[abduhl]

An interesting con to this LED lighting movement is that I have heard from a few CDOT engineers that the new LED lights do not put out enough heat to melt through snow that accumulates during storms and this has caused issues for traffic lighting. This is all second hand, of course.

[tghw]

Heat coils are very simple, as are thermostats. They could be added very easily to run when it's cold enough out that it would be helpful.

[GigabyteCoin]

A simple light sensing trigger (coupled with a timer) would do the trick.

Light should be on but see no light and it's winter time? Turn on the heater.

Same situation in the summer? Send out a tech, the light's probably out.

[abduhl]

And try to get a contractor to put them in out of the goodness of their heart or go through a rigorous study to prove equal compliance with federal and state regulations? Surely you jest.

[tghw]

They could be built as a part of the light, since we're changing all of that out anyway. Really not that hard.

Also, contractors shouldn't be studying compliance for new things. And you would pay them as you're installing the new lights. So not out of the "goodness of their heart" either. In fact, I have no idea what you're trying to get at here.

[abduhl]

Most items installed on a transportation project must meet the standard specifications for the state which generally incorporates federal requirements as needed. Anything installed must be "per spec" and manufacturers or contractors installed items that are not per spec can be grounds for a refusal of payment or refusal of acceptance.

Specifications compliance is solely the responsibility of the contractor (who generally passes it on to the manufacturer).

In order to install your lighting the contractor would have to prove specification compliance, include the additional cost of the lights, and still win the low-bid process that almost all state and federal transportation projects are subject to. Alternatively, the contractor could win the project without the new lights and then come back with a value-added change order and these are not uncommon in my experience.

I guess what I'm trying to say is that it's a good idea, it just isn't feasible in the field in my opinion.

[wwosik]

Well, what if specifications included something like minimum heat output? If government / society wants it, why wouldn't they include it in the specs?

[tghw]

Contractors don't spec roadway lighting, engineers do. The engineers provide guidelines that are (or should be) easy for the contractors to follow. Likewise, the DOT asking for bids could require certain types of lighting.

It's not always a quick process, but we do get innovations with some regularity.

[waterlesscloud]

So we'll never have any new lights?

[SwellJoe]

Nope. No new technology of any sort is allowed in government ever. No smartphones or tablets, because they don't meet the specifications for a computer. No electric vehicles because they don't meet the existing specification for automobiles that run on gas or diesel. Internet will never meet the specifications for a telephone system being installed into a government office...obviously that'll never fly.

Give up on anything new. Right now.

[Tyr42]

Check out http://ledsmagazine.com/features/2/5/8 It says that:

The energy consumed by a 100-watt GLS incandescent bulb produces around 12% heat, 83% IR and only 5% visible light. In contrast, a typical LED might produce 15% visible light and 85% heat.

You can't always put a LED light in a enclosed fixture, as it might even overheat. It needs some air flow to cool it's heat sinks.

[abduhl]

The question is a matter of power then. A 100W bulb at 5% light is 5W of light (assuming power vs energy can be compared this way... I don't do electrical engineering) which would correspond to a 35W LED producing less than one half of the heat when you consider that snow piling up in front of a light and the light enclosure will convert the IR to heat.

[mkesper]

It can: http://en.wikipedia.org/wiki/Radiant_flux

Light measurement depends on the "use case":

Needed energy/power vs. How much "light" can be used by the human eye. Or, how good is the light suited for selecting pairs of (black?) socks: http://en.wikipedia.org/wiki/Color_rendering_index

That's why there are so many ways of measuring light: http://en.wikipedia.org/wiki/Light#Units_and_measures