LED roadway markers causing seizures?

[Turbo_E]

pokemon for the win!

 

[Max]

Here's a good picture:

from Introduction to Pulse Width Modulation (PWM)

 

[hizzo3]

some of the infinitys are like that too, and the murano. I think there needs to be a DOT regulation on the PWM frequency.

 

[hizzo3]

Just wanted to add, by upping the frequency, it would instead of being on for 10% off for 90% it would be on for 5% and off for 45% at double the rate.

Here's a good picture:

from Introduction to Pulse Width Modulation (PWM)

 

[Max]

Just wanted to add, by upping the frequency, it would instead of being on for 10% off for 90% it would be on for 5% and off for 45% at double the rate.

No, no, no, no.

I left out frequency, but let's say you had a frequency of 100Hz, that would mean each cycle is 10ms. A 10% duty cycle would mean on for 1ms, off for 9ms. Upping the frequency to 200Hz means that it's still 10% on and 90% off, but now each cycle takes 5ms, i.e 0.5ms on and 4.5ms off. Upping the frequency to 10KHz (cycle time 10 microseconds) means 1 microsecond on, 9 microseconds off.

 

[CyByte]

Why are people who are prone to seizures allowed to pilot 2000lb vehicles that are more dangerous then firearms ?

 

[PhotonWrangler]

It depends on the severity of their problem. Many people find that they can control their symptoms with medication. In addition, this is a unique situation that hasn't happened prior to the use of LEDs in roadside indicators, so those people who are affected by this will need to re-evaluate their ability to cope with strobing lights in their field of view, at least until technology and regulations catch up to alleviate this stimuli.

 

[OCEANBEAMER]

us dot did research in the 1960's on the spaceing of road embedded reflectors that caused what was then referred to as "flicker vertigo" at a certain speed the reflectors synched with certain brain wave patterns and induced a trance like state...changes were made in intervals and hues and the problem was solved...

 

[PhotonWrangler]

"Flicker vertigo"... what an interesting term. Sounds like a name for a grunge band.

 

[Connor]

Why are people who are prone to seizures allowed to pilot 2000lb vehicles that are more dangerous then firearms ?

This may go a lil off-topic, but I don't want this to be left uncontradicted.
Cars are not designed to kill people. The only use for guns is to kill.
I really doubt cars are more dangerous than firearms.

-Connor

 

[MSHasegawa]

This may go a lil off-topic, but I don't want this to be left uncontradicted.
Cars are not designed to kill people. The only use for guns is to kill.
I really doubt cars are more dangerous than firearms.

-Connor

No, I disagree. Cars and guns are just tools. They can be whatever the owner wishes them to be. You can kill with a pencil if used with the intent.

BTW, killing is not guns' sole purpose. In the hands of police and other public safety personnel, they are an "implied threat".

Sorry for OT... had to say this.

 

[EngrPaul]

I don't know about anyone else's State's policy on driver's license renewal.

In Pennsylvania, you basically keep getting a driver's license at any age, as long as you pay money every 4 years, and some doctor hasn't notified the commonwealth of your inability to operate a motor vehicle.

 

[Stereodude]

I really doubt cars are more dangerous than firearms.

FWIW: Far more people are killed by cars than guns each year.

 

[hizzo3]

I don't know about anyone else's State's policy on driver's license renewal.

In Pennsylvania, you basically keep getting a driver's license at any age, as long as you pay money every 4 years, and some doctor hasn't notified the commonwealth of your inability to operate a motor vehicle.

here in texas ironically you dont even have to speak/read english either....which i find a huge danger. medical history is rarely checked. For the most part you have to have it on your record that your license was revoked for killing somone due to medical reasons (in most cases never happens anyway).

As far as people that are prone to seizures, its mostly controled with medications. It just that the company that makes the LED roadway markers should have taken them into account. They took into account how bright and dim it should be right. So long as they are on meds they are fully functional and fine. The case would be no different as if they just stuck the leds in full power and blinded you as a driver....

 

[Connor]

FWIW: Far more people are killed by cars than guns each year.

Maybe in the USA, but not on the entire planet. ;-)

Tool or not tool, you can't leave the reason what something was built for out of the equasion. I'm pretty sure you can use a nuclear warhead to hammer a nail into a wall, but that's not what it was designed to do .. and certainly noone would call a nuke less dangerous than a firearm, just because less people die because of them every year.

-Connor

 

[EngrPaul]

You don't have to be licensed to be a passenger... I'm sure having an episode could be distracting to the driver.

 

[jayflash]

Over 40,000 annual deaths & +100k injuries from automobile accidents indicates how lethal they are in the hands of a typical driver. I think the typical gun owners are far more aware of how dangerous their weapons are than the average driver realizes how lethal their vehicles can be. The average driver strikes me as clueless.

 

[senna94]

While straying way way off the initial subject. I will interject that it is probably not a good idea to activate your Fenix P1D CE in strobe mode while driving!!!! :lolsign:

 

[PhotonWrangler]

It occurred to me that if LEDs can cause Flicker Vertigo and seizures in some people, this justifies the claims of many here (myself included) that visible PWM in auto tail-lights is annoying!

 

[TORCH_BOY]

I have heard of that happening in disco's, it all depends on the frequency of the strobe.
It just makes the car a more lethal weapon