Five Section or doghouse signal head for left turns?

[Alps]

^^ However, the flashing red for a left turn is never treated as a complete stop unless opposing traffic is has not cleared.  See Tradephroic's discussion of Michigan above (which I am very familiar with).

Still, I think a flashing red is a little clearer than a flashing yellow in terms of what you're supposed to do. Flashing yellow generally means "it's the weekend, stop if it's red and then go, ignore if it's yellow," and you'd better not treat a FYA in that manner.

[roadfro]

^^ However, the flashing red for a left turn is never treated as a complete stop unless opposing traffic is has not cleared.  See Tradephroic's discussion of Michigan above (which I am very familiar with).

What you're describing is really no different than what the FYA is now.

The flashing red arrow introduced in the 2009 MUTCD (same time as the FYA in the national manual) has the same intent as the FYA, except that there is some engineering reason that decides that the driver making the permitted left turn MUST come to a full stop before turning. This "FRA" was also introduced with the optional supplementary R10-27 sign that reads "LEFT TURN YIELD ON FLASHING RED ARROW AFTER STOP".

[lepidopteran]

In the early 1970s, the city of Toledo, OH rapidly went around and replaced all the traffic signals in town.   The primary specs were:

• Mast arms (a handful of span wires remained, and top-bottom wires for longer spans)
• 12-inch only (they kept a lone 8-inch faced the the wrong way on one-way streets)
• Tunnel visors only
• Yellow-red flash mode after hours at minor intersections.
• 3M lenses for occasional left-turn signals, and at least one location where only the red section was 3M.  At least one diagonal intersection (Monroe-Sylvania) was ALL 3M.
• And a LOT of 5-section "towers" for left-turns and right-turns, seemingly to the point of overkill.  Protected-only left-turn-signals, like the occasional 3M, were rare.  With at least one exception, the towers were Crouse-Hinds with the boxy backs; the upgrades were about a 50-50 split between that and Econolite Bullseyes.

This intersection was formed and signalized in 1981.  http://goo.gl/maps/roJa8

This face is all towers: http://goo.gl/maps/r1Y19

And this intersection has a left-turn tower in each direction, except for SB which is a doghouse.  At least by the '90s, it seems like they started warming up to doghouses.

Edit: forgot to include the link for that last one.
https://www.google.com/maps?ll=41.646749,-83.564072&spn=0.375589,0.529404&cbp=12,279.75,,1,-0.21&layer=c&panoid=g6mYfkynY46tZUaiapq-vw&cbll=41.67762,-83.604973&t=h&z=11

For what it's worth, note that if you look 180° behind, you'll see a scraped up RXR on the pavement, followed by a paved-over grade crossing.  When these tracks were active, the signal flashed red in all directions when a train approached, along with the now-removed crossing lights. The tracks were ripped up in 2010.

[Mark68]

Colorado was mostly doghouse (probably as an add-on to the old 12-8-8 signals hanging from overhead wires in places such as Denver), then had some 4-sections and mostly 5-sections that were side-mounted (or center-mounted in the medians). Denver had some interesting ones with the normal 8-8-8 three section signals with two 12-inch signals added to the bottom for the green and yellow turn arrows. Now Aurora is installing the FYA (usually with four sections, some with three), Denver has installed their first two FYAs, and I have not heard of any other ones...yet...in other cities.

CDOT District 2 (Pueblo/Colorado Springs) uses them extensively. More so than the rest of the state put together.

Seems like they're popping up everywhere in Aurora. Have seen a lot of replacement installations with the FYA. Saw one a couple weeks ago in downtown Denver at Speer Blvd & Chopper Circle (entrance to Pepsi Center), with a 4-section FYA.

[mrsman]

Tradephoric was saying that a quick glance at the signal head might cause one to inadvertently assume a flashing yellow was becoming steady. I assert that if you make a quick glance and note that the yellow arrow has jumped sections, then that's when you'd need to worry--if the yellow is still in the same section as where it was flashing before, there's no need to worry. It's a lot more noticeable that a light has changed sections than it is to switch from flashing to steady in the same signal section. This is why I prefer the 4-section FYA to the 3-section variant.

Agreed, and that's why the MUTCD shows a separate section for the FYA from the SYA in its signal diagrams.

I agree with Tradephoric.  In my experience, the vast majority of protective/permissive signals have a lead-lead phasing.  The way that a person would typically turn during the permissive phase is to wait for a gap in left turning traffic, or if there is no gap, turn during the end of yellow or all-red phase.  Basically, the signals "train" us to think that both sides will have their green terminate at the same time. 

There is a perceived yellow trap, because this type of turn is so ingrained in the driving public.  I don't believe there is any way to train drivers out of that mindset safely, unless the thru signal lights were somehow blocked from the turning driver's view.

I grew up in California.  I don't believe California allows for the FYA, because of the perceived yellow trap, as Tradephoric describes.

I've seen the following configurations in California that they consider safe:

Protective lead   (RED ARROW or "Left turn on arrow only")
Protective lag (only after both thru directions get red)
Protective lead- Protective lead
Protective lead- Protective lag
Protective lag- Protective lag (only after both thru directions get red)

Protective/Permissive lead (Dog House on mast arm, 5 section signals on the side)
Protective/Permissive lead-Protective/Permissive lead
Protective/Permissive lag-Protective/Permissive lag (only after both thru directions get red)

Prohibited lead (NO LEFT OR U TURN) - Protective/Permissive lag (4 section signals)*
Prohibited lead - Protective lag
Protective lead (red arrow) - Protective/Permissive lag (4 section signal)

Where I currently live in Maryland, most of the protective/permissive signals are doghouses.  There is a flashing red arrow nearby, but it seems to employ a lead phasing every time I see it, so there is no yellow trap potential.  But I do worry that they may change it to allow a lagging left turn, which will lead to a perceived yellow trap.

* This arrangement is common at T-intersections or where a 2-way intersects with a one-way.  This is an ideal signal arrangement, in my opinion, since it follows the standard approach of allowing lefts at any time there's a gap, and if there is no gap in traffic, turn when opposing traffic  gets a red at the end of the cycle.  For this to really work, the opposing left/u turn must be absolutely prohibited.  An example is at First and Main in Downtown L.A.

[Brandon]

How about signals that appear protective/permissive but are protective phase only?

CDOT (Chicago DOT) does this rather often.  In direct violation of the MUTCD, I might add.

Lake Shore Drive:




Michigan Avenue:

[Mdcastle]

I've mentioned before that Chicago DOTs deliberate and blatant disregard for national standards here pisses me off.

[PurdueBill]

I was amazed/entertained/disgusted back in July when in Chicago I saw a CTA bus driver leaning on their horn and yelling (as if anyone could hear her outside the bus) at a car in front of her in the left turn lane who was obeying the sign at a green circular light on Michigan Ave.  Bad enough for CDOT to flaunt national standards so badly, but then for CTA bus drivers to act like that?  Sigh.

It seems like there ought to be enough room even on the narrow islands pictured here to have side-by-side 3-section signals for left turn and thru movements if they insist on protected turns; one could be red and the other green.

I have to give it to the MDC (or DCR or whoever is in charge of their roads now)....they may have some wacky nonstandard signals out there but they obey standards like green circles meaning permissive left. 

[PColumbus73]

Considering I don't see many 5-section towers, I tend to marvel at them whenever I come across one. I remember Fayetteville, NC had an intersection that had a couple 5-section towers, but never crossed the intersection from where they faced.

I like how California, Illinois and other states install a 5-section tower on the left (or center) of an intersection along with a tower or doghouse on the mast arm, or wire. Same goes with 3-section left turn signals.

Also, I'd like to see more states install at least one signal (which applies) on the near-side of the intersection. This is what South Carolina is starting to do, hanging a single light from the wire at busy, rural intersections.

[Big John]

Also, I'd like to see more states install at least one signal (which applies) on the near-side of the intersection. This is what South Carolina is starting to do, hanging a single light from the wire at busy, rural intersections.

Wisconsin always does this, and Illinois does it to a lesser extent in urban areas.

[PColumbus73]

I like how Wisconsin arranges its traffic lights, it looks like would improve visability. Since I've heard that Wisconsin is slowly converting to all vertical signals, when they do, I wonder if they will use the doghouse or the 5-section tower

[Big John]

I like how Wisconsin arranges its traffic lights, it looks like would improve visability. Since I've heard that Wisconsin is slowly converting to all vertical signals, when they do, I wonder if they will use the doghouse or the 5-section tower

Currently using the tower or FYA on new vertical installations.  Word is they might allow the doghouse in the future.

[DaBigE]

I like how Wisconsin arranges its traffic lights, it looks like would improve visability. Since I've heard that Wisconsin is slowly converting to all vertical signals, when they do, I wonder if they will use the doghouse or the 5-section tower

Currently using the tower or FYA on new vertical installations.  Word is they might allow the doghouse in the future.

New WisDOT installations are indeed going vertical, however, I have yet to see a new WisDOT installation with a 5-section tower. All the WisDOT stuff is either FYA or protected. Yes, I have heard from good authority that doghouses are in the toolbox, but I think it will be a long time before they ever appear as part of a WisDOT installation. A) the FYA option has made it all but obsolete, B) it would require a whole new stream of parts to stock, and C) there's very little fresh blood in the signaling sections of the regional offices (read: a lot of old-school, it ain't broke don't change it, types).

Municipalities are a bigger question mark. West Bend hasn't touched the FYA and is still installing 5-section signals both vertically and horizontally. The reconstruction of Monona Dr from the beltline to the Madison city limits features 5-section towers mounted to monotubes.

[Mdcastle]

How about a Flashing Yellow Arrow Doghouse.

New Minnesota standard for option lanes. Dedicated left turn lanes have a 4 head unless it's obvious the intersection can never, ever by protected/permissive, like if the left turn movements cross each other, in which case a 3 head is used.

[Big John]

^^ I don't think that is MUTCD compliant, in the use of a doghouse nor a bimodal lens for a FYA.

[codyg1985]

That is not confusing at all.

Nexus 5

[roadfro]

How about a Flashing Yellow Arrow Doghouse.
<video>
New Minnesota standard for option lanes. Dedicated left turn lanes have a 4 head unless it's obvious the intersection can never, ever by protected/permissive, like if the left turn movements cross each other, in which case a 3 head is used.

^^ I don't think that is MUTCD compliant, in the use of a doghouse nor a bimodal lens for a FYA.

The functional operation of this doghouse FYA would seem to be appropriate, and the bimodal lens is fine (it is the functional equivalent of the 3-section FYA with bimodal arrow). However, the use of this signal for option lanes is the problem. Turn arrows aren't supposed to be used for a shared lane unless operating in a protected mode.

Also, I've never seen a doghouse pole mounted on a side pole like this before...

[Mdcastle]

Minnesota has lots of 4-lane roads that have a protected / permissive in one direction and permissive only in the other direction, with no dedicated left turn lanes. Sometimes but not always at diamond intersections. The first doghouse in the state has the same indications but runs a bit differently, it switches between split phase during peak times to permissive only off-peak. If this setup isn't common elsewhere it may explain why it wasn't though of while developing FYA,s and why Mn/DOT and FHWA had to discuss things to come up with a solution. Implementing a doghouse was a bit of trouble in Minnesota because they never had an official way to attach one to permanent poles, and they're rare enough that they probably have to be special ordered rather than pulled from local distributors stock.

Here's the original FYA doghouse, as noted above it works differently than the video of the brand new one at 90th Street. Minnesota practice is to repeat whatever face is the leftmost on the overhead on the post to the left, so the post on this one is a 4 section, not a doghouse.

IMG_2834 by North Star Highways, on Flickr

[froggie]

That side-mounted FYA doghouse...gathering from your latest post that it's somewhere on 90th St in Bloomington, yes?

[Revive 755]

^^ I don't think that is MUTCD compliant, in the use of a doghouse nor a bimodal lens for a FYA.

It appears FHWA may have ruled in favor of it:
http://mutcd.fhwa.dot.gov/reqdetails.asp?id=834

[Mdcastle]

That side-mounted FYA doghouse...gathering from your latest post that it's somewhere on 90th St in Bloomington, yes?

Yes, 90th and I-35W ramps.
(I posted the same video on a traffic signals forum and a traffic signals Facebook group, so I'm having a hard time keeping track of what information I've shared where.)

[codyg1985]

Also, I've never seen a doghouse pole mounted on a side pole like this before...

Here is an example of one in Huntsville, AL along Old Madison Pike at the entrance to Defense Acquisition University. This IMO would be a great candidate for a FYA.

[froggie]

Also, I've never seen a doghouse pole mounted on a side pole like this before...

There's a smattering here and there.  I've seen examples in New Jersey (don't remember where offhand).  And those who attended the Burlington, VT meet this past weekend would've seen one on US 7 in Burlington.

[roadfro]

Also, I've never seen a doghouse pole mounted on a side pole like this before...

Here is an example of one in Huntsville, AL along Old Madison Pike at the entrance to Defense Acquisition University. This IMO would be a great candidate for a FYA.

That is a center pole mount, which I have seen done with a doghouse before. (Although usually, in my experience, a center pole mount doghouse is on a short pole with the doghouse signal being the only thing on the pole.) The one in the video appeared to be on the far left side pole of the intersection, which is unusual to me--such signals on the far left side are usually 5-section vertical towers. Installations like the one in this picture, with median mast poles, are also usually 5-section vertical towers...at least they are in Nevada.

Yes, this picture does depict a perfect candidate for a FYA display.

[roadman]

I was amazed/entertained/disgusted back in July when in Chicago I saw a CTA bus driver leaning on their horn and yelling (as if anyone could hear her outside the bus) at a car in front of her in the left turn lane who was obeying the sign at a green circular light on Michigan Ave.  Bad enough for CDOT to flaunt national standards so badly, but then for CTA bus drivers to act like that?  Sigh.

It seems like there ought to be enough room even on the narrow islands pictured here to have side-by-side 3-section signals for left turn and thru movements if they insist on protected turns; one could be red and the other green.

I have to give it to the MDC (or DCR or whoever is in charge of their roads now)....they may have some wacky nonstandard signals out there but they obey standards like green circles meaning permissive left. 

As part of the 2009 "merger - er - reorganization", MassDOT assumed full control of the Turnpike and the Metropolitan Highway System (i.e. Big Dig roadways and Boston Harbor tunnels, but only maintenance responsibility for many of the DCR roads like Storrow Drive.  Design and construction responsibilities on the MDC/DCR parkways still lie with DCR.