# LED traffic lights can't melt off snow and ice from their lens. **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [February 24, 2015, 1:39pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512 "2015-02-24T13:39:30Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Lamar\_Mundane](https://avatars.discourse-cdn.com/v4/letter/l/85f322/32.png) [@Lamar\_Mundane](https://boards.straightdope.com/u/Lamar_Mundane)\ **Post date:** [February 24, 2015, 8:17pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/41 "2015-02-24T20:17:35Z")
> [@aceplace57](#): > > How in the hell am I supposed to know if a particular city has converted to LED? It’s not exactly front page news. I watch the local tv news nearly every night and its never been reported. I’ve lived in the same city 30 years and I don’t know if mine has or not. I do know retrofits for any equipment costs money. Period. We’ve had a bad economy for years and tax dollars are not exactly flowing into city treasurers offices. > > I could care less what bulbs they use in traffic lights. What I do care about is that they work and they are visible in all weather conditions. I will be extremely pissed if a snow storm makes them difficult or hard to see. Especially at night. I don’t particularly care to get killed in a car crash because of some snow over the lens of a traffic light. That would be a pretty pathetic and senseless death for any family to endure. A city doesn’t have to replace every light they have all at once. They can replace the incandescents with LED when they burn out (or replace all the bulbs then.) They have to deploy the bucket truck either way. The light above my head right now has one incandescent bulb and one CFL. When one burns out, it’ll get replaced with LED or whatever the technology is then. I didn’t go running around the house throwing away perfectly good incandescent bulbs just because another technology was available. I knew they were going to burn out in a year or two anyway. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [February 24, 2015, 8:20pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/42 "2015-02-24T20:20:17Z")
> [@Amateur\_Barbarian](#): > > He says, writing from one of the known snowstorm belts in the US. :rolleyes: How is my place of residence relevant? ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [February 24, 2015, 8:21pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/43 "2015-02-24T20:21:23Z")
> [@hajario](#): > > How is my place of residence relevant? Maybe I should have added a more definite smiley, but advice on snow and ice issues from someone on the southern California coast is… interesting. 😃 ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 24, 2015, 8:21pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/44 "2015-02-24T20:21:30Z")
> [@hajario](#): > > Your lack of understanding of every single aspect of this issue is a thing to behold. LED technology has only been improved on in just the last few years. I can recall seeing LED bulbs in the stores even in 2010 that were extremely expensive. I happen to know because I wanted to buy them. They were ridiculously high priced. It’s only been in the last couple years that prices have dropped. The technology may be 10 or 20 years old but it certainly wasn’t affordable. From what I’ve read the tech is improving steadily. LED’s sold today are much better and brighter than they were even in 2010. There’s even been threads here on the dope discussing how much better LED’s are today. It won’t be long and they’ll make compact fluorescent obsolete. I didn’t realize earlier that no retrofit was needed for the traffic lights. If they can just pop in a LED bulb in the same socket than yes, that makes it much less expensive. I have read about problems with older home fixtures and LED. Sometime the LED fails prematurely and the only solution is to buy a different fixture. Something to do with too much heat or the angle that the socket holds the bulb. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [February 24, 2015, 8:28pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/45 "2015-02-24T20:28:12Z")
> [@Amateur\_Barbarian](#): > > Maybe I should have added a more definite smiley, but advice on snow and ice issues from someone on the southern California coast is… interesting. 😃 Well, yeah, but I have traveled from my place of origin and have seen snowy conditions at least a time or two. I have even designed things that had to work in cold and snowy conditions as part of my profession. 🆒 ---
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [February 24, 2015, 8:31pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/46 "2015-02-24T20:31:00Z")
> [@hajario](#): > > Well, yeah, but I have traveled from my place of origin and have seen snowy conditions at least a time or two. I have even designed things that had to work in cold and snowy conditions as part of my profession. 🆒 I thought I knew about snow, too, until I was staring at six feet of it packed on my deck, shovel in hand, with a bare dent in its volume after my shoulders and arms had given out. Or driven through a city that was like a 12-foot white hedge maze. Not quite the same as a refreshing day or weekend up around Tahoe. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [February 24, 2015, 8:46pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/47 "2015-02-24T20:46:36Z")
> [@Amateur\_Barbarian](#): > > I thought I knew about snow, too, until I was staring at six feet of it packed on my deck, shovel in hand, with a bare dent in its volume after my shoulders and arms had given out. Or driven through a city that was like a 12-foot white hedge maze. Not quite the same as a refreshing day or weekend up around Tahoe. I had in-laws in Minnesota and visited for Christmas. I was in a blizzard in Flagstaff of all places and to drive. I spent six weeks in Korea in the dead of winter. It’s not the same as living there but I have spent time in the white stuff. Of course, all of this was in the times before LEDs. ---
**Author:** ![garygnu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garygnu/32/2924_2.png) [@garygnu](https://boards.straightdope.com/u/garygnu)\ **Post date:** [February 24, 2015, 8:57pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/48 "2015-02-24T20:57:13Z")
> [@aceplace57](#): > > LED technology has only been improved on in just the last few years. I can recall seeing LED bulbs in the stores even in 2010 that were extremely expensive. I happen to know because I wanted to buy them. They were ridiculously high priced. > … The household LED bulbs you’re seeing are, in fact, pretty new. Getting the diodes to emit a white color close to other household bulbs took a long time, and getting the price down took more time. Colored bulbs, like red, green or yellow, have been around for much longer and are less expensive. ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [February 24, 2015, 8:58pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/49 "2015-02-24T20:58:03Z")
> [@CalMeacham](#): > > 1.) Does so much snow build up that the light can’t get through? If a layer of snow accumulated on the lenses of our traffic lights, I could still tell if green was lit. It’d come through the snow. It’s not the green lights that are a problem, it’s the red ones. If they are snow covered, they are dim & thus not easily as recognizable as a traffic light. I’m used to seeing dim red lights ‘in the sky’ where I live, whether the tail lights of a car up a hill from me or anti-collision lights from a radio tower. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [February 24, 2015, 9:02pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/50 "2015-02-24T21:02:02Z")
> [@aceplace57](#): > > I didn’t realize earlier that no retrofit was needed for the traffic lights. If they can just pop in a LED bulb in the same socket than yes, that makes it much less expensive. I have read about problems with older home fixtures and LED. Sometime the LED fails prematurely and the only solution is to buy a different fixture. Something to do with too much heat or the angle that the socket holds the bulb. they usually replace the original bulb, socket, lens, and reflector system with an integrated LED light module: [http://www.dialight.com/Product/Category/caltrans\_compliant\_arrows](http://www.dialight.com/Product/Category/caltrans_compliant_arrows) ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [February 24, 2015, 9:03pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/51 "2015-02-24T21:03:40Z")
> [@aceplace57](#): > > I doubt many cities have started the conversion. > [@aceplace57](#): > > How in the hell am I supposed to know if a particular city has converted to LED? It’s not exactly front page news. I watch the local tv news nearly every night and its never been reported. I’ve lived in the same city 30 years and I don’t know if mine has or not. Maybe you should get in the habit of asking questions instead of making assumptions that validate what you already believe. ---
**Author:** ![sevenwood](https://avatars.discourse-cdn.com/v4/letter/s/6de8d8/32.png) [@sevenwood](https://boards.straightdope.com/u/sevenwood)\ **Post date:** [February 24, 2015, 9:15pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/52 "2015-02-24T21:15:51Z")
> [@aceplace57](#): > > It’s only been in the last couple years that prices have dropped. The technology may be 10 or 20 years old but it certainly wasn’t affordable. Whether LED technology is “affordable” in a particular situation depends on several factors. Yes, they (still) cost a lot more than their incandescent and CFL brethren initially, but they cost a lot less to run and they last a lot longer. Lasting longer becomes important in situations where outages cause significant problems. You are worried about outages during snowstorms - how about outages in general? LED stopights are far more likely to be working at any given point in time than their incandescent or CFL brethren simply because they last a lot longer. Lasting longer also becomes important when replacing a burnt-out bulb is expensive. A burned-out bulb in my bathroom takes me a minute or two to replace. A couple of workers, a bucket truck, and an hour or so to get to a failed stoplight, replace the bulb, and drive back to the station costs a fair amount of money, so to a cash-strapped municipality that’s a significant factor. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [February 24, 2015, 9:15pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/53 "2015-02-24T21:15:52Z")
> [@aceplace57](#): > > You may still have the regular incandescent traffic lights. It’s going to be quite expensive to change all the lights to LED. I doubt many cities have started the conversion. . . . That’s been answered by several people. No need to pile on. Would like to add that Stockton has been converting to LED streetlights for at least a few years. > [@aceplace57](#): > > How in the hell am I supposed to know if a particular city has converted to LED? It’s not exactly front page news. . . . . True. Maintenance in never sexy. If your sewage treatment plant added tertiary treatment, that wouldn’t hit the news either. > [@aceplace57](#): > > . . . I do know retrofits for any equipment costs money. Period. We’ve had a bad economy for years and tax dollars are not exactly flowing into city treasurers offices. . . . . Others have mentioned the rolling changes with the regular signal bulb maintenance schedule. For safety reasons, incandescents are changed on a schedule before they burn out. One thing I like about LEDs is that they can lose a bunch of individual elements and still shine on. > [@aceplace57](#): > > . . . What I do care about is that they work and they are visible in all weather conditions. I will be extremely pissed if a snow storm makes them difficult or hard to see. . . . . I read the article expecting to see snowed up signals. What I saw were easy to see signals. Pics or it didn’t happen. So I went looking and found [this.](http://nowiknow.com/stopsicles/) The article has more cites as well. Only found [one other pic](http://www.kens5.com/picture-gallery/news/local/2014/06/13/10482633/) online. It’s hard to tell if either of them are actually LEDs. The first one looks like one of [these.](https://www.google.com/search?q=incandescent+traffic+signal+lamps&num=20&safe=off&rlz=1T4GGNI_enUS586US587&tbm=isch&tbo=u&source=univ&sa=X&ei=3-bsVOzWC7eSsQS-34IY&ved=0CEcQsAQ&biw=1505&bih=657#imgdii=_&imgrc=sGc4GaTgyVPkzM%253A%3BWqQui7Ho_ug6LM%3Bhttp%253A%252F%252Feducation.mrsec.wisc.edu%252Fbackground%252FLED%252Ftraffic_light%252Fimages%252Fgreenlens.jpg%3Bhttp%253A%252F%252Feducation.mrsec.wisc.edu%252Fbackground%252FLED%252Ftraffic_light%252Fspectra.htm%3B800%3B751) It’s also hard to tell if the snowed over signals they mention would have been snowed over even if they weren’t LED. From the dates, it looks like people are dealing with the issue, if it’s an issue in their area. Sometimes they give the street crews scrapers on sticks. If it’s a problem in your area, complain to City Hall and/or your Public Works Department. Check online for contact numbers and/or online request/complaint forms. For amusement - [sign](https://www.pinterest.com/pin/121597258658858887/) ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [February 24, 2015, 9:25pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/54 "2015-02-24T21:25:36Z")
> [@sevenwood](#): > > . . . Lasting longer becomes important in situations where outages cause significant problems. . . . . That reminds me. I’ve heard that some signal cabinets\* have batteries to cover short term interruptions in electricity. Since LEDs use less power, the batteries will keep them running longer during interruptions. Of course not all signals have battery backups. \*Speaking of not knowing, until I was checking plans, I had completely not noticed those [grey boxes](https://www.google.com/search?q=signal+cabinet&num=20&safe=off&rlz=1T4GGNI_enUS586US587&tbm=isch&tbo=u&source=univ&sa=X&ei=DuzsVOrNKs3jsAT16oCIAg&ved=0CB4QsAQ&biw=1505&bih=657#imgdii=_&imgrc=J24VIPPWO_L7aM%253A%3Blk3eD4Ss0bwcUM%3Bhttp%253A%252F%252Fwww.hubbellpowersystems.com%252Fenclosures%252Fpads%252Fimages%252FTraffic-Signal-Base.jpg%3Bhttp%253A%252F%252Fwww.hubbellpowersystems.com%252Fenclosures%252Fpads%252Fquazite-selection-guide%252Ftransportation-determine-pad-req.asp%3B250%3B332) at intersections. ---
**Author:** ![gigi](https://avatars.discourse-cdn.com/v4/letter/g/a587f6/32.png) [@gigi](https://boards.straightdope.com/u/gigi)\ **Post date:** [February 24, 2015, 11:02pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/55 "2015-02-24T23:02:45Z")
> [@Ethilrist](#): > > If not, can we at least get them to switch to 24/7/366 during leap years? Nobody is promising that they will be-there-for-you-no-matter-what on any given February 29. ---
**Author:** ![Euphonious\_Polemic](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/euphonious_polemic/32/3002_2.png) [@Euphonious\_Polemic](https://boards.straightdope.com/u/Euphonious_Polemic)\ **Post date:** [February 24, 2015, 11:31pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/56 "2015-02-24T23:31:24Z")
> [@aceplace57](#): > > You may still have the regular incandescent traffic lights. It’s going to be quite expensive to change all the lights to LED. I doubt many cities have started the conversion. I literally looked at the date on this post, as I assumed I had wandered into a zombie thread from many years ago. Dude. Major cities have already made the change. ---
**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:** [February 24, 2015, 11:33pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/57 "2015-02-24T23:33:22Z")
> [@Euphonious\_Polemic](#): > > I literally looked at the date on this post, as I assumed I had wandered into a zombie thread from many years ago. > > Dude. Major cities have already made the change. Not just for traffic lights, but _streetlights_. ---
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [February 24, 2015, 11:50pm UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/58 "2015-02-24T23:50:17Z")
Well, I learned something today. 😉 What led me astray was the home LED’s that were/are so expensive. I couldn’t imagine putting thousands of them in city traffic signals. Now I have learned there were cheaper alternatives that didn’t have the white light that home consumer lighting requires. Several posters made a valid point that labor costs a major factor. Doesn’t matter if the LED costs more to purchase because they don’t require changing as often. It’s like at my job. Maintenance will replace all the tubes in a fluorescent fixture. Changing just the bad tube would cost too much labor in the long run. If a maintenance electrician has to travel to our building (we have at least 14 multi-story buildings on campus), setup a ladder, then they want to replace all four tubes in the fixture. ---
**Author:** ![Mdcastle](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mdcastle](https://boards.straightdope.com/u/Mdcastle)\ **Post date:** [February 25, 2015, 3:13am UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/59 "2015-02-25T03:13:24Z")
Traffic signal modules cost more than white household LEDs, about $50 each if bought in quantity. Still cheaper than running incandescent lamps especially considering maintenance. Just for fun I’ve tried household LEDs in incandescent sockets my traffic signals. They generally look bad for the same reason they’re not, in my opinion, nearly as good as incandescents for household use, the color spectrum is different (a lot more yellow relative to red, although newer LEDs, and the Cree TW series especially, are better), and the directional quality of the individual LEDs and the need for a heatsink means they don’t throw light evenly in all directions. It can look bad in a household fixture and even worse in a traffic signal. ---
**Author:** ![Claverhouse](https://avatars.discourse-cdn.com/v4/letter/c/13edae/32.png) [@Claverhouse](https://boards.straightdope.com/u/Claverhouse)\ **Post date:** [February 25, 2015, 3:37am UTC](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512/60 "2015-02-25T03:37:46Z")
> [@beowulff](#): > > Not just for traffic lights, but _streetlights_. I live in a smallish village: a few years ago the parish council installed new LED streetlights — they have 14 [?] downward facing bulbs. The light is pure and white and clear. Better than the previous streetlights, and one million times better than the _Portes de l’Enfer_ lighting of vile sodium lamps, orange or amber, so many terrible places in Britain are cursed with. Bad enough that household incandescents have a cheap golden glow: the orange is worse yet. [Previous page](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512.md?page=2) [Next page](https://boards.straightdope.com/t/led-traffic-lights-cant-melt-off-snow-and-ice-from-their-lens/713512.md?page=4)