Traffic signal

[paulthemapguy]

I hadn't realized 'til now that the MUTCD spec for horizontal signals is different for heads with left vs. right turn arrows. With left-turn arrows, the green ball is at the right end of the head. But with right-turn arrows it's in the middle. Anyone know why the difference? You'd think it would be the same for both or at least I thought so....

I too would love some guidance on why this is.  Maybe the MUTCD is more particular about the left-turn sideways towers than the right-turn ones because right-turn arrows are more of an auxiliary addition to most intersections?

Also that Illinois signal pictured above is probably next to an airport, judging from the low height of the street lamps. Maybe that's the reason for the rare horizontal heads too, though you wouldn't think that would make any difference to low-flying planes. They don't fly that low!

You're absolutely right!  Further protrusions upward into the sky require a small red light to be attached to the end (see the street lamps in the pictures), per aviation guidelines.  Attaching a small red light to the top of a traffic signal head would be, well, confusing to say the least for drivers!! 
And it's not even just the proximity to the airport that's a problem...One of the airport runways leads DIRECTLY toward the intersection home to this signal.  Here's the location on google maps; note the location and orientation of the runway.  https://www.google.com/maps/@41.5147573,-88.1724664,16.62z

[SignBridge]

Well paul, I think Big John got it pretty much correct in his post above. The arrows are placed on the turning side of the green-ball. Makes sense.

[jakeroot]

^^
I think that's the best explanation. Same reason doghouses will have the arrows on the left or right side, depending on whether the doghouse is being used for a right or left turn. Might seem inconsistent, but it keeps the arrows on the correct side of the signal.

[steviep24]

How would FYA be done in a horizontal configuration?

[Big John]

^^

Section 4D.10 2009 MUTCD:

03 The relative positions of signal sections in a horizontally-arranged signal face, from left to right, shall be as follows:

    CIRCULAR RED
    Steady and/or flashing left-turn RED ARROW
    Steady and/or flashing right-turn RED ARROW
    CIRCULAR YELLOW
    Steady left-turn YELLOW ARROW
    Flashing left-turn YELLOW ARROW
    Left-turn GREEN ARROW
    CIRCULAR GREEN
    Straight-through GREEN ARROW
    Steady right-turn YELLOW ARROW
    Flashing right-turn YELLOW ARROW
    Right-turn GREEN ARROW

So it would be:  RA, YA, FYA, GA (for all left or all right arrows)

[roadman65]

Does Dade County, FL have FYA with their use of all horizontal signals? What about Texas?

[jakeroot]

We have a horizontal FYA here in Seattle, in the SODO area. It operates as prescribed above.

[US 89]

I saw this in Durango, CO and thought it was unique:



And here's the other direction:

[jakeroot]

Interesting that both a doghouse and side-by-side signal were used on the same mast arm in photo #2. Colorado certainly loves side-by-side signals, and there's plenty of doghouses, but I've never seen two used at the same intersection (never mind same mast arm).

If there's a straight-through movement in photo #1, it is odd to see a green left arrow on the right side of the intersection. Not unprecedented; I've seen it before. But it's certainly unusual!

[freebrickproductions]

Interesting that both a doghouse and side-by-side signal were used on the same mast arm in photo #2. Colorado certainly loves side-by-side signals, and there's plenty of doghouses, but I've never seen two used at the same intersection (never mind same mast arm).

If there's a straight-through movement in photo #1, it is odd to see a green left arrow on the right side of the intersection. Not unprecedented; I've seen it before. But it's certainly unusual!

I've seen the "side-by-side signals" referred to as "offset doghouses" before... But yea, not very often you see both on the same set-up, anywhere really...

And we used to have a set-up similar to Photo #1 here in Huntsville before, though the doghouse has since been replaced by an upside-down T signal (so I suppose it's still somewhat similar...).

[jakeroot]

Interesting that both a doghouse and side-by-side signal were used on the same mast arm in photo #2. Colorado certainly loves side-by-side signals, and there's plenty of doghouses, but I've never seen two used at the same intersection (never mind same mast arm).

If there's a straight-through movement in photo #1, it is odd to see a green left arrow on the right side of the intersection. Not unprecedented; I've seen it before. But it's certainly unusual!

I've seen the "side-by-side signals" referred to as "offset doghouses" before... But yea, not very often you see both on the same set-up, anywhere really...

I don't really know what to call them. I've called them something else other than side-by-side (something like your suggestion), but I got mauled by a couple of locals who insisted that "side by side" was the only appropriate term.

I personally really like them. Never been a big fan of having the red centered. Just an aesthetic preference.

[MikeCL]

What's the age on this one?

[traffic light guy]

What's the age on this one?

Dear God that camera quality is low

[freebrickproductions]

What's the age on this one?

Old. That's an AGA/SSC signal, so likely around the 1930s:
http://kbrhorse.net/signals/ssc_4way01.html

Where is that?

[Revive 755]

If there's a straight-through movement in photo #1, it is odd to see a green left arrow on the right side of the intersection. Not unprecedented; I've seen it before. But it's certainly unusual!

And possibly not MUTCD compliant either, depending on if the head on the mast arm shaft is considered a primary head or not for the left turn.

If supplemental signal faces are used, the following limitations shall apply:

A. Left-turn arrows and U-turn arrows to the left shall not be used in near-right signal faces.

If supplemental post-mounted signal faces are used, the following limitations shall apply:

A. Left-turn arrows and U-turn arrows to the left shall not be used in near-right signal faces.

The heads also look way too close to the stop bar.  Based on Streetview, IMHO they should have used a heavier duty mast arm on the far side and mounted most of the heads on it.

[MikeCL]

What's the age on this one?

Dear God that camera quality is low

That's like 5x on my iPhone X I was too far back and in my car

[MikeCL]

What's the age on this one?

Old. That's an AGA/SSC signal, so likely around the 1930s:
http://kbrhorse.net/signals/ssc_4way01.html

Where is that?

In Union City on Palisades it's funny now that I think about it for whatever reason here in NJ for one way streets they will still run a 4 sized signal and you will have a signal facing the one way street.. I'm thinking police and fire go down one ways the other way?

I love the visor on that old signal

[SignBridge]

That signal head might be from the 1930's but the mast-arm is definitely newer. Probably 1960's, 'cause I remember seeing them in that area in the early 1970's.

[freebrickproductions]

What’s the age on this one?

Old. That's an AGA/SSC signal, so likely around the 1930s:
http://kbrhorse.net/signals/ssc_4way01.html

Where is that?

In Union City on Palisades it’s funny now that I think about it for whatever reason here in NJ for one way streets they will still run a 4 sized signal and you will have a signal facing the one way street.. I’m thinking police and fire go down one ways the other way?

I love the visor on that old signal

Probably for pedestrians, so they can know when to cross.

That signal head might be from the 1930's but the mast-arm is definitely newer. Probably 1960's, 'cause I remember seeing them in that area in the early 1970's.

It was definitely re-hung at some point.

[roadman65]

https://www.google.com/maps/@42.4469843,-83.1028171,3a,75y,267.66h,103.19t/data=!3m6!1e1!3m4!1sKl_2ORnmzCTySPygBGVBXw!2e0!7i13312!8i6656
Is Michigan the only state to feature these cube back lit traffic control devices on their signals?

[jakeroot]

If there's a straight-through movement in photo #1, it is odd to see a green left arrow on the right side of the intersection. Not unprecedented; I've seen it before. But it's certainly unusual!

And possibly not MUTCD compliant either, depending on if the head on the mast arm shaft is considered a primary head or not for the left turn.
...
The heads also look way too close to the stop bar.  Based on Streetview, IMHO they should have used a heavier duty mast arm on the far side and mounted most of the heads on it.

Looks you might be on to something. I certainly don't mind the positioning, but I'm not sure how I feel about left or right arrows being on the incorrect sides of the intersection. If only one direction is permitted, I don't see the big deal. Of course, that's not the situation here, so I'd rather the signal were just a three-head signal.

I don't think there's anything wrong with having the signals on the near-side mast. And even using the far-side mast, there's only two lanes, so it's better not to crowd the mast arm; put any extra signals on posts or masts. Unless it's a near-side overhead signal (placed behind the opposite side's primary signal faces). In this case, it's possible that far-side mast arm would have been too far from the stop line (which has to be set back due to left turn overlaps). So they just decided to push back the stop lines a bit more, and put the signals on the near side. Honestly, it's a pretty nice setup. I'm just not a fan of the left-facing arrow on the right side. That's my only issue.

[jakeroot]

Found another flashing yellow arrow with a bi-modal lens. This one is in Auburn, WA. The signal faces right, towards a crosswalk. The top lens is a red orb, apparently to not mislead drivers into thinking right-on-red wasn't permitted (even though it would have been). The middle lenses are yellow arrows (solid and flashing), and the bottom is a bi-modal green/yellow arrow.

Given that the bottom lens is bi-modal, and the top a red orb, this right turn filter signal is almost a Frankenstein signal, basically being a standard 4-section right turn signal, but with two arrow displays in the middle, instead of green and yellow orbs. Literally halfway between a full-blown FYA, and a standard RYG-YA/GA signal.

Bi-modal green/yellow arrows are very common here for right-turn filter signals, so perhaps this is just their way of making the signal slightly more normal. Of course, now, Auburn has quite a few right-facing flashing yellow arrows (they appear to be the new standard for right turn lanes), though the rest are all standard operation, with the yellow arrow being used for the end of both the protected and permissive phases. Most of the others also use red arrows, instead of red orbs (since it doesn't legally matter here).

https://youtu.be/zYO_UTFHzwk

[paulthemapguy]

^So the signal has two sections for a solid yellow arrow.  Whyyyyyyyyyyyyyyyyy
I do like that they tried to specify when right turning traffic has the ROW in cooperation with the crosswalk signal though.

[jakeroot]

^So the signal has two sections for a solid yellow arrow.  Whyyyyyyyyyyyyyyyyy
I do like that they tried to specify when right turning traffic has the ROW in cooperation with the crosswalk signal though.

It's very common over here to have a 4-section right turn filter, so I guess they just tried to morph one into a flashing yellow arrow. It is pretty cool that the signals are used from bottom to top, like with a typical green orb signal.

[jakeroot]

This pole-mounted signal in Fife, WA is placed quite low to the ground, due to the pole being mounted slightly below ground level. The intersection is slightly elevated, but this signal pole doesn't seem to be. Oddly, the opposite direction's pole-mounted signal is mounted a bit higher than normal. Spin the GSV around a bit.

https://goo.gl/YpyDBM (Valley Ave @ Freeman Road)

It doesn't seem that low to me. But it might not be mounted at the minimum of 8 feet from sidewalk (or the pavement grade at the center of the roadway if there is no sidewalk) to bottom of signal housing [See MUTCD 4D.15]. The other pole/mast mounted signals at that intersection seem abnormally high... 

Come to think of it, I've seen that high mast mount in a few other examples you've posted. Must be a Washington thing...? NDOT's standard plans call for a side-mounted 3-section head to be 12 feet (on center) from the bottom of the mast (note the mast arm connects at 18.5 feet on center, so the signal is about 2/3 the way up the mast). And I'm fairly certain all the local agencies use NDOT's standard plans for their signal installations.

Apologies for taking a while to respond to this.

High-mounted supplemental signals are oddly common in WA, although pole-height supplemental signals are far more common. More often than not, they are placed up high when a slip lane is signalized, and a supplemental signal is placed on the near-side mast.

This placement style could be the result of our inexperience working with supplemental signals (they have become a lot more common in the last 15 years). Even on the same pole, you'll see them placed at different heights. I think a similar signal in NV would have the signals aligned a bit more carefully.

In Tacoma, the signals at the 15th and Commerce St intersection had to be located on the edges of the intersection due to trolley wires. This signal is oddly reminiscent of something you might see in DC, but nevertheless, the outer signals are still placed up rather high on the masts. This intersection also features a decidedly unusual [in WA] left-side green orb signal (and with a bi-modal arrow -- the protected left only activates when a train approaches from the south, to clear out waiting cars).

As you may have noticed in the link in my original post above, the far-side supplemental signal for northbound Freeman at Valley Ave in Fife is placed way above the supplemental left turn signal for traffic going from eastbound Valley to northbound Freeman (and closer to the height of the opposite movement's supplemental turn signal, which you already pointed out).