AARoads Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

New rules to ensure post quality. See this thread for details.

Author Topic: Have any of you seen a traffic light go out (or come back on) in front of you?  (Read 1440 times)

KCRoadFan

  • *
  • Offline Offline

  • Posts: 764
  • Enthusiastic fan of roads, sports, and waterparks.

  • Age: 29
  • Location: Kansas City, MO
  • Last Login: September 27, 2022, 11:48:33 PM

On a drive I took this morning in Johnson County, Kansas, I was eastbound on Shawnee Mission Parkway at the I-35 interchange, and the traffic light at the northbound on-ramp went to flashing red before returning to normal a few seconds later. What's more, within the next minute as I waited to turn left, the light went out and then came back on again.

Have any of you seen a traffic light go out as you were approaching it - or, better yet, come up to a non-working signal and seen it come back to life? If so, when and where did it happen? I'm curious to know!
Logged

Rothman

  • *
  • *
  • Offline Offline

  • Posts: 10874
  • Last Login: Today at 07:03:25 AM

Yep.  Not sure of the actual intersections, but have seen a signal conk out on two separate occasions.  Signal glitched and then went to flashing in both occasions, both as I was at the stop line in western MA.

Haven't seen one "come back to life."
Logged
Please note: All comments here represent my own personal opinion and do not reflect the official position(s) of NYSDOT.

jeffandnicole

  • *
  • Offline Offline

  • Posts: 13465
  • Age: 47
  • Location: South Jersey
  • Last Login: September 28, 2022, 11:00:22 PM

My experiences are the opposite of Rothman. Seen a few come back to life, haven't seen any go to flash mode (or off completely).
Logged

Dirt Roads

  • *
  • Offline Offline

  • Posts: 1887
  • Location: Central North Carolina
  • Last Login: September 28, 2022, 11:36:54 PM

Yikes!  I had an incident somewhere here in Central Carolina back maybe 20 years ago or so.  I was approaching a stoplight on a rural highway with a green signal at about 45 MPH when the power went off.  I was about 100 feet from the intersection and slowing down quickly when the power came back on.  Instead of the traffic signal going into a default flash mode, the traffic signal came back up red in my direction and the car on my right pulled out before I could stop.  I slammed on the brakes and did an avoidance maneuver to stop partway into the intersection.  I had to back up to let traffic to my left proceed when they got the green ball.  I couldn't be sure if the car on my right got a green ball immediately, but he sure acted like it.
Logged

KCRoadFan

  • *
  • Offline Offline

  • Posts: 764
  • Enthusiastic fan of roads, sports, and waterparks.

  • Age: 29
  • Location: Kansas City, MO
  • Last Login: September 27, 2022, 11:48:33 PM

Yikes!  I had an incident somewhere here in Central Carolina back maybe 20 years ago or so.  I was approaching a stoplight on a rural highway with a green signal at about 45 MPH when the power went off.  I was about 100 feet from the intersection and slowing down quickly when the power came back on.  Instead of the traffic signal going into a default flash mode, the traffic signal came back up red in my direction and the car on my right pulled out before I could stop.  I slammed on the brakes and did an avoidance maneuver to stop partway into the intersection.  I had to back up to let traffic to my left proceed when they got the green ball.  I couldn't be sure if the car on my right got a green ball immediately, but he sure acted like it.

Well, for me, my left-turn light was about to turn green when the signal went out again. I began turning left anyway, and the light came back on again - at which point I was facing a red light and the oncoming traffic had green. I backed up a little to let the oncoming traffic pass, and eventually I got the green left-turn arrow, at which point I finally completed the turn. A crazy sequence, indeed.
Logged

tdindy88

  • *
  • Offline Offline

  • Posts: 1755
  • Last Login: Today at 04:16:14 AM

Does it count if it's a normal occurrence? Since I work at nights and am up at nights even on my days off I find myself driving around when several nearby intersections switch to a flash mode each evening after 11pm or midnight. I've seen the last full cycle of lights at an intersection before they start flashing for the night, it's a bit strange but I've become used to it. Likewise I've seen the same intersections return to a normal light pattern at 6am.
Logged

jay8g

  • *
  • Offline Offline

  • Posts: 211
  • Location: Washington
  • Last Login: September 25, 2022, 06:51:33 PM

I once saw one that had been completely out come back on, and it went all flashing red for a while, then all solid red, then back into service -- which seems much more reasonable than what other people on here have mentioned! (I was on foot at the time, so I was able to watch it for a while to see exactly what happened. If I'm remembering correctly, there was actually someone on site working on it at the time, but I certainly would have hoped that they would behave more like this when coming back online after a power outage too!)
Logged

KCRoadFan

  • *
  • Offline Offline

  • Posts: 764
  • Enthusiastic fan of roads, sports, and waterparks.

  • Age: 29
  • Location: Kansas City, MO
  • Last Login: September 27, 2022, 11:48:33 PM

What’s your experience with traffic lights and power outages? Do they come right back on when power is restored, or do the techs have to restart them?
Logged

ilpt4u

  • *
  • Online Online

  • Posts: 2879
  • Location: Southern IL
  • Last Login: Today at 07:15:26 AM

I went thru one on Rt 13 in Carbondale when it when it was switching from Blinking Red/No Power mode to “Normal” phazed operations (or vice versa): Literally had the Blinking Red and the Solid Green Ball on at the same time, the direction I was traveling. I went thru without stopping. And I still am not sure what the Rules of the Road suggest to do in that scenario

And this is not a light that gives “Blinking Red” during the Overnight hours to Rt 13 traffic. It does go “Blinking Yellow” I think/Blinking Red for cross traffic. Only goes “Blinking Red” with a Power Outage or other failure of the normal operations
Logged

JoePCool14

  • *
  • Offline Offline

  • Posts: 2351
  • I'm surrounded by IDiOTs.

  • Age: 21
  • Location: Illinois / Wisconsin
  • Last Login: September 28, 2022, 05:50:10 PM

I once saw one that had been completely out come back on, and it went all flashing red for a while, then all solid red, then back into service -- which seems much more reasonable than what other people on here have mentioned! (I was on foot at the time, so I was able to watch it for a while to see exactly what happened. If I'm remembering correctly, there was actually someone on site working on it at the time, but I certainly would have hoped that they would behave more like this when coming back online after a power outage too!)

Signals should always be programmed to start in an all-red mode to prevent some of the problems described upthread. Anyone not paying attention and missing a malfunction, followed by a green light, could cause a lot of trouble.

For the record, I don't believe I have seen a light transition that I can remember.
Logged

:) Needs more... :sombrero: Not quite... :bigass: Perfect.
JDOT: We make the world a better place to drive.
My Travel Mapping stats

roadfro

  • *
  • *
  • Offline Offline

  • Posts: 4549
  • Age: 39
  • Location: Reno, NV
  • Last Login: September 28, 2022, 11:21:11 AM

I went thru one on Rt 13 in Carbondale when it when it was switching from Blinking Red/No Power mode to “Normal” phazed operations (or vice versa): Literally had the Blinking Red and the Solid Green Ball on at the same time, the direction I was traveling. I went thru without stopping. And I still am not sure what the Rules of the Road suggest to do in that scenario

Rules of the Road have nothing to suggest for you...that scenario should never happen. Even if transitioning from a red flash to stop-and-go, red and green should never be displayed simultaneously in the same signal face (5-section PPLT heads notwithstanding).

The transition out of flashing mode should go to steady red and then greens for the major street/movement (assuming it's an all-way red flash) or the flashing yellows go to green for the major movement and the flashing red go to steady red (assuming yellow/red flash). The flashing red with a simultaneous steady green makes me think there was some kind of fault or issue with the signal (or, if that's a regular occurrence, it's older, non-compliant signal programming).
Logged
Roadfro - AARoads Pacific Southwest moderator since 2010, Nevada roadgeek since 1983.

ilpt4u

  • *
  • Online Online

  • Posts: 2879
  • Location: Southern IL
  • Last Login: Today at 07:15:26 AM

I went thru one on Rt 13 in Carbondale when it when it was switching from Blinking Red/No Power mode to “Normal” phazed operations (or vice versa): Literally had the Blinking Red and the Solid Green Ball on at the same time, the direction I was traveling. I went thru without stopping. And I still am not sure what the Rules of the Road suggest to do in that scenario

Rules of the Road have nothing to suggest for you...that scenario should never happen. Even if transitioning from a red flash to stop-and-go, red and green should never be displayed simultaneously in the same signal face (5-section PPLT heads notwithstanding).

The transition out of flashing mode should go to steady red and then greens for the major street/movement (assuming it's an all-way red flash) or the flashing yellows go to green for the major movement and the flashing red go to steady red (assuming yellow/red flash). The flashing red with a simultaneous steady green makes me think there was some kind of fault or issue with the signal (or, if that's a regular occurrence, it's older, non-compliant signal programming).
Had never seen it before and have never seen it since at that signal. Something was malfuctioning.

And for more complete information: IL 13 at Striegel Rd on the west side of Carbondale
« Last Edit: May 31, 2022, 12:36:39 AM by ilpt4u »
Logged

jp the roadgeek

  • *
  • Offline Offline

  • Posts: 4295
  • Age: 46
  • Location: Outside the I-291 beltway
  • Last Login: Today at 02:37:44 AM

Take a ride down CT 10 at 10 pm or 6 AM, and you’ll see most of the lights either start flashing yellow (after a red cycle at precisely 10:00) or start working.
Logged
Interstates I've clinched: 97, 290 (MA), 291 (CT), 291 (MA), 293, 295 (DE-NJ-PA), 295 (RI-MA), 384, 391, 395 (CT-MA), 395 (MD), 495 (DE), 610 (LA), 684, 691, 695 (MD), 695 (NY), 795 (MD)

US 89

  • *
  • Offline Offline

  • Posts: 5280
  • 189 to Evanston

  • Location: Tallahassee, FL
  • Last Login: September 28, 2022, 05:47:33 PM
    • Utah Highways

Rules of the Road have nothing to suggest for you...that scenario should never happen. Even if transitioning from a red flash to stop-and-go, red and green should never be displayed simultaneously in the same signal face (5-section PPLT heads notwithstanding).

Does that apply to ramp meters too? I know Utah has/had some red/green (no yellow) meters that activated from dark mode by initially turning both the red and green lights on for several seconds. Took me a minute to figure out what was going on the first time I saw it.

roadfro

  • *
  • *
  • Offline Offline

  • Posts: 4549
  • Age: 39
  • Location: Reno, NV
  • Last Login: September 28, 2022, 11:21:11 AM

Rules of the Road have nothing to suggest for you...that scenario should never happen. Even if transitioning from a red flash to stop-and-go, red and green should never be displayed simultaneously in the same signal face (5-section PPLT heads notwithstanding).

Does that apply to ramp meters too? I know Utah has/had some red/green (no yellow) meters that activated from dark mode by initially turning both the red and green lights on for several seconds. Took me a minute to figure out what was going on the first time I saw it.

The MUTCD chapter on ramp meters is surprisingly vague on ramp meter operation, including transitions into and out of metering status.

Meters are supposed to follow rules for signals except where otherwise stated in the ramp meter chapter. So from that perspective, the operation you describe probably shouldn't be allowed... However, I don't know how you would activate a two-section ramp meter display from inactive/dark other than displaying just the green that wouldn't cause an immediate panic.

Nevada also uses the two-section ramp meter heads. Interestingly, I've never seen a ramp meter turn on from inactive, so I don't know what the startup routine for ours looks like...
Logged
Roadfro - AARoads Pacific Southwest moderator since 2010, Nevada roadgeek since 1983.

Dirt Roads

  • *
  • Offline Offline

  • Posts: 1887
  • Location: Central North Carolina
  • Last Login: September 28, 2022, 11:36:54 PM

I went thru one on Rt 13 in Carbondale when it when it was switching from Blinking Red/No Power mode to “Normal” phazed operations (or vice versa): Literally had the Blinking Red and the Solid Green Ball on at the same time, the direction I was traveling. I went thru without stopping. And I still am not sure what the Rules of the Road suggest to do in that scenario

Rules of the Road have nothing to suggest for you...that scenario should never happen. Even if transitioning from a red flash to stop-and-go, red and green should never be displayed simultaneously in the same signal face (5-section PPLT heads notwithstanding).

The transition out of flashing mode should go to steady red and then greens for the major street/movement (assuming it's an all-way red flash) or the flashing yellows go to green for the major movement and the flashing red go to steady red (assuming yellow/red flash). The flashing red with a simultaneous steady green makes me think there was some kind of fault or issue with the signal (or, if that's a regular occurrence, it's older, non-compliant signal programming).

Not the area of my signal experience, but systems that employ traditional relays and/or contactors are subject to all sorts of failure modes.  My understanding is that modern programmable traffic controller have a back-check of each relay/contactor that gets cross-checked with the outputs.  If an unsafe condition is detected, the traffic signal is programmed to go into flash mode or be shut down.  In my book, a traffic signal that has a stuck green should never go into flash mode.  On the other hand, a traffic signal with a stuck yellow or a stuck red could be placed into flash mode (might be confusing, but shouldn't be unsafe).  Plus, this type of a rule would need to be adjusted for signal heads that have flashing yellow arrows and perhaps other arrow arrangements.

Fun fact:  On railroad signals, we employ "light-out-protection" as a back-check for any signal where a burnt-out bulb could be misconstrued as an improvement in the aspect.  The classic situation is that a NORAC/GCOR red-over-green (medium clear/diverging clear) would be misinterpreted if the top red bulb was burnt out.  In this case, it would be typical to downgrade this signal to red-over-red (with the top red still burnt out) and downgrade the approach signal to yellow (approach).
Logged

jakeroot

  • *
  • Offline Offline

  • Posts: 14979
  • Transportation Design

  • Age: 26
  • Location: Renton, WA / Vancouver, BC
  • Last Login: Today at 01:02:12 AM
    • Flickr

Just last week, I saw this signal in the Port of Tacoma (along WA-509) go into flash mode. Any time a train passes on the right (short line rail road), the signal goes all red and then into flashing mode. Then all red, and then back to whichever direction. Takes a moment for traffic to figure it out, but eventually (within 30 seconds) people figure out what's going on.
Logged
Check out my Flickr | Add me on Facebook!

connroadgeek

  • *
  • Offline Offline

  • Posts: 236
  • Last Login: September 28, 2022, 09:42:27 PM

What’s your experience with traffic lights and power outages? Do they come right back on when power is restored, or do the techs have to restart them?
Assuming it fully runs out of its battery backup before the power is restored, they just come back up into normal cycle when the power comes back on.
Logged

Joe The Dragon

  • *
  • Offline Offline

  • Posts: 1017
  • Location: 60016
  • Last Login: September 25, 2022, 08:42:38 AM

What’s your experience with traffic lights and power outages? Do they come right back on when power is restored, or do the techs have to restart them?
Assuming it fully runs out of its battery backup before the power is restored, they just come back up into normal cycle when the power comes back on.
don't the newer ones save there config to NVRAM / some disk / flash? and don't just keep it RAM or have an battery for config settings like an PC that can last for an long time?
Logged

Joe The Dragon

  • *
  • Offline Offline

  • Posts: 1017
  • Location: 60016
  • Last Login: September 25, 2022, 08:42:38 AM

Rules of the Road have nothing to suggest for you...that scenario should never happen. Even if transitioning from a red flash to stop-and-go, red and green should never be displayed simultaneously in the same signal face (5-section PPLT heads notwithstanding).

Does that apply to ramp meters too? I know Utah has/had some red/green (no yellow) meters that activated from dark mode by initially turning both the red and green lights on for several seconds. Took me a minute to figure out what was going on the first time I saw it.
some ramp meters are peak times only
Logged

Joe The Dragon

  • *
  • Offline Offline

  • Posts: 1017
  • Location: 60016
  • Last Login: September 25, 2022, 08:42:38 AM

Yep.  Not sure of the actual intersections, but have seen a signal conk out on two separate occasions.  Signal glitched and then went to flashing in both occasions, both as I was at the stop line in western MA.

Haven't seen one "come back to life."
I have seen one running very fast light cycles very fast like 30 sec or less greens for main roads and like maybe like 5-15 sec arrows.

Later in the day it seemed to have been fixed.
Logged

ErmineNotyours

  • *
  • Offline Offline

  • Posts: 1027
  • Age: 54
  • Location: Renton, Washington
  • Last Login: Today at 05:45:57 AM

More related to the other answers was the time I saw traffic engineers working on a recent installation, a replacement due to a road widening.  This was now the only light on the intersection, completely unhooded, but the engineers were turning on random lights or rapidly switching between green and red.  There were several near misses, with one driver actually getting out and stepping on his running board to look around.  The engineers seemed pretty indifferent to the chaos they were nearly causing.
Logged

Dirt Roads

  • *
  • Offline Offline

  • Posts: 1887
  • Location: Central North Carolina
  • Last Login: September 28, 2022, 11:36:54 PM

What’s your experience with traffic lights and power outages? Do they come right back on when power is restored, or do the techs have to restart them?

Assuming it fully runs out of its battery backup before the power is restored, they just come back up into normal cycle when the power comes back on.

don't the newer ones save there config to NVRAM / some disk / flash? and don't just keep it RAM or have an battery for config settings like an PC that can last for an long time?

Sorry, microprocessors used in modern control systems don't work like rack-mounted industrial computers.  But indeed, control system microprocessors utilize a non-DRAM fixed memory chip, but they usually boot/reboot off of the same memory chip.  Typically, there is also a bootup bit calculation to determine whether the memory has changed.  I don't know about traffic signal controllers, but most safety control systems run this same type of error check fairly frequently during runtime as a data/software error check mode (and if it ever fails, the controller shuts down).  And as I mentioned earlier, there is a back-check (and cross-checks) of inputs/outputs to detect other faults and failures (which also is performed by traffic signal controllers).
Logged

Caps81943

  • *
  • Offline Offline

  • Posts: 90
  • Location: Virginia
  • Last Login: Today at 02:01:50 AM

3 times actually, two within the last six months.

First time was a while ago, and was not too surprising. I was a passenger and we came up to a light in flash mode. Clearly a malfunction, as it was the middle of the day at a busy intersection (so busy that there was a cop assisting with traffic flow) with no weather to speak of, and as we went through, someone from VDOT was working in the control box, so it was clearly gonna start working pretty soon. After we went through the intersection, I looked back to observe, and when we were about 50 feet clear of the intersection, the light came back into normal operation.

Second time was in January...late at night in a different state on a road trip and after we pulled off the highway to a place to stay, a light we were approaching (no more than 50 feet ahead) went from green to flashing yellow just as the clock turned 10PM, so I am almost certain it's nighttime operation because there was no weather (aside from it was less than 10 degrees), on a pretty minor and slow road, and it was working again in the morning.

Third time was recently with another malfunctioning light, but I was not in a car. I was taking a walk and one of the local lights seemed to be short circuiting or something...I saw it a couple times go from dark to flash mode to dark to flash mode every couple minutes. It was fixed by the next morning.
Logged

fwydriver405

  • *
  • Offline Offline

  • Posts: 472
  • UMaine - Civil Engineering & MBB Student Asst.

  • Location: Maine - NH - MA
  • Last Login: September 28, 2022, 06:37:45 PM

I actually caught one on video (as a passenger) on 22 Jun 21 in my hometown. The intersection of US Route 202 and River St sometimes tends to either go into flash (faulty MMU?) or even go out completely during heavy rainstorms or severe thunderstorms - it has happened twice in the same year. While I didn't catch it going from dark to flash, I did catch it going from flash to colours starting at all red.


Here was a picture I took of the signal tech flipping it from dark to flash:

Logged

 


Opinions expressed here on belong solely to the poster and do not represent or reflect the opinions or beliefs of AARoads, its creators and/or associates.