7 ms·

Hi-vis clothing for cyclists does not reduce number of crashes

30 points by colinprince 6y ago

chovy 6y ago
Pretty sure cyclists are why cyclists crash.
ekanes 6y ago
Related/similar: I remember reading that when cyclists wore helmets, drivers felt safer driving closer to them. Another IIRC is that safer cars meant that people just drove faster.
- parkersweb 6y ago
  I think this is the study you’re referring to : https://www.sciencedirect.com/science/article/abs/pii/S0001457506001540 https://www.sciencedirect.com/science/article/abs/pii/S00014... - wearing a wig (and iirc riding slightly erratically?) causes drivers to adjust their behaviour and give you a wider berth...
t-writescode 6y ago
What about high vis without lights? Please always use lights, but if all the jacket is doing is making a person more visible, then there should be a similar increase to having lights when only the jacket is used.
- fyfy18 6y ago
  In my city people seem to be opposed to having lights on their bikes, or they just have a rear light. Lights are not just about making you visible, but making you too obvious for a car to miss. Ideally you want a bright blinking light (depending on your local laws). Cars are dangerous, and the people who are driving them are probably tired from a long day of work, thinking about what they'll cook for dinner, or even worse distracted by their phone. I agree that drivers should be giving full attention to the road and checking carefully before every movement, but that's not reality - do what you can to make it easier for them to see you. If you are coming from behind a car at night without a light, the car won't see you. If it needs to turn across your path, the high vis alone will not make you visible. Same if cars are coming towards you. My city has a lot of streets that are bus lanes in one direction. If you are cycling along here at 20km/h a car turning left probably won't see you without lights, given you are much smaller than what they would expect to see there (a bus). The only case where I can see high vis being useful, where a light would not, is if a car is coming at you from the side.
  - raffraffraff 6y ago
    You're spot-on. At night, the luminous part of a high-vis is useless, they're designed for day use. The 3M reflective strip reflects light back only at the light source. The effect is one of those modern miracles of material technology. "LOL where are the batteries!!?" But while it's impressive, it's borderline useless for rear-view mirrors, which do not shine a light back at the cyclist.
    - seanhunter 6y ago
      > it's borderline useless for rear-view mirrors, which do not shine a light back at the cyclist. Not sure I understand what you're getting at here. Retroreflective strips reflect light back from the source to the viewer. In the case of a rear-view mirror, the light source is the tail light of the vehicle, which will hit the retroreflective material, reflect that back towards the vehicle where it will be seen by the driver in their rear-view mirror.
  - technimad 6y ago
    > Ideally you want a bright blinking light Please don't use blinking lights only. Due to the blinking others cannot estimate your location and speed. We humans can track a continuous light source pretty well, opposed do a blinking one.
    - upofadown 6y ago
      The blinking is to attract attention in the first place. Few people ride in total darkness.
- Someone 6y ago
  FTA: ”However there is greater evidence that cyclists using lights, even during the daytime, can help to reduce the number of collisions, with a 2013 Danish study finding that riders using flashing lights during the daytime were 47 per cent less likely to be involved in collisions with vehicles.”
gorgoiler 6y ago
I believe this is only for serious road traffic accidents. Continue wearing your vest if you believe it will stop drunks wandering under your wheels etc. This study is about the “number of bicycle and motorized vehicle collisions” reported in such a way as to be collated by the Italian government’s National Statistics department. None of my bike crashes, thankfully, have been sufficiently hairy as to require they be reported to the authorities. They would never have made it into a government database.
- parkersweb 6y ago
  I been thinking similarly- it might not have reduced the number of serious accidents but I wonder what impact it had on those more minor incidents that don’t typically get reported?
silexia 6y ago
I love my outdoor bike but am afraid of the injury rates I have read about... I will stick with zwift!
- anoncake 6y ago
  Stationary bikes are pretty useless for getting from A to B though.
jasonvorhe 6y ago
Totally not surprised about this. Accidents happen because people don't pay attention, not because cyclists wear all dark clothing at night and during bad weather. The number of people I see in their cars using their phones while driving is staggering. Especially commuters in cars overestimate their focus while driving while they're telling themselves that their route to work is routine by now. I'm seeing so many modern bikes in the street and they all feature bright LED lights that quite often even are far too bright for traffic as soon as they're improperly adjusted and motorists still manage to miss these mobile torches.
- beagle3 6y ago
  No one should be surprised, this happens in many areas, but is mostly equally perplexing to most people: - For a virus, other than burn-out or vaccine (SARS-Cov-1 burned out; SARS-Cov-2 likely won't), the number of dead people is basically independent of measures -- masks and lockdowns can change the distribution over time, but to first order, that's all they can do; (2nd order effects - collapse of the medical system, and development of better treatments such as clonal antibodies, vitamin D, etc - are also important, of course, and that's why we should employ masks and lockdowns - but we should measure their effect realistically compared to what they can actually achieve) - In a communication channel, the SnR is roughly speaking the only thing that determines the channel capacity. Knowing where the noise signal has been disruptive turns out to not change that capacity. (Although, again there is a 2nd order effect - if you can tell where and how the noise had been disruptive, you can considerably simplify the design of the transmitter and the receiver - but not increase the capacity). It's the difference between accidental and inherent complexity. I'm not saying that people's inattention is inherent -- it can be changed; however, given a level of inattention which is likely the inherent cause of accidents, high visibility clothing will possibly change the distribution of accidents over road kinds and time-of-day, but not their overall numbers.
  - mvdwoord 6y ago
    I really appreciate this take on complexity... thanks. Can you recommend some more reading on this line of thinking?
JoeAltmaier 6y ago
Wrong title: "Legislation about hi-vis clothing for cyclists does not reduce number of crashes". I didn't see quoted any stats about the wearing of hi-vis clothing. Just the assumption that legislation would lead to increased use. The study was done by a psychologist. Maybe that explains it.
- jaclaz 6y ago
  I would add by a psychologist with admitted important lacks of knowledge: From the paper abstract: >Lack of knowledge on how the law was introduced, the degree of enforcement by the police, and behavioral changes in response to the law makes it difficult to attribute the lack of effect on bicycle crashes.
elmolino89 6y ago
I wonder if this is apples to apples comparison. Did the total number of the road accidents stayed the same in the whole period? Number of kliometers driven per year? Number of the cyclists on the road?
rlucas 6y ago
Staff please update title — importantly the reported upon study indicates no effect of legislation mandating hi-viz, not the wearing of it. For example, perhaps everyone who would obey such a law is already wearing high viz.
tweetle_beetle 6y ago
Misrepresenting the title of the article aside, I would love to see further analysis about the different types of high visibility fabric on the market too, as they certainly aren't all made equal. As a cyclist, in terms of colour I'll only ever buy yellow kind, because as a driver I feel like this stands out much better than any others (greens, oranges, pinks). And I make sure to buy items which are as bright as possible. I also strongly feel that the current trend for using "silver" retroreflective fabric for entire products (as opposed to contrast panels) is a really bad one. In my experience as a driver, the light bouncing off, for example, a completely retroreflective jacket appears "flat". This reduces any perception of depth and means it takes noticeably longer to process and understand what it is am I looking at and react accordingly. Just a random video, but imagine seeing just this jacket from 30 metres away - https://www.youtube.com/watch?v=gVfUkCSw9Ew https://www.youtube.com/watch?v=gVfUkCSw9Ew
- elmolino89 6y ago
  Yep. This is too much of reflection for the driver's eyes. In the old not so good days a driver could encounter at night a horse driven buggy with no lights or reflective elements whatsoever. Just few days ago at night while going downhill on a steep road I have seen a well camouflaged hiker walking on my side of the road and stepping aside luckily in time. I will take reflective vest on a biker/pedestrian/hell, even on a horse anytime I am driving/biking and can hit them after spotting them too late.
specialist 6y ago
My current folk wisdom is that only three things reduce automobile vs cyclist incidents. More cyclist means less incidents (per capita). Something about safety in numbers and culture adjusting to new reality. More mom cyclists. Something about perception management, where hard core cyclists trigger resentment and mom cyclists gets automobilists to calm down. Set asides for cyclists. The Dutch model. I haven't experienced it, so take with salt grains. The half measures in my city may have helped, but mostly they still suck. Too many "railroad crossings", broken continuity.

30 points by colinprince 6y ago

Pretty sure cyclists are why cyclists crash.

Related/similar: I remember reading that when cyclists wore helmets, drivers felt safer driving closer to them. Another IIRC is that safer cars meant that people just drove faster.

parkersweb 6y ago
I think this is the study you’re referring to : https://www.sciencedirect.com/science/article/abs/pii/S0001457506001540 https://www.sciencedirect.com/science/article/abs/pii/S00014... - wearing a wig (and iirc riding slightly erratically?) causes drivers to adjust their behaviour and give you a wider berth...

t-writescode 6y ago

What about high vis without lights? Please always use lights, but if all the jacket is doing is making a person more visible, then there should be a similar increase to having lights when only the jacket is used.

fyfy18 6y ago
In my city people seem to be opposed to having lights on their bikes, or they just have a rear light. Lights are not just about making you visible, but making you too obvious for a car to miss. Ideally you want a bright blinking light (depending on your local laws). Cars are dangerous, and the people who are driving them are probably tired from a long day of work, thinking about what they'll cook for dinner, or even worse distracted by their phone. I agree that drivers should be giving full attention to the road and checking carefully before every movement, but that's not reality - do what you can to make it easier for them to see you. If you are coming from behind a car at night without a light, the car won't see you. If it needs to turn across your path, the high vis alone will not make you visible. Same if cars are coming towards you. My city has a lot of streets that are bus lanes in one direction. If you are cycling along here at 20km/h a car turning left probably won't see you without lights, given you are much smaller than what they would expect to see there (a bus). The only case where I can see high vis being useful, where a light would not, is if a car is coming at you from the side.
- raffraffraff 6y ago
  You're spot-on. At night, the luminous part of a high-vis is useless, they're designed for day use. The 3M reflective strip reflects light back only at the light source. The effect is one of those modern miracles of material technology. "LOL where are the batteries!!?" But while it's impressive, it's borderline useless for rear-view mirrors, which do not shine a light back at the cyclist.
  - seanhunter 6y ago
    > it's borderline useless for rear-view mirrors, which do not shine a light back at the cyclist. Not sure I understand what you're getting at here. Retroreflective strips reflect light back from the source to the viewer. In the case of a rear-view mirror, the light source is the tail light of the vehicle, which will hit the retroreflective material, reflect that back towards the vehicle where it will be seen by the driver in their rear-view mirror.
- technimad 6y ago
  > Ideally you want a bright blinking light Please don't use blinking lights only. Due to the blinking others cannot estimate your location and speed. We humans can track a continuous light source pretty well, opposed do a blinking one.
  - upofadown 6y ago
    The blinking is to attract attention in the first place. Few people ride in total darkness.
Someone 6y ago
FTA: ”However there is greater evidence that cyclists using lights, even during the daytime, can help to reduce the number of collisions, with a 2013 Danish study finding that riders using flashing lights during the daytime were 47 per cent less likely to be involved in collisions with vehicles.”

gorgoiler 6y ago

I believe this is only for serious road traffic accidents. Continue wearing your vest if you believe it will stop drunks wandering under your wheels etc. This study is about the “number of bicycle and motorized vehicle collisions” reported in such a way as to be collated by the Italian government’s National Statistics department. None of my bike crashes, thankfully, have been sufficiently hairy as to require they be reported to the authorities. They would never have made it into a government database.

parkersweb 6y ago
I been thinking similarly- it might not have reduced the number of serious accidents but I wonder what impact it had on those more minor incidents that don’t typically get reported?

silexia 6y ago

I love my outdoor bike but am afraid of the injury rates I have read about... I will stick with zwift!

anoncake 6y ago
Stationary bikes are pretty useless for getting from A to B though.

jasonvorhe 6y ago

Totally not surprised about this. Accidents happen because people don't pay attention, not because cyclists wear all dark clothing at night and during bad weather. The number of people I see in their cars using their phones while driving is staggering. Especially commuters in cars overestimate their focus while driving while they're telling themselves that their route to work is routine by now. I'm seeing so many modern bikes in the street and they all feature bright LED lights that quite often even are far too bright for traffic as soon as they're improperly adjusted and motorists still manage to miss these mobile torches.

beagle3 6y ago
No one should be surprised, this happens in many areas, but is mostly equally perplexing to most people: - For a virus, other than burn-out or vaccine (SARS-Cov-1 burned out; SARS-Cov-2 likely won't), the number of dead people is basically independent of measures -- masks and lockdowns can change the distribution over time, but to first order, that's all they can do; (2nd order effects - collapse of the medical system, and development of better treatments such as clonal antibodies, vitamin D, etc - are also important, of course, and that's why we should employ masks and lockdowns - but we should measure their effect realistically compared to what they can actually achieve) - In a communication channel, the SnR is roughly speaking the only thing that determines the channel capacity. Knowing where the noise signal has been disruptive turns out to not change that capacity. (Although, again there is a 2nd order effect - if you can tell where and how the noise had been disruptive, you can considerably simplify the design of the transmitter and the receiver - but not increase the capacity). It's the difference between accidental and inherent complexity. I'm not saying that people's inattention is inherent -- it can be changed; however, given a level of inattention which is likely the inherent cause of accidents, high visibility clothing will possibly change the distribution of accidents over road kinds and time-of-day, but not their overall numbers.
- mvdwoord 6y ago
  I really appreciate this take on complexity... thanks. Can you recommend some more reading on this line of thinking?

JoeAltmaier 6y ago

Wrong title: "Legislation about hi-vis clothing for cyclists does not reduce number of crashes". I didn't see quoted any stats about the wearing of hi-vis clothing. Just the assumption that legislation would lead to increased use. The study was done by a psychologist. Maybe that explains it.

jaclaz 6y ago
I would add by a psychologist with admitted important lacks of knowledge: From the paper abstract: >Lack of knowledge on how the law was introduced, the degree of enforcement by the police, and behavioral changes in response to the law makes it difficult to attribute the lack of effect on bicycle crashes.

elmolino89 6y ago

I wonder if this is apples to apples comparison. Did the total number of the road accidents stayed the same in the whole period? Number of kliometers driven per year? Number of the cyclists on the road?

rlucas 6y ago

Staff please update title — importantly the reported upon study indicates no effect of legislation mandating hi-viz, not the wearing of it. For example, perhaps everyone who would obey such a law is already wearing high viz.

tweetle_beetle 6y ago

Misrepresenting the title of the article aside, I would love to see further analysis about the different types of high visibility fabric on the market too, as they certainly aren't all made equal. As a cyclist, in terms of colour I'll only ever buy yellow kind, because as a driver I feel like this stands out much better than any others (greens, oranges, pinks). And I make sure to buy items which are as bright as possible. I also strongly feel that the current trend for using "silver" retroreflective fabric for entire products (as opposed to contrast panels) is a really bad one. In my experience as a driver, the light bouncing off, for example, a completely retroreflective jacket appears "flat". This reduces any perception of depth and means it takes noticeably longer to process and understand what it is am I looking at and react accordingly. Just a random video, but imagine seeing just this jacket from 30 metres away - https://www.youtube.com/watch?v=gVfUkCSw9Ew https://www.youtube.com/watch?v=gVfUkCSw9Ew

elmolino89 6y ago
Yep. This is too much of reflection for the driver's eyes. In the old not so good days a driver could encounter at night a horse driven buggy with no lights or reflective elements whatsoever. Just few days ago at night while going downhill on a steep road I have seen a well camouflaged hiker walking on my side of the road and stepping aside luckily in time. I will take reflective vest on a biker/pedestrian/hell, even on a horse anytime I am driving/biking and can hit them after spotting them too late.

specialist 6y ago

My current folk wisdom is that only three things reduce automobile vs cyclist incidents. More cyclist means less incidents (per capita). Something about safety in numbers and culture adjusting to new reality. More mom cyclists. Something about perception management, where hard core cyclists trigger resentment and mom cyclists gets automobilists to calm down. Set asides for cyclists. The Dutch model. I haven't experienced it, so take with salt grains. The half measures in my city may have helped, but mostly they still suck. Too many "railroad crossings", broken continuity.