# New GREEN LED traffic signals way too bright?



## Daniel Abranko (Aug 21, 2001)

Is anyone else here totally angry at the total lack of design sense put into the new LED green signals that are popping up all over the place? I think they're too bright to the point that I could almost have an accident from the extreme amounts of glare that they cause on rainy nights, and at night in general. I wonder sometimes, if the DOT approval board actually ever TESTS anything, or if they just approve anything that makes light. Why cant these lights have a photocell?

-Dan


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## Cyclops942 (Aug 22, 2001)

I've never had a problem with them, but I haven't encountered them much at night, and I've encountered them not at all on a rainy night.


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## NightShift (Aug 22, 2001)

They've changed a lot of them over where I live to LED traffic lights.
They don't seem to bother me at night, although I do agree they are very "attention grabbing" and they do glare a lot on the wet road when its rainy.
But I like them due to the fact that I love LEDs and the technology.
During the day, it is so much easier to see them:

        *LED Traffic Signal**Incandescent Traffic Signal*


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## Bart (Aug 23, 2001)

They've changed about 90% of them over on the route that I take to work. They are quite bright... but not too bright for me anyways. I could understand that for some people they might be pretty bright. They would be great for sunny days where it's harder to see them, but at night, I would agree that they should have some type of automatic brightness limiting circuit.


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## **DONOTDELETE** (Aug 23, 2001)

My first post here!





Being a junior transportation planner/ engineer, what I know is limited.

There are particular standards for the traffic signals to be followed, regular or new LED signal heads. Some of the organizations which are involved in the endeavor are Institute of Transportation Engineers (ITE, http://www.ite.org/), National Electronic Manufacturer Association (NEMA, http://www.nema.org/), etc. ITE and NEMA members, who are traffic engineers, planners, electrical engineers, do research and development of the standards that every manufacturer of traffic signals, signage, stripping and equipment strive to conform. These standards are what every transportation professional uses.

A dimmer is not what I would look for. Just another piece of equipment that can, and will, fail, IMHO. You never see street lights that dims, only on and off. It also creates the question, "is that a red/green light or a reflection?" That is a very dangerous thing. Traffic signal is an "either-or" thing. Either it is red or it is green. Yellow time gives enough time for you to brake (also an established national standard)

Try this link (just State of CA, plenty more out there):

Light Emitting Diode Program http://www.dot.ca.gov/hq/traffops/elecsys/led/ 

They are a little bright, but hey, at least u know it is telling YOU that it is green, and using a lot less energy in the process.

Hope it helps... there are lots of that I, a junior guy in the office, don't know


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## busbar (Aug 23, 2001)

The local electric utility reported a recent $100K rebate to a nearby meduim-sized city for wholesale incandescent-to-LED changeout of traffic signals.


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## The_LED_Museum (Sep 4, 2001)

Here in Seattle, I've only seen the red lamp changed over to LED, while the yellow and green lamps are still incandescent lamp bulbs. All but two of the pedestrian signals are either incandescent or neon discharge tubing, and I found the two LED ones at 7th and Olive:






These have a red LED "hand" illuminated for the don't walk signal, and a white LED "walking man" & red LED countdown timer for the walk signal.

Still waiting to see a green LED traffic lamp though...


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## Gransee (Sep 4, 2001)

For awhile my girlfriend and I had a "slugbug" game going everytime we saw an LED signal. Now they are everywhere. Besides being on buses, semi-trailers, and traffic signals, we have seen them in walk lights, reader boards and those flashing amber baricades on the side of the road.

Yes, they are brighter and higher contrast. I like the improved safety. 

One of the reasons we seem to always be back ordered on turquiose Arc-AAA's, is the traffic industry consumes almost every spare part so Nichia has a hard time sending us regular shipments. After an especially long delay on our last shipment I joked about making a midnight raid on our local traffic signal.

One of the reasons the new green signals may appear brighter is that they have more blue in them because they use the turquiose LEDs. As you know, blue is harsher to the eye than green.

Has anyone seen the luxeon stars used in traffic signals? One of our intersections here has them in the red signals. They look almost like a incandescent but you can see that the color is quite LED like and the pattern is different. The LS signals use a much larger LED and therefore do not have many discrete points of light. 

My favorite LED traffic signal? The white LED crosswalk lights. They used mixed ranks and so there is a lot of variation on tint and brightness among the LEDs in the signal. They look like a lite-bright set.

Peter


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## NightShift (Sep 4, 2001)

Every time i open my closet and see the lite bright box i think....how about an updated lite-bright that uses LEDs? That would really be a lite-BRIGHT





Maybe bad for the childrens' eyes





Interesting idea though...no?
Could use the new snap-led technology...


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## Bart (Sep 5, 2001)

stingmon... you don't have to go very far to see the green LED traffic signals. They're all over the redmond and issaquah area.


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## The_LED_Museum (Sep 5, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Bart:
*stingmon... you don't have to go very far to see the green LED traffic signals. They're all over the redmond and issaquah area.*<HR></BLOCKQUOTE>

They _are_ far if you don't have a car & don't want to fuss with Metro schedules or digging through the couch for bus fare.




Not my bag to travel 2 or more hours round trip just to look at a light bulb.





My normal travelling range (via motorized wheelchair) is north to the space needle, south to Safeco Field, west to the waterfront, and east to around 15th ave on the 'hill'. It is very rare that I venture outside of this area for any reason.

Offer free food under one of these new signals and I just might do it.


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## PeLu (Sep 11, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Stingmon:
*Here in Seattle, I've only seen the red lamp changed over to LED, *<HR></BLOCKQUOTE>

They have the highest saving there because traffic lights are red 90% of the time .-)

(maybe my observation is somewhat biased)


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## **DONOTDELETE** (Sep 12, 2001)

hey Stingmon, how many amp hours in your (edit) 'trike' batteries? - and what does the machine draw? (maybe we should have both a 'lights on' and 'lights off' amps number?) Maybe you could mount a bigger battery and go a little further some time..I got batteries for my photovoltaic system much cheaper at a distributor in Oxnard...


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## Bart (Sep 13, 2001)

stingmon, sorry... didn't know you were in a wheelchair. In that case, yes, it would be rather far.


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## The_LED_Museum (Sep 13, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Ted the Led:
*hey Stingmon, how many amp hours in your (edit) 'trike' batteries? - and what does the machine draw? (maybe we should have both a 'lights on' and 'lights off' amps number*<HR></BLOCKQUOTE>

For main power, it uses a pair of 31Ah gel-cell lead acid batteries in series (+24V).
The lights have their own completely independent battery, a 17Ah gell-cell mounted in between the two chair's batteries.
Like the wheelchair batteries, my lighting battery also has its own on-board charger, so I just park near an outlet and plug it in.

There is absolutely no difference in usable range whether I burn every light or run in "stealth" mode.





The reason I isolated the lighting wasn't originally to conserve battery power; but to help keep the chair's electronics isolated from radio noise. The immunity level of 20V/M as stipulated by the FDA for motorized wheelchairs therefore remains intact - and so does my warranty.





As for getting measurements of what the chair itself draws, that might be a bit difficult without actually cutting into a wire someplace and wrecking my warranty.

Current would also vary depending on terrain.
Loading on the especially steep hills in the Seattle area is probably on the order of 30-50 amps; while just going all-out on flat ground most likely uses around 5 to 6 amps average.

My old P.O.S. chair has a 55 amp controller, and a 35 amp pop-up breaker (which never went off during any time I used the chair).
This newer model chair has a 70 amp controller, and no user-resettable breaker (it's probably an auto-reset job on the controller board now).
I've also not had any circuit overload problems with the newer chair. But I see _other brands_ of chairs & scooters where the breaker will pop after going just a few hundred feet up a mild hill that my chair has no trouble with.

Now, the LED lighting package by itself (as currently in use) probably uses about 1A to 1.5A total; though I've never actually gotten a meter in there.


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## Daniel Abranko (Sep 17, 2001)

The main problem I'm seeing in all the Red/Yellow/Green led signals is that the Red/Yellow 8" ball has a 200-300lumen output while the "green" ball has 700-800 lumens output. Its not just my mind playing tricks... and in europe they DO have a day/night mode.


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## PeLu (Oct 19, 2001)

BTW at one of the lights I'm passing on my way home I've seen that there are at least 4 LEDs failing (in the green one). Have to stop and look at it closer, but I'm always in a hurry going home.


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## John N (Oct 28, 2001)

Actually, it does look like research is done on this type of thing. Check out:
http://www.lrc.rpi.edu/Ltgtrans/led/main-download.html 

It does look like they look at things like "discomfort".

Of course it's unclear that any given light was produced with these things in mind, or with an older spec. or whatever. 

I found these links when I started noticing that several lights around town seemed much brighter and the color was different than I had seen in an street light.

Interestingly, I couldn't determine if they were LED based or not. I thought they might be but haven't found any information about replacement projects, etc.

FWIW, I think I've seen one of these lights in downtown Seattle, near P-Square, I'll try to note the cross streets on my way home from work next week.

Oh, my impression of these lights were that they kicked butt. You are hard pressed not to notice them or mistake their state. I find them to be just a shade under "too bright".

-john


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## busbar (Oct 30, 2001)

Interesting link, John. There was an evening news report last year on a central-California city that got $150k from PG&E for relamping their signals with LEDs, so there must be something to it from a cost-savings standpoint.


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## John N (Oct 30, 2001)

Well, I think the light I was thinking about is at 5th and Cherry. I assume all directions are the same, but I travel eastbound, making the west facing light the one I'm looking at.

I'm not sure it is an LED based light. However, I do think it is different than previous lights and new. It appears brighter and of a different color than previous lights.

I've seen a lot of these pop up around the Seattle area and have been curious about them.

Of course, it could just be me imaging things.

-john


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## The_LED_Museum (Oct 30, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by John N:
*Well, I think the light I was thinking about is at 5th and Cherry*<HR></BLOCKQUOTE>

I'll have to check it out the next time I have a "lunch hour" to burn, or business to conduct in that region. Maybe when they blow up the library.






If the signal is newer and the color is "different" it could very well be an LED installation.
Gives me an excuse to clog up the internet with more bandwidth-wasting pictures.


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## sunspot (Nov 2, 2001)

Green led's in Alabama. Never thought to see them here but lo and behold(or gaoooolllllleee) the city of Vestavia Hills(B'ham suburb) converted. Had to detour there, demolition derby on the interstate. IMHO, overall it's nice. Way to bright when sitting on the starting line or going under them. My guess is the focus is to narrow. Does get your attention when it turns green. Welcome to the 21st century Alabama.


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## The_LED_Museum (Nov 2, 2001)

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by John N:
*Well, I think the light I was thinking about is at 5th and Cherry*<HR></BLOCKQUOTE>

I was at the post office yesterday, and while waiting for the light at 3rd and Union, I noticed the red ball has been changed over to LEDs. But all of the other traffic control devices in that intersection still have regular old light bulbs in them.


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## LEDagent (Nov 22, 2001)

Ii too have noticed the new lights here in San Diego, California. I was sooooo excited noticing them after gaining some knoledge here in CPF. I pointed them out to just about everyone i met and my brother too. But guess what there response was...."who cares?"

I think everyone should care as much as i do. These things do wonders, especially in mid day when the sun reaches a point exactly above the street lights so that you are blinded. These things can still be seen - better than the original reflector types. They also help at night when a big truck is blocking em, becuase the intense light output can be seen reflecting off of adjacent cars. All that, and LEDs are SOOOOooo cool - but i don't think they would care about that unless they were an addict like me.


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## Darell (Dec 5, 2001)

Craig -

If I could figure out how to get up there in my EV1, I could offer a line to you. I've got about 1500 Amp hours onboard (and 312 Volts). Be tough to keep the front wheels on the ground then!


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