Flashing Third Brake Light

[alpg88]

Good point, flashing brake can be mistaken for a turn signal, thou stock red turns are not flashing at the same rate as preflash brakes, but few would tell a difference right away, and make a correct decision quick enough.
I would actually think some may not associate flashes with a brake activity at all, and not even attempt to brake until flashings stops, this is how everyone is taught in driving school, in usa at least, steady bright red is a stop light, flashing red tail light are turns, hazards or an emergency vehicle on duty.

 

[M@elstrom]

I don't see anything wrong with the flashing brake lights. If anything it does seem to work pretty well to catch your attention.

During my probationary driver days, I mounted a third brake light to the rear parcel shelf and using an analogue indicator flasher can it was wired to flash (slow indicator pace) whilst the OEM brake lights remained constant (under braking), admittedly we have amber turn signals but the local Police saw no issue with the added attention it caused

 

[alpg88]

Cop may be ok with it, but if someone rear ends you they will bring up your modified tail lights to their insurance company, no guarantee that they will win, but that can affect the case, they may not end up being 100% at fault. they may even end up with less fault than you, all because your lights were modified by you, and they are no longer compliant. In that case the driver of the car that rear ended you may even take you to a civil court and sue you. and may even win, cuz you knowingly did something that made your car's regulated safety equipment no longer compliant. that may not be enough for a criminal court but for civil court it is plenty.
Thou those who enjoy living in a none "sue anyone for anything" country, as USA is, do not need to worry as much,

 

[turbodog]

+

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.

That sounds like an edge case....

Whereas a google search for 'flashing 3rd brake light collision studies' yields DOT, European, etc studies which support increased awareness, faster reaction times, and fewer collisions with this technology.

And last time I checked... hitting someone from behind puts you at fault regardless of lighting, time of day, etc.

And that's a wrap...

 

[orbital]

And last time I checked... hitting someone from behind puts you at fault regardless of lighting, time of day, etc.

+

Reread my post, that's what I said.

 

[N8N]

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.


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.

a) those are something else that needs to be gotten rid of ASAP. They're not even legal but nobody's doing anything about them. I've been blinded before following an ambulance at night not running code just driving because they're using bright, flashing strobe lights for brake lights. Makes me want to lay on the horn and shine a spotlight in the rear view mirror every time they brake, but I know it's not the driver's fault, it's the (redacted) (very bad person) who built the thing and doesn't give a damn about regulations or safety.

b) If it really is 2 Hz that might be OK, I believe the threshold is around 4-5Hz for most people. NFPA 72 limits strobes used for fire alarm visual signaling to a range between 1-2 Hz. In practice it is almost always 1 Hz to synchronize with Code-3 temporal horns. I don't have access at the moment to the explanatory material but my memory says that it explicitly states that that frequency was chosen specifically because of photosensitive epileptics.

c) the whole concept just smacks of "looka me! looka me! I'm doing something different!" like putting green bulbs in your parking lights or headlight halos. And I can tell you from experience that drawing attention to yourself is not always good; people tend to steer at what they're staring at.

 

[idleprocess]

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.

Good point, flashing brake can be mistaken for a turn signal, thou stock red turns are not flashing at the same rate as preflash brakes, but few would tell a difference right away, and make a correct decision quick enough.

Having seen these things in the wild a few times, a ~2s burst of >2Hz flashing high-center brake light is a very different animal from a lower-mounted ~1Hz continuous turn signal. It's about optimal to draw your attention to the edge event of braking beginning, and quite effective.

There is a good argument to be made that there should be a minimum rate of deceleration (or more simply brake pedal depression) for the pulse to trigger since they're marginal in stop-and-go traffic and for drivers that are in the unfortunate habit of decelerating on the highway using brakes rather than throttling down.

a) those are something else that needs to be gotten rid of ASAP. They're not even legal but nobody's doing anything about them. I've been blinded before following an ambulance at night not running code just driving because they're using bright, flashing strobe lights for brake lights.

Seen a few of those myself - albeit not strobe lights, just steady-state yet bright enough to be a beacon - and that's an experience for sure.

The strobes / flashing lightbar lights during an emergency call are simply ... part of the territory ... and mercifully mounted high.

b) If it really is 2 Hz that might be OK, I believe the threshold is around 4-5Hz for most people. NFPA 72 limits strobes used for fire alarm visual signaling to a range between 1-2 Hz. In practice it is almost always 1 Hz to synchronize with Code-3 temporal horns.

I'm gathering from some sources (pg 2-3) that it's as high as 5Hz although much of the testing looks to have been at 3.6Hz. And since it's a brake light of ordinary intensity I suspect that context will further dampen the impact - as opposed to fire strobes that are by necessity quite intense.

c) the whole concept just smacks of "looka me! looka me! I'm doing something different!" like putting green bulbs in your parking lights or headlight halos. And I can tell you from experience that drawing attention to yourself is not always good; people tend to steer at what they're staring at.

Of all the lighting bling that one can engage in this is too subtle to be bothered with of its own sake - as opposed to underbody lighting, color-changing halos, conspicuous rock lights, lightbars, scads of non-compliant marker lamps, foglights under normal conditions, animated pixel displays, etc. Since we're all accustomed to center brake lights it attracts attention to the fact that a braking event has begun then terminates.

 

[pnwoutdoors]

+

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

Indeed. But that's merely a wish. Frankly, I won't want to rely upon it. (For "wish" it is, particularly exacerbated by the sheer number of dolts who putter on the internet with their damned devices, while they drive.) Hence such triple-flash initial sequences on tail lights.

Aids. Hardly detracts, IMO. Necessary, until such time the great majority of drivers shows competency with and attention to the task at hand.

One might argue that a continuously-flashing sequence might detract. (Don't know based on what, other than fears, particularly if a random flashing pattern.) Came upon a utilities/servicing rig, the other day, and his monstrous flashing tail light bars were stunningly bright and easily picked up. He was flashing, while warning he was slowing; then he was steady-state, once stopped. The flashing aided in detecting him, didn't detract.

But in my own experience on a bike it's clear I get wider berth (during passing of me) when having twin tail lights that have varying flash sequences. It's very easy to pick out. Can't imagine that on a vehicle it's much different, that initial flashing. My only suggestion, for car makers, would be to make those initial flashing pulses be as excruciatingly bright as possible, similar to the harshest and most-visible, attention-getting cycling tail lights. As we get more vehicles with decent LED lighting systems, it ought to become more possible to have such attention-grabbing

 

[jaycee88]

There is a good argument to be made that there should be a minimum rate of deceleration (or more simply brake pedal depression) for the pulse to trigger since they're marginal in stop-and-go traffic and for drivers that are in the unfortunate habit of decelerating on the highway using brakes rather than throttling down.

Yes - in Europe, adaptive brake lamps only begin flashing under emergency braking and above a certain speed. So it's not something you'd normally see.

 

[N8N]

Seen a few of those (bright lights used as brake lights on emergency vehicles) myself - albeit not strobe lights, just steady-state yet bright enough to be a beacon - and that's an experience for sure.

The strobes / flashing lightbar lights during an emergency call are simply ... part of the territory ... and mercifully mounted high.

I've seen it far too much, the big square red LED lights that I assume are actually intended to be high mounted strobes being used as brake lights on an ambulance or fire truck in a position similar to the normal brake lights on e.g. a school bus. A lot of them have a what I'd guess to be a 3-4Hz flash for a brief instant before coming on solid too, but even when they're on solid they're just painfully bright and couldn't possibly be compliant with the FMVSS 108 requirements for a regular brake lamp.

 

[Monocrom]

Wondering if the bans on strobing brake lights might have something to do with individuals who get seizures due to such lights. Image a driver behind you getting a seizure and then plowing into the back of your vehicle.

 

[PhotonWrangler]

I see an upside and a downside to flashing brake lights,

The upside is that while it's annoying, it is attention getting and that's the whole point of noticing that the driver in front of you has hit the brakes.

The downside - let's say that everyone has them now, and you're driving on the freeway at night when something happens that causes everyone in front of you to slam on the brakes. Suddenly you're overpowered and disoriented by a virtual disco of flashing lights in front of you. This might cause you to brake harder, risking a rear end collision.

 

[alpg88]

I do my braking based on distance of the car in front of mine, and seeing how the back of the car in front lifts up during hard braking, a lot more than brake lights, during bright sunny days not all car's lights even visible. even if all of them started blinking, it would not make me brake any harder. if anything my passports' brake assist would be responsible if someone rear ended me, if i tap on brakes fast, it goes into full power braking mode, and wont let go off brakes even when i let the pedal go, only when the car almost stopped it releases the brakes, wish i could turn it off but i can not,