Federal Document No.98-
Initially, in 1994 … that is, 15 years ago …in another NPRM dated April 8, 1994, Federal Document No. 94-
Even the mild LED warm up exercise outlined in SAE 1889 is no where near stringent enough to qualify a LED Brake/Turn Signal for outdoor use in fully exposed Trailer applications, particularly when considering the fact that fully exposed Trailer Brake/Turn Lights are most needed to do their job when used on hot days in “close up” traffic while hanging out over very hot pavement.
In the 1998 NPRM (attached) …NHTSA gives absurd and nonsensical excuses in order to obviously avoid addressing the LED heat loss problem, and therefore, pass it on to the next generation of employees …and still today … nine years later …NHTSA still totally ignores this real life safety problem.
Basically, in 1998, NHTSA’s Rulemaking employees claimed it was too hard and too expensive to Test (and compare) various LED outputs at increased ambient temperatures when heated from room temperature while under full power up to ≈ 200°F Ambient for 10, 20 and 30 minute “on” cycles, and at the same time, measuring their Signaling Power losses. To this day, NHTSA employees continue to stick their heads in the sand on this issue, which is clearly a “dereliction of duty” and an insult to NHTSA’s main reason for “being”.
Who and where are the people who came up with such stupid excuses for not doing their job? … have they been fired as they would have immediately faced in U.S. Industry?
Regardless, since 1994 … the laws of Physics and Chemistry haven’t changed and it is still a known fact that LEDs lose about 10% of their output for every ≈ 18°F of increased “Junction temperature”. I’ve read in DOE reports that the “junction temperature” is always ≈20°F more than surrounding ambient temperature.
Therefore, a increase of say … from 72° to ≈150°F… which represents an easily attained internal temperature increase for a Trailer’s fully exposed Tail Light Assembly when used consistently on a hot day in close up traffic conditions while mounted only 15 inches from a hot, radiating pavement … produces a real life Candela loss of at least ≈50%. Further, if allowed to heat more … the LEDs can be destroyed.
Incredibly, room temperature is still acceptable to NHTSA as the official “Qualifying” Test Temp for LEDs and you can bet this is what the current, “walking the line”, cheapened LED Brake Lights are being tested at, where in real life use, they’ll lose ≈50% when used on a hot day in tight traffic.
Ask any LED Manufacturer about this subject and see what kind of answer you get!?
Last year, some of our traffic lights in Livermore, CA became so dim on very hot days, they had to be returned to the manufacturer. Think of the dangers this caused and the recall cost to the manufacturer.
NHTSA ignoring these realities produces a huge Public safety problem that can’t be ignored.
LOOK AT THE MILLIONS of “STAND IN” “LED” CHMSL FAILURES used on Caps/Shells, etc.
Anywhere in the U.S., you can see “Stand In” LED Center High Mounted Brake Lights (CHMSLs) mounted on the tops of “Caps/Shells/ Toppers/Canopies” that have accumulated over the past 10 years. Observe the 50% of non working ones and note that half of the half left LED types are only partially working and/or significantly dimmed.
*”Stand in” means a mandated Replacement CHMSL for the Factory provided one … which replaces the “covered CHMSL”, which results when a Cap/Topper/Shell/Canopy is mounted on a typical Pick -
Of course, any up close, bumper to bumper traffic represents conditions where bright and conspicuous Brake/Turn and Lane Changing Signals are needed the most.
Also, note that the half ± of the LED Stand In CHMSLs remaining working … generally work only partially or poorly! … and virtually all are “Effective Projected Luminous Lens Area” (EPLLA) deficient as well …check it out! –
Can you imagine how many Rear End Crashes will be caused by non working, dimmed, and EPLLA deficient Stand In LED CHMSLs that are used on (I estimate) 30 million Pick Up Trucks produced over the past 10 years? One-
Also, consider that the average following drivers’ brain is relying on using the CHMSL in front of them as its primary conscience and subconscious source for telling their foot to “Brake”, but since the CHMSL they’re counting on is Non Working or Dimmed … many more than ordinary Rear Enders are bound to occur to this group.
The same scenario exists in the case of “following drivers” directly behind (and in adjoining lanes) with a Trailer, RV, or Big Rig in front of or to the sides in “up tight traffic” … where the following driver’s attention will also consciously and/or subconsciously affix on the ahead vehicle’s “Conventional” Brake/Turn/Lane Changing Lights. If any Brake, Turn or Lane Changing Signal Light is ineffective … or not working … then what? What percent increase in Rear Ender and Clipping Collisions will take place over the lifespan of these kinds of vehicles?
Furthermore, since “LED” Brake Lights all produce only a narrow output of effective light, and their output is still allowed by NHTSA to drop to zero output at a mere 10° Up angle, the safety potential of low mounted Conventional Brake/Turn and Lane Changing Lights are greatly reduced – Example: A Brake Light on a Trailer that has its 10° Up Limited “LED” Brake Signals located only 15 inches off the pavement is not at all seen at closer than 16 feet by the average Auto driver. And also consider that at the 10° Up observation angle, the Signal’s intensity only is required to be 15 CP, where it could be as much as 300 CP. *How dumb is this?
This narrow output of LED Brake/Turn/Lane Changing Signal light is a great detriment to road safety no matter how you look at the situation. More LEDs pointing in varying directions are needed to accomplish what the Incandescent Brake light has always provided the public. More on this subject later!
Bottom Line, LED Brake/Turn Lights must be, at the least, as large, reliable, conspicuous and as effective as typical Incandescent Brake/Turn/Lane Changing lights… no matter how hot the day or no matter how “close up” the traffic is.
“FILL and DRAIN” SUBMERSIBLES DESTROY all Inside Reflex and Lens FACETING
Head Lights have always been required by NHTSA to be extensively tested using strict, detailed FMVSS #108 Physical Testing Mandates, so the Public is guaranteed their Headlights can’t collect degrading internal dust and grime, nor are they dimmed from internally trapped moisture precipitants. And when they burn out … after a reasonably long lifespan … a standardized, reliable, new Headlight bulb can be easily found anytime, anywhere by anybody!
It’s a known Physics fact that any Dust, Grime or Precipitation put on any inside Lens or Reflex surfaces decimate the light output. This is true of Headlights as well as for Brake Lights and Reflectors. Therefore, we have to ask … “Aren’t Brake/Turn and Lane Changing Signal Lights just as important for our road safety as Headlights”?
Referring to the Society of American Engineers on this issue:
SAE J1398, Section 6.2.4. says on this matter:
Where it is expected that lamps must perform an extremely severe environments, such as off-
For NHTSA to allow a so-
“AIR TRAPPING” DESIGNS must always PROTECT the REAR REFLECTOR from Grime and Dust
Multi Function, “Air Trapping”* Light Designs must provide Grime and Dust protection for any bottom positioned Reflector used in an Air Trapping, Submersible Design because the “Compression Water Column” in a typical Air Trapping, multi function light always travels ≈ 1” to 2+” up into the sealed Air-
Over the past 20 years, we have always provided a separate, clear protective window in our all “SP” Air Trapping Designs. This makes sure the important Rear Reflector doesn’t degrade from Grime or Dust deposits and therefore become a Safety Hazard for public use.
You will not find this “Fail Safe, Protective Feature” built into Peterson®, Wesbar® (Cequent®) or Optronics® so-
Many years ago, I was getting my hand bandaged for a chemical burn at our small town Livermore hospital when Ambulances brought in a whole family that had pulled off onto the shoulder of a local highway and “crashed” into a “left behind Boat Trailer” that had a flat tire. They were all hurt and bleeding and I could hear the father saying “I didn’t see the trailer because I didn’t see any reflectors”.
I’ve told this story over the years to all boat trailer manufacturers that would listen … trying to warn them of the Liability involved with allowing Reflectors to degrade below FMVSS #108 minimal mandated requirements.
These kinds of liability circumstances can produce large jury awards and large out of court Settlements you’ll never read about. You should always think about the unexpected when selecting your Lighting. Yes! currently FMVSS #108 does not address inner lens and inner reflex grime and dust degradation problems … but, of course, it should! However, you should be aware that NHTSA is under obligation to Recall any kind of apparent safety hazard on our roadways covered by Federal Motor Safety Standards or not … using the main objective statement of the 1966 Vehicle Safety Act – check it out!
This means if the Lights and Reflectors you use are not designed to take Submersion* and Dusty Roads without dropping below the minimal outputs spelled out in FMVSS #108 – your Liability is greatly increased.
To knowingly or unknowingly ignore these realities and facts produces liabilities that should be avoided.