I hadn't ever seen this one before; on a very commercialized stretch of southbound PA 145 heading downhill toward the US 22 intersection, there are traffic lights whose red LED ball contains a horizontal stripe of high-intensity white LEDs that flash when the red light's lit.
It was a very effective way to make those signals stand out against the visual distractions surrounding them. Are these getting installed elsewhere?
Strobe lights within red signal indications, although installed by some agencies some years ago, are not permitted. From the FHWA Traffic Signal FAQ:
Quote
7.Q: Are strobe lights allowed in red signals?
A: No, they are not allowed. Section 4D.06 of the 2009 MUTCD specifically prohibits strobes within or adjacent to any signal indication. Research and experimentation over the years with white strobe lights as a circular "halo" outer ring around the red signal or as horizontal bar across the red signal has found no lasting safety benefit and, in some cases, the strobes resulted in increased crash frequency. Based on this experience, FHWA made a determination in 1990 that no further experimentation with strobe lights in traffic signals would be approved and that all existing strobes were to be removed. In 1995 a report by the Virginia Transportation Research Council provided an updated review of strobe light effectiveness in the States where they had been used. That report validated the previous analyses and came to the same basic conclusion, that there is no evidence that strobe lights are consistently effective in reducing crashes. Therefore, it is still FHWA's position that strobe lights are not allowed in or adjacent to traffic signals and that no further experimentations with these types of strobe lights in traffic signals will be approved.
https://www.google.com/maps/@42.5908816,-71.9606788,3a,30.2y,335.55h,92.12t/data=!3m6!1e1!3m4!1sxa6kqxbhBwJ3Qj_0XJ5ZSw!2e0!7i13312!8i6656
Apparently in 2016 this one in Gardner MA still existed. You can see the filament in the red of the far right signal. It was there when I moved out that way in 2005. All four sides of the intersection had them on the solid red signals. Both roads, especially 140, are high-speed roads. At least by Massachusetts standards.
Portsmouth NH also had a few west of I-95 and downtown.
Roadman's find shows how sometimes states and municipalities just don't give a damn at all about the MUTCD.
I remember a signal, I think in Fort Worth, that had multiple white LEDs around the circumference of the red light that would flash when the red light was activated. I also thought it seemed like a good way to draw attention, but that's just a single instance of a subjective observation. I never thought about whether it was allowed.
New York has plenty of them - some new. One is on the long downgrade to Ithaca at the entrance to Ithaca College, where the speed limit drops from 50 MPH to 40 MPH. It's a heavy pedestrian crossing. More could be done - for instance, add turn lanes, curbs, sidewalks, lighting... but that's for another topic.
Quote from: hubcity on May 10, 2018, 01:39:27 PM
I hadn't ever seen this one before; on a very commercialized stretch of southbound PA 145 heading downhill toward the US 22 intersection, there are traffic lights whose red LED ball contains a horizontal stripe of high-intensity white LEDs that flash when the red light's lit.
It was a very effective way to make those signals stand out against the visual distractions surrounding them. Are these getting installed elsewhere?
Parts of Central PA have strobe lights
Are you sure these are LEDs or xenon strobes? As far as I know most of these strobes are xenon.
I recall a few strobes in Virginia, but off the top of my head I don't know if any are still in use. One was in Alexandria–eastbound Duke Street (VA-236) at Diagonal Road/Dulany Street. The light is located right after you crest a slight rise as you cross an overpass above the railroad tracks, so I guess they wanted to make the red light more visible in an area with a fair amount of pedestrian traffic and turning vehicles (due to a subway station, hotel, and several restaurants nearby; much of the other development there is all newer). The other ones I remember were on US-29 between Warrenton and Charlottesville, but I don't remember the exact locations anymore. There were maybe two of them. In both cases, the traffic light was located after a long stretch with no lights and presumably VDOT wanted to make sure drivers saw the lights.
I recall that strobe lights can supposedly cause problems for some people with certain medical conditions, which is one reason why at certain Broadway shows they warn the audience if strobes are in use. I have no idea whether that can happen with a traffic light strobe (I suspect the distance and slower flash compared to a nightclub or a show would mitigate the effect), but if it can, that'd be a reason not to allow them.
The ones I've seen installed new in New York are LED.
I recall Xenon strobes along OH 32 east of Cincinnati but all are now gone.
These (https://www.google.com/maps/@39.9159033,-75.3064193,3a,75y,142.54h,83.3t/data=!3m6!1e1!3m4!1s8hIYEG1UmOjD18bXGhkhhA!2e0!7i13312!8i6656) have been there for at least 10 to 15 years. Note the large 2-way W1-6 sign placed between the two signalheads. That sign along with the flashing white bar strobe in the red signal lenses were installed following a horrific accident where an errant car (coming from Bishop Ave.) went straight through the intersection and hit the house in the background.
To my knowledge, there hasn't been another similar accident since the strobes & the sign were installed.
BTW, a similar topic thread already exists (https://www.aaroads.com/forum/index.php?topic=1931.25).
Quote from: PHLBOS on May 10, 2018, 05:28:32 PM
These (https://www.google.com/maps/@39.9159033,-75.3064193,3a,75y,142.54h,83.3t/data=!3m6!1e1!3m4!1s8hIYEG1UmOjD18bXGhkhhA!2e0!7i13312!8i6656) have been there for at least 10 to 15 years. Note the large 2-way W1-6 sign placed between the two signalheads. That sign along with the flashing white bar strobe in the red signal lenses were installed following a horrific accident where an errant car (coming from Bishop Ave.) went straight through the intersection and hit the house in the background.
To my knowledge, there hasn't been another similar accident since the strobes & the sign were installed.
BTW, a similar topic thread already exists (https://www.aaroads.com/forum/index.php?topic=1931.25).
Heck, the intersection that the OP cited was specifically mentioned in that thread...
https://www.aaroads.com/forum/index.php?topic=1931.msg45053#msg45053
Someone please tell me how the presence of a strobe could increase the number of wrecks, or how FHWA could determine that the presence of strobes caused the increase in accidents.
Quote from: roadman on May 10, 2018, 01:48:18 PM
Quote
Research and experimentation over the years with white strobe lights as a circular "halo" outer ring around the red signal or as horizontal bar across the red signal has found no lasting safety benefit and, in some cases, the strobes resulted in increased crash frequency.
There used to be one (horizontal bar in the middle of the red light) on southbound US 23 at the southern Business 23 intersection in Wise, Va. This signal is in a fairly busy commercial area on a slight downhill grade. It was removed, presumably during a signal upgrade, because it was present well after these were banned in 1990.
The last time I was in Newport, Tenn., there was a circular strobe outline at the signal on southbound US 25W/eastbound US 70 at the US 25E intersection. This intersection, too, is at the bottom of a slight grade.I have a picture somewhere from not all that many years ago. Not sure if it's still there or not.
I personally like them. They call attention to the signal.
Alabama has a few spread out across the state, though they're slowly disappearing.
I think there was one on the NY-17 Quickway in Parksville, NY (before the intersection was converted to a diamond interchange, of course). This made sense, since it was the first signal going WB, and many miles since the last one going EB.
At the end of an off-ramp from I-75 in southern Tennessee, I remember a flashing strobe, but with one difference: there was an additional, single-section face on the span wire that was red-only. It only came on when the rest of the signal faces in that direction were red -- and that was where the strobe was. If you look at GSV for the Lenoir City exit, the 2012 view has that extra signal face (though I'm not sure it's for the same purpose, as I think these are sometimes used for emergency vehicles). But by the 2017 view they are gone.
Greenbelt, MD had something I never saw anywhere else -- a flashing strobe in the yellow section. It only flashed for the 2-3 seconds the yellow indication was lit. It was at Greenbelt Rd. and 63rd Ave facing west, and in the 2008 GSV picture you might be able to make out that the middle section of one of the signal heads is of a different make than the other sections.
Quote from: hbelkins on May 10, 2018, 06:24:22 PM
Someone please tell me how the presence of a strobe could increase the number of wrecks[...]
Strobe lights can cause seizures in individuals with photosensitive epilepsy (https://en.wikipedia.org/wiki/Photosensitive_epilepsy).
Quote from: Scott5114 on May 11, 2018, 12:21:08 AM
Quote from: hbelkins on May 10, 2018, 06:24:22 PM
Someone please tell me how the presence of a strobe could increase the number of wrecks[...]
Strobe lights can cause seizures in individuals with photosensitive epilepsy (https://en.wikipedia.org/wiki/Photosensitive_epilepsy).
I know that, but this wasn't cited in the MUTCD language, which to me implies that's not the reason.
Quote from: hbelkins on May 11, 2018, 11:09:01 AM
Quote from: Scott5114 on May 11, 2018, 12:21:08 AM
Quote from: hbelkins on May 10, 2018, 06:24:22 PM
Someone please tell me how the presence of a strobe could increase the number of wrecks[...]
Strobe lights can cause seizures in individuals with photosensitive epilepsy (https://en.wikipedia.org/wiki/Photosensitive_epilepsy).
I know that, but this wasn't cited in the MUTCD language, which to me implies that's not the reason.
strobe lights and similar effects make things harder in general for me to see, and i'm just moderately light-sensitive.
The few times I've encountered red lights with strobe bars, I've always considered the white bar to distract from the signal indications, rather than emphasize them. Sort of like newer cars, where the red brake light is wrapped around the amber turn signal, thus drawing attention away from the turn signal.
Quote from: 1995hoo on May 10, 2018, 04:07:55 PM
I recall a few strobes in Virginia, but off the top of my head I don't know if any are still in use. One was in Alexandria–eastbound Duke Street (VA-236) at Diagonal Road/Dulany Street. The light is located right after you crest a slight rise as you cross an overpass above the railroad tracks, so I guess they wanted to make the red light more visible in an area with a fair amount of pedestrian traffic and turning vehicles (due to a subway station, hotel, and several restaurants nearby; much of the other development there is all newer). The other ones I remember were on US-29 between Warrenton and Charlottesville, but I don't remember the exact locations anymore. There were maybe two of them. In both cases, the traffic light was located after a long stretch with no lights and presumably VDOT wanted to make sure drivers saw the lights.
Alexandria's had a few over the years. The others that I recall were:
1) VA-7 eastbound at Beauregard St / Walter Reed Dr
2) Edsall Rd eastbound at Yoakum Pkwy
Both strobe locations had one commonality: it was located at the bottom of a hill approaching the intersection, especially on Edsall Rd.
This was a couple of years ago, but the last time I drove through Buena Vista, VA, I found that that it had retrofitted some existing signals with 12" reds with circular strobes. GMSV actually managed to pick one up in action: https://goo.gl/maps/mHNizMtLQKq
I remember in Virginia Beach, VA these were frequently installed at fire station signals. Not sure if they are still being installed or not.
I remember a few locations in Virginia with these. US 58 had them at two locations, one at US 58 BUS in Emporia and one at VA 35 (before that intersection was upgraded to an interchange).
Newport News had it at the intersection of Jefferson Ave (VA 143) and Oyster Point Rd, then they switched to the circular LED flash around the red ball (gone now).
If I remember correctly there were also vertical bars in the red light on US 60 at VA 155 or VA 106, I forget which one.
Denton TX had the white strobe in front of the red indication.
Loop 288 at Kings Row had them, which was understandable, given that the signal was on an expressway
US 380/ I-35 had them, which was totally unnecessary, given that this is a frontage road/urban arterial intersection
Some signals on US 72 in NE Alabama have an extra single red indication between the heads
The DRPA added them to the Commodore Barry Bridge's center lane red indicators, which are often red for no reason other than the DRPA only likes to have 2 lanes open per direction unless absolutely necessary.
Quote from: hbelkins on May 11, 2018, 11:09:01 AM
Quote from: Scott5114 on May 11, 2018, 12:21:08 AM
Quote from: hbelkins on May 10, 2018, 06:24:22 PM
Someone please tell me how the presence of a strobe could increase the number of wrecks[...]
Strobe lights can cause seizures in individuals with photosensitive epilepsy (https://en.wikipedia.org/wiki/Photosensitive_epilepsy).
I know that, but this wasn't cited in the MUTCD language, which to me implies that's not the reason.
The MUTCD issues guidance on what's permitted and not permitted. If they had to quantify their reasoning for every statement, the guide would be 40 times larger.
Quote from: HTM Duke on May 11, 2018, 08:19:41 PM
Quote from: 1995hoo on May 10, 2018, 04:07:55 PM
I recall a few strobes in Virginia, but off the top of my head I don't know if any are still in use. One was in Alexandria–eastbound Duke Street (VA-236) at Diagonal Road/Dulany Street. The light is located right after you crest a slight rise as you cross an overpass above the railroad tracks, so I guess they wanted to make the red light more visible in an area with a fair amount of pedestrian traffic and turning vehicles (due to a subway station, hotel, and several restaurants nearby; much of the other development there is all newer). The other ones I remember were on US-29 between Warrenton and Charlottesville, but I don't remember the exact locations anymore. There were maybe two of them. In both cases, the traffic light was located after a long stretch with no lights and presumably VDOT wanted to make sure drivers saw the lights.
Alexandria's had a few over the years. The others that I recall were:
1) VA-7 eastbound at Beauregard St / Walter Reed Dr
2) Edsall Rd eastbound at Yoakum Pkwy
Both strobe locations had one commonality: it was located at the bottom of a hill approaching the intersection, especially on Edsall Rd.
This was a couple of years ago, but the last time I drove through Buena Vista, VA, I found that that it had retrofitted some existing signals with 12" reds with circular strobes. GMSV actually managed to pick one up in action: https://goo.gl/maps/mHNizMtLQKq
Yeah, I saw in the other thread someone linked that I had mentioned Edsall at Yoakum there, and I was chagrined to have forgotten it for this thread because my wife lived on Yoakum (in the Watergate at Landmark) before we got married, so I saw that strobe many times.
There were some circle versions on TX 146 not far south of I-10 when I was there in January.
North Carolina used to use them...in the 1970s there were slit flash versions on what is now I-95 Bus in Fayetteville at the first stoplight in each direction after the freeway ended.
I believe US 17 had several as well coming into larger towns...
There are strobe lights somewhere in PA, but Ian has pictures
Quote from: jeffandnicole on May 12, 2018, 02:44:29 AM
Quote from: hbelkins on May 11, 2018, 11:09:01 AM
Quote from: Scott5114 on May 11, 2018, 12:21:08 AM
Quote from: hbelkins on May 10, 2018, 06:24:22 PM
Someone please tell me how the presence of a strobe could increase the number of wrecks[...]
Strobe lights can cause seizures in individuals with photosensitive epilepsy (https://en.wikipedia.org/wiki/Photosensitive_epilepsy).
I know that, but this wasn't cited in the MUTCD language, which to me implies that's not the reason.
The MUTCD issues guidance on what's permitted and not permitted. If they had to quantify their reasoning for every statement, the guide would be 40 times larger.
Reasons for prohibition of a certain traffic control device -- or justification for the requirement for or option to use one -- are a bit different than the classic parental "Because I (we) said so!"
If the feds are going to tell cities and states that they can't use something, they should at least have to explain why.
Quote from: Brian556 on May 12, 2018, 01:49:15 AM
Some signals on US 72 in NE Alabama have an extra single red indication between the heads
They also used to be present along US 431 in southeast Alabama, and as I recall, it was on these single heads (not the regular three-head signals) that the strobes were. Here is one of them in action (https://www.google.com/maps/@31.3537804,-85.3273245,3a,30y,179.51h,93.07t/data=!3m7!1e1!3m5!1sBSOQxKjuTCngJe_4cuef0Q!2e0!5s20130701T000000!7i13312!8i6656), removed sometime between 2013 and 2016.
Quote from: traffic light guy on May 12, 2018, 10:18:01 AM
There are strobe lights somewhere in PA, but Ian has pictures
There are quite a few left all around Pennsylvania. Too many to count even.
Quote from: hbelkins on May 12, 2018, 03:11:09 PM
Quote from: jeffandnicole on May 12, 2018, 02:44:29 AM
Quote from: hbelkins on May 11, 2018, 11:09:01 AM
Quote from: Scott5114 on May 11, 2018, 12:21:08 AM
Quote from: hbelkins on May 10, 2018, 06:24:22 PM
Someone please tell me how the presence of a strobe could increase the number of wrecks[...]
Strobe lights can cause seizures in individuals with photosensitive epilepsy (https://en.wikipedia.org/wiki/Photosensitive_epilepsy).
I know that, but this wasn't cited in the MUTCD language, which to me implies that's not the reason.
The MUTCD issues guidance on what's permitted and not permitted. If they had to quantify their reasoning for every statement, the guide would be 40 times larger.
Reasons for prohibition of a certain traffic control device -- or justification for the requirement for or option to use one -- are a bit different than the classic parental "Because I (we) said so!"
If the feds are going to tell cities and states that they can't use something, they should at least have to explain why.
They can, but in other documents.
Most publications use footnotes for such detail, so one can look at the source behind the reasoning.
Quote from: Eth on May 12, 2018, 07:32:37 PM
Quote from: Brian556 on May 12, 2018, 01:49:15 AM
Some signals on US 72 in NE Alabama have an extra single red indication between the heads
They also used to be present along US 431 in southeast Alabama, and as I recall, it was on these single heads (not the regular three-head signals) that the strobes were. Here is one of them in action (https://www.google.com/maps/@31.3537804,-85.3273245,3a,30y,179.51h,93.07t/data=!3m7!1e1!3m5!1sBSOQxKjuTCngJe_4cuef0Q!2e0!5s20130701T000000!7i13312!8i6656), removed sometime between 2013 and 2016.
There is (and was) also a number of them on US 231 between Montgomery and Florida. Cherokee, AL also has some non-functional (very early) strobes on the edge of the town.
Used to be strobe signals at US-360 and Woodlake Village Parkway in Midlothian VA. I obtained both of them in 2015 and still have one in my garage.
SM-G930V
Signals on the Saw Mill River Parkway at Readers Digest Road in Chappaqua NY have strobes crossing the red ball.
Quote from: Ian on May 12, 2018, 10:29:00 PM
Quote from: traffic light guy on May 12, 2018, 10:18:01 AM
There are strobe lights somewhere in PA, but Ian has pictures
There are quite a few left all around Pennsylvania. Too many to count even.
I occasionally come across this one every now and then.
https://www.google.com/maps/@40.0415581,-76.3252235,3a,43.7y,173.24h,96.51t/data=!3m7!1e1!3m5!1s2UjcEHwoSOxtOVyY66OHmA!2e0!5s20110901T000000!7i13312!8i6656
Alternate view:
https://www.google.com/maps/@40.0414445,-76.3251909,3a,15y,338.33h,104.37t/data=!3m7!1e1!3m5!1szmtZOlGuoK3qLkZEGsJUGA!2e0!5s20171101T000000!7i13312!8i6656
White Plains has them as well.