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-   -   How safe is high-visibility clothing? (http://www.bikeforums.net/advocacy-safety/623722-how-safe-high-visibility-clothing.html)

cplager 12-03-12 11:51 AM

Quote:

Originally Posted by I-Like-To-Bike (Post 15010473)
I prefer opinions and guesses labeled as such, rather than the results of "studies that say the same thing [as my anecdotes]"

I don't like reference to unnamed studies, or reference to studies that are do not relate to the subject being discussed (in this case effects of forward facing flashing bicycling lights), or articles that have "conclusions" based on nothing but the conclusion writer's opinion, guesswork, and extrapolations not supported by the data on hand.

I think you're missing the forest for the trees. This isn't a forum for people studying for Ph.D. in bicycle safety. If you aren't happy with my description, then start here instead. I have no delusions about being able to change your mind and that's fine with me. My personal experience and what people who study bicycle safety have said lead me to the same conclusion:

Being seen is extremely important to bicycle safety. In the daytime, flashing lights help a lot with this goal.

jputnam 12-09-12 08:55 AM

There have been some efforts to study the question beyond mere anecdote, e.g.
[h=1]Conspicuity and bicycle crashes: preliminary findings of the Taupo Bicycle Study.[/h]http://www.ncbi.nlm.nih.gov/pubmed/18245309

[h=4]OBJECTIVE:[/h]To describe the methods, characteristics of participants, and report on the preliminary findings of a longitudinal study of cyclists.
[h=4]DESIGN:[/h]Web-based survey to establish a cohort of cyclists.
[h=4]SETTING:[/h]Participants in the largest mass-participation bicycle event in New Zealand, the Wattyl Lake Taupo Cycle Challenge.
[h=4]PARTICIPANTS:[/h]2469 riders who had enrolled online in the 2006 Wattyl Lake Taupo Cycle Challenge.
[h=4]MAIN OUTCOME MEASURES:[/h]Self-reported crashes in preceding 12 months.
[h=4]RESULTS:[/h]Of 5653 eligible riders, 2469 (44%) completed the study questionnaire. Mean age was 44 years, 73% were male, and the average number of kilometers cycled per week in the preceding 12 months was 130. The annual incidence of crashes leading to injury that disrupted usual daily activities for at least 24 h was 0.5 per cyclist/year. About one-third of these crashes resulted in presentation to a health professional. The mean number of days absent from work attributable to bicycle crashes was 0.39 per cyclist/year. After adjustment for potential confounders and exposure (kilometers cycled per year), the rate of days off work from bicycle crash injury was substantially lower among riders who reported always wearing fluorescent colors (multivariate incidence rate ratio 0.23, 95% CI 0.09 to 0.59).
[h=4]CONCLUSIONS:[/h]Low cyclist conspicuity may increase the risk of crash-related injury and subsequent time off work. Increased use of high-visibility clothing is a simple intervention that may have a large impact on the safety of cycling.



or



[h=1]Motorcycle rider conspicuity and crash related injury: case-control study.[/h]http://www.ncbi.nlm.nih.gov/pubmed/14742349

[h=4]OBJECTIVE:[/h]To investigate whether the risk of motorcycle crash related injuries is associated with the conspicuity of the driver or vehicle.
[h=4]DESIGN:[/h]Population based case-control study.
[h=4]SETTING:[/h]Auckland region of New Zealand from February 1993 to February 1996.
[h=4]PARTICIPANTS:[/h]463 motorcycle drivers (cases) involved in crashes leading to hospital treatment or death; 1233 motorcycle drivers (controls) recruited from randomly selected roadside survey sites.
[h=4]MAIN OUTCOME MEASURES:[/h]Estimates of relative risk of motorcycle crash related injury and population attributable risk associated with conspicuity measures, including the use of reflective or fluorescent clothing, headlight operation, and colour of helmet, clothing, and motorcycle.
[h=4]RESULTS:[/h]Crash related injuries occurred mainly in urban zones with 50 km/h speed limit (66%), during the day (63%), and in fine weather (72%). After adjustment for potential confounders, drivers wearing any reflective or fluorescent clothing had a 37% lower risk (multivariate odds ratio 0.63, 95% confidence interval 0.42 to 0.94) than other drivers. Compared with wearing a black helmet, use of a white helmet was associated with a 24% lower risk (multivariate odds ratio 0.76, 0.57 to 0.99). Self reported light coloured helmet versus dark coloured helmet was associated with a 19% lower risk. Three quarters of motorcycle riders had their headlight turned on during the day, and this was associated with a 27% lower risk (multivariate odds ratio 0.73, 0.53 to 1.00). No association occurred between risk and the frontal colour of drivers' clothing or motorcycle. If these odds ratios are unconfounded, the population attributable risks are 33% for wearing no reflective or fluorescent clothing, 18% for a non-white helmet, 11% for a dark coloured helmet, and 7% for no daytime headlight operation.
[h=4]CONCLUSIONS:[/h]Low conspicuity may increase the risk of motorcycle crash related injury. Increasing the use of reflective or fluorescent clothing, white or light coloured helmets, and daytime headlights are simple, cheap interventions that could considerably reduce motorcycle crash related injury and death.

I-Like-To-Bike 12-09-12 11:01 AM

See http://www.bikeforums.net/showthread...1#post15006746

SnorkleMcCorkle 12-23-12 03:26 PM

1 Attachment(s)
The army and Marine corp, Navy and Airforce ALL use Bright Yellow Reflective safety Belts... for PT, Road Gaurds etc... They work Me with out the Belthttp://bikeforums.net/attachment.php...hmentid=289820

SnorkleMcCorkle 12-23-12 03:28 PM

1 Attachment(s)
and Me with:http://bikeforums.net/attachment.php...hmentid=289821

Rimmer 12-24-12 03:12 PM

Quote:

Originally Posted by SnorkleMcCorkle (Post 15081143)
The army and Marine corp, Navy and Airforce ALL use Bright Yellow Reflective safety Belts... for PT, Road Gaurds etc... They work Me with out the Belt

I heard some guy a few years back in my area doing PT while wearing a belt still managed to get hit by a car.

jputnam 12-24-12 07:19 PM

Quote:

Originally Posted by Rimmer (Post 15084278)
I heard some guy a few years back in my area doing PT while wearing a belt still managed to get hit by a car.

No preventive measure is 100% effective, or even close to it; the best you can hope for is a significant reduction in risk.

That's the point of conducting statistically-valid research, to tell whether a safety measure has any real benefit, and if so, how much. See, for example, http://www.biomedcentral.com/1471-2458/10/39 "The use of conspicuity aids by cyclists and risk of crashes involving other road users: a protocol for a population based case-control study", which also includes a good bibliography of relevant prior research.

Rimmer 12-25-12 08:18 PM

Just from own anecdotal observances, during the day, I've had more close encounters with motorists than I ever had at night time. I feel much safer at night for this reason. A couple drivers have explicitly told me that they didn't see me. I do ride more during the daytime hours though, so bear in mind that. This doesn't prove anything. It's just what I've observed.

I'm not convinced hi-vis clothing provides a significant risk reduction during the day. It probably helps a bit assuming the user doesn't think he/she is invincible and rides riskier. I might get one.

vol 12-27-12 09:17 AM

I posted this on another forum but this one would be more suitable and I'd like to hear comments:

It seems to me sometimes it may be better (or at least does no harm) if the drivers thought I was a moving vehicle from my lights, than if they knew I was a cyclist with reflective body profile. Almost all drivers would try to avoid hitting another vehicle to injure themselves, but not all of them would try (at least not as much) to avoid hitting a cyclist. So, for example, if a driver knew you're a bike, he may still squeeze past you or even swipe you, but not if he thought you were a car.

Does anyone share my view?

Looigi 12-29-12 08:50 AM

Quote:

Originally Posted by vol (Post 15091390)
...Does anyone share my view?

Kinda. The first reflexive action is instinctive self preservation. It takes time for some thought and consideration to evaluate a situation and perhaps choose something more altruistic, like hitting a wall instead mowing down a cyclist... However, I don't think trying to impersonate a cement abutment or large truck would be productive. The point of lights and bright apparel is to help ensure motorists are aware of your presence. There isn't much you can do about how they are going to react.

mrt2you 12-29-12 09:13 AM

i always wear high vis Jerseys. i think the high vis ones are actually cheaper than the fancy printed ones.
i sometimes get comments from car drivers at stop signs about my visibility. i think it's the high powered headlight and 3 high powered tail lights for the comments. but anything to make you easily seen won't hurt.

daredevil 12-29-12 12:04 PM

In my opinion, the only truly high vis color is neon lime green...all the rest are pretenders. Because a jersey has 'loud' colors does not necessarily make it visible. Orange and yellow may be better than nothing but just barely. Only neon lime 'pops'.

I used to have a photo of a stadium crowd of 10's of thousands of people and the handful that actually stood out, were the vendors wearing lime vests.

10 Wheels 12-29-12 12:19 PM

1 Attachment(s)
Quote:

Originally Posted by daredevil (Post 15098035)
In my opinion, the only truly high vis color is neon lime green...all the rest are pretenders. Because a jersey has 'loud' colors does not necessarily make it visible. Orange and yellow may be better than nothing but just barely. Only neon lime 'pops'. I used to have a photo of a stadium crowd of 10's of thousands of people and the handful that actually stood out, were the vendors wearing lime vests.

http://bikeforums.net/attachment.php...hmentid=290711

Looigi 12-29-12 01:58 PM

IMO, the main thing is a color that clearly stands out amid the surroundings, and that can vary. I noted one spring day that bright sunlight shining on the new light green foliage along the roadside made the lime green my wife was wearing blend right in. A bright orange was much more prominent on subsequent rides. Likewise, even bright orange can stand out much less distinctly against brightly lit fall foliage.

daredevil 12-29-12 03:36 PM

Quote:

Originally Posted by 10 Wheels (Post 15098066)

I see some yellow jerseys in the foreground.

In the picture I spoke of, from over 100 yards away, the only visible color that was distinct, was neon lime green and you could identify every vendor. Why do you suppose they dress them like that and not in yellow or orange?

daredevil 12-29-12 03:47 PM

1 Attachment(s)
http://bikeforums.net/attachment.php...hmentid=290770

I've seen better examples but for lack of anything else right now...

For me, if I'm in any significant traffic, I've got this color on and will add a daytime visible tail light if the situation calls for it.

unterhausen 12-29-12 11:14 PM

I have followed someone wearing a yellow jersey and it was visible from a fairly impressive distance. I'm not sure I buy into the superior visibility of lime green. I have noticed that they backed off on lime green warning signs. We are pretty well conditioned to notice yellow, and a bright safety yellow is pretty hard to miss.

jputnam 12-30-12 12:03 AM

Quote:

Originally Posted by unterhausen (Post 15099549)
I have followed someone wearing a yellow jersey and it was visible from a fairly impressive distance. I'm not sure I buy into the superior visibility of lime green. I have noticed that they backed off on lime green warning signs. We are pretty well conditioned to notice yellow, and a bright safety yellow is pretty hard to miss.

Actually, fluorescent yellow-green signs used to be optional but are now (2009 MUTCD) mandatory for warning signs and plaques for school area traffic control; they're optional for general pedestrian and bicycle signage. Before the current standardization they were used somewhat randomly; now their greater conspicuity is reserved for protecting the highest-vulnerability road users.

daredevil 12-30-12 08:00 AM

Quote:

Originally Posted by unterhausen (Post 15099549)
We are pretty well conditioned to notice yellow

So well conditioned they are frequently ignored or not noticed. Precisely why I want something different from the norm. Let me ask again, why are vendors in lime green? Is it not because it is more noticeable?

daredevil 12-30-12 08:01 AM

Quote:

Originally Posted by jputnam (Post 15099632)
now their greater conspicuity is reserved for protecting the highest-vulnerability road users.

thank you!

Rimmer 12-30-12 04:53 PM

Check this out

http://3.bp.blogspot.com/_P-m5uioCLi...iz+horse+1.jpg

lol

johnbol1 12-31-12 03:22 AM

Quote:

Originally Posted by RobertHurst (Post 15009450)
There is no substitute for a rider's awareness and anticipation of being overlooked. Hi-vis clothing is no substitute. Flashing lights are no substitute. Lane position is no substitute.

Is true also. When I took my motorcycle test and passed the rules on awareness and observing deifnately made me also be a far better car driver too.

Chris516 01-02-13 04:21 AM

Quote:

Originally Posted by unterhausen (Post 15099549)
I have followed someone wearing a yellow jersey and it was visible from a fairly impressive distance. I'm not sure I buy into the superior visibility of lime green. I have noticed that they backed off on lime green warning signs. We are pretty well conditioned to notice yellow, and a bright safety yellow is pretty hard to miss.

Two days ago, I replaced my yellow long-sleeve windbreaker(the other one was nine years old, and had started to fade some time ago), with another yellow long-sleeve windbreaker. My only problem is, the old one had a convenient chest pocket, without side pockets. The new one is the reverse, no chest pocket, but with two side pockets. The version like my old one, was only available online at the LAB's website. I have forsaken credit cards for the last fifteen years. So I have to get it from the LAB, directly.

njkayaker 01-02-13 05:25 PM

Quote:

Originally Posted by vol (Post 15091390)
I posted this on another forum but this one would be more suitable and I'd like to hear comments:

It seems to me sometimes it may be better (or at least does no harm) if the drivers thought I was a moving vehicle from my lights, than if they knew I was a cyclist with reflective body profile. Almost all drivers would try to avoid hitting another vehicle to injure themselves, but not all of them would try (at least not as much) to avoid hitting a cyclist. So, for example, if a driver knew you're a bike, he may still squeeze past you or even swipe you, but not if he thought you were a car.

Does anyone share my view?

Drivers can assume that other moving cars are moving at about their same speed. That's why there are often minimum speed requirements for highways. That is, it might not be safer mimicing a car.

Quote:

Originally Posted by Looigi (Post 15097609)
Kinda. The first reflexive action is instinctive self preservation. It takes time for some thought and consideration to evaluate a situation and perhaps choose something more altruistic, like hitting a wall instead mowing down a cyclist... However, I don't think trying to impersonate a cement abutment or large truck would be productive. The point of lights and bright apparel is to help ensure motorists are aware of your presence. There isn't much you can do about how they are going to react.

I think vol is suggesting looking like a car.

Anyway, I suspect that it's safer to be identifiable as a cyclist. The sooner that identification is done, the more time the driver has to choose to compensate for the cyclist.

There are a fair amount of "conditioned response" (automatic behavior) in the act of driving. Cyclists may get hit when that automatic behavior is overridden by higher-level consciousness. Higher visibilty gives a longer time for the consciousprocess to kick-in.

njkayaker 01-02-13 05:38 PM

Quote:

Originally Posted by daredevil (Post 15098564)
http://bikeforums.net/attachment.php...hmentid=290770

I've seen better examples but for lack of anything else right now...

For me, if I'm in any significant traffic, I've got this color on and will add a daytime visible tail light if the situation calls for it.

One reason they are so visible is that they are all standing up and the vast majority of the spectators are sitting down.

Quote:

Originally Posted by daredevil (Post 15100004)
So well conditioned they are frequently ignored or not noticed. Precisely why I want something different from the norm. Let me ask again, why are vendors in lime green? Is it not because it is more noticeable?

Clearly, it's to make the noticeable. That fact doesn't establish that lime-green is more noticeable than alternatives. (There isn't that much need to make them noticeable beyond some reasonable distance.)


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