SJCguy
Topic Author
Posts: 569
Joined: Thu Apr 05, 2001 4:39 pm

Lights Brighter On Your Stoplights?

Sat May 26, 2001 4:20 pm

I have noticed around here in the Bay Area they are installing new red/yellow/green light units on each stoplight. They are a single ball made up of tiny lights which look to be more true color and much brighter than the bulb and lense. They are installing them all around here in Los Gatos and San Jose. They almost seem too bright, are they doing it anywhere else?

SJCguy
 
LH423
Posts: 5868
Joined: Sun Jul 11, 1999 6:27 am

RE: Lights Brighter On Your Stoplights?

Sat May 26, 2001 11:30 pm

Yeah, they've done that to most of the red lights in Boston, and now seem to be working on getting the green lights done. I never really noticed a difference in lumination until about two weeks ago, I was driving at night, and stopped at a red light and noticed how bright it was.

The only thing I've noticed, is that over time, the individual lights go out, so you get left with little dark patches on the red light. Kinda strange to look at.

LH423
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aa737
Posts: 830
Joined: Wed Oct 06, 1999 5:49 am

RE: Lights Brighter On Your Stoplights?

Sun May 27, 2001 12:20 am

I think I read in the newspaper that these lights have to do with the whole power issue. I think they use less power then normal lights so towns have started to instal them. I haven't noticed any around San Mateo near my house, but there might be some and I just haven't seen them yet.
 
sccutler
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Joined: Thu Jan 27, 2000 12:16 pm

RE: Lights Brighter On Your Stoplights?

Sun May 27, 2001 12:26 am

Those are the new LED (Light Emitting Diode) signals; they use less power; they switch faster (turn on and off faster); and since they are an aray of many small lamps, they "fail soft," meaning there can be a number of individual LED's out but the signal still works.

LEDs are more costly to manufacture but the long-term cost is lower.

You'll also notice that many cars are beginning to have LED tail lamps.
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turbulence
Posts: 876
Joined: Sun Nov 14, 1999 1:33 am

RE: Lights Brighter On Your Stoplights?

Sun May 27, 2001 1:40 am

Not only in Boston or California. Here in Barcelona, too. As Aa737 says, it has to do with the power needed. As Sccutler says, it has to do with both long term cost and less failure probabilities. Actually, LEDs have a very very very long useful life.
But there's also some other good points. For example, in very sunny places, like California in this case, or in Southern Europe, when sun is low, you can find yourself in front of a traffic light of the "bulb-and-lens" system, and be absolutely unable to guess which of the three lights is on. Some twenty years ago the municipality of Barcelona tried to solve this problem installing coloured bulbs behind transparent or smerilized glasses. But LEDs are being successfully used during the last two-three years. This way, the two "lights" off look grey, and the one on, brightly coloured.
As for the cars, you have only to look for one (there's quite a lot of them) that have the two "normal" brake lights with bulb, and the third one in the middle with LEDs. If you pay attention, you'll see the center one be fully lightened about 2/10ths of a second faster. This, if your car has one of these LED lights, means, expressed in distance covered at US limit speed 55mph (88kms/h), that the person driving the car behind yours is going to see your indication 2,44 metres sooner. At a limit probability, imagine the difference between he/she managing to stop his/her car, let's say 44 cms far behind, or... 2 metres inside yours!!!!
That's why some cars are starting to incorporate their three brake lights made of LEDs

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N312RC
Posts: 2584
Joined: Mon Aug 28, 2000 10:58 am

RE: Lights Brighter On Your Stoplights?

Sun May 27, 2001 1:43 am

Yeah, weve got those in the Detroit-Metro Area too... They are supposed to last like 5 times longer than normal traffic lights. They are way sharper (much crisper) and WAAAAY brighter. In Detroit, they also have sun shields on the lights, so you usually dont have a problem seeing them anyways.
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