Double left turns with permissive phasing

[steviep24]

^^ Those are typical of what NYC often installs. (The Flatbush and Ave U example.) Those are not NYSDOT.

These examples are typical of what NYSDOT installs outside of NYC.

Recent installations:

https://www.google.com/maps/@43.1471182,-77.7112622,3a,75y,246.57h,90t/data=!3m6!1e1!3m4!1sexC28q_yeddycXQKeGOLcQ!2e0!7i13312!8i6656?hl=en&authuser=0


https://www.google.com/maps/@43.1476884,-77.7091322,3a,75y,246.57h,90t/data=!3m6!1e1!3m4!1skk9NwnqJgq3syra0_ZUvPg!2e0!7i13312!8i6656?hl=en&authuser=0

Older installations;

https://www.google.com/maps/@43.0725792,-77.6445313,3a,75y,6.81h,90t/data=!3m6!1e1!3m4!1s_tEVblEC6eu7mTefVNiy-A!2e0!7i13312!8i6656?hl=en&authuser=0

https://www.google.com/maps/@43.0681274,-77.646874,3a,75y,210h,90t/data=!3m6!1e1!3m4!1sKERFq8yxjte_HQBcfYTtJw!2e0!7i13312!8i6656?hl=en&authuser=0

As you can see their more recent installs use back plates and often have FYA. Also, NYSDOT is big on span wire but are using mast arms a lot more than they used to. Also, for span wire installs they have been moving toward box span for large intersections. (probably to meet newer signal per lane requirements.) NYSDOT doesn't use side mounted signals except on rare occasions.

I know this has been going off topic but I thought I'd throw this in there.

[jakeroot]

Now, what should rank last (IMO)? This is a great example (near Graham, WA) (this is not far from where I grew up, so I can assure you there is no bias). This is a 55-mph approach. If you are behind a tall vehicle, there's a decent chance that you cannot see the signals for a good portion of the approach. None of the BS you mentioned above (backplates, indication size, etc) matters if you can't even see a signal.

The worst I've personally driven through is this example in Coahuila.  A single overhead signal for each direction of a four-lane divided federal highway with very heavy commercial traffic.

Yikes, that is bad. Looks to run split-phasing as well. Also not so good.

I know this has been going off topic but I thought I'd throw this in there.

No no, it's good. I'm glad you brought it up (despite my terrible attempt in my own post). Amtrakprod indicated that the above signal at Flatbush/Ave U was a good example of how New York State "ranks last" in signals, despite it being a NYC install. Even I know, living primarily on the opposite side of the country, that the state has totally different traffic signals. IMO, they're not as good as the city, although they have newer features (backplates, signal per lane) that give the appearance of being "better". I still prefer NYC signals, though, on account of their placement strategies.

[mrsman]

Now, what should rank last (IMO)? This is a great example (near Graham, WA) (this is not far from where I grew up, so I can assure you there is no bias). This is a 55-mph approach. If you are behind a tall vehicle, there's a decent chance that you cannot see the signals for a good portion of the approach. None of the BS you mentioned above (backplates, indication size, etc) matters if you can't even see a signal.

The worst I've personally driven through is this example in Coahuila.  A single overhead signal for each direction of a four-lane divided federal highway with very heavy commercial traffic.

Yikes, that is bad. Looks to run split-phasing as well. Also not so good.

I know this has been going off topic but I thought I'd throw this in there.

No no, it's good. I'm glad you brought it up (despite my terrible attempt in my own post). Amtrakprod indicated that the above signal at Flatbush/Ave U was a good example of how New York State "ranks last" in signals, despite it being a NYC install. Even I know, living primarily on the opposite side of the country, that the state has totally different traffic signals. IMO, they're not as good as the city, although they have newer features (backplates, signal per lane) that give the appearance of being "better". I still prefer NYC signals, though, on account of their placement strategies.

NYC definitely operates on a "if it ain't broke don't fix it" mentality.  As mentioned on other threads, they are still using 1960's tech on all their signals except to the extant it has been superseded by MUTCD.  Many 8-8-8 signals.  Guy wires.

Signal placement has definitely improved at many intersections.  A common NYC install was to have lamppost masts at two diagonally opposite corners.  A guy wire mast arm would extend diagonally into the intersection from each lamppost mast.  Hanging from the mast arm would be a four-sided* 8-8-8 signal head.  As noted by others above, this means that the locations are not ideal and it's often hard to see the signals as they won't be placed where the driver is looking.

See this example: 5 Av / 9 St in Brooklyn

https://www.google.com/maps/@40.6692312,-73.9862775,3a,75y,105.55h,91.21t/data=!3m7!1e1!3m5!1sQt9FaaiXXeypuuBnhYRVcg!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3DQt9FaaiXXeypuuBnhYRVcg%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D305.70407%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656?hl=en

But many of these intersections in NYC are being corrected and signals are getting better placement, but it's a slow process.  In Manhattan, it seems to be working better, as one of the diagonal guy-wires is replaced for more conventional supplemental signals as can be seen along Lexington Ave. 

https://www.google.com/maps/@40.7421612,-73.9828895,3a,75y,193.72h,91.97t/data=!3m6!1e1!3m4!1s12URtX6UkUBz9O0Wp_1rmA!2e0!7i16384!8i8192?hl=en




I don't know the history at Flatbush & U, but I would gather that it was originally a single left turn lane with a PPLT 5 signal display.  With increased traffic (headed from the Mall towards Belt Parkway), they decided to make it a double left, but did not at the same time change the signal to an exclusive RA-YA-GA signal.  Maybe it's laziness, but it does allow for a double permissive turn.

Give NYC some credit - Chicago would make a 5 signal display into protected only by sign (as done on Michigan Ave).

https://www.google.com/maps/@41.8845407,-87.6244069,3a,75y,342.48h,83.16t/data=!3m6!1e1!3m4!1s63MFkaHIWSj_xZE4FQ74YA!2e0!7i13312!8i6656?hl=en


* Since there are so many one-way streets in NYC, it's rare that you'll have 4-sided signal faces as 3-sided and 2 sided are more common.

[kphoger]

The worst I've personally driven through is this example in Coahuila.  A single overhead signal for each direction of a four-lane divided federal highway with very heavy commercial traffic.

Yikes, that is bad. Looks to run split-phasing as well. Also not so good.

While split phasing is quite common in Mexico, I don't think this one does.  I could be wrong, but I don't see any left turn arrows to make me think it does either.

[jakeroot]

The worst I've personally driven through is this example in Coahuila.  A single overhead signal for each direction of a four-lane divided federal highway with very heavy commercial traffic.

Yikes, that is bad. Looks to run split-phasing as well. Also not so good.

While split phasing is quite common in Mexico, I don't think this one does.  I could be wrong, but I don't see any left turn arrows to make me think it does either.

I was basing it on these views:

https://goo.gl/maps/ME7bkpc2ZEvL1yFPA

https://goo.gl/maps/BMJgXEpGcc6ZgCTq5

[kphoger]

Yeah, I noticed that too.  I don't remember from personal experience, but I don't see how that would work without arrows.

[fwydriver405]

Give NYC some credit - Chicago would make a 5 signal display into protected only by sign (as done on Michigan Ave).

And recently,  Boston as well with this bizarre setup. The last time I was there at that intersection (24 July 2019), many drivers flat out ignored the LEFT ON GREEN ARROW ONLY sign and turned left after yielding to oncoming traffic on the green ball like it used to be...

Kneeland St and Surface Rd:
October 2018 w/ LEFT TURN YIELD ON GREEN
19 May 2019 - present w/ LEFT ON GREEN ARROW ONLY

[Amtrakprod]

Give NYC some credit - Chicago would make a 5 signal display into protected only by sign (as done on Michigan Ave).

And recently,  Boston as well with this bizarre setup. The last time I was there at that intersection (24 July 2019), many drivers flat out ignored the LEFT ON GREEN ARROW ONLY sign and turned left after yielding to oncoming traffic on the green ball like it used to be...

Kneeland St and Surface Rd:
October 2018 w/ LEFT TURN YIELD ON GREEN
19 May 2019 - present w/ LEFT ON GREEN ARROW ONLY

I've seen this in Cambridge too, what I wish Boston did instead is install a red arrow up top and not have the green/yellow ball lights work, or install straight green and yellow arrows so when the left turn phase ended the red ball could stay on.


iPhone

[kphoger]

Give NYC some credit - Chicago would make a 5 signal display into protected only by sign (as done on Michigan Ave).

I was driving down Kellogg the other day and thought of you because of this sign.

[fwydriver405]

I've seen this in Cambridge too, what I wish Boston did instead is install a red arrow up top and not have the green/yellow ball lights work, or install straight green and yellow arrows so when the left turn phase ended the red ball could stay on.

If there was an issue with people "blocking the box", queuing of the left turn lanes, or accidents due to permissive left turns, I would have replaced the doghouse with FYA, and use TOD phasing to make the turns protected only during the rush hour and protected/permissive during the off-peak hours, Monday-Friday, similar to what New Hampshire does. Furthermore, I would change the phasing from leading to lagging left at this intersection as well.

BTW... your proposal of installing "straight green and yellow arrows so when the left-turn phase ends, the red ball could stay on" is prohibited in the 2009 MUTCD. See below:

10 The following combinations of signal indications shall not be simultaneously displayed on any one signal face:

CIRCULAR RED with CIRCULAR YELLOW;
CIRCULAR GREEN with CIRCULAR RED; or
Straight-through GREEN ARROW with CIRCULAR RED;

[jakeroot]

BTW... your proposal of installing "straight green and yellow arrows so when the left-turn phase ends, the red ball could stay on" is prohibited in the 2009 MUTCD. See below:

10 The following combinations of signal indications shall not be simultaneously displayed on any one signal face:

CIRCULAR RED with CIRCULAR YELLOW;
CIRCULAR GREEN with CIRCULAR RED; or
Straight-through GREEN ARROW with CIRCULAR RED;

That only applies to a "one signal face", not an overall setup. Protected turns with circular red indications are also a sort of engineering-faux pas at this point. I think it's allowed, but discouraged.

[Amtrakprod]

I've seen this in Cambridge too, what I wish Boston did instead is install a red arrow up top and not have the green/yellow ball lights work, or install straight green and yellow arrows so when the left turn phase ended the red ball could stay on.

If there was an issue with people "blocking the box", queuing of the left turn lanes, or accidents due to permissive left turns, I would have replaced the doghouse with FYA, and use TOD phasing to make the turns protected only during the rush hour and protected/permissive during the off-peak hours, Monday-Friday, similar to what New Hampshire does. Furthermore, I would change the phasing from leading to lagging left at this intersection as well.

BTW... your proposal of installing "straight green and yellow arrows so when the left-turn phase ends, the red ball could stay on" is prohibited in the 2009 MUTCD. See below:

10 The following combinations of signal indications shall not be simultaneously displayed on any one signal face:

CIRCULAR RED with CIRCULAR YELLOW;
CIRCULAR GREEN with CIRCULAR RED; or
Straight-through GREEN ARROW with CIRCULAR RED;

I actually don't know of any Flashing yellow arrow in the state (and we have over 350 of them), that uses TOD phasing!


iPhone

[mrsman]

I've seen this in Cambridge too, what I wish Boston did instead is install a red arrow up top and not have the green/yellow ball lights work, or install straight green and yellow arrows so when the left turn phase ended the red ball could stay on.

If there was an issue with people "blocking the box", queuing of the left turn lanes, or accidents due to permissive left turns, I would have replaced the doghouse with FYA, and use TOD phasing to make the turns protected only during the rush hour and protected/permissive during the off-peak hours, Monday-Friday, similar to what New Hampshire does. Furthermore, I would change the phasing from leading to lagging left at this intersection as well.

BTW... your proposal of installing "straight green and yellow arrows so when the left-turn phase ends, the red ball could stay on" is prohibited in the 2009 MUTCD. See below:

10 The following combinations of signal indications shall not be simultaneously displayed on any one signal face:

CIRCULAR RED with CIRCULAR YELLOW;
CIRCULAR GREEN with CIRCULAR RED; or
Straight-through GREEN ARROW with CIRCULAR RED;

I actually don't know of any Flashing yellow arrow in the state (and we have over 350 of them), that uses TOD phasing!


iPhone

I can't speak to whether the intersection in Boston mentioned needs or doesn't need protected only left turns at all times, but I can say that there is a driver expectation in most of the country (other than some of the states in the Pacific Northwest*) that a doghouse signal (or 5 phase towers) are protected/permissive and that RA-YA-GA signals are protected only.  This standard should be kept, because a sign like the one in Boston seems kind of small and is very easy to overlook.  If I were driving there, I probably would not notice the sign and make a left turn on green orb even without a green arrow, and I could be subject to a ticket.

Simply change the signal to RA-YA-GA if you really want left turn on arrow only.  Change it to a FYA if time of day signalling is warranted.

*Jakeroot and others can confirm but in WA state (and probably a few other nearby states) left turn on red arrow is permitted onto a one-way street or a one-way freeway onramp.  There is no similar rule to my knowledge in any East Coast state.

[mrsman]

Give NYC some credit - Chicago would make a 5 signal display into protected only by sign (as done on Michigan Ave).

I was driving down Kellogg the other day and thought of you because of this sign.

WHile the construction makes the signal placement ugly, this sign is not nearly as bad as the Chicago or Boston examples.  It seems pretty clear that the left signal controls left turns and the other two signals control straight.  Seeing the red ball (especially while the other signals are green) would lead me to at least suspect that the left signal controls left turns.

While the latest MUTCD recommends (or requires, not sure how to actually interpret it) that new exclusive left turn signals have red arrows instead of red balls, there are plenty of signals out there that are R-Y-GA that control a protected only left turn.  They are still very common in PA and VA which use the sign "Left turn signal".  This was also the standard for a while in CA, where they had a sign that read "Left turn on arrow only"  (the only arrow was a green one), but in that case the left turn signal was in a 3M or louvered so as not to confuse nearby straight traffic.  Very few of those remain in CA as most have been converted to red arrow.

[jeffandnicole]

I’ve seen this in Cambridge too, what I wish Boston did instead is install a red arrow up top and not have the green/yellow ball lights work, or install straight green and yellow arrows so when the left turn phase ended the red ball could stay on.

If there was an issue with people "blocking the box", queuing of the left turn lanes, or accidents due to permissive left turns, I would have replaced the doghouse with FYA, and use TOD phasing to make the turns protected only during the rush hour and protected/permissive during the off-peak hours, Monday-Friday, similar to what New Hampshire does. Furthermore, I would change the phasing from leading to lagging left at this intersection as well.

BTW... your proposal of installing "straight green and yellow arrows so when the left-turn phase ends, the red ball could stay on" is prohibited in the 2009 MUTCD. See below:

10 The following combinations of signal indications shall not be simultaneously displayed on any one signal face:

CIRCULAR RED with CIRCULAR YELLOW;
CIRCULAR GREEN with CIRCULAR RED; or
Straight-through GREEN ARROW with CIRCULAR RED;

I actually don’t know of any Flashing yellow arrow in the state (and we have over 350 of them), that uses TOD phasing!


iPhone

I can't speak to whether the intersection in Boston mentioned needs or doesn't need protected only left turns at all times, but I can say that there is a driver expectation in most of the country (other than some of the states in the Pacific Northwest*) that a doghouse signal (or 5 phase towers) are protected/permissive and that RA-YA-GA signals are protected only.  This standard should be kept, because a sign like the one in Boston seems kind of small and is very easy to overlook.  If I were driving there, I probably would not notice the sign and make a left turn on green orb even without a green arrow, and I could be subject to a ticket.

Simply change the signal to RA-YA-GA if you really want left turn on arrow only.  Change it to a FYA if time of day signalling is warranted.

*Jakeroot and others can confirm but in WA state (and probably a few other nearby states) left turn on red arrow is permitted onto a one-way street or a one-way freeway onramp.  There is no similar rule to my knowledge in any East Coast state.

45 states permit a left turn on red from a one-way street to a one-way street, so that's not unusual. If a turn can be made on a red arrow (in either direction) is harder to pinpoint it appears, and I don't believe an accurate list has ever been made.

[kphoger]

45 states permit a left turn on red from a one-way street to a one-way street, so that's not unusual. If a turn can be made on a red arrow (in either direction) is harder to pinpoint it appears, and I don't believe an accurate list has ever been made.

I had started working on a list a couple of years ago, but I gave up quickly because it was so time-consuming to find the states' vehicle codes one at a time.

[jakeroot]

*Jakeroot and others can confirm but in WA state (and probably a few other nearby states) left turn on red arrow is permitted onto a one-way street or a one-way freeway onramp.  There is no similar rule to my knowledge in any East Coast state.

45 states permit a left turn on red from a one-way street to a one-way street, so that's not unusual. If a turn can be made on a red arrow (in either direction) is harder to pinpoint it appears, and I don't believe an accurate list has ever been made.

Not quite the same thing. In WA (and OR, BC and MI), you can turn left onto a one-way street from both one and two way streets (RCW 46.61.055 ~3A and 3C).

This means that left turns like this are legal on red (arrow or otherwise); this is very unusual compared to virtually every other state.

[mrsman]

*Jakeroot and others can confirm but in WA state (and probably a few other nearby states) left turn on red arrow is permitted onto a one-way street or a one-way freeway onramp.  There is no similar rule to my knowledge in any East Coast state.

45 states permit a left turn on red from a one-way street to a one-way street, so that's not unusual. If a turn can be made on a red arrow (in either direction) is harder to pinpoint it appears, and I don't believe an accurate list has ever been made.

Not quite the same thing. In WA (and OR, BC and MI), you can turn left onto a one-way street from both one and two way streets (RCW 46.61.055 ~3A and 3C).

This means that left turns like this are legal on red (arrow or otherwise); this is very unusual compared to virtually every other state.

Correct.  In the context of protected and pemissive left turns, I am necessarily discussing left turns from a two-way street, not from a one-way street.

Outside of WA, OR, and MI (where a red left arrow would not restrict you from turning left onto  a one-way):

If you are on a 2-way street, the normal expectation for a permissive/protected turn is a doghouse signal or similar variant.  Basically a signal face that lacks a red arrow or other clear indication to not turn.  Examples are: doghouse, 5 aspect tower [i.e. a linear doghouse], 4 aspect tower [used in some lagging turns if yellow arrow would normally be displayed at the same time as yellow orb], 4 aspect towers with bimodal arrows. 

If you are on a 2-way street, the normal expectation for a turn that requires you to wait for the arrow would be a signal with a red arrow.  Another variant is the R-Y-GA accompanied by a sign that this is a "left turn signal" or equivalent.

The 4-aspect FYA signal is sort of a hybrid.  While normally it also indicates a permissive/protected turn, that is only true during the FYA phase.  During the red arrow phase, you must wait for either the green arrow or the FYA before you can turn.  And in some places with TOD phasing, it may be several hours before you can make the permissive turn.

It is terrible practice to have a doghouse or any other signal face that is normally permissive/protected used for a protective only signal.  And on top of that, the sign in Boston is quite small and hard to see.

For those in WA, OR, and MI, the same holds true as well with an added proviso.  Since the red arrow does not restrict the turn onto a one-way street, if the DOT in those states wanted to make the intersection a left turn on green arrow situation, the only possible way to do so is with a sign.   The hope is that they pick a big enough sign.  The other 47 states (including MA and IL) don't have this problem.  Use a red arrow signal and don't force us to read signs that defy normal expectations.

[fwydriver405]

Give NYC some credit - Chicago would make a 5 signal display into protected only by sign (as done on Michigan Ave).

I was driving down Kellogg the other day and thought of you because of this sign.

WHile the construction makes the signal placement ugly, this sign is not nearly as bad as the Chicago or Boston examples.  It seems pretty clear that the left signal controls left turns and the other two signals control straight.  Seeing the red ball (especially while the other signals are green) would lead me to at least suspect that the left signal controls left turns.

While the latest MUTCD recommends (or requires, not sure how to actually interpret it) that new exclusive left turn signals have red arrows instead of red balls, there are plenty of signals out there that are R-Y-GA that control a protected only left turn.  They are still very common in PA and VA which use the sign "Left turn signal".  This was also the standard for a while in CA, where they had a sign that read "Left turn on arrow only"  (the only arrow was a green one), but in that case the left turn signal was in a 3M or louvered so as not to confuse nearby straight traffic.  Very few of those remain in CA as most have been converted to red arrow.

Today while travelling from UMaine Orono to Bangor, I found this strange signal configuration downtown:

Main St and Route 222

Setup as a lead-lag signal, the leading side only allows turns on the green arrow, and the lagging side allows permissive-protected turns. This is a close example that Amtrakprod mentioned with the straight arrows:

I've seen this in Cambridge too, what I wish Boston did instead is install a red arrow up top and not have the green/yellow ball lights work, or install straight green and yellow arrows so when the left turn phase ended the red ball could stay on.

[mrsman]

Give NYC some credit - Chicago would make a 5 signal display into protected only by sign (as done on Michigan Ave).

I was driving down Kellogg the other day and thought of you because of this sign.

WHile the construction makes the signal placement ugly, this sign is not nearly as bad as the Chicago or Boston examples.  It seems pretty clear that the left signal controls left turns and the other two signals control straight.  Seeing the red ball (especially while the other signals are green) would lead me to at least suspect that the left signal controls left turns.

While the latest MUTCD recommends (or requires, not sure how to actually interpret it) that new exclusive left turn signals have red arrows instead of red balls, there are plenty of signals out there that are R-Y-GA that control a protected only left turn.  They are still very common in PA and VA which use the sign "Left turn signal".  This was also the standard for a while in CA, where they had a sign that read "Left turn on arrow only"  (the only arrow was a green one), but in that case the left turn signal was in a 3M or louvered so as not to confuse nearby straight traffic.  Very few of those remain in CA as most have been converted to red arrow.

Today while travelling from UMaine Orono to Bangor, I found this strange signal configuration downtown:

Main St and Route 222

Setup as a lead-lag signal, the leading side only allows turns on the green arrow, and the lagging side allows permissive-protected turns. This is a close example that Amtrakprod mentioned with the straight arrows:

I've seen this in Cambridge too, what I wish Boston did instead is install a red arrow up top and not have the green/yellow ball lights work, or install straight green and yellow arrows so when the left turn phase ended the red ball could stay on.

Without employing FYAs, the leading side of a lead-lag signal must be left turn on arrow only in order to avoid yellow trap.  The problem here is that the signal is irregular and if you don't see the sign, you may end up having an accident as you expect the oncoming traffic to begin to stop as you see yellow.

And you really have to be careful how to read the sign too.  When doghouses first came on the scene in Los Angeles, the vast majority of them had no sign whatsoever.  I imagine the DOT believed that it was understood that if there was no sign saying otherwise, left turns were permitted on green orb.  Well, at many of those intersections, people would just wait regardless, so they started putting up (in some places, not all) "Left turn yield on green."  The problem with this is that now you have to read very carefully to determine if you are allowed to go on green or "left turn on green arrow only."  At an intersection, there is so much to think about that the subtleties between these two signs, which mean opposite things, can easily be missed.

It is far better to have a clear rule.  No left turn on red arrow.  If there is no red arrow, you may turn left on green ball if you yield to opposing traffic.

[fwydriver405]

Without employing FYAs, the leading side of a lead-lag signal must be left turn on arrow only in order to avoid yellow trap.  The problem here is that the signal is irregular and if you don't see the sign, you may end up having an accident as you expect the oncoming traffic to begin to stop as you see yellow.

The only major problem with not employing FYA in your example is that yellow trap can still occur on the lagging side if phase skip were to recall the leading left turn phase.

When our new high school opened on 11 Oct 2018 (the intersection wasn't signalised until sometime in February 2019), the signal had to be reprogrammed last-minute with anti-backup logic to prevent phase 1 (protected only) from yellow trapping phase 2 (5-section PPLT) on northbound Main St as pictured below:



Once FYA's are retrofitted into this intersection in 2021, then the normal phase skip is OK as then the yellow trap would be removed by continually flashing the yellow arrow when the oncoming green on Main St has a green light for the southbound thru traffic.

[MNHighwayMan]

Having put on a plentiful number of miles in WA, OR, and BC (all places where the maneuver is legal), I have seen perhaps 10 or 15 people ever take advantage of it. I highly doubt ODOT specifically times their left turns to encourage this. I think they know as well as I do that people rarely actually turn left on red from a two-way to one-way. Problem is, all three places are full of people from places where the maneuver is not legal. Obviously they aren't aware of our laws. What would be nice, is if more places used these types of signs, commonly used by Seattle DOT. Then you get people to actually do the maneuver

Seems to me they should use a flashing red arrow, where left on red is permitted, instead of a solid red arrow plus (maybe) a sign.

[jakeroot]

Having put on a plentiful number of miles in WA, OR, and BC (all places where the maneuver is legal), I have seen perhaps 10 or 15 people ever take advantage of it. I highly doubt ODOT specifically times their left turns to encourage this. I think they know as well as I do that people rarely actually turn left on red from a two-way to one-way. Problem is, all three places are full of people from places where the maneuver is not legal. Obviously they aren't aware of our laws. What would be nice, is if more places used these types of signs, commonly used by Seattle DOT. Then you get people to actually do the maneuver

Seems to me they should use a flashing red arrow, where left on red is permitted, instead of a solid red arrow plus (maybe) a sign.

The problem, as far as I know, is that all three places, at the top-level (provincial/state), do not allow any sort of permissive left turn with more than one lane. All three have examples, but they're all city installs. Now, technically, all sanction such maneuvers by allowing these left turns on red (though I have seen signs disallowing the turn where it would be obvious in other states that it would not be allowed), but they apparently don't want to come out and just make the maneuver obvious with flashing red arrows. I guess that would be too forward? They leave it up to people to read the relevant statutes!

[mrsman]

Having put on a plentiful number of miles in WA, OR, and BC (all places where the maneuver is legal), I have seen perhaps 10 or 15 people ever take advantage of it. I highly doubt ODOT specifically times their left turns to encourage this. I think they know as well as I do that people rarely actually turn left on red from a two-way to one-way. Problem is, all three places are full of people from places where the maneuver is not legal. Obviously they aren't aware of our laws. What would be nice, is if more places used these types of signs, commonly used by Seattle DOT. Then you get people to actually do the maneuver

Seems to me they should use a flashing red arrow, where left on red is permitted, instead of a solid red arrow plus (maybe) a sign.

I would strongly prefer this approach as well, as it would be more consistent with the rules of the other 47 states.

Here's a qn for Jake (or anyone else really familiar with WA/OR/BC rules), let's say you have the intersection of a 2-way street with a 1-way street.  (Not at a T-intersection) And let's say that the left turn is controlled by a RA-YA-GA signal.  This would mean that you should be able to make a permissive turn at all times, assuming you first come to a complete stop if you see a RA.  (Obviously, the turn is protected with a green arrow.)

Is there any way for you to know, while you see the RA, whether you have to yield to opposing traffic or whether you have to yield to the traffic on the one-way street that is coming from your right?  And what about when the traffic signal changes, is there an obvious point in time when you are aware that you have to change your yield from side street to opposing traffic (and vice versa).

I've always heard that the justification for this move is that it is not any different from a LTOR from one-way to one-way, permitted in a majority of states.  (And in that case, IMO correctly, the states contend that LTOR one-way to one-way is equivalent to RTOR and generally safe.)  But it seems like the need to contend with opposing traffic makes this, left from a 2-way to 1-way on red, a far riskier move.

[mrsman]

Without employing FYAs, the leading side of a lead-lag signal must be left turn on arrow only in order to avoid yellow trap.  The problem here is that the signal is irregular and if you don't see the sign, you may end up having an accident as you expect the oncoming traffic to begin to stop as you see yellow.

The only major problem with not employing FYA in your example is that yellow trap can still occur on the lagging side if phase skip were to recall the leading left turn phase.

When our new high school opened on 11 Oct 2018 (the intersection wasn't signalised until sometime in February 2019), the signal had to be reprogrammed last-minute with anti-backup logic to prevent phase 1 (protected only) from yellow trapping phase 2 (5-section PPLT) on northbound Main St as pictured below:



Once FYA's are retrofitted into this intersection in 2021, then the normal phase skip is OK as then the yellow trap would be removed by continually flashing the yellow arrow when the oncoming green on Main St has a green light for the southbound thru traffic.

I'm sorry that I'm missing something in your explanation.  I'm not trained in TE, but obviously somewhat interested based on my posts on this forum.  (I don't really understand the timing diagram.)

In my example, the normal phases are:

1. Eastbound straight and left (leading phase)
2. E & W straight, EB left prohibited by red arrow, WB left permissive on green orb.
3. Westbound straight and left (lagging phase)
4. N-S traffic on side street.

Now, from what I understand, the phase skip that you are suggesting is that at the conclusion of phase 3, phase 4 is skipped so now we are back at phase 1.  If phase 3 properly closes with a yellow ball and then a red, I don't see a yellow trap problem.  To allow the eastbound left, you have to prohibit the westbound straight.

If both phases 4 and 1 are skipped, then in some ways phase 3 acts like a leading left as well.  You don't get a yellow arrow with a classic RYG-GA signal that was commonplace for lagging lefts, but that is still not yellow trap as those cars will now yield to opposing traffic, since the green arrow vanished.

So I guess you must mean the possibility that you are at phase 2, and phase 3 and phase 4 are skipped so you head back to phase 1.  The westbound side gets yellow and red, but not the eastbound side.  This is a yellow trap, since counter-intuitively phase 1 acts as a lagging phase due to the skipping of both phases 3 and 4.  So as you correctly note, if both phases 3 and 4 are skipped, you must properly end phase 2 with a quick yellow and red, before allowing for phase 1 to come again.

To be honest, I have never seen that in practice.  Since phase 3 allows for left turn filtering, from what i have seen it will usually be programmed for the busier left turn and will rarely get skipped.

Here is an intersection that years ago had lead-lag phasing, with protected only lead and PPLT lag.  (Now both directions have protected only turns.)
Sunset at Hilgard - Copa de Oro in Los Angeles, right outside the UCLA campus.

https://www.google.com/maps/@34.0782706,-118.4393688,3a,75y,240.33h,78.77t/data=!3m7!1e1!3m5!1sWkNR_wJMf61DMNamoaADsQ!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3DWkNR_wJMf61DMNamoaADsQ%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D12.513728%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192

In this example, years ago, the EB left from Sunset to Copa was leading protected only.  Copa is a very minor street and got very little traffic.  The WB left from Sunset to Hilgard was really major as it was a key way for traffic on Sunset (a major street in L.A.) to reach several entrances to the UCLA campus (closer to the main buildings of campus) and Westwood Village.  The main bus on Sunset also made this turn, for this reason.  I could never fathom the possibility that the left turn to Hilgard would ever be skipped at any cycle [phase 3], as well as the phase for Hilgard itself [phase 4] in order to service the left turn at Copa [phase 1]. I have no idea if there was ever any phase skipping precautions made here [doubt it], but it was simply unnecessary as a practical matter.

I guess the signal that in your town is different, and of course proper signaling is always important.