Flashing Third Brake Light

JAS

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A friend of mine gave me a replacement LED for the third brake light on my Ram 1500 this winter.

I finally installed it a week ago and noticed that it flashes three time when the brakes are applied.

From what I am finding on-line, it is not legal in Minnesota, which is where I live.

It seems like it would be a good thing for states to consider to improve safety.
 
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idleprocess

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From what I am finding on-line, it is not legal in Minnesota, which is where I live.
While the law is doubtlessly clear more than a few OEMs that supply these and I doubt...
  1. The OEM is making state-specific versions
  2. LEOs are routinely handing out citations for a statute that is presently or is soon likely to be pre-empted by federal law
It seems like it would be a good thing for states to consider to improve safety.
Agreed so long as it's reasonably defined so as to draw attention without a strobe effect. However I do not believe that this has been mandated or even fully promulgated. A quick search finds that this is hardly a new idea to the NHTSA:
The less-familiar FMCSA looks to have granted a limited exception to FMVSS 108 in 2020 to National Tank Truck Carriers to install a red or amber brake-activated pulsating lamp on the rear of trailers.

The automotive OEMs may well be supplying these things on a similar provisional basis.
 

KITROBASKIN

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I pulse my brakes a lot anyways, though a panic stop won't, that's for sure. Curiously, our 2019 Tacoma smoothed out its braking surfaces by about 20,000 miles (what I remember).

We have a lot of significant grades here and the idea is to try to keep the discs and pads cooler to last longer by pulsing.

Any information on that, yea or nay?
 

idleprocess

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A tad OT...

We have a lot of significant grades here and the idea is to try to keep the discs and pads cooler to last longer by pulsing.
Back of the napkin a given mass going down a given slope that must not exceed a maximum speed going downhill will have X joules to dissipate one way or another. Braking strategies elongating braking duration will reduce peak heat but that X joules is still absorbed by the brakes thus the wear will probably be about the same. Conspicuous engine braking or more subtle throttle management can displace a sizeable fraction of X as compression heat in the cylinders - which will go out the radiator rather than metal brake components (there's some contention that engine braking is Bad Thing™ however I submit that it's little different to the engine than propelling the vehicle).
 

alpg88

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I once got stuck behind an ambulance with preflash brakes, in traffic, but its brake lights were insanely bright, mounted high and were huge, now that was annoying, regular cars with preflash i see almost daily, after a while you stop paying attention to that. I honestly do not think that contributes to safety.
It was believed that led stop lights will reduce rear end collisions, cuz leds lights up sooner than a bulb, thus giving a driver extra few feet, turns out it had no effect on rear end collisions, at least data does not show that.
 

DRW

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It was believed that led stop lights will reduce rear end collisions, cuz leds lights up sooner than a bulb, thus giving a driver extra few feet, turns out it had no effect on rear end collisions, at least data does not show that.
NTHSA says there is a 3.6% reduction using LED brake lights.

A Fleet Manager claims a 33% decrease with the pulsating brake lights.
 

theory816

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Who cares if its not legal in Minnisota. What are they going to do, replace the taillights? LOL. Besides, I doubt they have a good reason to ban it.

I don't see anything wrong with the flashing brake lights. If anything it does seem to work pretty well to catch your attention. If I were to put in a change order, I would make it flash only at high speeds. Doesn't make much sense to flash at low speeds. Hell, I would even turn off the high power brake light mode when at a stop. You don't need all that lumen as I can tell your car is right there when we are stopped.
 

N8N

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Count me in the camp of hating these things. Anything that makes it less clear what a driver in front of you is doing is not good, and I seriously doubt they have been evaluated for safety for photosensitive epileptics.

For a real safety benefit, I do like LEDs as opposed to incandescents, as they have a visibly noticeably faster rise time.
 

idleprocess

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Anything that makes it less clear what a driver in front of you is doing is not good
Whenever I've seen these things it's been crystal clear what the other vehicle is doing. Pulse rate is markedly faster than a turn signal, out of the relative plane of the tail/signal lights.

I find the ongoing allowance for tail light as turn signal immensely more confusing and wish DOT would end it.

and I seriously doubt they have been evaluated for safety for photosensitive epileptics.
Since overpowering strobe lights have been in widespread and longstanding use for emergency vehicles I've got my doubts that a ~2s duration pulse at ~2Hz at ordinary brake light intensity is going to be a problem.
 
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turbodog

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Whenever I've seen these things it's been crystal clear what the other vehicle is doing. ...

Yup, 100%. +1 on the tail/turn combination also. And add to that, we need to spec amber turn signals. Talk about confusing... can't tell if someone's turning or has a burnt out light on one side.
 
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I find the ongoing allowance for tail light as turn signal immensely more confusing and wish DOT would end it.
I agree. As far back as driving a 1978 Chevy Nova with an unreliable distributor, I realized the flaw of combining a brake light with a turn signal. I would put on my hazards, but as soon as I touched the brake, they would stop flashing and be constant on. Talk about ambiguity! Amber signals would be ideal, but even separating to two red lamps would be helpful.
 

pnwoutdoors

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God I hope not. Those things are annoying ...

Annoying, perhaps. But, attention-getting. Which is the point.

People can take a pill, if they get too bummed. (Far too many reactionaries in the world, as it is.)

But if it aids in detection and increases the likelihood an attention-wavering person will see the need to slow/stop, then it ought to be a worthwhile feature.

On a bicycle, I frequently ride on some roads that have much-reduced lighting along some stretches, due to dappled sunlight and a great amount of foliage on the trees. Having a bright flashing taillight and a bright random taillight helps in noticeably increasing the space of vehicles passing me from behind as well as noticeably reducing the incidence of close-following vehicles.

On my own vehicle, there's a console setting to select whether to do a three-flash brake light or a steady-on pattern. Since going to the three-flash mode, I've noticed fewer cars brake dangerously closely (under similar circumstances). Hard to know for certain, in either the bike or car case, but it seems to be so.

I'm sure it'll vary from place to place dependent on the level of disregard inherent in much of the driving population, and very possibly by which vehicles implement such features (ie, some are bright, while some have pointless or even deliberately-dimmed lighting levels). Couldn't say. But it seems to work better in my area, for my car and bike.

On a bike, a couple of these go a long way toward being seen:

 
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idleprocess

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orbital

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If you're actually paying attention while driving, it's not really necessary.

Having the brake lights stay On for a couple seconds after releasing the pedal, yes.
> there are left turn scenarios that it would help.
 

idleprocess

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If you're actually paying attention while driving, it's not really necessary.
Statistically speaking, sufficiently few drivers are actually paying attention, thus the proliferation of safety aids like tires with tread patterns, antilock brakes, lighting, seat belts, etc. And even for those that are, the additional margins of this sort of feature are welcome.
 

turbodog

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If you're actually paying attention while driving, it's not really necessary.

Having the brake lights stay On for a couple seconds after releasing the pedal, yes.
> there are left turn scenarios that it would help.

Given that 50% of drivers are worse than average... is that a conversation we want to even explore?
 

alpg88

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NTHSA says there is a 3.6% reduction using LED brake lights.

A Fleet Manager claims a 33% decrease with the pulsating brake lights.
I'm a part owner of a body shop, in about 16 years i have a stake in it, I see no decrease in rear ended cars, and cars with smashed front end that did rear ending, coming to our shop, thou 3.6% is too small to really notice.
I claim that fleet manager in question is full of crap, 33%?!?!,. lmoa sure i believe it.
 

orbital

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There could be a situation where there's a sea if blinking taillights in front of you & it hide/mask a genuine turn signal, particularly at night.
If you plow into someone in front of you, you're at fault.
 
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