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Flashing Yellow Arrows that have been removed

Started by jakeroot, June 25, 2018, 04:24:35 AM

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jakeroot

...without further modifications to the road (i.e. lane additions, widening, etc)

I just thought of this, after noticing the removal of a flashing yellow arrow that existed for only maybe five years (see below).

There are three locations that I know of in Washington where flashing yellow arrows existed; two removed for no obvious reason, and a third due to crash concerns:

Left turn onto Fruitvale Blvd from WB US-12 in Yakima: before and after.

Left turns onto SE 7/8 St from Lake Hills Connector in Bellevue: before and after (installed 2012, removed 2016 or 17).

A double left FYA existed in Silverdale for several years, but was removed (perhaps too hastily and without fully considering all options) after crash concerns: before and after (existed from 2010-2015).

Certainly traffic engineers have their methods, but sometimes I am left wondering what's going on. The Yakima example is odd since the opposite left turn remains a flashing yellow arrow. I know that many cities use a certain crash threshold to determine when left turn phasing must be changed from permissive to protected, but I still seldom see the left turn signals changed without any other modifications (such as widening, or even narrowing). Most cities that I know of won't change anything for quite some time, if at all, so it's strange to see these tiny modifications without any obvious explanation.


paulthemapguy

I can tell you why they changed it to protected-only on the second example--because the road meets the other road at a curve.  That means, on flashing yellow arrows, people were pulling into the middle of the intersection anticipating a turn.  When people do that, they tend to pull straight ahead--and not in alignment with the road.  This can lead to side-swiping by the parallel thru traffic.
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jakeroot

Quote from: paulthemapguy on June 25, 2018, 04:58:41 PM
I can tell you why they changed it to protected-only on the second example--because the road meets the other road at a curve.  That means, on flashing yellow arrows, people were pulling into the middle of the intersection anticipating a turn.  When people do that, they tend to pull straight ahead--and not in alignment with the road.  This can lead to side-swiping by the parallel thru traffic.

I'll have to get a hold of the city of Bellevue to see if there's an official answer. Usually when people pull forward here, it is (against traditional wisdom) at an angle (when possible due to a wide median), mostly to improve visibility. The left turns actually seemed pretty well-designed, as they were offset left turns.

US 89

Here’s one, from 2600 South onto Wildcat Way in Woods Cross, Utah.

This intersection was a doghouse until 2-3 years ago, when 2600 South was widened as part of a larger I-15 project. Initially this left turn was controlled by a FYA, but within a year it was converted to a protected left. My guess for why the change was made is the high left turn volumes, especially the movement from EB 2600 to NB Wildcat. That left-turn line often fails to clear in a cycle and frequently backs up into the main travel lanes.

Although I can’t think of any at the moment, there are probably intersections that were initially FYAs but were converted to dual-left lanes, which in Utah require a protected-only left turn.

jakeroot

Quote from: US 89 on June 25, 2018, 09:30:34 PM
Here's one, from 2600 South onto Wildcat Way in Woods Cross, Utah.

This intersection was a doghouse until 2-3 years ago, when 2600 South was widened as part of a larger I-15 project. Initially this left turn was controlled by a FYA, but within a year it was converted to a protected left. My guess for why the change was made is the high left turn volumes, especially the movement from EB 2600 to NB Wildcat. That left-turn line often fails to clear in a cycle and frequently backs up into the main travel lanes.

Wow! I thought a few years was a short span, but "within a year" is on the verge of being ridiculous. Agencies really need at least two or three years of before/after data to make a sound decision. Seems they were a bit rash.

The backups are worse now, if I understand correctly?

Quote from: US 89 on June 25, 2018, 09:30:34 PM
Although I can't think of any at the moment, there are probably intersections that were initially FYAs but were converted to dual-left lanes, which in Utah require a protected-only left turn.

Yeah, that seems to be the reason for 99% of permissive signal removals, since so few agencies use double permissive left turns. Often, I see a road widened so that two left turn lanes can be accommodated, but only one is painted, and pro/per phasing is utilised. When the extra lane is inevitably put into use, the phasing switches to protected.

US 89

Quote from: jakeroot on June 26, 2018, 02:12:30 AM
Quote from: US 89 on June 25, 2018, 09:30:34 PM
Here’s one, from 2600 South onto Wildcat Way in Woods Cross, Utah.

This intersection was a doghouse until 2-3 years ago, when 2600 South was widened as part of a larger I-15 project. Initially this left turn was controlled by a FYA, but within a year it was converted to a protected left. My guess for why the change was made is the high left turn volumes, especially the movement from EB 2600 to NB Wildcat. That left-turn line often fails to clear in a cycle and frequently backs up into the main travel lanes.
Wow! I thought a few years was a short span, but "within a year" is on the verge of being ridiculous. Agencies really need at least two or three years of before/after data to make a sound decision. Seems they were a bit rash.

The backups are worse now, if I understand correctly?

Now that I think about it, it could have been a little more than a year, but it was certainly less than two years. I don’t really remember if the backups were any different before the change was made, but it’s a very busy intersection.

Actually, another theory of mine is that the change was made when the development to the northeast became a thing. At first there was an old Kmart there, but that was torn down and  replaced by a new Smiths and several restaurants. Those generate a lot of traffic, and the raised median on 2600 requires a left turn on Wildcat to get there. That may have raised left turn volumes to the point where a protected left was required. On the other hand, it may well have been because of high crash rates.

Amtrakprod

Massdot has been doing this a lot, I emailed them to ask why, here's there response: Also dont Also don't understand why the text glitches that way.


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Troubleshooter

Quote from: US 89 on June 25, 2018, 09:30:34 PM
Here's one, from 2600 South onto Wildcat Way in Woods Cross, Utah.

This intersection was a doghouse until 2-3 years ago, when 2600 South was widened as part of a larger I-15 project. Initially this left turn was controlled by a FYA, but within a year it was converted to a protected left. My guess for why the change was made is the high left turn volumes, especially the movement from EB 2600 to NB Wildcat. That left-turn line often fails to clear in a cycle and frequently backs up into the main travel lanes.

Although I can't think of any at the moment, there are probably intersections that were initially FYAs but were converted to dual-left lanes, which in Utah require a protected-only left turn.

3 and 4 lane oncoming approaches should not have permissive turns across them.

jakeroot

Quote from: Troubleshooter on March 29, 2023, 11:46:25 PM
Quote from: US 89 on June 25, 2018, 09:30:34 PM
Here's one, from 2600 South onto Wildcat Way in Woods Cross, Utah.

This intersection was a doghouse until 2-3 years ago, when 2600 South was widened as part of a larger I-15 project. Initially this left turn was controlled by a FYA, but within a year it was converted to a protected left. My guess for why the change was made is the high left turn volumes, especially the movement from EB 2600 to NB Wildcat. That left-turn line often fails to clear in a cycle and frequently backs up into the main travel lanes.

Although I can't think of any at the moment, there are probably intersections that were initially FYAs but were converted to dual-left lanes, which in Utah require a protected-only left turn.

3 and 4 lane oncoming approaches should not have permissive turns across them.

Don't agree at all. The Japanese approach is far superior, IMO: permissive until proven to need protected phasing.

iBallasticwolf2

There's two former 4 section flashing yellllw arrow signal that were wapped to be 3 section protected only at KY 1892 and Newport Pavillion for a signal rebuild project. I remember how chaotic it was when I was there when it was installed  :bigass:

https://maps.app.goo.gl/3dW1gDkre5UggV866
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CovalenceSTU

#10
US-101 / Ensign Ln in Warrenton, OR is one that I know of. It opened with FYA's for left turns and 5-section signals for right turns (2008 for one side and 2010 for the other, I think) but in August 2018 both were removed due to multiple related crashes. My memory's a bit fuzzy on those but (being a short multi-lane stretch) passing on the right at up to 65mph was common and with increasing traffic volumes + FYAs it was a conflict waiting to happen.

Original:

Current:

wanderer2575

When the signal at Haggerty Road and Grand River Avenue in Novi MI was replaced several years ago, the new signal originally had FYAs in all four directions.  Recently, the fixtures for Haggerty Road were replaced to allow only fully-protected left turns.

Original:  https://goo.gl/maps/DeyshJDSWUcWSoASA

Current:  https://goo.gl/maps/JP6BKfQNtb7ZemRN8

fwydriver405

I can think of two examples in New Hampshire and Massachusetts:

In Salem NH, at S Broadway at Central and Angelas (GSV is not up to date):

  • When the signals were installed in 2017 or 18, the Central St left turn approach initially was activated with protected only phasing (via a RA-SYA-FYA/GA bimodal signal), and the Angelas left turn approach permissive only (green ball).
  • Sometime in 2019 or 20, the Central St left turn approach was changed from protected only to FYA permissive only, with the Angelas approach remaining left turn yield on green.
  • In mid-2021, the Angelas left turn approach was converted from left turn yield on green to protected only, but the Central left turn approach remained FYA permissive only.
  • As of 27 December 2021-present, all left turn approaches at the intersection were converted to protected only.

In Boston, this happened at Stewart at Tremont St, near Chinatown. The signals on westbound Stewart have had their left turn signals changed twice:

I've always wondered this for a while. I thought the purpose of an all arrow 4-section FYA (or 3-section bimodal FYA) was the ability to easily switch between left turn modes easily. If that's the case, why do most agencies opt to swap the FYA signal with a 3-section protected only signal, instead of simply just disabling the FYA and running it as protected only?

Big John

Quote from: fwydriver405 on April 09, 2023, 08:16:55 PM

I've always wondered this for a while. I thought the purpose of an all arrow 4-section FYA (or 3-section bimodal FYA) was the ability to easily switch between left turn modes easily. If that's the case, why do most agencies opt to swap the FYA signal with a 3-section protected only signal, instead of simply just disabling the FYA and running it as protected only?
A signal head with a permanently disabled aspect can be misleading to the public.

jakeroot

Quote from: Big John on April 09, 2023, 10:46:22 PM
Quote from: fwydriver405 on April 09, 2023, 08:16:55 PM

I've always wondered this for a while. I thought the purpose of an all arrow 4-section FYA (or 3-section bimodal FYA) was the ability to easily switch between left turn modes easily. If that's the case, why do most agencies opt to swap the FYA signal with a 3-section protected only signal, instead of simply just disabling the FYA and running it as protected only?

A signal head with a permanently disabled aspect can be misleading to the public.

What would be misleading?

Quote from: fwydriver405 on April 09, 2023, 08:16:55 PM
I can think of two examples in New Hampshire and Massachusetts:

In Salem NH, at S Broadway at Central and Angelas (GSV is not up to date):

  • When the signals were installed in 2017 or 18, the Central St left turn approach initially was activated with protected only phasing (via a RA-SYA-FYA/GA bimodal signal), and the Angelas left turn approach permissive only (green ball).
  • Sometime in 2019 or 20, the Central St left turn approach was changed from protected only to FYA permissive only, with the Angelas approach remaining left turn yield on green.
  • In mid-2021, the Angelas left turn approach was converted from left turn yield on green to protected only, but the Central left turn approach remained FYA permissive only.
  • As of 27 December 2021-present, all left turn approaches at the intersection were converted to protected only.

What a chaotic set of changes. I really don't see the need for any protected-only phasing for any of the approaches.

Side-note, I like the supplemental signal heads. I don't recall that being common in NH?

CovalenceSTU

Quote from: fwydriver405 on April 09, 2023, 08:16:55 PM
I've always wondered this for a while. I thought the purpose of an all arrow 4-section FYA (or 3-section bimodal FYA) was the ability to easily switch between left turn modes easily. If that's the case, why do most agencies opt to swap the FYA signal with a 3-section protected only signal, instead of simply just disabling the FYA and running it as protected only?
It is rather odd, although it happened just up the road from the one I posted - it opened with FYAs in 2018, but they were disabled within a year (not sure why) yet the 4-section signals remain.

https://goo.gl/maps/uT46pkQQ64txFaEJ9

fwydriver405

Quote from: jakeroot on April 10, 2023, 02:03:00 AM
Quote from: Big John on April 09, 2023, 10:46:22 PM
A signal head with a permanently disabled aspect can be misleading to the public.
What would be misleading?

I'm probably guessing something to do with driver expectation about timings and phasing - drivers expect consistancy when they approach a signal. For example, a driver may not expect TOD phasing at some intersections (protected only during the day, and PPLT during the night) and may be caught off guard if the approach the intersection at different times of the day. The same time applies to intersections that switch the lead-lag direction based on time of day.

A source from MaineDOT states that an engineering study needs to be conducted to justify regulatory signing for time-of-day (TOD) operations and restrictions.

Quote from: jakeroot on April 10, 2023, 02:03:00 AMWhat a chaotic set of changes. I really don't see the need for any protected-only phasing for any of the approaches.

Intersting to note, that 3-section bimodal signal is still there, but obviously still running on protected only phasing. Wonder if they wanted to try something but decided to fall back on protected only either due to capacity or safety reasons. This is also the same intersection with the strange right turn signal phasing (3-section, but red ball and green/yellow arrows)

Quote from: jakeroot on April 10, 2023, 02:03:00 AM
Side-note, I like the supplemental signal heads. I don't recall that being common in NH?

Probably a contractor thing to be honest. NHDOT signal standards don't usually call for supplemental signal heads, unlike with MassDOT standards which calls for them sometimes

jakeroot

Quote from: fwydriver405 on April 11, 2023, 12:01:17 PM
Quote from: jakeroot on April 10, 2023, 02:03:00 AM
Quote from: Big John on April 09, 2023, 10:46:22 PM
A signal head with a permanently disabled aspect can be misleading to the public.
What would be misleading?

I'm probably guessing something to do with driver expectation about timings and phasing - drivers expect consistancy when they approach a signal. For example, a driver may not expect TOD phasing at some intersections (protected only during the day, and PPLT during the night) and may be caught off guard if the approach the intersection at different times of the day. The same time applies to intersections that switch the lead-lag direction based on time of day.

A source from MaineDOT states that an engineering study needs to be conducted to justify regulatory signing for time-of-day (TOD) operations and restrictions.

My mind went to TOD phasing as well. And I guess that's where our personal observations are going to influence our thoughts; time of day phasing is crazy common in the Seattle region; many flashing yellow arrows (usually those against heavy traffic) are only active during off-peak hours; some jurisdictions (Bellevue and Puyallup come to mind) also use red arrows during the walk phase.

At any rate, I see FYA signals changing their operations all the time, I've never noticed any drivers being actively confused or creating dangerous situations as a result. There may be some driver confusion ("this light was flashing earlier, now it's not"), but I don't see how that confusion is actually problematic. The only potential issue might be if a driver creeps out against a red arrow, and the oncoming left gets a lagging green arrow (a sort of fake yellow trap).

Quote from: fwydriver405 on April 11, 2023, 12:01:17 PM
...This is also the same intersection with the strange right turn signal phasing (3-section, but red ball and green/yellow arrows)

There's an intersection in Fife, WA that operates just like this, with a shared yellow and red orb but entirely separate green arrow: https://goo.gl/maps/GfLtNcg1cwnssA5u6

fwydriver405

Quote from: jakeroot on April 11, 2023, 10:20:52 PM
At any rate, I see FYA signals changing their operations all the time, I've never noticed any drivers being actively confused or creating dangerous situations as a result. There may be some driver confusion ("this light was flashing earlier, now it's not"), but I don't see how that confusion is actually problematic. The only potential issue might be if a driver creeps out against a red arrow, and the oncoming left gets a lagging green arrow (a sort of fake yellow trap).

All of the new LT FYAs installed in coordination with the MaineDOT BUILD GRANT have both "FYA Delay" and LPIs set - the FYA is disabled for a few seconds before oncoming traffic is released and/or during a conflicting WALK phase. Surprised I haven't been seeing any false starts from drivers due to both of these parameters set. I think the "FYA Delay" setting is mostly a Northern New England thing (some newer NH and VT installs also enable this) - and the LPI isn't recycled if the WALK signal gets recycled as well.

Quote from: jakeroot on April 11, 2023, 10:20:52 PM
Quote from: fwydriver405 on April 11, 2023, 12:01:17 PM
...This is also the same intersection with the strange right turn signal phasing (3-section, but red ball and green/yellow arrows)

There's an intersection in Fife, WA that operates just like this, with a shared yellow and red orb but entirely separate green arrow: https://goo.gl/maps/GfLtNcg1cwnssA5u6

I think I remember seeing this intersection on another thread a while ago - interesting why a doghouse wasn't chosen here.

By the way, that strange overlap at the Salem NH intersection only happened after all of the left turns were converted to protected-only. Prior to all left turns being protected only, the right turn signal operated like a normal 3-section protected-only right turn signal.

fwydriver405

#19
As of 21 April 2023... The FYA on SB Payne Road at Holmes Rd in Scarborough (ME) was completly removed and replaced with a protected only head, because now the left turn crosses two thru approach lanes. The signals got replaced from doghouses to FYAs in all directions in 2021. Technically, the Northbound Payne Rd approach got widened and reconfigured from a L-T-R to a L-T-TR configuration in 2022, however, the FYA configuration remained unchanged with the two thru lanes for like 6-9 months when work completed around August 2022.

It's worth noting that the mast arms in this photo (taken from the back seat) are brand new and installed in 2023 - the doghouse (pre-2021) and 1st FYA (2021) configurations used a box spanwire setup for the signals.



Sidenote: This signal doesn't use the FYA delay I menetioned in Reply #18. It appears it's more of a VHB (contractor) decision as opposed to being statewide from what I found out.

jakeroot

Quote from: fwydriver405 on April 27, 2023, 12:16:26 PM
As of 21 April 2023... The FYA on SB Payne Road at Holmes Rd in Scarborough (ME) was completly removed and replaced with a protected only head, because now the left turn crosses two thru approach lanes. The signals got replaced from doghouses to FYAs in all directions in 2021. Technically, the Northbound Payne Rd approach got widened and reconfigured from a L-T-R to a L-T-TR configuration in 2022, however, the FYA configuration remained unchanged with the two thru lanes for like 6-9 months when work completed around August 2022.

Has there been a history of crashes? I find this policy completely bizarre.

I'm laughing in my head at the thought of a typical Maine driver over here in Japan, where two lanes of turning traffic against three lanes of high-speed traffic on a blind corner is perfectly fine.

ran4sh

Quote from: jakeroot on April 10, 2023, 02:03:00 AM
Quote from: Big John on April 09, 2023, 10:46:22 PM
Quote from: fwydriver405 on April 09, 2023, 08:16:55 PM

I've always wondered this for a while. I thought the purpose of an all arrow 4-section FYA (or 3-section bimodal FYA) was the ability to easily switch between left turn modes easily. If that's the case, why do most agencies opt to swap the FYA signal with a 3-section protected only signal, instead of simply just disabling the FYA and running it as protected only?

A signal head with a permanently disabled aspect can be misleading to the public.

What would be misleading?


Yeah I agree that it wouldn't be misleading.

As for "driver expectation"... I remember when FYA was becoming more common in my area or a nearby area, there was advice from some official source (the DOT or some police department, I don't remember) that specified, due to how flexible FYAs are regarding being able to run different programming at different times of day, that drivers should not try to predict what the light is going to do. That's good advice for traffic lights in general but really important for FYA signals

---

For the OP of this post, there are a few intersections in Athens GA that opened with FYA or had FYA installed, then were changed to protected-only without changing the signals.

Intersections like these come to mind:

* https://goo.gl/maps/FzRLWs33hV718fJf7 (Georgia standard FYA sign is still there, but an FYA is not displayed, at least in the daytime)

* https://goo.gl/maps/TpEuWtEE76kxqExWA (Sign was changed to the protected-only standard R10-5, but the signal still contains the FYA face)
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fwydriver405

Quote from: jakeroot on April 28, 2023, 02:01:45 AM
Quote from: fwydriver405 on April 27, 2023, 12:16:26 PM
As of 21 April 2023... The FYA on SB Payne Road at Holmes Rd in Scarborough (ME) was completly removed and replaced with a protected only head, because now the left turn crosses two thru approach lanes. The signals got replaced from doghouses to FYAs in all directions in 2021. Technically, the Northbound Payne Rd approach got widened and reconfigured from a L-T-R to a L-T-TR configuration in 2022, however, the FYA configuration remained unchanged with the two thru lanes for like 6-9 months when work completed around August 2022.

Has there been a history of crashes? I find this policy completely bizarre.

Not that I can recall of, nor has there been any High Crash Location data since 2012 at this intersection.

Quote from: jakeroot on April 28, 2023, 02:01:45 AM
I'm laughing in my head at the thought of a typical Maine driver over here in Japan, where two lanes of turning traffic against three lanes of high-speed traffic on a blind corner is perfectly fine.

I'm very curious about how much signal operations will fare with new signals are set to go in as part of the Build Grant from PPLT to protected only like these two intersections in Sanford (1,2) which will get new signals later this year- so far in the Augusta region, this former permissive only left, as well as this leading permissive-protected left were all changed to protected-only setups as of early 2023.

fwydriver405

Drove by a few signals in Newton on Washington St / MA 16 last night, and noticed that three left-turn and two right turn FYAs got recently removed with 4-section bimodal people/RT signals, and a few dedicated left and right turning lanes got switched out with shared left/right thru lanes. Not sure if they changed the phasing especially since they were pretty complex with the bicycle phasing and there were a few yellow traps especially at the Washington / Cherry St intersection.

This is what they were before the change-over. The GSV images are what they were previously when FYA was implmented.

Washington St (MA 16) at Cherry St:
Eastbound Washington St (MA 16) at Cherry St, left turn FYA got replaced with 4-section PPLT bimodal and left turn lane changed to left-thru (phase skip caused yellow trap)

Westbound Washington St (MA 16) at Cherry St, right turn signal replaced with 4-section PPRT and right turn lane changed to thru-right (right turners got yellow trapped at parts of the cycle)

Washington St (MA 16) at Highland St:
Westbound Washington St (MA 16), left turn FYA got replaced with 4-section PPLT bimodal and left turn lane changed to left-thru

Washington St at Chestnut St:
Westbound Washington St, left turn FYA got replaced with 4-section PPLT bimodal and left turn lane changed to left-thru

Northbound Chestnut St approach, right turn signal replaced with 4-section PPRT



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