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One-aspect traffic lights (aka "perpetual green light")

Started by KCRoadFan, February 13, 2022, 11:45:37 PM

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KCRoadFan

Around the Kansas City metro, where I live, I have seen numerous signalized intersections where the cross-street only goes left, and while the left lane has a standard left-turn signal, the right lanes have this weird one-aspect signal that is simply a perpetual green arrow. Here they are, with Street View links:

Metcalf Avenue southbound at Blue Valley Parkway in Overland Park - https://www.google.com/maps/@38.9148542,-94.6688298,3a,37.5y,185.79h,89.21t/data=!3m6!1e1!3m4!1sqbAC7rh3FLrwD-8xa5Uo3g!2e0!7i16384!8i8192

US 56 westbound at Old 56 Highway on the east side of Gardner, near New Century Air Center - https://www.google.com/maps/@38.8132529,-94.9036987,3a,37.5y,220.79h,90.18t/data=!3m6!1e1!3m4!1sWsfIh7IdhAxr18Ovxy07UQ!2e0!7i16384!8i8192

7th Street northbound at the westbound I-70 on-ramp in KCK - https://www.google.com/maps/@39.0953935,-94.6260578,3a,75y,2h,102.44t/data=!3m6!1e1!3m4!1sLM6dTBA3aFYWkvdFBIJ_ZA!2e0!7i16384!8i8192

US 24/40 (State Avenue) westbound at the southbound K-7 on-ramp in Bonner Springs - https://www.google.com/maps/@39.116132,-94.8963941,3a,37.5y,269.06h,96.28t/data=!3m6!1e1!3m4!1sTvai9to8O_YP29YkFJU30g!2e0!7i16384!8i8192

Of note, all four of these signals are on the Kansas side of the metro. Is this a Kansas thing in particular? Also, where else throughout the country have you seen such installations? I'm sure there must be at least a few of them out there somewhere.


tolbs17

I'm pretty sure I've saw those around Greensboro, I just can't remember where.

US 89

That type of setup is extremely common in Utah with green straight arrows. Here are just a few examples from across the state.

I know there is a one-aspect green ball somewhere in the Atlanta metro area, but I cannot for the life of me remember where it is.

SkyPesos

Quote from: KCRoadFan on February 13, 2022, 11:45:37 PM
Of note, all four of these signals are on the Kansas side of the metro. Is this a Kansas thing in particular? Also, where else throughout the country have you seen such installations? I'm sure there must be at least a few of them out there somewhere.
Not sure about the Missouri side of the KC metro, but the Missouri side of the St Louis metro have no shortage of them:
- MO 141 NB to I-64 WB on-ramp
- Chesterfield Pkwy to I-64 EB on-ramp
- I-64 EB to MO K off-ramp
- Murdoch Ave to I-44 WB on-ramp
- Former: Delmar Blvd to I-170 NB on-ramp. Removed when a pedestrian crossing was added.
- Former: Jefferson Ave to I-64 WB on-ramp. Removed when the other half of the interchange was constructed.

Bruce

So these are just seagull intersections?

There's a few around the Seattle area, like this example on Broadway in Everett:


Big John


1995hoo

Here's a two-for-one–a flashing yellow arrow and two "eternal greens" on the same mast arm. (Apologies to Max Rockatansky for a GSV link, but I've never bothered to take a picture there both because the light is always green when I go through and because the car's built-in Bluetooth locks out my phone's touchscreen unless I remember to unlock it in advance, which I never do through there.)

Commerce Street at I-95 in Springfield, Virginia.
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

Flint1979

#7
We have one not too far from where I live that is like that.

https://www.google.com/maps/@43.4373033,-84.0440129,3a,44.1y,284.78h,101.88t/data=!3m6!1e1!3m4!1sYZi-uWdOitF_S-ubTFHslw!2e0!7i16384!8i8192

The reason this intersection is designed the way it is is because M-47 north of M-58 and all of M-58 used to be US-10 before the freeway between Midland and Bay City was built. US-10 would use the curve there to change from Midland Road to State Street and it was just left there when US-10 was moved to the freeway. M-47 used to go east on US-10 to where M-84 is at and then went north on Bay Street to Bay City, M-84 took over some of old M-47. The only stretch of M-47 that is original to the highway is between M-46 and M-58.

KCRoadFan

Quote from: Big John on February 14, 2022, 08:42:24 AM
Eternal green light thread: https://www.aaroads.com/forum/index.php?topic=17664.0

Thanks.

Anyway, I've only been a member since June 2020, so I wasn't expecting to have known that there was a thread on the topic from 2016. Anyway, do you believe the threads should be merged?

PurdueBill

#9
Ohio uses them sometimes and I wish I could remember where there was once a sign depicting such a single-headed signal instead of a signal itself (i.e., a green arrow inside a black circle, with "continuous" printed underneath).  As I recall, it's gone now....where-ever it was. 

Edit: found one although it is not quite what I remembered (sign plus signal head); maybe I remembered wrong but this one got replaced with a more boring sign with a signal head that looks to not work as well.  https://goo.gl/maps/fRM5imAYs4pEzhBV8
Ohio doesn't always get it right; the YIELD sign here was added around the time the signals were updated; it makes no sense to have YIELD and green arrow.  Complaining to ODOT years ago yielded nothing.  https://goo.gl/maps/QgFvTvWBiyc8zxtX8

My favorite is this one near the old Stapleton site in Denver, with DOWNWARD arrows instead of the correct upward ones.


It is tricky because there are some sites where replying to a thread with no replies for more than 30-90 days will get people mad (but this is generally not that kind of place).  Then again, there have been thread necros of almost 10 years around here too.

1995hoo

Looking at that other thread prompted me to recall several intersections on US-1 near Melbourne, Florida, in which the two right lanes on northbound Route 1 had continuous greens (and warning signs advising of them). I haven't been there in several years because our visits to the area were to see my wife's sister in Viera, but she died of cancer two years ago and we thus don't have much reason to stop there anymore. It appears from GSV that they may have gotten rid of the continuous greens. I wonder whether there might have been a problem with accidents because the continuous-green design relied on drivers making left turns onto Route 1 to turn into the correct lane, which in my observation elsewhere is not something you should expect anyone to do.

This post I made in another thread has older GSV links showing what those intersections used to look like, along with the advance signage. Easier just to link my old post because the GSV links there use the old imagery.
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.

GaryV

The one I mentioned in the other thread, 14 Mile Rd at I-75, is no longer there. It's been converted into a DDI.

mrsman

One of my favorites in L.A.  It help maintain expressway status in the southbound direction along the La Cienega "freeway" in Ladera Heights (on the way to LAX for many coming from Beverly Hills and West Hollywood)

https://www.google.com/maps/@33.9981747,-118.369778,3a,37.5y,149.9h,87.66t/data=!3m6!1e1!3m4!1smddmm13JmS2x00g3FOMO5w!2e0!7i16384!8i8192

In my youth, I remember two of these signal faces here on the mast arm, and the left turn arrow was not on the mast arm.  It appears that about 10 years ago, this perpetual green used a standard RYG signal, but only green lit up.  This can be seen on the older GSV images.  The current one seems overdone with too many signal aspects (four!) for what is not really a signal, since it is always green.

The vast majority of these one-aspect greens seem to be green arrow, as opposed to green ball.  They seem to frequently be joined with a RA-YA-GA protected left turns, but 1995hoo did find one that is connected with a FYA left turn signal.  I don't believe any exist with doghouses, as it might be confusing if the doghouse never turns red.

A very unique signal appears in Vancouver at Kingsway and King Edward.  A common Canadian permissive left turn signal is the 4 aspect in a line signal where the bottom signal is bimodal and can be either green arrow or yellow arrow.  Imagine that signal and then chopping off the top two signals (for red ball and yellow ball aspects) and you get the following.  For those who are color blind, the top aspect is indeed a perpetual green and the bottom aspect is an occasional green (or yellow) arrow for the protected turn.

https://www.google.com/maps/@49.2484992,-123.0721762,3a,75y,283.72h,85.46t/data=!3m7!1e1!3m5!1sAdAaggLyRDnHyA1nrTIk_w!2e0!5s20210201T000000!7i16384!8i8192





PurdueBill

Quote from: 1995hoo on February 14, 2022, 10:18:28 AM
Looking at that other thread prompted me to recall several intersections on US-1 near Melbourne, Florida, in which the two right lanes on northbound Route 1 had continuous greens (and warning signs advising of them). I haven't been there in several years because our visits to the area were to see my wife's sister in Viera, but she died of cancer two years ago and we thus don't have much reason to stop there anymore. It appears from GSV that they may have gotten rid of the continuous greens. I wonder whether there might have been a problem with accidents because the continuous-green design relied on drivers making left turns onto Route 1 to turn into the correct lane, which in my observation elsewhere is not something you should expect anyone to do.

This post I made in another thread has older GSV links showing what those intersections used to look like, along with the advance signage. Easier just to link my old post because the GSV links there use the old imagery.

Separating the thru lanes with continuous green from those that might stop with an island (or at least plastic delineators) would have been better than just striping.
My favorite such setup is still kicking in El Paso over 20 years after I first saw it, with the same single 3M green arrow head for the continuous green.
https://goo.gl/maps/3cMpmA1mu6ndyedE8

formulanone

Continuous green sign in Merritt Island, Florida:



It's been removed (Street View) since this photo was taken in 2016.

ran4sh

Florida seems to have decided to remove those continuous green type intersections statewide, there are some I remember in Jacksonville from the early 2010s that are not that way anymore according to GSV.

Quote from: US 89 on February 13, 2022, 11:55:57 PM
I know there is a one-aspect green ball somewhere in the Atlanta metro area, but I cannot for the life of me remember where it is.

There are several in the Atlanta area, the typical use case is at a partial diamond interchange where there is sufficient left-turn demand onto the onramp for a signal, in which case the single-aspect green lights are mounted over the straight-thru lanes. Examples: Sidney Marcus at SR 400 (https://goo.gl/maps/BCSYDgfB3j9JyuKz8), Peachtree-Dunwoody at I-285, Glenridge Dr at I-285, etc.

The SR 141 (Peachtree Industrial) and I-285 interchange has them too (https://goo.gl/maps/J3gMNPhTQpGqJhaLA)

Quote from: mrsman on February 16, 2022, 08:32:51 PM

The vast majority of these one-aspect greens seem to be green arrow, as opposed to green ball.  They seem to frequently be joined with a RA-YA-GA protected left turns, but 1995hoo did find one that is connected with a FYA left turn signal.  I don't believe any exist with doghouses, as it might be confusing if the doghouse never turns red.


Here's a Georgia example with a 5-section signal (what would normally be a doghouse but this one is horizontal instead): https://goo.gl/maps/zKCapCSNgait6Ys1A I don't think the unused red (and unused yellow circular indication) would really be a problem
Control cities CAN be off the route! Control cities make NO sense if signs end before the city is reached!

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US 89

Quote from: ran4sh on February 17, 2022, 01:13:19 AM
Quote from: US 89 on February 13, 2022, 11:55:57 PM
I know there is a one-aspect green ball somewhere in the Atlanta metro area, but I cannot for the life of me remember where it is.

There are several in the Atlanta area, the typical use case is at a partial diamond interchange where there is sufficient left-turn demand onto the onramp for a signal, in which case the single-aspect green lights are mounted over the straight-thru lanes. Examples: Sidney Marcus at SR 400 (https://goo.gl/maps/BCSYDgfB3j9JyuKz8), Peachtree-Dunwoody at I-285, Glenridge Dr at I-285, etc.

The SR 141 (Peachtree Industrial) and I-285 interchange has them too (https://goo.gl/maps/J3gMNPhTQpGqJhaLA)

Yeah, I knew about most of those, especially the one on Peachtree Industrial which I drive through fairly often - but those are all one-aspect green arrows. I’m almost positive there is at least one single circular green ball indication somewhere in the north half of the metro, and I feel like it’s at some sort of free right type movement.

epzik8

Maryland has these all over, but the through lane doesn't have a light.
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____________________________

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frankenroad

There are a couple near me.  The first is at Northland and Sharon Roads in Forest Park, and another on Springfield Pike at Congress on the border between Woodlawn and Glendale.  This one is interesting because there are (apparently) red and yellow globes but they never get used.   There are no crosswalks at this location.
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SkyPesos

Quote from: frankenroad on February 17, 2022, 03:14:12 PM
There are a couple near me.  The first is at Northland and Sharon Roads in Forest Park, and another on Springfield Pike at Congress on the border between Woodlawn and Glendale.  This one is interesting because there are (apparently) red and yellow globes but they never get used.   There are no crosswalks at this location.
I haven't seen that many myself in the Cincy area, but the one that stands out the most to me is a right turn one on the I-71 NB Pfeiffer Rd ramp (exit 15).

7/8

I can't remember seeing any in Ontario, but I did see this one in Saskatoon, SK when I visited 5 years ago. This example also has the interesting "double red" lights they use for left turn signals. Circle Dr at Airport Dr GSV link.

Dirt Roads

These were common in Charleston, West Virginia back in the 1960s and 1970s.  Both the upriver lanes of Southside Expressway (southbound WV-61) and Kanawha Boulevard (sometimes Alt US-60, eastbound lanes) were equipped with full signals in the left lane and thru perpetual green signals on the right lanes (with Bots Dots between the lanes) at most of the signalized intersections.  It was funny to see out-of-towners pass on the left only to get snagged by the traffic signal, whereas locals just doodled in the right lane but kept moving.  There were so many in a row on The Boulevard that during rush hour, it effectively created a single lane eastbound with a dedicated turn lane.  By the mid-1970s, so many businesses were moving out of the West End that there was hardly any need for left turns off the Boulevard during the morning rush hour.

rellis97

There are a few examples in Metro Detroit. Here's one I've found in Livonia, this is facing eastbound on Seven Mile Rd at I-275/I-96.

1995hoo

Quote from: Dirt Roads on February 18, 2022, 12:14:37 PM
These were common in Charleston, West Virginia, back in the 1960s and 1970s.  Both the upriver lanes of Southside Expressway (southbound WV-61) and Kanawha Boulevard (sometimes Alt US-60, eastbound lanes) were equipped with full signals in the left lane and thru perpetual green signals on the right lanes (with Bots Dots between the lanes) at most of the signalized intersections.  It was funny to see out-of-towners pass on the left only to get snagged by the traffic signal, whereas locals just doodled in the right lane but kept moving.  There were so many in a row on The Boulevard that during rush hour, it effectively created a single lane eastbound with a dedicated turn lane.  By the mid-1970s, so many businesses were moving out of the West End that there was hardly any need for left turns off the Boulevard during the morning rush hour.

As of 2017, there was at least one such signal remaining at the corner of Kanawha and Greenbrier near the State Capitol. I had never been to Charleston before and we made a left from Greenbrier onto southbound Kanawha and as I completed my turn someone came FLYING through in the other lane going extremely fast (easily 60 mph or more). Startled the shit out of me because I wasn't aware of the configuration and the guy appeared out of nowhere very quickly. At least there were plastic bollards between the lanes (exactly what some comments up the thread have suggested are necessary in these situations).

There may be other such setups remaining in Charleston, but that's the only one I remember encountering.
"You know, you never have a guaranteed spot until you have a spot guaranteed."
—Olaf Kolzig, as quoted in the Washington Times on March 28, 2003,
commenting on the Capitals clinching a playoff spot.

"That sounded stupid, didn't it?"
—Kolzig, to the same reporter a few seconds later.



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