# Purple streetlights: Anyone else seen this in their area? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [November 19, 2022, 5:14am UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184 "2022-11-19T05:14:40Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [November 19, 2022, 5:14am UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/1 "2022-11-19T05:14:40Z")
Several LED street light bulbs have turned purple in my area, and people seem to either love it, or hate it. Other cities have had the same phenomenon, and the explanation is a defect in the bulb’s coating. Some places are working to replace them, and others aren’t doing so as aggressively. Here’s the story from my area; there’s actually another story from April, but it’s basically clickbait so I won’t post that link. > **[Street lights aren’t supposed to be purple](https://www.ourquadcities.com/news/local-news/street-lights-arent-supposed-to-be-purple/)** > > You might see an odd color of light when driving at night in the Quad Cities. Purple lights are illuminating the streets instead of a bright white or yellow hue. They are showing up around the area… And this one is from the CBC, specifically about Vancouver, BC > **[Why hundreds of Vancouver street lights are turning purple | CBC News](https://www.cbc.ca/news/canada/british-columbia/purple-street-lights-vancouver-1.6604599)** > > The indigo lights have spawned theories online about everything from vampires to vaccines, but the City of Vancouver says the LED street lights now shining purple are the result of a manufacturing defect. ---
**Author:** ![solost](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/solost/32/11776_2.png) [@solost](https://boards.straightdope.com/u/solost)\ **Post date:** [November 19, 2022, 2:00pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/2 "2022-11-19T14:00:53Z")
When I saw the post title I was thinking this would be in the Minneapolis area. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [November 19, 2022, 2:24pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/3 "2022-11-19T14:24:02Z")
Interesting. We have those lights all over town, and I hate them. I just assumed it was some new fad the city traffic engineers decided to follow, for safety reasons or whatever. Good to know it’s a defect and they will (hopefully, eventually) be replaced. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [November 19, 2022, 2:28pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/4 "2022-11-19T14:28:56Z")
They are, however, supposed to be bluer than the old streetlamps, as we can see further with less light in the bluer spectrum. But violet is going too far for that. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [November 19, 2022, 4:48pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/5 "2022-11-19T16:48:08Z")
My wife pointed them out here in NC last winter. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [November 19, 2022, 9:31pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/6 "2022-11-19T21:31:10Z")
That’s why lights along airport runways are blue. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [November 19, 2022, 9:34pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/7 "2022-11-19T21:34:06Z")
And of course, there are some conspiracy theorists who are taking this and running with it. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [November 19, 2022, 9:51pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/8 "2022-11-19T21:51:59Z")
> [@nearwildheaven](#): > > That’s why lights along airport runways are blue. Actually no. Runway edge and centerline lights are a light amber. Although the new LED ones are a brighter pure white with a slight blue-ish cast. The fixtures also have lenses to focus most of the illumination in a narrow ~20 degree cone along the runway’s axes; they’re much, much dimmer when viewed from off-axis. _Taxi_way edge lights are blue. And omnidirectional. And not nearly as bright as runway lights. They’re obvious up close while taxiing, but are hard to see from even half a mile away as one approaches the runway. This is by dy design, so the maze of taxiways more or less blends into the darkness and the light amber-outlined runway stands out. ---
**Author:** ![bump](https://avatars.discourse-cdn.com/v4/letter/b/7c8e57/32.png) [@bump](https://boards.straightdope.com/u/bump)\ **Post date:** [November 20, 2022, 5:43pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/9 "2022-11-20T17:43:25Z")
I’ve seen them in the Houston area, Dallas area, and oddly enough, in a couple of towns between Houston and Dallas. In every case, it wasn’t a consistent thing- like one light out of ten might be purple, or there might be a stretch of purple lights inbetween normal colored ones. Just like you’d expect defective lights to be installed as replacements, now that you point that out. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [November 20, 2022, 5:53pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/10 "2022-11-20T17:53:05Z")
I’d love to know the mechanism behind this failure, since the phosphor in LED lamps is a very well-developed technology. I have white LEDs that are approaching 100,000 hours of operation with no sign of degradation. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [November 20, 2022, 6:04pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/11 "2022-11-20T18:04:33Z")
Poking around on google, it looks like it was one particular batch of the lights that was manufactured in 2018 that has the issue. So it’s a manufacturing issue and not a design issue. The laminate that converts the violet light into white light is defective in this batch, and degrades quickly over time. The lamps become more and more violet as the laminate degrades and peels off. I couldn’t find any details about exactly what was done wrong in the production of this batch’s laminate. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [March 15, 2023, 7:43pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/12 "2023-03-15T19:43:13Z")
Saw this last night on Tatum near Cave Creek: [[Album] imgur.com ![](https://i.imgur.com/usGxNpl.jpeg?fb "imgur.com") ](https://imgur.com/a/qXkY0EP) ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [March 15, 2023, 9:54pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/13 "2023-03-15T21:54:44Z")
> [@nearwildheaven](#): > > And of course, there are some conspiracy theorists who are taking this and running with it. I mean, if THAT doesn’t prove the world is flat - then what would? > [@beowulff](#): > > I’d love to know the mechanism behind this failure, since the phosphor in LED lamps is a very well-developed technology. I have white LEDs that are approaching 100,000 hours of operation with no sign of degradation. did you money go to the CHEAPEST offer? … that might explain a bit … 😉 ---
**Author:** ![DorkVader](https://avatars.discourse-cdn.com/v4/letter/d/73ab20/32.png) [@DorkVader](https://boards.straightdope.com/u/DorkVader)\ **Post date:** [March 15, 2023, 10:08pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/14 "2023-03-15T22:08:13Z")
Huh! We have one round-about in the next county over that I know of that has street lights that were blue a couple months ago. I wonder if they’re from the same defective batch. I should get over there one evening this week and see if they’ve gotten more purpley. ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [March 15, 2023, 11:11pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/15 "2023-03-15T23:11:03Z")
I can’t tell Son-of-a-wrek. He going crazy right now because there’s a stretch of highway here where 80% of the houses have blue porch lights. He can’t figure it out. 🤔 ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [March 16, 2023, 5:38am UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/16 "2023-03-16T05:38:26Z")
Support for the police, perhaps? ---
**Author:** ![Princhester](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Princhester](https://boards.straightdope.com/u/Princhester)\ **Post date:** [March 16, 2023, 7:29am UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/17 "2023-03-16T07:29:56Z")
Actually from outer space the pattern of purple leading lights points to Mar-a-Lago, so that aliens can find and kiss the hand of the Emporer of Planet Earth. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [March 22, 2023, 1:15pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/18 "2023-03-22T13:15:06Z")
Something interesting I have noticed the last couple days. I’m driving to work just about the time the sun is coming up. The weather’s been overcast/rainy/foggy. It’s light enough that all the regular street lights are off, but the purple ones are still lit. Does the purple light somehow affect the sensors that turn the streetlights on and off? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [April 1, 2023, 3:09pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/19 "2023-04-01T15:09:36Z")
I happened to have my DSLR with a 400mm lens last night when I stopped for groceries, and saw a purple streetlight. Here is what the array looks like: [![Imgur](https://i.imgur.com/aPB8aBp.jpeg "imgur.com") ](https://imgur.com/aPB8aBp) So, the explanation that it’s some sort of filter separate from the LEDs is bunk. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [April 3, 2023, 1:03pm UTC](https://boards.straightdope.com/t/purple-streetlights-anyone-else-seen-this-in-their-area/975184/20 "2023-04-03T13:03:35Z")
There’s a gas station/convenience store chain around here called Sheetz, and in many of their stores they’ve installed blue lights in the restrooms to discourage intravenous drug use (it’s difficult if not impossible to find a vein in blue light). When I saw blue/purple streetlights I assumed they were for the same reason (truckers often stop and rest on the highway shoulder under the lights), then I read about the manufacturing defect when I looked it up out of curiosity.