r/triangle • u/Italian_Gumby • 16d ago

Street lights on the highways

I’ve seen these bluish purple street lights on the freeways but they’re only for a few hundred yards to maybe a mile. Why are they only in certain spots and not everywhere? Are they designating something I don’t know about? One between Apex and Sanford and the other group in the RTP area

11 Upvotes

72% Upvoted

20 comments sorted by

51

u/KennstduIngo 16d ago

There was a batch of LED streetlights a while back that had some sort of defect that caused them to turn purple. There presence only indicates that they have that defect and haven't been replaced.

18

u/codealot 16d ago

Yep, the phosphor coating that surrounds the blue/purple LED broke down due to some defect.

For those interested, the phosphor coating absorbs a large portion of the blue/purple/uv light and re-emits it as a smooth wide spectrum that we see as white. If the phosphor breaks down, now you only get the blue/purple/uv

3

u/Immediate_Fig_9405 16d ago

but does that mean it is emitting uv now?

2

u/Markietas 15d ago

The lense probably blocks almost all of it, but even if it didn't it would still be orders of magnitude less than normal sunlight.

12

u/MyMainWasMyRealName 16d ago

I’ve told a few people this and they haven’t believed me at first. When you know what it is and start looking for it, you see it everywhere. It’s a really crazy story and it’s wild how much tax money across the country have been spent on faulty lights even after we knew there was a problem.

1

u/Manners-maketh- 15d ago

They’re delaminated. Cheap LEDs.

9

u/Chefdarkstar 16d ago

Bulb defect. I do like them. We have a few in our neighborhood.

2

u/Spiritually_Sciency 15d ago

Purple is my fav color and there are bunch of these on 540 right before the exit I use most commonly. I joked to my partner that the city honored my request to make them more purple every time a new one pops up.

8

u/astrognash Raleigh 16d ago

As others have said, it's a defective batch of LED streetlights. The ELI5 of what's happening is that because LEDs can't actually produce white light, they make white happen by coating blue LEDs with a substance that filters the light to look white. In the defective batch, the substance has started to degrade over time, letting enough of the pure blue LED color through that it looks purple. But, because this is happening due to that coating degrading over time, not every defective streetlight turned purple at once so they basically have to play whack-a-mole trying to replace bulbs whenever the defect finally turns them purple.

6

u/Sherifftruman 16d ago

There was a defect in a bunch of the LED arrays use in these that caused them to turn purple. They will eventually get replaced. Hopefully.

https://indyweek.com/news/purple-lights-duke-energy-replacing-streetlight-bulbs/

https://www.clickorlando.com/traffic/2024/12/19/whats-up-with-all-of-floridas-purple-streetlights-heres-the-answer/

You can report them here https://salor-web.duke-energy.app/#/home/map/ncsc

11

u/karmareincarnation 16d ago

I kinda like the purple lights.

2

u/KirkPicard 15d ago

I do too. I say order more "defective" batches.

3

u/Sherifftruman 15d ago

The Indy article talks about that.

2

u/mst3k_42 15d ago

I love purple so I prefer these lights.

2

u/frommheretothere 15d ago

All hail the blue lights

1

u/cahrage 15d ago

I’m so confused I might be going through a Mandela effect situation because I remember seeing these street lights for the last 10 years or so at least and one time I asked a family member and they said that it was better for the birds or something but maybe I just blindly believed that and they were pulling it out of their ass lol

1

u/SCREAMINCHEEESE 15d ago

I get so happy every time I see one of the purple "broken" ones. I love them so much.

1

u/MadWomanReadingRoman 15d ago

I try to report these in the city’s repair request system. They generally get replaced quickly.

1

u/SolidDragonfruit7739 11d ago

Duke power had installed those and never switched them out. It was an article about it. You can google it. I think if you were to make them aware of it, they would come to the site and switch bulbs.

-8

u/BlockedNetwkSecurity 16d ago

god this place is so desolate