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Comment by Fnoord | Hacker News Reader

In The Netherlands some cyclists have this brilliant idea to put their lights on flash/flicker. I suppose some think they'll be easier to get noticed.

It is not allowed by law (the light has to be either constantly on, or it may be turned off if it isn't dark), it can trigger epilepsy, it is distracting, and it is selfish and not 'cool' at all.

It also appears to be common in PC desktops to enable all kind of LEDs, without allowing them to be disabled. Especially in all kind of colours (which Razor dubbed 'Chroma'). Not my cup of tea, a waste of aesthetic and electricity but the worst thing about it is that I pay premium for such feature because it is deemed 'cool' by the target market.

FWIW, I use a strong light in the morning to wake up. It doesn't flash.

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Well, I don't like those lights either, but calling it selfish, is kinda hard when you compare it to how many cyclists get killed every year because some motorist didn't see them.

My focus constantly shifts back to the blinking, missing that bike that has no lights on or less-obvious lights on.

The problem being that judging the motion of a blinking light is nearly impossible. A blinking light is both more attention grabbing and less safe for the user.

This is something that should really be solved by regulating bicycle lights sold, or a very broad public awareness campaign.

These cheap Chinese LED lights for the bicycle all come with a blink-setting, and like the <blink>-tag of yore, it serves no practical purpose. People tend to think blinking means you are easier to spot in the dark, which is true in the sense that it grabs attention, but as you mention, you can't really extrapolate where someone is going with a blinking light.

The use of the blinking setting is usually born from naivety. People use the setting, because it is included with the light — why else would it be there, if not to use it? Now imagine if every cyclist on a busy cycleway used the blink-setting. At that point this behaviour is downright selfish.

It's not too hard to regulate really. After all, you are already legally limited in what you can use (white/yellow front, red back, no blinking).

I believe the blink mode is documented as extending the battery life, at least in the manuals I've read.

The significant battery drain is driving the LED when it's on, so having it on only half of the time effectively doubles the battery life.

That still doesn't explain the (rather common) lights with about 7 different types of blinking.

In an urban environment there will usually be more than enough light to see and predict the course of a cyclist. The trick is attracting the attention of people that are not looking in the first place. Flashing lights work very well for stimulating peripheral vision in a moving visual field.

There are more environments than urban ones. Bicycle lights should be adequate for all environments one might encounter.

> The trick is attracting the attention of people that are not looking in the first place.

This is also known as "distracting drivers" and it's hardly a good thing.

Distracting drivers from what, exactly?

Distracting them from not seeing cyclists?

I wonder what you think of emergency sirens/lights? Too distracting?

> I wonder what you think of emergency sirens/lights? Too distracting?

If unnecessary, yes.

> Distracting drivers from what, exactly? > Distracting them from not seeing cyclists?

We only have a finite attention span; hence such is going to be distracting the driver from other important things on the road. Not every cyclist is so important to be noticed.

You should also take into account that a blinking light means the driver is changing lane or course. Two blinking light means danger. If every bicyclist would all the time be signalling "danger, danger", people become desensitised to such signal.

>Not every cyclist is so important to be noticed.

Excuse me for keeping my flashing lights on the bike when there's people with attitudes like yours controlling several ton killing machines within meters of me.

Maybe I'll order some brighter lights...

As someone who just spent a week in the Netherlands, they are super serious about their biking infra and have gone great lengths to make it safe: https://www.dutchreach.org/car-child-murder-protests-safer-n...

In the NL, yes I might call it selfish. In NYC, not so much.

There are quite a lot of these in the UK too, again I'm not sure of the legality.

As a driver I've two things to say about them.

Firstly, they do make it easier to spot the cyclist over a solid light so that's a good thing. However, it's almost impossible to track their movement and that is a very very bad thing.

The best solution I feel is to have a flashing light which draws attention in addition to a solid light which is much easier to keep track of in your peripheral.

The rules in the UK have changed somewhat over the years; it used to be that flashing lights were only permitted in addition to a constant lamp.

Now its fine to only use flashing lights - Rule 60 of the highway code:

"At night your cycle MUST have white front and red rear lights lit. It MUST also be fitted with a red rear reflector (and amber pedal reflectors, if manufactured after 1/10/85). White front reflectors and spoke reflectors will also help you to be seen. Flashing lights are permitted but it is recommended that cyclists who are riding in areas without street lighting use a steady front lamp."

With the insane brightness now possible I wish they had to meet the same light pattern rules car headlights do. I think that would help the flashing being so distracting.

I occasionally run across bicyclists now with modern LED lights that are more blinding than automobile headlights.

Pray you don't run across this bike light:

https://hackaday.com/2018/10/17/diy-arc-light-makes-an-unnec...

A very bright bike light makes it much more comfortable to ride a bike at night, you need to compete with car headlights so that you can see the surface of the road in front of you. Cars don't need to worry about the road conditions as much as cyclists since if they hit a pothole or a stick, it's no big deal.

I'm hoping cars (and bikes) evolve over the next few years into less blinding headlights. The infatuation we have with projectors makes even halogen lights blinding. I see some newer Acuras coming with multiple LED projectors on each side lately, which ought to help (so long as overall output is constant, and each projector is dimmer)

There are also lights which resemble Kitt from Knightrider which seem to provide the benefits of both ie motion and constantly on.

Really good point. It's worth noting that the bikes belonging to our official bikeshare here in NYC all have blinking white lights on the front and solid red ones on the back. You'd think a bike share would be able to get this right. Maybe they should have both blinking and solid ones in both places.

I'll take that over the huge amount of teenagers I see on their bikes with no lights fitted to their bikes at all.

Blinking lights save power and lead to longer battery life, hence the cycle lights with different blink settings. The power savings can be substantial, one of the back lights I use switches between 'full on' (3 leds, full power) and 'walking blink' (¼ second on/off). Subtract the (negligible) power used by the timer IC and you end up with a factor 6 difference in favour of the blinking light. Here in Sweden blinking lights are still allowed, one of the places where you'll meet them is on the railroad as Swedish trains have blinking back lights.

Blinking headlights on bicycles are not allowed in Sweden. (It's hard to argue with the market forces of millions little LED lamps though, combined with disregard or not knowing about the law.)

http://www.gp.se/nyheter/g%C3%B6teborg/inga-blinkande-framlj...

Headlights, no. Blinking taillights are allowed though (with a minimum blink frequency of ~3.3 Hz / 200 per minute) and those are the ones I mentioned. Blinking taillights do make bicycles stand out more which can only help in a country like Sweden where cycle paths are as rare as hen's teeth. In the Netherlands (where I'm from originally) this is less urgent as there are plenty of cycle paths.

If you speak of for instance Stockholm, they are rare. In some other cities (I don't want to out myself) they are everywhere.

Flashing bike lights are ubiquitous in the United States. I prefer them because I can distinguish a cyclist from what could be a slow car missing a tail light.

Belgium had similar rules for cyclists, but recently updated them. Cycling around like a strobing christmas tree is now allowed. sigh

Here in the south of Spain I regularly see scooters (mopeds) that are 20+ years old. Older scooters often have headlights that are so dim you can barely see them (the bulbs just get dimmer, they don't burn out). As a car driver I'd much prefer to see a bright and flashing light so I notice the vehicle, and a bicycle doesn't make any noise so I'm not going to hear it.

Survival is inherently 'selfish', selfishness is the fundamental basis of organic life.

That doesn't justify this behavior.

If I were in a trolley problem and would have to decide between my own life or my daughter's I would die to save her life.

Likewise, if this society does things which endanger my daughter's life I'd like such threats eliminated.

I'm convinced this is one of the destructive examples, especially if it becomes popular or the norm.

Your daughter's life is pretty closely tied to the survival of your genes. This sort of philosophical debate has been discussed for centuries though.

So if your daughter was cycling, would you want her to have flashing lights so she can be seen by drivers?

Of course not, she'll be seen by normal lights.

Well, according to some research flashing lights are more likely to be noticed:

https://www.lrc.rpi.edu/resources/pdf/iesna01a.pdf

> Flashing lights will be perceived as having higher brightness than steady-burning lights, up to a flash frequency of about 15 flashes per second. Such brightness enhancement can aid in conspicuity, and several rear lighting systems have been designed to have a flash rate between 5 and 9 flashes per second in order to maximize their perceived brightness.

I think deep down we all know this anyway, which is why we want flashing lights if we are on a bike amongst traffic. Why on earth would emergency vehicles and maintenance vehicles use flashing lights if they were equally effective to steady lighting?

Your daughter's bike would be far more noticeable with flashing lights.

That paper is about rear lights on snowmobiles, in snow (in upstate New York). My daughter doesn't have blinking lights on the back of her snowmobile. It barely even snows here. If it snows, the roads can be dangerous for bicyclists due to weather conditions. I'd rather bring her to school myself in such a situation, or buy her public transport instead.

Blinking lights in traffic serve to warn us about danger. Bicyclists are just normal cyclists; so the other users of traffic get warning fatigue via your method. A reflector (legally required to be on a bicycle on the back) is going to adequately help them. As a runner, I also wear clothes which contain reflections.

I think the general idea that flashing is more noticeable than steady can be taken from the paper. Seems like common sense to me.

I'm a cyclist and I'll stick with my flashing lights, thanks. I have steady lights as well so drivers can track my motion.

Whatever it takes for those oblivious and distracted SUV idiots to actually notice that I'm there. I've had a few very close calls already, I guess those poor long-suffering drivers must have had warning fatigue. /s

I'm a driver as well and I don't find flashing lights on bikes very distracting while driving. What's much worse are the cyclists with no lights, which makes it difficult to judge their position, or even to notice their existence at all.

It's not only about the flicker, but sometimes those lights are as intense as high-beams!

But cyclists tend to get a pass with almost everything for some reason.

You have a much greater need on a bike to see road detail, you need to look out for potholes and sticks on the road. In a car, you just need to be able to see the road lines and reflect light off of signs.

I use a 1200 lumen bike light, powered by two 3500mah 18650s.

That's great for you, now imagine the guy coming the opposite direction being blasted with 1200 lumen in the eyes. Sure you made him aware of your presence but you also made him blind to any other stuff or people besides you.

They get a pass for having lights because they are the most vulnerable people on the road.

It's more about saving battery life than being noticed.

And as they are illegal to use they should probably be illegal to buy, at least when marketed as bike lamps.

I thought only certain frequencies trigger epilepsy?

If you find blinking lights on cyclists annoying, that means you noticed them. So they accomplish their mission. Blinking lights are significantly easier to notice from peripheral vision.

Seeing something is not the same as having enough information about that thing to avoid an accident.

The christmas tree effect probably doesn't keep cyclists safe, although it's tricky to research this.

Well you certainly have more information than if you don't see them at all.

But less information than with a non-blinking light. By blinking you are making it harder to extrapolate direction and speed from your observations.

You're saying "don't see them at all", but we don't know if that's what happens. We don't know that drivers don't see fixed lights, or see flashing lights more often. And we don't know what information they get from the lights.

>Seeing something is not the same as having enough information about that thing to avoid an accident.

I'm really confused by this thinking. If there is a blinking white light pointed at you it means the cyclist is on the other side of the road, traveling with traffic in the opposite direction. If it is blinking red then you are approaching the cyclist traveling in the same direction as you, on your side of the road. If you see both lights blinking, with the white light on the left, then the bike is traveling left across your direction of travel. White on the right for the opposite. What information am I missing here? I feel like any of these combinations should be enough for a driver to notice a cyclist and to give them a sufficiently wide berth.

> If there is a blinking white light pointed at you it means the cyclist is on the other side of the road, traveling with traffic in the opposite direction.

Do drivers know this? Or do they think the flashing light is something else? Do they even see the flashing light? It's possible that eye movement across a scene means the eye travels over the cyclist in the off-time of the light.

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