Is the Sodium Vapor Streetlight Becoming Extinct?

[Henry]

Back in 2008, the mercury vapor streetlight found itself on the endangered list, thanks to its being banned for sale in the U.S., and it seemed that high-pressure sodium was going to stick around forever, but now it is being replaced by LED in metropolitan areas. So the question is, are HPS lights finally facing extinction as well? As much as I despised the orange-yellow colors they gave out at night, at least HPS luminaires themselves are superior in design to the hideous LEDs, and they have lots of variety as well. What are your thoughts on this?

[MNHighwayMan]

Good riddance to that icky yellow-orange color.

[UCFKnights]

As much as I despised the orange-yellow colors they gave out at night, at least HPS luminaires themselves are superior in design to the hideous LEDs, and they have lots of variety as well. What are your thoughts on this?

I love the LEDs, and lots of varieties of them as well...

LED seems to have been the default for new installs for the past couple years around here, and just recently, they finally started replacing HPS with LEDs more proactively.

[Brandon]

Good riddance to the HPS lights and their ugly orange-yellow glow.  I much prefer the "daylight" LEDs.  Much crisper, cleaner light.

[index]

They're starting to go up in my neighborhood. Last thing I need is to have my window blasted with bright white light when I'm trying to get to sleep, the sodium light near my house already shines in a whole bunch and it's rather dim.

[ErmineNotyours]

Allow me to second: good riddance to sodium vapor, especially since I had to work for months under orange sodium vapor at the post office.  Even though it was by the airport, the power went off twice when I worked there, and things actually got more color balanced at those times.

On the other hand, when I was riding through San Diego at night in 2010, I could swear I saw widespread roadside installations that looked like a yellow filter wrapped around fluorescent light tubes.  I never got out to take a closer look, but they were more yellow than orange.  I'm guessing they were like this to discourage bugs from swarming the lights.  They never had to apply a yellow filter to sodium vapor lights, so they may have their uses.  (I can't seem to find a Street View of these lights, and the archive goes back to 2010.)

[Buffaboy]

There's nothing better than to see the sky lit up orange from sodium vapor lights.

[Pink Jazz]

There's nothing better than to see the sky lit up orange from sodium vapor lights.

Interestingly, some cities are actually now installing amber LED lights in lieu of white.

[txstateends]

Allow me to second: good riddance to sodium vapor, especially since I had to work for months under orange sodium vapor at the post office.  Even though it was by the airport, the power went off twice when I worked there, and things actually got more color balanced at those times.

On the other hand, when I was riding through San Diego at night in 2010, I could swear I saw widespread roadside installations that looked like a yellow filter wrapped around fluorescent light tubes.  I never got out to take a closer look, but they were more yellow than orange.  I'm guessing they were like this to discourage bugs from swarming the lights.  They never had to apply a yellow filter to sodium vapor lights, so they may have their uses.  (I can't seem to find a Street View of these lights, and the archive goes back to 2010.)

Decades ago, I remember seeing some businesses using yellow florescent tube lights outdoors.  I don't know if it was because those places liked yellow light, or they were trying to do something about attracting bugs at night.

[mgk920]

Allow me to second: good riddance to sodium vapor, especially since I had to work for months under orange sodium vapor at the post office.  Even though it was by the airport, the power went off twice when I worked there, and things actually got more color balanced at those times.

On the other hand, when I was riding through San Diego at night in 2010, I could swear I saw widespread roadside installations that looked like a yellow filter wrapped around fluorescent light tubes.  I never got out to take a closer look, but they were more yellow than orange.  I'm guessing they were like this to discourage bugs from swarming the lights.  They never had to apply a yellow filter to sodium vapor lights, so they may have their uses.  (I can't seem to find a Street View of these lights, and the archive goes back to 2010.)

Decades ago, I remember seeing some businesses using yellow florescent tube lights outdoors.  I don't know if it was because those places liked yellow light, or they were trying to do something about attracting bugs at night.

Those are low-pressure sodium vapor lamps.  There is an extremely narrow light spectrum on those, essentially making everything around them look black and white (or more accurately black and yellow-orange).

The more familiar lamps that are now on their way out are high-pressure sodium vapor lamps.

Newer LEDs come in various color temperatures, the cooler ones are closer to incandescent in appearance while the hotter ones are the harsher white ones.

Mike

[Michael]

Since 2012 or so, Auburn has had LED streetlights along the Arterial, and in a few other places.  The LEDs are super bright, but they don't have a wide spread, so it gets a bit dark between the streetlights.

Technology Connections has two good videos on HPS street lighting, and converting them to LED:

EDIT: I forgot to mention the interchange at I-690 and NY 695 has LED high-mast lighting.  I think it was installed in 2017, but I never paid that much attention until I consciously noticed the white light last year.  It's so weird to see white instead of orange lights.

[roadfro]

With the advances in LED technology, I do think HPS street lighting is going to make a slow exit.


Some jurisdictional observations from Nevada:

• City of Las Vegas converted nearly all its HPS street lighting to LED several years ago. Any standard cobrahead-style fixture was replaced, but parts of town using different street light designs wasn't replaced (they might have been at this point, not down there enough to know). Interestingly, most cobrahead luminaires on traffic signal masts still use HPS.
  
• City of Henderson several years ago converted much of its HPS street lighting to an induction (this was before Las Vegas switched).
  
• City of Reno has converted nearly all cobrahead luminaires on traffic signal masts to LED, but regular cobrahead street lights are still predominantly HPS. The different street light standards used in downtown and some redevelopment corridors use a different type of lighting entirely (white-ish light bulbs, fairly sure it's not LED).
  
• NDOT in Northern Nevada has converted much of its HPS lighting to LED, at least as far as cobrahead street lights and BGS sign lighting in the Reno area. There are still significant stretches of I-580 with cobrahead HPS fixtures though, and all high-masts are still HPS.
  
• NDOT in Southern Nevada hasn't really gotten rid of any HPS, as many high-masts, cobraheads and overhead sign fixtures are still HPS. However, newer installations of high-masts are now LED.

[Duke87]

One thing to keep in mind here is that there are different reasons motivating each of these technological shifts.

Mercury Vapor lights were phased out because of impacts to the environment from the disposal of products containing mercury, and pretty much for that reason alone. High Pressure Sodium lights, as well as the newer Metal Halide lights which use similar physical principles to produce whiter light, are in the same class of "High Intensity Discharge" (or "HID") lighting along with Mercury Vapor and they're all similar in both efficiency and in how long the bulbs and ballasts last before they burn out.

LEDs are a completely different technology, though - they consume about half as much electricity as HID to produce the same amount of light, and they also last about twice as long. The switch to LEDs is, therefore, motivated primarily by lower operating costs.

That said, it is certainly possible that at some point Sodium and Metal Halide lights will also see a federal phase out for the sake of energy efficiency - standard incandescent lamps, as well as T12 fluorescent lamps and magnetic ballasts, have been subject to prior phaseouts for this reason.

[sparker]

Here in the South Bay, the phase-out of high-pressure sodium lighting varies from city to city; Santa Clara and San Jose both seem to have quite a few HPS lights left, particularly in the industrial zones in the north part of both cities -- it's likely those would be the last to be replaced simply because the areas are largely vacant during the evening hours, and therefore less likely to be the source of complaints about color washout, sleep deprivation, and other issues ascribed to both HPS and predecessor mercury vapor.  Curiously, there are still patches of MV lighting -- such as the remaining grounds of the original IBM facility in Santa Teresa Valley that originally produced mainframe power supplies; part of the grounds became the southern terminal depot and yard for the MAX light rail -- that area remains HPS, with the last big patch of MV lighting right next door in the highly truncated IBM property.  My own neighborhood has gone to LED, although to the south in Robertsville and Cambrian Park, HPS still prevails.  Most of the smaller cities along the base of the Santa Cruz Mountains (Los Gatos, Saratoga, and Cupertino) have gone almost exclusively to LED -- but again with the exception of their industrial parks, which remain largely HPS.  It's likely San Jose, with its public commitment to energy saving, will eventually be all LED -- but they seem to have a huge inventory of HPS replacement heads available for deployment in the industrial north; these probably won't be replaced until that back-stock is depleted (energy-saving or not, it's still a city that, like most, will delay extra expenditure as long as possible!).  BTW, the other "holdout" areas for HPS and even some MV are the local shopping malls and "campuses" -- even some relatively new such developments have deployed HPS lighting in the last couple of years -- probably because it was initially less expensive.  Also -- most of the San Jose residential LED lighting utilizes "warm white" LED arrays that mimic old incandescent lighting -- although with markedly less lumens than the standard "flashlight white" LED's commonly used for lighting because of their increased light output per ampere consumed; apparently the consensus of the residents is that they would rather have "natural" lighting even with somewhat reduced evening visibility. 

[invincor]

There's an excellent Youtube video on this topic here:
https://youtu.be/wIC-iGDTU40

[ztonyg]

There's nothing better than to see the sky lit up orange from sodium vapor lights.

Interestingly, some cities are actually now installing amber LED lights in lieu of white.

The streetlight in front of my house (in the city of Phoenix) has amber LED lighting.

[ET21]

Chicago has slowly begun to replace the orange with LEDs. Tollway began a few years ago and continue to replace their orange fixtures with LEDs when they rebuild/redo sections

[Henry]

Chicago has slowly begun to replace the orange with LEDs. Tollway began a few years ago and continue to replace their orange fixtures with LEDs when they rebuild/redo sections

I took notice of that on my last visit home. I would like to add that I like them better at night with the white glow.

I've also seen the large-scale conversions in Seattle.

[kphoger]

I still remember moving back to Chicago for college (Harlem Ave), after having lived in a very rural area since 4th grade.  The pink haze in the evenings was definitely weird to get used to.

[Mark68]

Where I live, in the Town of Parker, all overhead lights on traffic light installations are LEDs. There are very few (non-decorative) street lights in Parker (thus trying to maintain a "rural" atmosphere in a town of 50k), but the ones that do exist are LED. Ironically, Parker also has internally-lit street signs installed on the mast arms, instead of LED street blades.

As far as Denver Metro, it's hit or miss. It seems that all new lights in the City & County of Denver are LEDs, but there are plenty of HPS lights, both on street lights and traffic lights. I have yet to see any LEDs in Aurora, even on new installs (and there are a lot of them).

CDOT seems to be phasing out the HPS in favor of LEDs on highways

[txstateends]

City signal lights in Dallas that have attached street lighting, have largely been converted to white LED.  The median HPSes are still around in the city for the most part.  TxDOT is a mixed bag around north TX for LED vs. remaining HPS.  On TX 360 between TX 180 and I-20, all the median mast lights and high-mast lights are LED.  So far, this is one of the few longer stretches of highway in the area that has a total LED presence.  The newer highway lighting installs in the last few years on US 175 in Seagoville and Crandall have been LEDs.  I'm glad that most places around here have gone away from MVs; they always had a sick color and were quite dim.  Now that I've seen what LED lighting can look like on streetlights, it'll be good to see more LED rollout and not so much of the area marinated in orange.

[Henry]

City signal lights in Dallas that have attached street lighting, have largely been converted to white LED.  The median HPSes are still around in the city for the most part.  TxDOT is a mixed bag around north TX for LED vs. remaining HPS.  On TX 360 between TX 180 and I-20, all the median mast lights and high-mast lights are LED.  So far, this is one of the few longer stretches of highway in the area that has a total LED presence.  The newer highway lighting installs in the last few years on US 175 in Seagoville and Crandall have been LEDs.  I'm glad that most places around here have gone away from MVs; they always had a sick color and were quite dim.  Now that I've seen what LED lighting can look like on streetlights, it'll be good to see more LED rollout and not so much of the area marinated in orange.

I never noticed any sick colors for MVs, and while they were indeed dim compared to the HPS lights, their blue-green light was much more pleasant than the orange-yellow from their counterparts.

[MikieTimT]

City signal lights in Dallas that have attached street lighting, have largely been converted to white LED.  The median HPSes are still around in the city for the most part.  TxDOT is a mixed bag around north TX for LED vs. remaining HPS.  On TX 360 between TX 180 and I-20, all the median mast lights and high-mast lights are LED.  So far, this is one of the few longer stretches of highway in the area that has a total LED presence.  The newer highway lighting installs in the last few years on US 175 in Seagoville and Crandall have been LEDs.  I'm glad that most places around here have gone away from MVs; they always had a sick color and were quite dim.  Now that I've seen what LED lighting can look like on streetlights, it'll be good to see more LED rollout and not so much of the area marinated in orange.

I never noticed any sick colors for MVs, and while they were indeed dim compared to the HPS lights, their blue-green light was much more pleasant than the orange-yellow from their counterparts.

I think the thought was that humans look like zombies under MV.  Makes the skin look gaunt and sickly.

[Dustin DeWinn]

Since 2012 or so, Auburn has had LED streetlights along the Arterial, and in a few other places.  The LEDs are super bright, but they don't have a wide spread, so it gets a bit dark between the streetlights.

Technology Connections has two good videos on HPS street lighting, and converting them to LED:

EDIT: I forgot to mention the interchange at I-690 and NY 695 has LED high-mast lighting.  I think it was installed in 2017, but I never paid that much attention until I consciously noticed the white light last year.  It's so weird to see white instead of orange lights.

I searched to see if these videos have been posted. I have one more. Here he does a tear-down of an LED traffic light module

[OracleUsr]

NC is going hog-wild with the new LED lamps.  Even my local streets have them.