Advocacy & Safety - Okay, I don't get this whole "judging distance" thing....

As it relates to rear lights. I keep seeing the same argument for solid lights over and over and over again.....vehicles being able to judge the distance better. But tell me SPECIFICALLY in what circumstance is that IMPERATIVE for a vehicle to know? Do you really want vehicles thinking about such things.....or would you rather have a vehicle see you first and foremost and give you a wider berth because maybe they can't judge the distance properly regardless? They (the vehicle and driver) are coming up behind you. It's a rear light. The implied sense of them judging distance makes it seem like it's important for them to figure out just HOW CLOSE they can get. I want them to react, not think. I want them to go around me or stay back as far as possible if they can't get around (ie if I'm taking the lane and they can't safely pass). It would seem to me in that set of circumstances you would want the brightest, most annoying light possible. Doesn't a blinking light suggest THAT even beyond the point of initial recognition? Doesn't the unique flashing pattern of a Superflash, for example, command more respect than a solid light in that regard?

Finally, if a flashing pattern does indeed distort the judging distance as many keep indicating.....just exactly how is the perception altered? Is it a distortion of the object actually being closer or actually being further away? Or does it matter? Don't you still want the vehicle to not worry about distances and avoid you completely (ie going around you or staying WAY back)? Or is the lateral distance affected too?

As is the case with most things, including the majority of arguments pro and con in this bike forum, I'm not looking for a definitive answer.....more of a consensus. What am I missing here? :crash:

It would seem to me in that set of circumstances you would want the brightest, most annoying light possible. Doesn't a blinking light suggest THAT even beyond the point of initial recognition? Doesn't the unique flashing pattern of a Superflash, for example, command more respect than a solid light in that regard?



You don't want to blind or distract the driver either.

I drive a lot, and most of my driving is done while it is dark. New cars have these horribly super bright lights now, and I'm sure the drivers of cars with those lights think they're being safe ... but they aren't! When a car approaches me with super bright lights, I can't see anything ... I'm blinded. i can't see where the road goes, or if there's an animal running out in front of me, or anything. If a car with super bright lights comes up behind me, it's the same thing ... not only does it give me a nasty headache, but the reflection off my mirrors also blinds me, so I drive with my mirrors tilted so I have some hope of seeing where I'm going.

While cycling in the dark, I've had drivers flash me to turn down my lights so I know they are bright. If they are too bright, or perhaps pointed in the wrong direction, they could also blind the driver. And that's the last thing I'd want as a cyclist ... a blind driver coming at me.

Plus there was some evidence published some time ago that drunk drivers are attracted by flashing lights ... that they feel compelled to drive toward the light. And as a cyclist, I can't say I'd want that either.

Not to mention that if you're cycling in a large group of cyclists, the last thing you want is to have some or all of them with flashing lights ... it's annoying and dizzying.

I always use the flasher in the dark. Having passed plenty of bikes in the dark, in my car, I tink flashers are clearly better.

I think the theory is that with only a blinking light the driver may think you are farther away than you really are and run into you. I'm not sure I believe this. Besides, if you are wearing an honest to goodness reflective safety vest, that will by far be the brightest steady or "solid" light a driver sees, way brighter than your little blinkie. Have you ever seen how strongly these vests reflect headlamp light?

i always use the flasher in the dark. Having passed plenty of bikes in the dark, in my car, i tink flashers are clearly better.

+1.

Not so much for distance, I don't think anyone can accurately judge the distance to a light in the dark, particularly not a single light, but spacial awareness. Is that light moving? A flashing light is a better attention gainer than a light that is continuously on. It's much easier to tell if a steady light is moving.

Better to have multiple lights. For example: I run one bank of my seatpost mounted Cateye TL-LD1000 on flashing, the other bank is continuously on. The Mars 3.0 on the back of my helmet is continuously on. The Cateye TL-LD500 on the back of my rear rack is continuously on, unless I'm towing a trailer. If I'm towing a trailer, as I will be this morning, I have a TL-LD500 on each rear corner of the trailer running continuously on.

I've given up on the flashing lights feature of my reflective vest. I have decided that I don't like have flashing red lights to the front.

learn about how the cones and rods in your eyes transmit signals to the brain
and how the brain processes information



a solid light sends a clean signal to the dome and allows the observer more mental
freedom to process other aspects, like distance

a blinking light introduces additional neuron firing that just makes the job more difficult

You don't want to blind or distract the driver either.

I drive a lot, and most of my driving is done while it is dark. New cars have these horribly super bright lights now, and I'm sure the drivers of cars with those lights think they're being safe ... but they aren't! When a car approaches me with super bright lights, I can't see anything ... I'm blinded. i can't see where the road goes, or if there's an animal running out in front of me, or anything. If a car with super bright lights comes up behind me, it's the same thing ... not only does it give me a nasty headache, but the reflection off my mirrors also blinds me, so I drive with my mirrors tilted so I have some hope of seeing where I'm going.

While cycling in the dark, I've had drivers flash me to turn down my lights so I know they are bright. If they are too bright, or perhaps pointed in the wrong direction, they could also blind the driver. And that's the last thing I'd want as a cyclist ... a blind driver coming at me.

Plus there was some evidence published some time ago that drunk drivers are attracted by flashing lights ... that they feel compelled to drive toward the light. And as a cyclist, I can't say I'd want that either.

Not to mention that if you're cycling in a large group of cyclists, the last thing you want is to have some or all of them with flashing lights ... it's annoying and dizzying.

But are there any bike taillights that are anywhere near the brightness of car head lights? Perhaps there are and I'm just not knowledgeable about them, but I've never seen them.

I'm bi. I picked up a second tail light and set one on constant and one on blink mode. And I wear the safety vest.

The distance perception problem occurs with the strobe lights fitted on some aircraft. These only flash on for a period of 1/1000 sec and air traffic controllers reported problems judging distance and sorequest steady lights in addition to the flashers. This problem doesnt happen with LED blinkies.

But are there any bike taillights that are anywhere near the brightness of car head lights? Perhaps there are and I'm just not knowledgeable about them, but I've never seen them.

Why compare headlights to taillights?

But are there any bike taillights that are anywhere near the brightness of car head lights? Perhaps there are and I'm just not knowledgeable about them, but I've never seen them.

I'm sure you can build or buy ones that aren't bike-specific. However, bike taillights don't need to be anywhere near as bright as car headlights; car taillights aren't nearly anywhere as bright as car headlights. Ditto with motorcycles. A Dinotte 400 taillight (300 lumens) will easily match or exceed motorcycle taillights and is comparable to car taillights.

Why compare headlights to taillights?

I was referencing Machka's post where she talks about being blinded by car headlights.

You don't want to blind or distract the driver either.

I drive a lot, and most of my driving is done while it is dark. New cars have these horribly super bright lights now, and I'm sure the drivers of cars with those lights think they're being safe ... but they aren't! When a car approaches me with super bright lights, I can't see anything ... I'm blinded. i can't see where the road goes, or if there's an animal running out in front of me, or anything. If a car with super bright lights comes up behind me, it's the same thing ... not only does it give me a nasty headache, but the reflection off my mirrors also blinds me, so I drive with my mirrors tilted so I have some hope of seeing where I'm going.

While cycling in the dark, I've had drivers flash me to turn down my lights so I know they are bright. If they are too bright, or perhaps pointed in the wrong direction, they could also blind the driver. And that's the last thing I'd want as a cyclist ... a blind driver coming at me.

Plus there was some evidence published some time ago that drunk drivers are attracted by flashing lights ... that they feel compelled to drive toward the light. And as a cyclist, I can't say I'd want that either.

Not to mention that if you're cycling in a large group of cyclists, the last thing you want is to have some or all of them with flashing lights ... it's annoying and dizzying.

Your problem is your light is pointed up too much and into the drivers face and not actually on the road in front of you. I've not had a single driver complain about my P7 being too bright and believe me...that thing is bright if you stare right into it. Being blinded by the headlights of other cars is caused by the same thing...improperly adjusted lights. Lights need to be bright, but at the same time you need to know how to aim them. If you are at the bottom of the hill and there is a car at the top, yeah their lights will hit you in the eyes, you can't do much about that, light isn't affected by the earths gravity enough over such a short distance.

Plus there was some evidence published some time ago that drunk drivers are attracted by flashing lights ... that they feel compelled to drive toward the light. And as a cyclist, I can't say I'd want that either.
Doncha mean there were some Internet Rumors and Speculations posted about this moth-like phenomona allegedly being the cause of a handful of accidents, rather than any credible "evidence" published?

The steady blinking lights tend to attract the (unwanted) attention of drunk drivers; and for others it affects their depth perception, and makes it tougher for them to really judge closing distances. A pulsing light such as the Planet Bike Superflash or the various Dinotte models gives you the same perceived motion so as to attract the eye, but not fixate on your tail light.

Still it's a good idea to run two lights at night -- one flashing to attract attention, and one steady, to help motorists better judge their distance from you.

The steady blinking lights tend to attract the (unwanted) attention of drunk drivers...

Could you post some scientific sources supporting this speculation?

...it's a good idea to run two lights at night -- one flashing to attract attention, and one steady, to help motorists better judge their distance from you.


I picked up a second tail light and set one on constant and one on blink mode.

Yay! I win!

What's my prize?

the Moth Effect.

http://www.visualexpert.com/Resources/motheffect.html

Conclusion:
The "moth-effect" is a myth in one sense and reality in another. The idea that drivers may steer off the road when they fixate flashing lights is likely correct, but they are not drawn to the lights like moths to a flame. Rather, they inadvertently steer rightward, which may or may not take them into collision with the roadside vehicle. Even normal, alert drivers in daylight conditions may steer in the direction of eye position during periods of intense fixation. The cause is likely error in judging heading under eccentric fixation when optic flow cues are minimal and when attentional focus prevents sensing of the need to correct the error. Although bright lights and fascination are not required, of course, it is impossible to rule out these factors in some accidents.

Beware of having both rear lights on flashing mode lest you have "blonde driver"
not willing to pass you because he/she didn't know which was you were going!
This actually happened to me 3 years back.
dogbitteneear

I'm bi. I picked up a second tail light and set one on constant and one on blink mode. And I wear the safety vest.

I roll both ways too! SuperFlash on flash and a Dinotte on steady. Blinded and mesmerized at the same time...

the Moth Effect.

http://www.visualexpert.com/Resources/motheffect.html

Conclusion:

So it's got nothing to do with inebriation, potentially affects all drivers, day or night, and should not be attributed to being "drawn to the blinking light", but rather, with steering rightward. Note the article also doesn't comment on the unlikelihood of this occurring in real life situations. Hopefully someone can circulate this article whenever someone else posts the obligatory "I don't use flashing lights because drunk drivers will hit me" meme from now on.

not to hijack this thread or anything but does anyone besides me ever want to just yell at bikers riding in the night with nothing on to tell them to get a blinkie and a vest? because on my work today right at the last min i saw this biker with nothing on except pedal reflectors. and i needed to be in the lane he was in the turn so i kind of cut him off :( but while passing him i wanted to roll down my window and throw a vest at him and tell him to get a blinkie. part of me just wants to buy a handful of reflective vests from work (like $1 a pop) and keep em in the car and throw them at cyclists riding at night with nothing on. just my $0.02

not to hijack this thread or anything but does anyone besides me ever want to just yell at bikers riding in the night with nothing on to tell them to get a blinkie and a vest? because on my work today right at the last min i saw this biker with nothing on except pedal reflectors. and i needed to be in the lane he was in the turn so i kind of cut him off :( but while passing him i wanted to roll down my window and throw a vest at him and tell him to get a blinkie. part of me just wants to buy a handful of reflective vests from work (like $1 a pop) and keep em in the car and throw them at cyclists riding at night with nothing on. just my $0.02

I believe you're looking for this (http://www.bikeforums.net/showthread.php?t=491407) thread.

the Moth Effect.

http://www.visualexpert.com/Resources/motheffect.html

Conclusion:

Also note that the conclusion about the murky possibility of a Moth Effect of bright lights doesn't make any distinction between flashing or constant bright light "distractions."

Also note that the conclusion about the murky possibility of a Moth Effect of bright lights doesn't make any distinction between flashing or constant bright light "distractions."

Yup... but the write up does... read the whole thing and decide for yourself.

Who here has ever seen a riders, with blinkies on either them or their bikes, and been unable to judge the distance? If what you could see was the light only, perhaps that would be difficult, but I have never seen a blinkie flashing without also being able to see the rider (unless they were so far away that only the blinkie could be seen and were therefore in no danger from me, either riding or driving).

We use all visual clues, including the changing size of the cyclists as we approach them.

Only this evening, I saw a rider coming in the opposite direction with a strobe-bright flashing front light. I had no difficulty seeing how far away he was. He had a similarly bright flashing rear light and seeing the rider himself and how far away he was getting, in my door mirror, presented not the slightest problem.

It seems to me that we are seeing the beginning of a new urban/cycling myth.

By the way, how many drivers are drawn into collisions with emergency vehicles because of their flashin lights?

Until I see evidence to the contrary (i.e. a qualified, scientific study); my personal experience tells me that a flashing light garners more attention than a solid light. Especially so amongst a sea of other lights.

I'm sticking to my current lighting rig. I run a PB blinkie at the bottom of my left seat stay, a Mars 2.0 on the back of my rack, a Mars 3.0 high up on my seatpost and a white Xenon flasher a little lower on my seatpost. I notice cars moving over much earlier than when I ran just a solid red tail light. Nothing scientific, just my own anecdotal observations.

I run one solid and one flashing, one on top of the other. The flashing to draw the eye, and the steady so that the eye has a good reference point to judge speed.

I don't think it's so much that a flashing light causes one to misjudge distance, but rather that a flashing light makes it difficult to judge speed because the eye has to re-find the light when it turns on and judge speed by the distance the light moved between blinks. Just thinking logically, this cannot be as accurate as an eye which tracks a steady light.

This is probably most applicable to blinkers which flash slow enough so the light appears to go on and off to the eye. Most blinkers flash at a faster rate than this, so it'll appear to the eye to be always on and merely oscillating in luminosity, meaning that the faster blinking lights should not have any different effect compared to a steady light. I notice that newer blinkers flash at faster rates, which might be in response to this effect. Also note that the overall average luminosity of a steady light will be greater than that of a flashing light. That's another reason why I run one solid along with the one flashing.

Either way, I figure that having one flashing and one steady is better than subscribing to one theory or the other.

Let's put it this way... put enough lights on and you will be noticed and seen.

Let's put it this way... put enough lights on and you will be noticed and seen.


Bingo!!:cheers:

I run a DiNotte 140L in "fast flash" mode, plus a Planet Bike Superflash (also in flashing mode).

I prefer blinking rear lights because they're interpreted by most drivers as - "Bike Ahead".

A steady state light could be misinterpreted as a stationary light source off to the side of the road.

My commuter bike also has reflective red tape on the rear fender, reflective silver tape on the cranks, reflective leg bands, and I wear an ANSI Class II lime green vest with reflective silver stripes outlined in bright orange.

If I ever get hit at night, I (or my estate) will own whoever hits me.