"Left Turn Yield On Green" Sign

[7/8]

Sorry if this is a silly question, but I'm curious about this sign since we don't have them in Ontario (and I think all of Canada for that matter).



Why is this sign needed? This seems like a common sense rule to me. Would it not be better to sign the opposite situation instead (no left without arrow?), or are there places where permissive lefts are rare? I'm guessing that in most places, permissive lefts are more common than protected-only lefts.

Also, are these signs required at all permissive left intersections, or only some?

[UCFKnights]

Sorry if this is a silly question, but I'm curious about this sign since we don't have them in Ontario (and I think all of Canada for that matter).



Why is this sign needed? This seems like a common sense rule to me. Would it not be better to sign the opposite situation instead (no left without arrow?), or are there places where permissive lefts are rare? I'm guessing that in most places, permissive lefts are more common than protected-only lefts.

Also, are these signs required at all permissive left intersections, or only some?

Its by area, and sometimes its used somewhat randomly. Around here, they seem to try to do it where there is little opposing traffic so people get used to feeling like they have the protected left when they don't... but they only use it with doghouses. The other common usage around here was when protected lefts got replaced with permissive. Infact, its almost used with doghouses/5 section signals... I feel they're often most warranted on lefts without any protected signal.

Some areas stick them on every doghouse, some areas don't use them at all. The FYA should make it obsolete (although some areas are sticking "left turn yield on fya" signs on them (some of which are just temporary and are getting removed after the lights been operational for a month or so).

[MisterSG1]

It's an extra reminder when used in PPLT situations. Think of it kind of like the yellow signs in downtown Toronto, for pedestrians which read "Pedestrians Obey Your Signals"

[US 89]

Sorry if this is a silly question, but I'm curious about this sign since we don't have them in Ontario (and I think all of Canada for that matter).



Why is this sign needed? This seems like a common sense rule to me. Would it not be better to sign the opposite situation instead (no left without arrow?), or are there places where permissive lefts are rare? I'm guessing that in most places, permissive lefts are more common than protected-only lefts.

Also, are these signs required at all permissive left intersections, or only some?

The sign is needed because some people will see that there can be an arrow signal, and so they wait for it even though it's a permissive intersection. The sign reminds these people that these intersections are not protected only.

Here in UT, the signs are installed with every doghouse signal, but never with any other signals. They also use a "Left then yield on flashing yellow arrow" with every FYA installed. There are a few "left on green arrow only" signs scattered around at protected only signals, but they are not installed regularly. I wish they were, but from a financial standpoint they probably are not needed, since a red arrow always means stop.

[MisterSG1]

Can y'all please stop calling it a "doghouse" signal. It's a 5 section signal or PPLT signal.

[jakeroot]

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond). They seem to be used when the opposite movement is protected (chiefly single left opposite a double left):

Can y'all please stop calling it a "doghouse" signal. It's a 5 section signal or PPLT signal.

Regional nomenclature. Parts of the US exclusively use the doghouse setup so that's what they get called.

[US 89]

Can y'all please stop calling it a "doghouse" signal. It's a 5 section signal or PPLT signal.

The term "doghouse" is useful because it distinguishes that specific setup from setups which have all 5 sections in one column. And the term "PPLT signals" can include FYA as well.

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond):

Is that a split phased intersection? The 4-section signal head seems to suggest it, although that type of intersection would have no need for the sign.

[jakeroot]

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond):

http://i.imgur.com/06i0Sbs.jpg

Is that a split phased intersection? The 4-section signal head seems to suggest it, although that type of intersection would have no need for the sign.

No that's the normal PPLT display used in Canada. The bottom lens is a dual flashing green arrow/solid yellow arrow. Flashing green arrow in most of Canada means protected left.

[jeffandnicole]

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond):

http://i.imgur.com/06i0Sbs.jpg

Is that a split phased intersection? The 4-section signal head seems to suggest it, although that type of intersection would have no need for the sign.

No that's the normal PPLT display used in Canada. The bottom lens is a dual flashing green arrow/solid yellow arrow. Flashing green arrow in most of Canada means protected left.

NJ uses 4 head signals statewide.

And they use this sign statewide as well.

[jakeroot]

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond):

http://i.imgur.com/06i0Sbs.jpg

Is that a split phased intersection? The 4-section signal head seems to suggest it, although that type of intersection would have no need for the sign.

No that's the normal PPLT display used in Canada. The bottom lens is a dual flashing green arrow/solid yellow arrow. Flashing green arrow in most of Canada means protected left.

NJ uses 4 head signals statewide.

And they use this sign statewide as well.

Bi-modal signals are used all over the place. They're the most common PPLT display in Snohomish County, WA by a country mile. But Canada's are slightly different with the flashing green arrow (to distinguish the two a bit better).

[MisterSG1]

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond):

http://i.imgur.com/06i0Sbs.jpg

Is that a split phased intersection? The 4-section signal head seems to suggest it, although that type of intersection would have no need for the sign.

No that's the normal PPLT display used in Canada. The bottom lens is a dual flashing green arrow/solid yellow arrow. Flashing green arrow in most of Canada means protected left.

Do the green left arrows flash in British Columbia? I'm fairly sure they do in the prairies and I've seen that being the standard mostly in Newfoundland (a PPLT intersection in Carbonear has a steady green arrow though)

The standards of green arrows flashing is mentioned in the TAC Manual aka MUTCD for Canada.

I never was a fan of that flashing arrow business which has now crept into both Waterloo and Durham Regions in Ontario.

[Brian556]

I've always felt that these were unnecessary clutter signs. There are a few rare circumstances, however, where they could actually be useful

Like this one. Dallas Dr / Bell Ave at Eagle Dr in Denton TX. This was originally a protected only left, with green arrows and red balls, however, due to the need for more throughput, a permissive phase was added. It is weird seeing the green ball and green arrow together here since the signal is for traffic that can only turn left. That could be confusing. There are no heads for the straight movement. This is has since been converted to a FYA


This is the location:
https://www.google.com/maps/@33.2064226,-97.1319285,47m/data=!3m1!1e3

[jakeroot]

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond):

http://i.imgur.com/06i0Sbs.jpg

Is that a split phased intersection? The 4-section signal head seems to suggest it, although that type of intersection would have no need for the sign.

No that's the normal PPLT display used in Canada. The bottom lens is a dual flashing green arrow/solid yellow arrow. Flashing green arrow in most of Canada means protected left.

Do the green left arrows flash in British Columbia? I'm fairly sure they do in the prairies and I've seen that being the standard mostly in Newfoundland (a PPLT intersection in Carbonear has a steady green arrow though)

The standards of green arrows flashing is mentioned in the TAC Manual aka MUTCD for Canada.

I never was a fan of that flashing arrow business which has now crept into both Waterloo and Durham Regions in Ontario.

Yes that's the standard in BC. The only steady green protected left arrows are at protected-only turns (i.e. when you'd use a three-head signal). I've never seen a bi-modal PPLT display with a solid green arrow, though I've heard they're more popular out east. All of the green arrows that I've encountered in Alberta have been flashing as well, I think even at the protected-only turns.

I personally prefer the flashing green arrow as it better distinguishes the green arrow from the yellow arrow, which might be helpful if you struggle to tell the difference between green and yellow (I'm certain that a form of colour-blindness matches this).

[US 89]

I've always felt that these were unnecessary clutter signs. There are a few rare circumstances, however, where they could actually be useful

Like this one. Dallas Dr / Bell Ave at Eagle Dr in Denton TX. This was originally a protected only left, with green arrows and red balls, however, due to the need for more throughput, a permissive phase was added. It is weird seeing the green ball and green arrow together here since the signal is for traffic that can only turn left. That could be confusing. There are no heads for the straight movement. This is has since been converted to a FYA


This is the location:
https://www.google.com/maps/@33.2064226,-97.1319285,47m/data=!3m1!1e3

It sounds like the signals in that photo use Dallas phasing, which I think is the one application where the yield on green signs are truly necessary. Other installations are useful, but not totally necessary.

If the signals were installed correctly, the left turn signals (especially the green and yellow balls) should be visible only from the left turn bay. It appears that is not the case in your photo.

[jakeroot]

I've always felt that these were unnecessary clutter signs. There are a few rare circumstances, however, where they could actually be useful

Like this one. Dallas Dr / Bell Ave at Eagle Dr in Denton TX. This was originally a protected only left, with green arrows and red balls, however, due to the need for more throughput, a permissive phase was added. It is weird seeing the green ball and green arrow together here since the signal is for traffic that can only turn left. That could be confusing. There are no heads for the straight movement. This is has since been converted to a FYA

http://i1209.photobucket.com/albums/cc395/Brian5561/9.4.12%20030_zpsgmdmykfq.jpg

It sounds like the signals in that photo use Dallas phasing, which I think is the one application where the yield on green signs are truly necessary. Other installations are useful, but not totally necessary.

If the signals were installed correctly, the left turn signals (especially the green and yellow balls) should be visible only from the left turn bay. It appears that is not the case in your photo.

A similar setup is used at the N Mill/W Hastings seagull intersection north of Spokane, WA. I never gave it much thought before, but it does seem to be unusual. The sign just says "LEFT TURN YIELD ON GREEN". I've seen "LEFT TURN SIGNAL | LEFT TURN YIELD ON GREEN" before. This seems like a good application for that version (although an FYA would be superior overall):

(OT: note Spokane's rather unique use of post-mounted doghouse PPLTs -- most agencies would use 5-section towers in this case)

[7/8]

They have been used in Vancouver. This one always sticks out to me (Sea Island Way @ Great Canadian Way, Richmond):

http://i.imgur.com/06i0Sbs.jpg

Is that a split phased intersection? The 4-section signal head seems to suggest it, although that type of intersection would have no need for the sign.

No that's the normal PPLT display used in Canada. The bottom lens is a dual flashing green arrow/solid yellow arrow. Flashing green arrow in most of Canada means protected left.

Do the green left arrows flash in British Columbia? I'm fairly sure they do in the prairies and I've seen that being the standard mostly in Newfoundland (a PPLT intersection in Carbonear has a steady green arrow though)

The standards of green arrows flashing is mentioned in the TAC Manual aka MUTCD for Canada.

I never was a fan of that flashing arrow business which has now crept into both Waterloo and Durham Regions in Ontario.

Yes that's the standard in BC. The only steady green protected left arrows are at protected-only turns (i.e. when you'd use a three-head signal). I've never seen a bi-modal PPLT display with a solid green arrow, though I've heard they're more popular out east. All of the green arrows that I've encountered in Alberta have been flashing as well, I think even at the protected-only turns.

I personally prefer the flashing green arrow as it better distinguishes the green arrow from the yellow arrow, which might be helpful if you struggle to tell the difference between green and yellow (I'm certain that a form of colour-blindness matches this).

Waterloo Region (Ontario) uses flashing green left arrows (including on three-head signals), while right arrows are non-flashing. It looks weird in this instance, since they're side-by-side. I agree with your point on colour blindness, since my Dad is red-green colourblind (the most common type) and he tends to distinguish the lights based on their vertical position. I think 5-head signals would be the best, but my area seems to prefer 4-head siignals.

[US 89]

I've always felt that these were unnecessary clutter signs. There are a few rare circumstances, however, where they could actually be useful

Like this one. Dallas Dr / Bell Ave at Eagle Dr in Denton TX. This was originally a protected only left, with green arrows and red balls, however, due to the need for more throughput, a permissive phase was added. It is weird seeing the green ball and green arrow together here since the signal is for traffic that can only turn left. That could be confusing. There are no heads for the straight movement. This is has since been converted to a FYA

http://i1209.photobucket.com/albums/cc395/Brian5561/9.4.12%20030_zpsgmdmykfq.jpg

It sounds like the signals in that photo use Dallas phasing, which I think is the one application where the yield on green signs are truly necessary. Other installations are useful, but not totally necessary.

If the signals were installed correctly, the left turn signals (especially the green and yellow balls) should be visible only from the left turn bay. It appears that is not the case in your photo.

A similar setup is used at the N Mill/W Hastings seagull intersection north of Spokane, WA. I never gave it much thought before, but it does seem to be unusual. The sign just says "LEFT TURN YIELD ON GREEN". I've seen "LEFT TURN SIGNAL | LEFT TURN YIELD ON GREEN" before. This seems like a good application for that version (although an FYA would be superior overall):

(OT: note Spokane's rather unique use of post-mounted doghouse PPLTs -- most agencies would use 5-section towers in this case)

Does that straight green arrow on the right ever turn red? If not, they could have installed one-section signals, which are commonplace in my area. I can think of at least 5, one of which is at Beck St and Victory Rd in Salt Lake City.

[7/8]

Sorry if this is a silly question, but I'm curious about this sign since we don't have them in Ontario (and I think all of Canada for that matter).



Why is this sign needed? This seems like a common sense rule to me. Would it not be better to sign the opposite situation instead (no left without arrow?), or are there places where permissive lefts are rare? I'm guessing that in most places, permissive lefts are more common than protected-only lefts.

Also, are these signs required at all permissive left intersections, or only some?

The sign is needed because some people will see that there can be an arrow signal, and so they wait for it even though it's a permissive intersection. The sign reminds these people that these intersections are not protected only.

Here in UT, the signs are installed with every doghouse signal, but never with any other signals. They also use a "Left then yield on flashing yellow arrow" with every FYA installed. There are a few "left on green arrow only" signs scattered around at protected only signals, but they are not installed regularly. I wish they were, but from a financial standpoint they probably are not needed, since a red arrow always means stop.

From what I understand from your post, all protected-only lefts in Utah would use a red left arrow to tell drivers to not make a permissive left. If this is the case, then shouldn't drivers realize that at a doghouse signal, they can make a permissive left, since there's no red left arrow? If drivers could figure this out, the DOT could probably save decent money by not needing these signs.

The only use I see so far that makes a lot of sense to me is when a signal is changed from protected-only to allowing permissive lefts. Otherwise, the sign just seems like an expensive reminder that most motorists shouldn't need.

[US 89]

Sorry if this is a silly question, but I'm curious about this sign since we don't have them in Ontario (and I think all of Canada for that matter).



Why is this sign needed? This seems like a common sense rule to me. Would it not be better to sign the opposite situation instead (no left without arrow?), or are there places where permissive lefts are rare? I'm guessing that in most places, permissive lefts are more common than protected-only lefts.

Also, are these signs required at all permissive left intersections, or only some?

The sign is needed because some people will see that there can be an arrow signal, and so they wait for it even though it's a permissive intersection. The sign reminds these people that these intersections are not protected only.

Here in UT, the signs are installed with every doghouse signal, but never with any other signals. They also use a "Left then yield on flashing yellow arrow" with every FYA installed. There are a few "left on green arrow only" signs scattered around at protected only signals, but they are not installed regularly. I wish they were, but from a financial standpoint they probably are not needed, since a red arrow always means stop.

From what I understand from your post, all protected-only lefts in Utah would use a red left arrow to tell drivers to not make a permissive left. If this is the case, then shouldn't drivers realize that at a doghouse signal, they can make a permissive left, since there's no red left arrow? If drivers could figure this out, the DOT could probably save decent money by not needing these signs.

The only use I see so far that makes a lot of sense to me is when a signal is changed from protected-only to allowing permissive lefts. Otherwise, the sign just seems like an expensive reminder that most motorists shouldn't need.

That is correct, all protected lefts use a red left arrow here to indicate "don't turn left, wait for a green left arrow". And you're right, drivers really should realize that they can make a permissive left on a doghouse, but as always, the DOT has to cater to the lowest common denominator of driver. The reasoning is that some drivers think along the lines of "well, since there is a space for a green arrow, and it's off, I have to wait until it comes on". I agree with you that these signs could be removed (or just not installed anymore) and it wouldn't really make a difference.

For what it's worth, these signs are so common around here that something seems off to me if I see a doghouse without one.

[jakeroot]

Waterloo Region (Ontario) uses flashing green left arrows (including on three-head signals), while right arrows are non-flashing. It looks weird in this instance, since they're side-by-side.

Huh. What an odd choice. ICBC (i.e. the government) explains the purpose of the flashing green arrow here (page "45"). Does the MTO have a similar explanation (which may explain why left turns flash but not those pointing right)?

I agree with your point on colour blindness, since my Dad is red-green colourblind (the most common type) and he tends to distinguish the lights based on their vertical position. I think 5-head signals would be the best, but my area seems to prefer 4-head siignals.

AFAIK, 5-section signals aren't used in Canada, at least anymore? I know some exist (none in British Columbia for sure), but I don't think they're still installed.

Does that straight green arrow on the right ever turn red? If not, they could have installed one-section signals, which are commonplace in my area. I can think of at least 5, one of which is at Beck St and Victory Rd in Salt Lake City.

Yes, it turns red. There's a pedestrian crossing just before the median.

[7/8]

I agree with your point on colour blindness, since my Dad is red-green colourblind (the most common type) and he tends to distinguish the lights based on their vertical position. I think 5-head signals would be the best, but my area seems to prefer 4-head siignals.

AFAIK, 5-section signals aren't used in Canada, at least anymore? I know some exist (none in British Columbia for sure), but I don't think they're still installed.

There's a couple of 5-head signals in Waterloo Region.

Here's one at River Rd and King St in Kitchener


There's also one at University Ave and King St in Waterloo.

You might be right about them being phased out, since I don't see many of them.

[jakeroot]

I agree with your point on colour blindness, since my Dad is red-green colourblind (the most common type) and he tends to distinguish the lights based on their vertical position. I think 5-head signals would be the best, but my area seems to prefer 4-head siignals.

AFAIK, 5-section signals aren't used in Canada, at least anymore? I know some exist (none in British Columbia for sure), but I don't think they're still installed.

There's a couple of 5-head signals in Waterloo Region.

Here's one at River Rd and King St in Kitchener

http://i.imgur.com/0mYnpoI.jpg

That one's a bit odd. Typically, the top three signals might be one assembly, and the bottom two would be the left turn assembly. A typical "Tacoma Tower" (Tacoma, WA's version of a PPLT, different from most of Washington which uses four-section signals or doghouses almost exclusively) has the two arrows stuck onto the bottom of the left-most overhead signal as a way to implement PPLT phasing at a later date (though this practice has ended with the advent of FYAs):

[7/8]

I agree with your point on colour blindness, since my Dad is red-green colourblind (the most common type) and he tends to distinguish the lights based on their vertical position. I think 5-head signals would be the best, but my area seems to prefer 4-head siignals.

AFAIK, 5-section signals aren't used in Canada, at least anymore? I know some exist (none in British Columbia for sure), but I don't think they're still installed.

There's a couple of 5-head signals in Waterloo Region.

Here's one at River Rd and King St in Kitchener

http://i.imgur.com/0mYnpoI.jpg

That one's a bit odd. Typically, the top three signals might be one assembly, and the bottom two would be the left turn assembly. A typical "Tacoma Tower" (Tacoma, WA's version of a PPLT, different from most of Washington which uses four-section signals or doghouses almost exclusively) has the two arrows stuck onto the bottom of the left-most overhead signal as a way to implement PPLT phasing at a later date (though this practice has ended with the advent of FYAs):

http://i.imgur.com/97TtsR9.png

Maybe it would be odd in the US, but it seems reasonable in Ontario. The signal head pattern in my photo from top to bottom is red ball, yellow ball, green ball, yellow solid arrow, and flashing green arrow (like your Tacoma example). So it's basically like a standard Ontario PPLT 4-head signal, except the green and yellow arrows each get their own signal head.

[Revive 755]

The only use I see so far that makes a lot of sense to me is when a signal is changed from protected-only to allowing permissive lefts. Otherwise, the sign just seems like an expensive reminder that most motorists shouldn't need.

IMHO, the sign can be useful for locations where an opposing movement is not expected (such as a frontage road opposing the exit from a folded diamond or parclo interchange) and a flashing yellow arrow has not been installed yet or is not feasible (maybe due to the presence of a shared left-thru lane).

Otherwise, I think some places install the sign where there is a decent number of left turn accidents and they do not want to go to left on arrow only nor use a flashing yellow arrow.

[jakeroot]

I agree with your point on colour blindness, since my Dad is red-green colourblind (the most common type) and he tends to distinguish the lights based on their vertical position. I think 5-head signals would be the best, but my area seems to prefer 4-head siignals.

AFAIK, 5-section signals aren't used in Canada, at least anymore? I know some exist (none in British Columbia for sure), but I don't think they're still installed.

There's a couple of 5-head signals in Waterloo Region.

Here's one at River Rd and King St in Kitchener

http://i.imgur.com/0mYnpoI.jpg

That one's a bit odd. Typically, the top three signals might be one assembly, and the bottom two would be the left turn assembly. A typical "Tacoma Tower" (Tacoma, WA's version of a PPLT, different from most of Washington which uses four-section signals or doghouses almost exclusively) has the two arrows stuck onto the bottom of the left-most overhead signal as a way to implement PPLT phasing at a later date (though this practice has ended with the advent of FYAs):

http://i.imgur.com/97TtsR9.png

Maybe it would be odd in the US, but it seems reasonable in Ontario. The signal head pattern in my photo from top to bottom is red ball, yellow ball, green ball, yellow solid arrow, and flashing green arrow (like your Tacoma example). So it's basically like a standard Ontario PPLT 4-head signal, except the green and yellow arrows each get their own signal head.

But such a setup would imply that the bottom three signals replaced a single, maybe green arrow? If the bottom lens was already a green orb, why replace it? Just add on the two arrows to the bottom. Your photo seems to imply that the local authority left the top two signals of the original light, replacing the bottom lens (whatever it originally was) with three lenses.

Here's a signal on the SFPR (Hwy 17) in metro Vancouver. While the bottom bi-modal flashing green arrow/solid yellow arrow lens has always been there, the setup implies that the top three signals are one assembly, and the bottom lens is another assembly (though placed directly next to each other). Unlike the Ontario example, the BCMOT could easily remove the bottom lens from the setup without adversely affecting the original three-orb assembly. Removing the bottom assembly from your photo would leave the light without a green indication.