Traffic signal

[jakeroot]

Time-of-day based left turn in Independence, Ohio at Rockside Rd to the SB I-77 on-ramp. Single lane protected-permissive left turn, and double lane protected only left turn. Notice the 4 section signal to the right of the FYA. Not sure if the arrow is bimodal.

https://www.google.com/maps/@41.3968064,-81.6533776,3a,20.6y,301.27h,92.26t/data=!3m6!1e1!3m4!1soKiZ4oskn3_v0ysO3554mw!2e0!7i16384!8i8192

You can see the FYA in operation here while the #2 lane is set to straight-ahead.

That's an odd setup. Looks like the 4-section shared signal has a three orb setup with a green arrow on the bottom. This isn't really ideal, as when it's set to left turn mode, it displays a red arrow orb as you've shown in your link. During straight-ahead mode, it looks acceptable with a standard green orb. Seems the only way to make it compliant would be to use a blank out "LEFT TURN SIGNAL" sign.

In my area, when the left turn becomes busy enough that it needs a second lane, it is either made into a double permissive left or a double protected left. I'd love if anyone in the Cleveland area could describe a bit more about this setup and why it was necessary.

FTFY, Jakeroot

They could probably make this semi-compliant with louvers on the circular red and yellow sections, but the blank out "Left turn signal" idea is probably best.

I think this is a somewhat clever setup. I can think of a location near me where a similar use case could potentially be beneficial.

Thank you. Fixed!

Honestly, my preferred fix would be a single FYA signal over the middle of the two left lanes, and a second FYA signal on the far left corner. There would be a blank out sign to the right of the overhead signal to indicate whether turns were permitted or not (based on time of day, it would either show a left arrow or straight arrow). The FYA would go protected-only during peak hours, as I'm guessing Ohio would prefer, and there'd still be the ideal minimum two signals for when the protected double left mode was active (there'd be an extra signal when it was operating as protected-permissive) but without the confusion of "which movement is this signal for?".

Yet further proof, in my opinion, that signal per lane is not always ideal, and that moving the second or third signal onto a pole allows for greater flexibility.

[fwydriver405]

Time-of-day based left turn in Independence, Ohio at Rockside Rd to the SB I-77 on-ramp. Single lane protected-permissive left turn, and double lane protected only left turn. Notice the 4 section signal to the right of the FYA. Not sure if the arrow is bimodal.

https://www.google.com/maps/@41.3968064,-81.6533776,3a,20.6y,301.27h,92.26t/data=!3m6!1e1!3m4!1soKiZ4oskn3_v0ysO3554mw!2e0!7i16384!8i8192

You can see the FYA in operation here while the #2 lane is set to straight-ahead.

That's an odd setup. Looks like the 4-section shared signal has a three orb setup with a green arrow on the bottom. This isn't really ideal, as when it's set to left turn mode, it displays a red arrow orb as you've shown in your link. During straight-ahead mode, it looks acceptable with a standard green orb. Seems the only way to make it compliant would be to use a blank out "LEFT TURN SIGNAL" sign.

In my area, when the left turn becomes busy enough that it needs a second lane, it is either made into a double permissive left or a double protected left. I'd love if anyone in the Cleveland area could describe a bit more about this setup and why it was necessary.

FTFY, Jakeroot

They could probably make this semi-compliant with louvers on the circular red and yellow sections, but the blank out "Left turn signal" idea is probably best.

I think this is a somewhat clever setup. I can think of a location near me where a similar use case could potentially be beneficial.

Thank you. Fixed!

Honestly, my preferred fix would be a single FYA signal over the middle of the two left lanes, and a second FYA signal on the far left corner. There would be a blank out sign to the right of the overhead signal to indicate whether turns were permitted or not (based on time of day, it would either show a left arrow or straight arrow). The FYA would go protected-only during peak hours, as I'm guessing Ohio would prefer, and there'd still be the ideal minimum two signals for when the protected double left mode was active (there'd be an extra signal when it was operating as protected-permissive) but without the confusion of "which movement is this signal for?".

Yet further proof, in my opinion, that signal per lane is not always ideal, and that moving the second or third signal onto a pole allows for greater flexibility.

Another possible solution... keep the 4-section head, but have the circular red and yellow be able to change to arrows when the time of day restrictions are in place. That would eliminate the need of placing a "LEFT TURN SIGNAL" sign and the red ball over a left turn lane. If Ohio is intending to use protected-only operation during the time two left turn lanes are active, that would work (circular green is not permitted over dedicated left-turn lanes), although you could change out the bottom green arrow for a bimodal green/yellow arrow for FYA operation.

Example in Utah where they have flex lanes in use, the circular red changes to an arrow:

[jeffandnicole]

Ever notice how New Jersey's long mast-arms seem to droop. Some other states build them with a slight upward angle to avoid that.

Of those that do, they seem designed to do that, and there really isn't any additional droppage later in its life.   The newer, thicker mast arms shoot straight out.

[jakeroot]

Another possible solution... keep the 4-section head, but have the circular red and yellow be able to change to arrows when the time of day restrictions are in place. That would eliminate the need of placing a "LEFT TURN SIGNAL" sign and the red ball over a left turn lane. If Ohio is intending to use protected-only operation during the time two left turn lanes are active, that would work (circular green is not permitted over dedicated left-turn lanes), although you could change out the bottom green arrow for a bimodal green/yellow arrow for FYA operation.

Example in Utah where they have flex lanes in use, the circular red changes to an arrow:

https://www.youtube.com/watch?v=xs1iix82hc4&ab_channel=ChrisDay

That could work too. Seems awfully technical for such a simple setup, but it could work.

Seems like my suggestion would be simpler. I do think UDOT's creativeness is pretty cool, though.

[Dirt Roads]

Example in Utah where they have flex lanes in use, the circular red changes to an arrow:
https://www.youtube.com/watch?v=xs1iix82hc4&ab_channel=ChrisDay

It looks like something is missing in the changeover phase.  About 2:37 into the video the green left arrow clearout phase for lane four is complete, followed by a yellow left turn until almost 2:40, then everything goes blank and the left turn is transferred over to a red left turn arrow in lane three.  But if someone was driving hard in lane four to try to beat the cycle, they never see a red signal.  Seems like it would be too easy to get stuck in no-man's-land. 

For the record, I'm a railroad signal engineer with some experience in traffic signals associated with railroad crossings.  Obviously, I have a bias since we are required to make this kind of operation fail-safe.

[roadman65]

Noticed how GA uses a box suspended away from the strain poles.

https://live.staticflickr.com/65535/50612503926_98a6bd05c7_4k_d.jpg

[mrsman]

Another possible solution... keep the 4-section head, but have the circular red and yellow be able to change to arrows when the time of day restrictions are in place. That would eliminate the need of placing a "LEFT TURN SIGNAL" sign and the red ball over a left turn lane. If Ohio is intending to use protected-only operation during the time two left turn lanes are active, that would work (circular green is not permitted over dedicated left-turn lanes), although you could change out the bottom green arrow for a bimodal green/yellow arrow for FYA operation.

Example in Utah where they have flex lanes in use, the circular red changes to an arrow:

https://www.youtube.com/watch?v=xs1iix82hc4&ab_channel=ChrisDay

That could work too. Seems awfully technical for such a simple setup, but it could work.

Seems like my suggestion would be simpler. I do think UDOT's creativeness is pretty cool, though.

Another possibility for the Ohio situation would be if the signal over the #2 lane were a 6-aspect doghouse:

RA-R
YA-Y
GA-G

During straight ahead hours, only RYG would be used.  During left turn hours, RA-YA-GA would be used. 

UDOT's system is good too and perhaps with LED it may be quite simple to convert an "orb" (array of LED lights that look like a circle from far) to an arrow disply quite easily.  [Much of the complexity in UDOT's video also had to do with the reversible lane changeover - the Ohio situation doesn't have that.  All lanes in question are always westbound, its just that the #2 lane is sometimes straight only and sometimes left only.]*

Given the fancy stuff you see people using programmable LEDs for in some of the grander versions of Christmas light displays, I'm sure just using LEDs to change from a circle to an arrow (or to change color from red to yellow to green) is a piece of cake.

And while I can't speak to the specific situation here in Cleveland, I definitely know of other situations where a left turn is so heavy during rush hour that the straight lane on an optional lane setting is a de facto left turn lane, while during other times of day, the left turn is not so busy and it would be better for all with a single dedicated left turn lane allowing permissive/protected turning.  In a jurisdiction where permissive double lefts are discouraged, something like this accommodates the best of all worlds - limited double lefts during peak and single permissive lefts at other times.


* On another thread (or perhaps on this thread a few months ago, IDK), someone mentioned the reversible setup on Nicholasville Rd outside of Lexington, KY.  The road is five lanes, but reversible setups allow for 3-L-1, 2-L-2, or 1-L-3 depending upon the time of day.  They also have the issue of four aspect signals in a strange way that would force during parts of the day for a red orb to act like a red arrow without the ability to use a "left turn signal" sign, unless it were lit up (which it doesn't).  I also posited the suggestion of a 6-aspect doghouse for any lane that is sometimes straight or sometimes left.  (all lefts are protected only).


https://www.google.com/maps/@38.0191844,-84.5139557,3a,75y,38.36h,79.37t/data=!3m6!1e1!3m4!1s-Cj4vL1QVpzP4LuBEm0ZNA!2e0!7i16384!8i8192

[Amtrakprod]

https://www.google.com/maps/@35.1971473,-111.647808,3a,75y,311.65h,99.6t/data=!3m6!1e1!3m4!1sHwaiOss7FNE1xOQjDm2UnA!2e0!7i16384!8i8192

[jakeroot]

https://www.google.com/maps/@35.1971473,-111.647808,3a,75y,311.65h,99.6t/data=!3m6!1e1!3m4!1sHwaiOss7FNE1xOQjDm2UnA!2e0!7i16384!8i8192

What are we looking at?

UDOT's system is good too and perhaps with LED it may be quite simple to convert an "orb" (array of LED lights that look like a circle from far) to an arrow disply quite easily.  [Much of the complexity in UDOT's video also had to do with the reversible lane changeover - the Ohio situation doesn't have that.  All lanes in question are always westbound, its just that the #2 lane is sometimes straight only and sometimes left only.]*

My primary concern with lights that change their displayed "shapes" is that it might be confusing for drivers who rely on reasonably-consistent engineering practices to safely operate their vehicle. It seems to me that a signal that can change its shape may lead to drivers misinterpreting the meaning of that signal. If a signal goes from a solid green orb to solid green arrow, or vice-versa, drivers who are used to that signal being displayed one way or the other may continue to believe that it's displaying the signal "it always does" even after the switch, especially if they only catch a passing glance of the signal as they move down the highway.

My other concern is that LEDs are prone to failure for various reasons, and the LED orbs can sometimes become a random shape of LEDs; the point being that there is a potential integrity issue with this type of signal. This type of failure isn't too common (although a glance around New Orleans shows how common it can actually be), but I would not want to rely on a signal being able to change shape. That UDOT signal appears to use a bunch of tiny LEDs to change the shape. Which is cool, but again, I would be worried about LED cluster failures.

[hotdogPi]

https://www.google.com/maps/@35.1971473,-111.647808,3a,75y,311.65h,99.6t/data=!3m6!1e1!3m4!1sHwaiOss7FNE1xOQjDm2UnA!2e0!7i16384!8i8192

What are we looking at?

My guess would be that there's a signal on the far left despite left turns being banned.

[UnumProvident101]

https://www.google.com/maps/@34.9915909,-85.2522514,3a,75y,204.54h,86.31t/data=!3m6!1e1!3m4!1s5ROQHcBPQvfRh-PbsrJOkg!2e0!7i13312!8i6656

the only reason I posted this without a description is that I don't know what kind of traffic light that is

[jakeroot]

https://www.google.com/maps/@35.1971473,-111.647808,3a,75y,311.65h,99.6t/data=!3m6!1e1!3m4!1sHwaiOss7FNE1xOQjDm2UnA!2e0!7i16384!8i8192

What are we looking at?

My guess would be that there's a signal on the far left despite left turns being banned.

Not likely. That's normal in many states, including Arizona.

[jakeroot]

https://www.google.com/maps/@34.9915909,-85.2522514,3a,75y,204.54h,86.31t/data=!3m6!1e1!3m4!1s5ROQHcBPQvfRh-PbsrJOkg!2e0!7i13312!8i6656

Can we please stop with description-less links?

Again, no idea what to look at here.

[jeffandnicole]

https://www.google.com/maps/@34.9915909,-85.2522514,3a,75y,204.54h,86.31t/data=!3m6!1e1!3m4!1s5ROQHcBPQvfRh-PbsrJOkg!2e0!7i13312!8i6656

Can we please stop with description-less links?

Again, no idea what to look at here.

It's pretty obvious. The green sign is pointing at the yellow lights with white arrows.   

[STLmapboy]

https://www.google.com/maps/@35.1971473,-111.647808,3a,75y,311.65h,99.6t/data=!3m6!1e1!3m4!1sHwaiOss7FNE1xOQjDm2UnA!2e0!7i16384!8i8192

What are we looking at?

My guess would be that there's a signal on the far left despite left turns being banned.

Not likely. That's normal in many states, including Arizona.

Yeah, I still don't know what the link is referring to. Amtrakprod, if you'd like to clear the air...?

[CJResotko]

8-8-8 signal with a 12-inch adapter in Taylor, MI: https://www.google.com/maps/@42.2520016,-83.2601358,3a,15y,239.26h,126.51t/data=!3m6!1e1!3m4!1smxjGSkBKofVI_6geTsDfvg!2e0!7i16384!8i8192

[roadman65]

Interesting sight to see. Two doghouses with back plate corners missing in Thomson, GA.

[STLmapboy]

There are tons of doghouses with backplates partially missing. Broken backplates seem to be more common on doghouses; I think it has something to do with the signal design requiring more exposed backplate.

[fwydriver405]

There are tons of doghouses with backplates partially missing. Broken backplates seem to be more common on doghouses; I think it has something to do with the signal design requiring more exposed backplate.

The doghouses in my area (and in Massachusetts as well) sometimes use a full "square" backplate (most common I've seen in ME), and some, just around the outline. (most common I've seen in MA)

Not sure what is more advantageous or disadvantageous in terms of visibility, (wind) loading, etc.

[Amtrakprod]

https://www.google.com/maps/@35.1971473,-111.647808,3a,75y,311.65h,99.6t/data=!3m6!1e1!3m4!1sHwaiOss7FNE1xOQjDm2UnA!2e0!7i16384!8i8192

Don't know why this link sent. I meant to send anothe street view link and now I forgot what I was going to send. Sorry about this!


iPhone

[jakeroot]

There are tons of doghouses with backplates partially missing. Broken backplates seem to be more common on doghouses; I think it has something to do with the signal design requiring more exposed backplate.

The doghouses in my area (and in Massachusetts as well) sometimes use a full "square" backplate (most common I've seen in ME), and some, just around the outline. (most common I've seen in MA)

Not sure what is more advantageous or disadvantageous in terms of visibility, (wind) loading, etc.

I've wondered this myself as well. I've seen both around my area, although the "full square" style is more common by about 8 to 1. I can't quite figure out what the advantage is. Wind loading requirements seems like a decent explanation, although I've seen the two combined at one intersection.

[STLmapboy]

There are tons of doghouses with backplates partially missing. Broken backplates seem to be more common on doghouses; I think it has something to do with the signal design requiring more exposed backplate.

The doghouses in my area (and in Massachusetts as well) sometimes use a full "square" backplate (most common I've seen in ME), and some, just around the outline. (most common I've seen in MA)

Not sure what is more advantageous or disadvantageous in terms of visibility, (wind) loading, etc.

I've wondered this myself as well. I've seen both around my area, although the "full square" style is more common by about 8 to 1. I can't quite figure out what the advantage is. Wind loading requirements seems like a decent explanation, although I've seen the two combined at one intersection.

MO has the full square style mostly, with a few exceptions. Ohio's the only state I've seen that predominantly uses the outline backplate. Well, also some in CO and WV (using their weirdly aligned backplates).

[Big John]

Green Bay with another strange use of an arrow.  A  signal head has been recently replaced and it contains a 4-section split phase head.  It is left-most signal.  The signal behaves normally as a split phase.  The problem is instead of the normal vertical R-Y-G-GA, it has a R-YA-G-GA configuration.

[SignBridge]

Re: the durability of backplates, there must be different levels of quality in backplates or different materials used in different states. In Calif. and the Chicago area they seem to remain intact for many years. Yet in Long Island, NY where NYSDOT Region-10 goes on a campaign of new backplate installations every twenty-five years or so, they seem to disappear over time. I assume they are poor quality and just crack, break away and fall to the roadway.

In one good example, in front of the Home Depot on S.R. 25 in the Westbury-Jericho area, new signals were erected within the last five years and half the backplates are already gone.

[US 89]

There are tons of doghouses with backplates partially missing. Broken backplates seem to be more common on doghouses; I think it has something to do with the signal design requiring more exposed backplate.

The doghouses in my area (and in Massachusetts as well) sometimes use a full "square" backplate (most common I've seen in ME), and some, just around the outline. (most common I've seen in MA)

Not sure what is more advantageous or disadvantageous in terms of visibility, (wind) loading, etc.

I've wondered this myself as well. I've seen both around my area, although the "full square" style is more common by about 8 to 1. I can't quite figure out what the advantage is. Wind loading requirements seems like a decent explanation, although I've seen the two combined at one intersection.

Utah does not install backplates on 99% of its doghouses despite using them very consistently on all of its other signals.