Traffic signal

[roadfro]

I did a quick search in the MUTCD but didn't find an answer to this question:

For dual left-turn lanes that use an R10-10 sign, is there any official guidance on how many signs should be used?

Two signals, one sign each:  https://maps.app.goo.gl/8WVN51d7VPgwLY8E9

Two signals, a single shared sign:  https://maps.app.goo.gl/WFCby4eyoDAF3Nd9A

The current MUTCD doesn't specify a number of signs, but my interpretation of this guidance statement in Section 2B.59 suggests each signal head would need a sign. And that makes sense, because "left turn signal" is singular, so it doesn't make sense to put the sign between two signal heads—which one is the left turn signal?

Guidance:

03 If used, the LEFT ON GREEN ARROW ONLY sign, the LEFT TURN SIGNAL sign, the LEFT TURN YIELD ON GREEN (symbolic circular green)) sign, the LEFT TURN YIELD ON FLASHING YELLOW ARROW sign, or the LEFT TURN YIELD ON FLASHING RED ARROW AFTER STOP) sign should be located adjacent to the left-turn signal face.

Better question for the linked examples is why red arrows were not used. Those both appear to be relatively new signal installations...new enough to be installed in the time where MUTCD prohibited circular signal indications for exclusive left turn lanes and, you know, in the period of time where red arrows have existed...

[jakeroot]

I thought "LEFT TURN SIGNAL" signs had been deprecated. I haven't seen a new one in 20+ years.

[Brandon]

I thought "LEFT TURN SIGNAL" signs had been deprecated. I haven't seen a new one in 20+ years.

Depends on the state.  Illinois uses "Left Turn on Green Arrow Only".  I've seen "Left Turn Signal" in some of the adjacent states like Indiana and Missouri.

[kphoger]

Better question for the linked examples is why red arrows were not used. Those both appear to be relatively new signal installations...new enough to be installed in the time where MUTCD prohibited circular signal indications for exclusive left turn lanes and, you know, in the period of time where red arrows have existed...

I thought "LEFT TURN SIGNAL" signs had been deprecated. I haven't seen a new one in 20+ years.

Oh, don't worry, there are plenty of intersections around town that BOTH use a red ball for left turns AND ALSO don't have a sign.

https://maps.app.goo.gl/rSWfa6Qk3oaJz9tL7
https://maps.app.goo.gl/uiC1geePb2939beg8

[PColumbus73]

Better question for the linked examples is why red arrows were not used. Those both appear to be relatively new signal installations...new enough to be installed in the time where MUTCD prohibited circular signal indications for exclusive left turn lanes and, you know, in the period of time where red arrows have existed...

I thought "LEFT TURN SIGNAL" signs had been deprecated. I haven't seen a new one in 20+ years.

Oh, don't worry, there are plenty of intersections around town that BOTH use a red ball for left turns AND ALSO don't have a sign.

https://maps.app.goo.gl/rSWfa6Qk3oaJz9tL7
https://maps.app.goo.gl/uiC1geePb2939beg8

"LEFT TURN SIGNAL" signs are fairly common in South Carolina, on some recent installations, they've used the lane use arrows

Like so

[freebrickproductions]

https://maps.app.goo.gl/uiC1geePb2939beg8

That one is arguably more compliant seeing as the left turn head is a PV signal, and, thus, at least in theory, shouldn't be visible from the thru lanes.

[jakeroot]

I thought "LEFT TURN SIGNAL" signs had been deprecated. I haven't seen a new one in 20+ years.

Depends on the state.  Illinois uses "Left Turn on Green Arrow Only".  I've seen "Left Turn Signal" in some of the adjacent states like Indiana and Missouri.

The "on green arrow only" signs aren't used in WA to my knowledge, since left turns are also permitted on yellow. They do seem common elsewhere, but I cannot recall seeing one here.

At any rate, my point is just that "LEFT TURN SIGNAL" signs no longer serve a purpose, they were succeeded by dedicated left turn signals with all-arrow displays.

Oh, don't worry, there are plenty of intersections around town that BOTH use a red ball for left turns AND ALSO don't have a sign.

https://maps.app.goo.gl/rSWfa6Qk3oaJz9tL7
https://maps.app.goo.gl/uiC1geePb2939beg8

I've seen stuff like this in WA, but they're not new. My only point is the sign shouldn't be installed anymore, because installs like these, requiring them, are not installed anymore.

[fwydriver405]

The "on green arrow only" signs aren't used in WA to my knowledge, since left turns are also permitted on yellow. They do seem common elsewhere, but I cannot recall seeing one here.

Turns on steady yellow are also permitted in MA and ME like many other states too, and they use the "Left/Right on Green Arrow Only" signs sometimes. They seem to be used in these scenarios, though this is case-by-case per intersection approach:

- Where one side is fully protected, and the other side is fully permissive OR protected-permissive*,
- Removing permissive left turns and converting to fully protected (not all of the time, see 1 above),
- Converting an unsignalised intersection with approaches with fully protected phasing (Mostly in Maine, Left turn, Right Turn), or
- In MA, sometimes if the left or right turn is fully protected due to signal separation between vehicle traffic, pedestrians, transit, and/or bike movement. Though I mostly see No Turn on Red, R3-5, or even no signs in most cases. 

* Only usually done if there is a risk of the fully protected side running the red as the opposing side has their permissive phase.

Oh, don't worry, there are plenty of intersections around town that BOTH use a red ball for left turns AND ALSO don't have a sign.

https://maps.app.goo.gl/rSWfa6Qk3oaJz9tL7
https://maps.app.goo.gl/uiC1geePb2939beg8

I've seen stuff like this in WA, but they're not new. My only point is the sign shouldn't be installed anymore, because installs like these, requiring them, are not installed anymore.

Yup, was going to say there's also cases like this in MA (and one example in NH) but very rare. Except for the Arlington and Medford examples, these were recently replaced within the decade:

Arlington MA
Cambridge MA (Gerry's Landing Rd - DCR)
Cambridge MA (to Mount Auburn Ave - DCR)
Medford MA (mix of PV and standard - DCR)
Watertown MA (doesn't show in GSV. But the FYA has circular red and yellow instead of the required steady red and steady yellow arrows in the display)
Portsmouth NH (used to be compliment until it got knocked down. Used to be all circular for the left turn movement, now has a green arrow, but still circular red and yellow as of Nov 2025)
Portsmouth NH (fully permissive FYA just has circular red and yellow)

[PColumbus73]

Found a Japanese-spec traffic signal in Botswana

https://www.google.com/maps/@0.3128209,32.5828894,3a,24y,233.71h,109.49t/data=!3m8!1e1!3m6!1siIMe-cIgDd_7ZbPMxDksnA!2e0!5s20150301T000000!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-19.489920944163245%26panoid%3DiIMe-cIgDd_7ZbPMxDksnA%26yaw%3D233.70628760718648!7i13312!8i6656?entry=ttu&g_ep=EgoyMDI2MDExMS4wIKXMDSoKLDEwMDc5MjA2N0gBUAM%3D

[freebrickproductions]

While heading to record a siren sounding for the monthly test last week, I came across these Red-Yellow-Flashing Yellow McCain signals on Dunlop Boulevard in western Huntsville, AL, close to the airport. I believe these are the only R-Y-FY signals in the city, and I think this is the first time I've seen signals like this used for low-flying aircraft (specifically helicopters, in this case, it seems).

IMG_1297 by freebrickproductions, on Flickr

IMG_1296 by freebrickproductions, on Flickr

[PColumbus73]

While heading to record a siren sounding for the monthly test last week, I came across these Red-Yellow-Flashing Yellow McCain signals on Dunlop Boulevard in western Huntsville, AL, close to the airport. I believe these are the only R-Y-FY signals in the city, and I think this is the first time I've seen signals like this used for low-flying aircraft (specifically helicopters, in this case, it seems).

IMG_1297 by freebrickproductions, on Flickr

IMG_1296 by freebrickproductions, on Flickr

Sign is a bit unclear; guess we're supposed to use red signals when attack helicopters are present?

[mrsman]

While heading to record a siren sounding for the monthly test last week, I came across these Red-Yellow-Flashing Yellow McCain signals on Dunlop Boulevard in western Huntsville, AL, close to the airport. I believe these are the only R-Y-FY signals in the city, and I think this is the first time I've seen signals like this used for low-flying aircraft (specifically helicopters, in this case, it seems).

IMG_1297 by freebrickproductions, on Flickr

IMG_1296 by freebrickproductions, on Flickr

How does this signal operate?

Is it on flashing yellow at all times, except that it will change to solid yellow and then red when aircraft passes by?

Or is it more like a HAWK and is normally off unless they start the signal process when an aircraft is nearby and then FY -> solid Y -> red?

I think that a better fit for this scenario would be similar to a railroad crossing, with flashing red lights, and most importantly gates.

Gibraltar has a road that crosses the airport's runway.  Traffic signals and gates are used to stop roadway traffic when planes take off and land.

[freebrickproductions]

While heading to record a siren sounding for the monthly test last week, I came across these Red-Yellow-Flashing Yellow McCain signals on Dunlop Boulevard in western Huntsville, AL, close to the airport. I believe these are the only R-Y-FY signals in the city, and I think this is the first time I've seen signals like this used for low-flying aircraft (specifically helicopters, in this case, it seems).

IMG_1297 by freebrickproductions, on Flickr

IMG_1296 by freebrickproductions, on Flickr

How does this signal operate?

Is it on flashing yellow at all times, except that it will change to solid yellow and then red when aircraft passes by?

It's definitely that way, presumably only changes when helicopters are about to take-off or land from the business just to the right.

[roadman65]

Who operates the signal?  Is it the tower of the field it lands on or someone else?

[freebrickproductions]

Who operates the signal?  Is it the tower of the field it lands on or someone else?

I'm honestly not entirely sure, my guess is that it's radio-controlled though, at the very least. Here's the location of it:
https://www.google.com/maps/@34.6654059,-86.7479353,3a,75y,120.2h,89.24t/data=!3m7!1e1!3m5!1sPU9UUJs0ZcYmRT-dRzHkHg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D0.75881121499134%26panoid%3DPU9UUJs0ZcYmRT-dRzHkHg%26yaw%3D120.20190937847966!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI2MDExMy4wIKXMDSoASAFQAw%3D%3D

[Tendies]

I saw an interesting one a couple days ago: A new light installation with intention to become FYA, but has only been partially activated in that the light is technically active, but the FYA isnt, thus operates in perment permissive only mode. The leftmost signal head, clearly designed to be an FYA repeater, is temporarily reporposed as a normal 3 section RYG head. The bottommost bulb is covered, but the open bulbs only display RYG circles, as a normal 3 section head would. Note the poorly covered "Left turn yield on [FYA]" sign and completely covered 4 section FYA head beside it.
VERY LATE EDIT 06-19: Found GSV showing the sign but 3 section signal heads
https://maps.app.goo.gl/NNYeRxdVBWL2Rsye7


I don't have a picture for this one, but in downtown Phoenix, at 5th av/Van Buren, the FYA is covered up and left turns are prohibited due to construction, but the bulbs are still active, and are visible through the cloth at night. The arrow is permanently red.
Edit 02-15: Upon further inspection, I do in fact have a picture, taken at the exact moment the light changes from yellow to red leading to a perfectly timed double exposure. Note the lack of a double exposure on the left turn signal, as would be expected if operating in FYA mode.


And here's a permanently covered up light in Peoria, AZ. The signal heads facing the school have seemingly been permanently disabled for years, and are covered in cloth. It appears to be a school bus exit that is no longer used. Unlike the previous example however, the signal heads have no power. Following is a link to an old google street view where the light was green. Nowadays, the cloth has partially ripped, exposing the red bulb on the middle signal head, which has either burned out or had power cut, as it is always dark. See Jan 2025 view. I've never seen the green circle peeking through the cloth, and I do pass by there often enough to know if it did work. It would be interesting to test if the sensor on the school side still works, howevr I'm not willing to risk trespassing + ??? charges for doing so. Unrelated, but the street name signs are also outdated spec for Peoria.
https://maps.app.goo.gl/YFdVSQJYTi284ccG6

And while im on the tangent of inactive traffic signals, there used to exist unused signal heads at an intersection in Glendale, AZ at the east Arrowhead Mall entrance on 75 Av. These were permanently dark and served absolutely no purpose, as they faced the empty side of a T intersection. They were eventually removed in 2024. A brief survey of Historic Aerials suggests that there used to be a parking lot entrance there that was converted to a bike trail in 1998.
https://maps.app.goo.gl/KHxy1h4y2JxE2DpR6

[freebrickproductions]

And here's a permanently covered up light in Peoria, AZ. The signal heads facing the school have seemingly been permanently disabled for years, and are covered in cloth. It appears to be a school bus exit that is no longer used. Unlike the previous example however, the signal heads have no power. Following is a link to an old google street view where the light was green. Nowadays, the cloth has partially ripped, exposing the red bulb on the middle signal head, which has either burned out or had power cut, as it is always dark. See Jan 2025 view. I've never seen the green circle peeking through the cloth, and I do pass by there often enough to know if it did work. It would be interesting to test if the sensor on the school side still works, howevr I'm not willing to risk trespassing + ??? charges for doing so. Unrelated, but the street name signs are also outdated spec for Peoria.
https://maps.app.goo.gl/YFdVSQJYTi284ccG6

You could always push one of the ped buttons and see if the green comes on that way.

And while im on the tangent of inactive traffic signals, there used to exist unused signal heads at an intersection in Glendale, AZ at the east Arrowhead Mall entrance on 75 Av. These were permanently dark and served absolutely no purpose, as they faced the empty side of a T intersection. They were eventually removed in 2024. A brief survey of Historic Aerials suggests that there used to be a parking lot entrance there that was converted to a bike trail in 1998.
https://maps.app.goo.gl/KHxy1h4y2JxE2DpR6

Looks like they were still fully incandescent as well, likely owing to them having essentially been abandoned in place for a few years (and missed being upgraded to LED as a result).

[Tendies]

And here's a permanently covered up light in Peoria, AZ. The signal heads facing the school have seemingly been permanently disabled for years, and are covered in cloth. It appears to be a school bus exit that is no longer used. Unlike the previous example however, the signal heads have no power. Following is a link to an old google street view where the light was green. Nowadays, the cloth has partially ripped, exposing the red bulb on the middle signal head, which has either burned out or had power cut, as it is always dark. See Jan 2025 view. I've never seen the green circle peeking through the cloth, and I do pass by there often enough to know if it did work. It would be interesting to test if the sensor on the school side still works, howevr I'm not willing to risk trespassing + ??? charges for doing so. Unrelated, but the street name signs are also outdated spec for Peoria.
https://maps.app.goo.gl/YFdVSQJYTi284ccG6

You could always push one of the ped buttons and see if the green comes on that way.

I'm about 99% sure the green doesnt come on, as I've driven through there often enough at night. Every time I pass by there I look up at the defunct signal head to see if I can see any light, but have never seen any. Given that the light was covered up by 2017, it's likely that all the circular bulbs have long burnt out by now.

https://maps.app.goo.gl/tK3H1TPS1rLyPmgR9

I was mainly curious if the sensors (either video or magnetic loop) on the now unused school side would still trigger the light to change. If so, it would be interesting to see if it still attempts a left turn cycle, whether the bulb still works or not. The only other situation would be if the sensors fail and the light defaults to full cycling, will it still attempt to cycle the now-unused left turn phase, or just the currently active phases.

[freebrickproductions]

And here's a permanently covered up light in Peoria, AZ. The signal heads facing the school have seemingly been permanently disabled for years, and are covered in cloth. It appears to be a school bus exit that is no longer used. Unlike the previous example however, the signal heads have no power. Following is a link to an old google street view where the light was green. Nowadays, the cloth has partially ripped, exposing the red bulb on the middle signal head, which has either burned out or had power cut, as it is always dark. See Jan 2025 view. I've never seen the green circle peeking through the cloth, and I do pass by there often enough to know if it did work. It would be interesting to test if the sensor on the school side still works, howevr I'm not willing to risk trespassing + ??? charges for doing so. Unrelated, but the street name signs are also outdated spec for Peoria.
https://maps.app.goo.gl/YFdVSQJYTi284ccG6

You could always push one of the ped buttons and see if the green comes on that way.

I'm about 99% sure the green doesnt come on, as I've driven through there often enough at night. Every time I pass by there I look up at the defunct signal head to see if I can see any light, but have never seen any. Given that the light was covered up by 2017, it's likely that all the circular bulbs have long burnt out by now.

https://maps.app.goo.gl/tK3H1TPS1rLyPmgR9

I was mainly curious if the sensors (either video or magnetic loop) on the now unused school side would still trigger the light to change. If so, it would be interesting to see if it still attempts a left turn cycle, whether the bulb still works or not. The only other situation would be if the sensors fail and the light defaults to full cycling, will it still attempt to cycle the now-unused left turn phase, or just the currently active phases.

I think they're more than likely just disconnected in that case, as the indications appear to be all LED.

[7/8]

Here's a very rare example of a round visor on a pedestrian signal head in Ontario. I can't recall seeing any others (all others I know of are square, including the other one on this same pole).

This is at Victoria/Edna in Kitchener, ON. The fact that all the lights at this intersection are mounted on hydro poles and span wires makes me think it's a temporary traffic signal setup, though strangely it's been around for a while and I'm unaware of any future construction at this intersection.

[freebrickproductions]

Here's a very rare example of a round visor on a pedestrian signal head in Ontario. I can't recall seeing any others (all others I know of are square, including the other one on this same pole).

This is at Victoria/Edna in Kitchener, ON. The fact that all the lights at this intersection are mounted on hydro poles and span wires makes me think it's a temporary traffic signal setup, though strangely it's been around for a while and I'm unaware of any future construction at this intersection.

Is it possible that the original visor got damaged/destroyed/knocked off, and the crew replacing it just grabbed a spare visor meant for a traffic light they had lying around? Per street view, another ped signal on that same side also has a round traffic signal visor on it as well:
https://www.google.ca/maps/@43.4608654,-80.4754401,3a,15y,46.11h,101.9t/data=!3m7!1e1!3m5!1s_1e-Cbnc6mQaNl0FO-snww!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-11.902753247351313%26panoid%3D_1e-Cbnc6mQaNl0FO-snww%26yaw%3D46.114299089730366!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI2MDIxNy4wIKXMDSoASAFQAw%3D%3D
The two also appear to be mounted right above a curb, so I could very well see some kind of box truck or 18-wheeler riding a bit too close to the curb and striking both visors.

[7/8]

Is it possible that the original visor got damaged/destroyed/knocked off, and the crew replacing it just grabbed a spare visor meant for a traffic light they had lying around? Per street view, another ped signal on that same side also has a round traffic signal visor on it as well:
https://www.google.ca/maps/@43.4608654,-80.4754401,3a,15y,46.11h,101.9t/data=!3m7!1e1!3m5!1s_1e-Cbnc6mQaNl0FO-snww!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fcb_client%3Dmaps_sv.tactile%26w%3D900%26h%3D600%26pitch%3D-11.902753247351313%26panoid%3D_1e-Cbnc6mQaNl0FO-snww%26yaw%3D46.114299089730366!7i16384!8i8192?entry=ttu&g_ep=EgoyMDI2MDIxNy4wIKXMDSoASAFQAw%3D%3D
The two also appear to be mounted right above a curb, so I could very well see some kind of box truck or 18-wheeler riding a bit too close to the curb and striking both visors.

Certainly could be. There's lots of truck traffic as Highway 7 changes from the Expressway to Victoria via Edna and Bruce, plus there's the Wonder Bread facility on the north side.

[kphoger]

https://maps.app.goo.gl/wML9diRdfwGUZ9XN6

The arrows on the post-mounted signal should be swapped, shouldn't they?

[Big John]

https://maps.app.goo.gl/wML9diRdfwGUZ9XN6

The arrows on the post-mounted signal should be swapped, shouldn't they?

yes: straight, left, right is the order to be used.

[freebrickproductions]

https://maps.app.goo.gl/wML9diRdfwGUZ9XN6

The arrows on the post-mounted signal should be swapped, shouldn't they?

yes: straight, left, right is the order to be used.

Looks like they took an overhead horizontal signal and rotated everything 90° to make it vertical.