theory you could make the turn because oncoming traffic hasn't started moving yet but you should stop because your phase is turning "red"? Based on my observations, I feel like it's the latter. FYA signals eliminate this problem.

It means the former. The term relates to the problem that occurs when the "pull out into the intersection" people see their direction getting a red light and automatically assume that the other direction is also getting a red light, so they turn, but the other direction in fact has an extended green. The flashing yellow arrow is intended to tell you that oncoming traffic still has a green light.
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

JoePCool14

Quote from: 1995hoo on September 27, 2022, 11:50:00 AM
Quote from: JoePCool14 on September 27, 2022, 11:34:27 AM
I can't think of any I've seen around me. There's not many intersections I can think of with this pattern.

Also, could someone explain what the "yellow trap" is, please? Is it the case of when you want to turn left and your direction turns yellow while oncoming traffic gets an extended green, confusing you as to whether oncoming traffic will stop or not? Or is it when you get the yellow arrow of a 5-light tower/doghouse where in theory you could make the turn because oncoming traffic hasn't started moving yet but you should stop because your phase is turning "red"? Based on my observations, I feel like it's the latter. FYA signals eliminate this problem.

It means the former. The term relates to the problem that occurs when the "pull out into the intersection" people see their direction getting a red light and automatically assume that the other direction is also getting a red light, so they turn, but the other direction in fact has an extended green. The flashing yellow arrow is intended to tell you that oncoming traffic still has a green light.

Thank you. I guess FYAs technically also resolve the second problem too. By adding that red light, you theoretically mandate people to stop.

:) Needs more... :sombrero: Not quite... :bigass: Perfect.
JDOT: We make the world a better place to drive.
Travel Mapping | 60+ Clinches | 260+ Traveled | 8000+ Miles Logged

1995hoo

Quote from: JoePCool14 on September 27, 2022, 11:54:16 AM
Quote from: 1995hoo on September 27, 2022, 11:50:00 AM
Quote from: JoePCool14 on September 27, 2022, 11:34:27 AM
I can't think of any I've seen around me. There's not many intersections I can think of with this pattern.

Also, could someone explain what the "yellow trap" is, please? Is it the case of when you want to turn left and your direction turns yellow while oncoming traffic gets an extended green, confusing you as to whether oncoming traffic will stop or not? Or is it when you get the yellow arrow of a 5-light tower/doghouse where in theory you could make the turn because oncoming traffic hasn't started moving yet but you should stop because your phase is turning "red"? Based on my observations, I feel like it's the latter. FYA signals eliminate this problem.

It means the former. The term relates to the problem that occurs when the "pull out into the intersection" people see their direction getting a red light and automatically assume that the other direction is also getting a red light, so they turn, but the other direction in fact has an extended green. The flashing yellow arrow is intended to tell you that oncoming traffic still has a green light.

Thank you. I guess FYAs technically also resolve the second problem too. By adding that red light, you theoretically mandate people to stop.

I'm not sure I follow. What red light? At least as they are used around here, a flashing yellow arrow does not have an accompanying red light on the same signal head. If I see a flashing yellow arrow and I can see nobody is coming the other way, I know it means I don't need to stop–I can go ahead and make my turn. If they wanted traffic to stop before turning, a flashing red arrow would presumably be more appropriate.

(I say "at least as they are used around here" because I have no idea whether there might be situations somewhere else where a flashing yellow arrow is retrofitted onto a doghouse signal or similar. I'm sure that's not "supposed to" happen, but that doesn't mean it doesn't.)
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

JoePCool14

Quote from: 1995hoo on September 27, 2022, 12:06:26 PM
I'm not sure I follow. What red light? At least as they are used around here, a flashing yellow arrow does not have an accompanying red light on the same signal head. If I see a flashing yellow arrow and I can see nobody is coming the other way, I know it means I don't need to stop–I can go ahead and make my turn. If they wanted traffic to stop before turning, a flashing red arrow would presumably be more appropriate.

(I say "at least as they are used around here" because I have no idea whether there might be situations somewhere else where a flashing yellow arrow is retrofitted onto a doghouse signal or similar. I'm sure that's not "supposed to" happen, but that doesn't mean it doesn't.)

In cases of a leading green arrow only. The sequence goes green, yellow, red, flashing yellow. With a tower/doghouse, you get green arrow, yellow arrow, green ball (or green arrow, yellow arrow, red ball - not what I'm referring to here). With the tower/doghouse, there's no official stop. So even after the arrow has gone out, you could theoretically turn since opposing traffic is just beginning to move.

I'm not talking about something like the old Michigan flashing red ball left. Hopefully that makes it clearer.

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JDOT: We make the world a better place to drive.
Travel Mapping | 60+ Clinches | 260+ Traveled | 8000+ Miles Logged

1995hoo

I'm still not sure I follow what you're saying. I'm thinking of an intersection like this one in Fairfax County, Virginia. Both directions normally get the green arrow at the same time. The arrows then change to flashing yellow, without first going red, when the green light comes on for traffic going straight. Sometimes, if there is no traffic waiting at the light on the cross street (which is admittedly rare) but there is traffic waiting in one of the left-turn lanes, the light for traffic coming the other way will turn red and the flashing yellow arrow will change back to a green arrow. Meanwhile, traffic coming the other way wanting to turn left will continue to see the flashing yellow arrow.

The scenario I just described, of the flashing yellow arrow changing back to a green arrow without having to wait through a full light cycle for the other street, is one big advantage I've observed over the doghouse signals–doghouse signals here didn't do that. It's also a reason why I often prefer to wait behind the stop bar at a light with a dedicated turn arrow and a flashing yellow arrow, rather than pulling out into the intersection to wait to turn–waiting behind the line makes it more likely the flashing yellow arrow will change back to a green arrow.

(The scenario described above is more likely to occur at a different intersection located nearby rather than at the one I linked above, but the one linked above has a better Street View image.)
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

JoePCool14

It doesn't really matter much. It's just a quirky "you could make a theoretical or legal argument" if you were given a citation for turning when you shouldn't have.

:) Needs more... :sombrero: Not quite... :bigass: Perfect.
JDOT: We make the world a better place to drive.
Travel Mapping | 60+ Clinches | 260+ Traveled | 8000+ Miles Logged

ran4sh

I've seen those signs in use in Northern NJ, where the purpose seemed to be to substitute for having green arrow indications for split phased traffic signals. I.e. instead of having a green left arrow to indicate that both straight-through and left turn movements are protected (due to the opposing movements getting their own phase), you're supposed to infer it from the leading green/delayed green signage.
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Dirt Roads

Quote from: kphoger on September 27, 2022, 11:36:46 AM
I have watched the normal cycle.  I used to live less than ¾ mile from that intersection back in 2000.  Southbound traffic got a lagging left arrow, even with no train approaching.

Gotcha.  Then the sign is indeed for the "yellow trap" and I still haven't seen it used for railroad preemption.  But it certainly makes sense in those cases, as well.

Dirt Roads

Quote from: JoePCool14 on September 27, 2022, 11:34:27 AM
I can't think of any I've seen around me. There's not many intersections I can think of with this pattern.

Also, could someone explain what the "yellow trap" is, please? Is it the case of when you want to turn left and your direction turns yellow while oncoming traffic gets an extended green, confusing you as to whether oncoming traffic will stop or not? Or is it when you get the yellow arrow of a 5-light tower/doghouse where in theory you could make the turn because oncoming traffic hasn't started moving yet but you should stop because your phase is turning "red"? Based on my observations, I feel like it's the latter. FYA signals eliminate this problem.

Quote from: 1995hoo on September 27, 2022, 11:50:00 AM
It means the former. The term relates to the problem that occurs when the "pull out into the intersection" people see their direction getting a red light and automatically assume that the other direction is also getting a red light, so they turn, but the other direction in fact has an extended green. The flashing yellow arrow is intended to tell you that oncoming traffic still has a green light.

Quote from: JoePCool14 on September 27, 2022, 11:54:16 AM
Thank you. I guess FYAs technically also resolve the second problem too. By adding that red light, you theoretically mandate people to stop.

In the railroad circles, there's been a fair amount of discussion as to whether FYAs can cause other types of "trap issues" related to the track clearout phase.  In particular, the particular crossing layout presented by the OP has all of the markings of the most deadly traffic signal concern, which incidentally is called the "track clear green trap".  That's the situation where the protected left turn green phase that was triggered by the railroad preemption expires (and turns yellow) before the FLS&G (flashing light signals and gates) are activated.  The "track clear green trap" is even worse if the green through ball expires at the same time.  More cars can (and will) cross the railroad and start to stack up/back up onto the crossing with no hope of another opportunity for a safe left turn.  In most states, the railroad has no input into the timing of the traffic signal and can only pray that the DOT will hold both the protected left turn green arrow and the through green ball until the gates are fully down for at least 5 seconds.

Issues such as the extra track clearout time for semi-trailers, extra time for pedestrian signals and extra time for pedestrian gates (which all appear at this particular crossing) increase the likelihood of a "track clear green trap".

roadfro

Quote from: JoePCool14 on September 27, 2022, 12:11:32 PM
Quote from: 1995hoo on September 27, 2022, 12:06:26 PM
I'm not sure I follow. What red light? At least as they are used around here, a flashing yellow arrow does not have an accompanying red light on the same signal head. If I see a flashing yellow arrow and I can see nobody is coming the other way, I know it means I don't need to stop–I can go ahead and make my turn. If they wanted traffic to stop before turning, a flashing red arrow would presumably be more appropriate.

In cases of a leading green arrow only. The sequence goes green, yellow, red, flashing yellow. With a tower/doghouse, you get green arrow, yellow arrow, green ball (or green arrow, yellow arrow, red ball - not what I'm referring to here). With the tower/doghouse, there's no official stop. So even after the arrow has gone out, you could theoretically turn since opposing traffic is just beginning to move.
Quote from: 1995hoo on September 27, 2022, 12:24:34 PM
I'm still not sure I follow what you're saying. I'm thinking of an intersection like this one in Fairfax County, Virginia. Both directions normally get the green arrow at the same time. The arrows then change to flashing yellow, without first going red, when the green light comes on for traffic going straight.

I think the confusion comes from differences in signal timing philosophy between jurisdictions. Some jurisdictions will use a red clearance interval after every yellow light (even if it's as short as 0.5 seconds) for safety reasons. So for FYA operations where a leading protected turn phase is followed by permitted turns, some jurisdictions will have a very short red arrow to end the protected phase before the permitted turns (and opposing through traffic) begins–other jurisdictions omit this red arrow.

JoePCool was indicating that the brief red arrow in the FYA operation introduces a short period in the transition between protected and permitted phases where left turn drivers must stop. In jurisdictions where the short red arrow is not used, as well as an old doghouse/tower configuration (assuming your direction has an adjacent through green), there is no period where left turn drivers must stop–the signal goes directly from protected yellow arrow to the permitted left indication (FYA, or green ball on the doghouse/tower).
Roadfro - AARoads Pacific Southwest moderator since 2010, Nevada roadgeek since 1983.

JoePCool14

Quote from: roadfro on October 02, 2022, 03:01:11 PM
I think the confusion comes from differences in signal timing philosophy between jurisdictions. Some jurisdictions will use a red clearance interval after every yellow light (even if it's as short as 0.5 seconds) for safety reasons. So for FYA operations where a leading protected turn phase is followed by permitted turns, some jurisdictions will have a very short red arrow to end the protected phase before the permitted turns (and opposing through traffic) begins–other jurisdictions omit this red arrow.

JoePCool was indicating that the brief red arrow in the FYA operation introduces a short period in the transition between protected and permitted phases where left turn drivers must stop. In jurisdictions where the short red arrow is not used, as well as an old doghouse/tower configuration (assuming your direction has an adjacent through green), there is no period where left turn drivers must stop–the signal goes directly from protected yellow arrow to the permitted left indication (FYA, or green ball on the doghouse/tower).

Exactly. Except, the "old" 5-light towers are still heavily prominent in some areas. I have yet to see IDOT D1 use them, though other local jurisdictions have.

:) Needs more... :sombrero: Not quite... :bigass: Perfect.
JDOT: We make the world a better place to drive.
Travel Mapping | 60+ Clinches | 260+ Traveled | 8000+ Miles Logged


Dirt Roads

Quote from: index on October 03, 2022, 02:43:47 PM
Waxhaw, NC:
https://www.google.com/maps/@34.9247086,-80.7436167,3a,75y,336.95h,82.75t/data=!3m7!1e1!3m5!1sfQTaQ52FurLnrnXYsCCeFg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DfQTaQ52FurLnrnXYsCCeFg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D321.29852%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

Nice.  I was just there a few weeks ago, but I came across the tracks and turned right onto NC-75 northbound.  That is the proper way to address the possibility of leading green due to railroad preemption.  It is not required, but the MUTCD does have some specific rules about how to manage yellow balls and flashing yellow left turn arrows when that sign is installed due to railroad preemption.

ran4sh

Quote from: Dirt Roads on October 03, 2022, 04:26:01 PM
Quote from: index on October 03, 2022, 02:43:47 PM
Waxhaw, NC:
https://www.google.com/maps/@34.9247086,-80.7436167,3a,75y,336.95h,82.75t/data=!3m7!1e1!3m5!1sfQTaQ52FurLnrnXYsCCeFg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DfQTaQ52FurLnrnXYsCCeFg%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D321.29852%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

Nice.  I was just there a few weeks ago, but I came across the tracks and turned right onto NC-75 northbound.  That is the proper way to address the possibility of leading green due to railroad preemption.  It is not required, but the MUTCD does have some specific rules about how to manage yellow balls and flashing yellow left turn arrows when that sign is installed due to railroad preemption.

I would prefer FYA signals as the solution to yellow trap, but I understand that at that intersection it cannot be done because there is no exclusive left turn lane, left turn and straight traffic share the same lane.
Control cities CAN be off the route! Control cities make NO sense if signs end before the city is reached!

Travel Mapping - Most Traveled: I-40, 20, 10, 5, 95 - Longest Clinched: I-20, 85, 24, 16, NJ Tpk mainline
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