Bimodal green arrow/yellow arrow (not FYA)

[Pink Jazz]

I would like to know, does anyone know what cities use bimodal green arrows/yellow arrows (not FYA)?

I noticed there are lots of them in Scottsdale.  I wonder if it may have anything to do with the fact that Scottsdale mostly uses lagging left turn phasing.  Gilbert and Goodyear also mostly use lagging left turn phasing but do not use bimodal heads.  For signals that allow permissive left turns, Gilbert mostly used 5-section towers (although there are a few doghouses), while Goodyear mostly uses "crooked" doghouses (Goodyear uses modular poles, which have a separate two-head signal with arrows next to a regular three head signal with circular indications).

[jakeroot]

Cities shouldn't use them, for what it's worth, but in my area:

- mostly in place of doghouses for protected rights (most cases)
- In and around Tacoma, Washington (particularly downtown), there's quite a few bimodal arrows for left turns
- Milton/Edgewood, Washington (small town south of Seattle) did a recent street upgrade where most/all of the signals are of the bimodal type
- Tukwila, Washington (larger city south of Seattle) has quite a few along major arterials
- I don't see very many new installations given the recent preference for the FYA

Given my experience with Canada, I'd love to try an experiment with the bimodal arrows whereby the green arrow flashed, indicating a protected turn, then stopped flashing on an amber arrow, then disappeared (this should help distinguish between the two for color-blind individuals).

[Pink Jazz]

Given my experience with Canada, I'd love to try an experiment with the bimodal arrows whereby the green arrow flashed, indicating a protected turn, then stopped flashing on an amber arrow, then disappeared (this should help distinguish between the two for color-blind individuals).

Of course, that may cause confusion with some Mexican drivers, as a flashing green indication in Mexico indicates that the green phase is about to end.

[jakeroot]

Given my experience with Canada, I'd love to try an experiment with the bimodal arrows whereby the green arrow flashed, indicating a protected turn, then stopped flashing on an amber arrow, then disappeared (this should help distinguish between the two for color-blind individuals).

Of course, that may cause confusion with some Mexican drivers, as a flashing green indication in Mexico indicates that the green phase is about to end.

Well, I guess that's a geographical thing, since I've never actually seen a car with Mexico plates outside of San Diego. I'm more used to seeing Canadian plates.

[Pink Jazz]

Well, I guess that's a geographical thing, since I've never actually seen a car with Mexico plates outside of San Diego. I'm more used to seeing Canadian plates.

I have seen several Mexican plates in Arizona and New Mexico.  However, both are border states.

[Brandon]

I would like to know, does anyone know what cities use bimodal green arrows/yellow arrows (not FYA)?

Rockford, Illinois still has a ton of them.



Some IDOT districts used to use them as recently as a few years ago, but many have been phased out recently.

[M3019C LPS20]

Bi-modal signals are unheard of in New York City and will likely not appear in the future; however, a lot of towns and cities here in New Jersey use them. Doghouses (traditional setup) are in use, too, but they are not common.

[corco]

Helena, MT has several, as does Oro Valley, AZ.

[Rick1962]

They're fairly common in Johnson County, Kansas (suburban KC), also in Enid, Oklahoma.

[jeffandnicole]

...however, a lot of towns and cities here in New Jersey use them. Doghouses (traditional setup) are in use, too, but they are not common.

Technically, almost all of NJ uses bimodals, and in NJ the bimodal G/Y is the traditional setup, not the doghouse.  A few counties may use doghouses as their primary install, but that's against the norm.  There's a rare NJDOT doghouse or tower as well.  It's not really up to the towns, as it's installed by NJDOT or the county, regardless of the town.

[6a]

Dublin, Ohio uses them, mostly for traffic turning right.

[SSOWorld]

They're not MUTCD compliant - for sure

[jeffandnicole]

They're not MUTCD compliant - for sure

They are compliant.

The 2009 MUTCD refers to them in sections 4D.09 & 4D.10, Standard 04.  The text from 4D.09:

If a dual-arrow signal section (capable of alternating between the display of a GREEN ARROW and a YELLOW ARROW signal indication) is used in a vertically-arranged signal face, the dual-arrow signal section shall occupy the same position relative to the other sections as the signal section that displays the GREEN ARROW signal indication in a vertically-arranged signal face would occupy.

[freebrickproductions]

Haven't seen any of these in Huntsville or anywhere in Alabama for that matter.

[Revive 755]

Given my experience with Canada, I'd love to try an experiment with the bimodal arrows whereby the green arrow flashed, indicating a protected turn, then stopped flashing on an amber arrow, then disappeared (this should help distinguish between the two for color-blind individuals).

I would rather see flashing green arrows used for situations where a turning movement has the right of way, but other vehicles that could conflict with said turn do not have a red ball or arrow.  Best example would be a right turn movement that does not have a parallel crosswalk, but the opposing left turn has a FYA.  The way the MUTCD currently seems to read is that this right turn should use a FYA if it is not using a green ball in a shared signal face.  Using a FYA for the right turn in this case does not see appropriate, since the right turn has nothing to yield to.

Some IDOT districts used to use them as recently as a few years ago, but many have been phased out recently.

They are forbidden in the Chicago District. 

[jeffandnicole]

I think colorblind people can see yellow.  So even if they couldn't see the exact color of the green arrow, they would know when it is yellow.

[US81]

I think colorblind people can see yellow.  So even if they couldn't see the exact color of the green arrow, they would know when it is yellow.

Many but not all; there are many kinds of color-blindness. There are those who see the world only in shades of grey.

[jakeroot]

Maybe I'm being pre-historic, but what's the big deal if they can't tell the difference between green and yellow? Most people blow through yellow anyways.

[jeffandnicole]

Maybe I'm being pre-historic, but what's the big deal if they can't tell the difference between green and yellow? Most people blow through yellow anyways.

I was thinking the same thing - many years ago there was only a green arrow, then it turned dark - no yellow interval.

But then again, we didn't need a FYA because people understood to yield on green before making a left turn...

[jakeroot]

Maybe I'm being pre-historic, but what's the big deal if they can't tell the difference between green and yellow? Most people blow through yellow anyways.

I was thinking the same thing - many years ago there was only a green arrow, then it turned dark - no yellow interval.

Perhaps it would help solidify the fact that if a doghouse signal is green, and the arrow goes from green to yellow to blank, yellow doesn't mean slam on the brakes and wait behind the stop line ... it means keep going because you still have a green light and they haven't been able to move off yet. At least that's how I think about it. If you just did away with yellow altogether, there wouldn't be a "I see yellow therefore I stop" group of people ruining things for everyone.

But then again, we didn't need a FYA because people understood to yield on green before making a left turn...

FYAs do have advantages over traditonal 5-section housings, but I see your point.

[roadfro]

Given my experience with Canada, I'd love to try an experiment with the bimodal arrows whereby the green arrow flashed, indicating a protected turn, then stopped flashing on an amber arrow, then disappeared (this should help distinguish between the two for color-blind individuals).

I would rather see flashing green arrows used for situations where a turning movement has the right of way, but other vehicles that could conflict with said turn do not have a red ball or arrow.  Best example would be a right turn movement that does not have a parallel crosswalk, but the opposing left turn has a FYA.  The way the MUTCD currently seems to read is that this right turn should use a FYA if it is not using a green ball in a shared signal face.  Using a FYA for the right turn in this case does not see appropriate, since the right turn has nothing to yield to.

[/quote]

For the instance of a dedicated right turn lane with no parallel/conflicting crosswalk, an FYA would not be appropriate. A circular green or green arrow (depending on geometry) would be the appropriate signal display. If this right turn has a dedicated phase with a green arrow, the opposing left turn would not have a FYA active at the same time due to the turning conflict.

[Pink Jazz]

I think colorblind people can see yellow.  So even if they couldn't see the exact color of the green arrow, they would know when it is yellow.

Many but not all; there are many kinds of color-blindness. There are those who see the world only in shades of grey.

I know with both forms of red-green color blindness (protanopia and deuteranopia), you cannot distinguish between reds, yellows, and greens.  With blue-yellow color blindness (tritanopia), however, yellow and green are distinguishable, although yellow doesn't actually appear yellow (looks pinkish) and blues look greenish.

[OracleUsr]

Charlottesville, VA, has them all over town.  Last time I was up there, I wanted to know if they still had them and they do.  I think that's a really cool way to use just four lamps, and it seems more intuitive than the FYA.

[cl94]

Quite common in Western New York. Region 5 installed them until 3-4 years ago and some of the counties (Erie and Monroe), cities, and towns use them for the majority of PPLTs. Heck, Erie County installed some as recently as last summer.

[US81]

I think colorblind people can see yellow.  So even if they couldn't see the exact color of the green arrow, they would know when it is yellow.

Many but not all; there are many kinds of color-blindness. There are those who see the world only in shades of grey.

I know with both forms of red-green color blindness (protanopia and deuteranopia), you cannot distinguish between reds, yellows, and greens.  With blue-yellow color blindness (tritanopia), however, yellow and green are distinguishable, although yellow doesn't actually appear yellow (looks pinkish) and blues look greenish.

Achromatopsia (total absence of color in vision) that I alluded to earlier is actually rather rare.