Hi-viz, does it make a difference in rider visibility?

[Bradles]

During day time riding I think it makes little difference. My opinion during night time wavers, and I think it may help in low light conditions.

Just to balance up the research you have.

The largest motorcycle safety research done in the world was the HURT report, done in the US, in the late 70's. It found the use of daytime head lights or the use of high-viz helped. The consequence of this is that many countries started introducing compulsory headlight laws. Sure it took NZ 30 years to follow suit, but we did the same.
The reason the study said "or" was because there wasn't much of a difference in safety doing both.

The second largest study done in the world was the MAIDS report in Europe. It looks at the general issue on conspicuity. It found that it made little difference, and that some cases, such as riders wearing white helmets, that those riders where involved in more accidents than those riders wearing black helmets.
HOWEVER, the results showing that wearing more highly visible items made your safety worse were within the margin of error, and certainly less than the "5 sigma" test to be confident it was correct.

Then the much smaller Auckland University study that you quoted was done. It showed the opposite of the larger MAIDS report, and that there was an improvement in safety by being more visible. HOWEVER, just like the MAIDS report, the results fell car short of the "5 sigma" test of confidence, so you can't really consider it statistically significant.

FYI, currently 23% of all injury based motor vehicle accidents (that's all classes of vehicles, not just motorcycles) list driver inattention as a contributing cause. That's the old "sorry, I didn't see you". These are predominantly car drivers you didn't see other cars and trucks (the majority of road users). With this category there are reasons listed like "changing radio/music", TXTing, etc.
If you can appreciate that this is a very large group of the accidents, and that cars and trucks are highly visible compared to motorbikes - you can quickly come to the conclusion that being more visible wont help you. If someone is TXTing or changing the radio - or anything where they simply aren't looking where they are driving - then you could be naked and it still isn't going to help.

And then you get excellent psychological research like the "Invisible Gorilla" (You Tube it for a quick example). Basically the research shows that the brain only sees what it is expecting to see. To demonstrate this, they get a person to dress up in a Gorilla suit and walk through the middle of a basketball game. Afterwards they surveyed the people watching, and only 50% saw the gorilla. Once again, if the brain is not expecting to see a gorilla it probably wont see it.

So if you lane splitting for example, and a driver is not expecting to see you, then they probably wont see you. It doesn't matter how visible you make your self.

And then there are other issues like motion camouflage.


I could probably go on and on quoting you more studies and statistics, but at the end of the day it is up to you. Personally, during day time use, I feel that if you already have a head light on, high-viz is going to do almost nothing for you.

This is much better than what I was going to say but here's my contribution anyway.
While the study the OP points to does attempt for some confounding variables it doesn't take into consideration the rider's attitude to riding/personality.
At a guess people who tend to be more cautious are probably more likely to wear hi-vis vests.
At a guess people who tend to be more cautious are probably less likely to be involved in an accident.
Essentially there is a pretty obvious third variable that they haven't attempted to control for so the take home message could be people who are more cautious are involved in less accidents.
In fact, assuming that the above guesses are correct, if they did some kind of cautiousness measure you would probably find that the relationship between wearing vests and being in accidents would decline and the relationship between being cautious and having accidents would be much larger than the relationship they have reported between vests and accidents.

Essentially what I'm saying is it's hard to know if the study is actually looking at the effect of wearing a vest or something else.

[Matariki]

As long as the hi-viz is built into your gear and not some sort of add on that flaps in the wind, can get uncomfortable, (you know the way you can wear something a 100 times but just hat once it wont sit right), or in any other way distract you from your primary function whilst on the bike. The draw back of built in hi-viz being that it will discolour and loose some of its affect before you are finished with your gear.

I too used to think I was noticing the hi-viz better but then realised I was spotting the bike a split second before but noticing and recording the hi-viz.

But as said above, providing the way you are wearing it is doing no harm, you realise that in some rear conditions it can make you harder to spot and generally it wont help alot and its not forced on you then why not. Truth is wit hte way you are thinking your riding style is probably doing more to protect you than hi-viz ever will and wearing it will just show you are a careful rider.

I agree 100%, for Hi-Viz I have a helmet that's Chartreuse, and I wear Hi-Viz vest over my jacket that I can zip up (rather than the velcro), I wear it when I'm in areas with lots of traffic (motorway's, supermarkets etc., or in area's I'm unfamiliar with) or in overcast weather, or at night. I don't worry about wearing it when I'm in a low traffic area (like the country side) but I like to keep my vest in my back pack just in case. My jacket has reflective material built in it, but it's not Hi-Viz. But even when I am wearing it, I always make sure I ride as If I'm invisible.

[Matariki]

During day time riding I think it makes little difference. My opinion during night time wavers, and I think it may help in low light conditions.

Just to balance up the research you have.

The largest motorcycle safety research done in the world was the HURT report, done in the US, in the late 70's. It found the use of daytime head lights or the use of high-viz helped. The consequence of this is that many countries started introducing compulsory headlight laws. Sure it took NZ 30 years to follow suit, but we did the same.
The reason the study said "or" was because there wasn't much of a difference in safety doing both.

The second largest study done in the world was the MAIDS report in Europe. It looks at the general issue on conspicuity. It found that it made little difference, and that some cases, such as riders wearing white helmets, that those riders where involved in more accidents than those riders wearing black helmets.
HOWEVER, the results showing that wearing more highly visible items made your safety worse were within the margin of error, and certainly less than the "5 sigma" test to be confident it was correct.

Then the much smaller Auckland University study that you quoted was done. It showed the opposite of the larger MAIDS report, and that there was an improvement in safety by being more visible. HOWEVER, just like the MAIDS report, the results fell car short of the "5 sigma" test of confidence, so you can't really consider it statistically significant.

FYI, currently 23% of all injury based motor vehicle accidents (that's all classes of vehicles, not just motorcycles) list driver inattention as a contributing cause. That's the old "sorry, I didn't see you". These are predominantly car drivers you didn't see other cars and trucks (the majority of road users). With this category there are reasons listed like "changing radio/music", TXTing, etc.
If you can appreciate that this is a very large group of the accidents, and that cars and trucks are highly visible compared to motorbikes - you can quickly come to the conclusion that being more visible wont help you. If someone is TXTing or changing the radio - or anything where they simply aren't looking where they are driving - then you could be naked and it still isn't going to help.

And then you get excellent psychological research like the "Invisible Gorilla" (You Tube it for a quick example). Basically the research shows that the brain only sees what it is expecting to see. To demonstrate this, they get a person to dress up in a Gorilla suit and walk through the middle of a basketball game. Afterwards they surveyed the people watching, and only 50% saw the gorilla. Once again, if the brain is not expecting to see a gorilla it probably wont see it.

So if you lane splitting for example, and a driver is not expecting to see you, then they probably wont see you. It doesn't matter how visible you make your self.

And then there are other issues like motion camouflage.


I could probably go on and on quoting you more studies and statistics, but at the end of the day it is up to you. Personally, during day time use, I feel that if you already have a head light on, high-viz is going to do almost nothing for you.

This is what I call a very well informed post. I know of the articles and the tests that you quoted, and I'll say I agree with you. Having your lights on (especially if they're LED) is better than wearing Hi-Viz, but wearing Hi-Viz is better than not having your lights on. My Dad (as I mentioned before is an optometrist) believes that its a good idea to have both. Though thinking about it, a driver is probably more likely to spot a rider wearing a Hi-Viz helmet than a vest (because the vest is obscured by the front of the bike and at times a backpack if the rider is wearing one, or if the rider is carrying a pillion passenger). But like others have said, if a driver doesn't spot your lights, Its unlikely that they're going to spot your Hi-Viz.

[Matariki]

Talking about selective attention tests, I wonder why they aren't included in the drivers test? Here's the famous 'Invisible Gorilla' test;

http://www.youtube.com/watch?v=vJG698U2Mvo

[p.dath]

Talking about selective attention tests, I wonder why they aren't included in the drivers test? Here's the famous 'Invisible Gorilla' test;
...

Because if the populace was subjected to a series of 5 tests, only 3.1% of the population would pass (without cheating). It is simply the way our brains have developed over the last 60,000 years thanks to Cerebrum development.

[rastuscat]

It is simply the way our brains have developed over the last 60,000 years thanks to Cerebrum development.

And thus, we are condemned to die by the faults of our humanity.

Folk who wear hi viz are safety conscious, so ride like they are safety conscious.

Folk who object to hi viz go to all sorts of lengths to justify their positions.

I don't GAF. I'll wear it sometimes, sometimes not, depends on how I feel, and how many layers I'm needing.

So there.

[scumdog]

And thus, we are condemned to die by the faults of our humanity.

Folk who wear hi viz are safety conscious, so ride like they are safety conscious.

Folk who object to hi viz go to all sorts of lengths to justify their positions.

I don't GAF. I'll wear it sometimes, sometimes not, depends on how I feel, and how many layers I'm needing.

So there.

Nicely summed up.

How many still think that wearing seat-belts encourages drivers to care less about their safety when driving?

'Cos once upon a time people thought that too...

[Matariki]

Because if the populace was subjected to a series of 5 tests, only 3.1% of the population would pass (without cheating). It is simply the way our brains have developed over the last 60,000 years thanks to Cerebrum development.

Wouldn't that be a good thing (at least for us motorcyclists)? I'll probably start up another thread addressing issue to see what you guys think.

[rastuscat]

Printed off the study that someone posted the link to.

The summary on Page 5 says

"Wearing reflective or flourescent clothing and white or light coloured helmets and using headlights in daytime could reduce serious injuries or death from motorcycle crashes by up to one third."

This is not my opinion, merely what the research based study found.

So there.

[Kickaha]

"Wearing reflective or flourescent clothing and white or light coloured helmets and using headlights in daytime could reduce serious injuries or death from motorcycle crashes by up to one third."

Could isn't the same as will

[oneofsix]

Printed off the study that someone posted the link to.

The summary on Page 5 says

"Wearing reflective or flourescent clothing and white or light coloured helmets and using headlights in daytime could reduce serious injuries or death from motorcycle crashes by up to one third."

This is not my opinion, merely what the research based study found.

So there.

No donuts for that. We already have the headlight law there most, if not all, of that possible 1/3 reduction could already be accounted for. Nice piece of propaganda though.

[p.dath]

Wouldn't that be a good thing (at least for us motorcyclists)? I'll probably start up another thread addressing issue to see what you guys think.

If only 3.1% of the population could pass the test, then you should assume you wouldn't pass - you would loose the "right" to be on the public road in/on a motorised vehicle.

In NZ we have a culture of everyone driving. It's partially because of our geography and how far apart everything is, and partly due to the lack of options getting there, and the control over those options.

Any test that told 96.9% of the population they were no longer allowed to drive is [IMHO] harsh and opressive.

[oneofsix]

Nicely summed up.

How many still think that wearing seat-belts encourages drivers to care less about their safety when driving?

'Cos once upon a time people thought that too...

Nice wind up. Comparing something that restrains you in a safety cage and prevents you impacting hard surfaces with something that is the equivalent of the Gorilla on the basketball court.

[p.dath]

...The summary on Page 5 says

"Wearing reflective or flourescent clothing and white or light coloured helmets and using headlights in daytime could reduce serious injuries or death from motorcycle crashes by up to one third."

This is not my opinion, merely what the research based study found.
...

That would be the Auckland University study. Try reading the two other larger studies I cited, the HURT report and the MAIDS report.

And as I hinted at previously, did you see the 95% confidence interval in table 3 for high-viz use? 0.37 to 0.82, or somewhere between 37% and 82%? That's almost a 50% difference in the confidence interval range about weather it has an impact. If it was 37% then the odds aren't that high that it does have an impact. It is is 82% then the odds are pretty high. They ended up taking an average and saying it was 55%, and concluded it was having an impact (as more than 50%).

But the error margin is so high you'd have to be brave to call that conclusion.


Let me also add in the two other quotes from the section you mentioned, as it indicates more clearly the lack of certainty that the researchers felt.

Low conspicuity, or the inability of the motorcycle and rider
to be seen by other road users, is thought to be associated
with motorcycle crash related injury and death

Previous studies suggest a benefit from daytime use of
motorcycle headlights, although the evidence is limited

The reason they use words like "thought to" and "suggest" is because the research couldn't come to a confident conclusion. The error margins were just too high.

[MSTRS:Me]

The reason they use words like "thought to" and "suggest" is because the research couldn't come to a confident conclusion. The error margins were just too high.

Correct. And also that little gem 'could'.

There are no absolute answers to the dilemma of not being seen.
Headlights on is no answer. The number of cars with daytime lights means a bike is just one of the crowd. FFS people pull in front of trains and their light is WAY brighter than any bike.
Hi-viz is a step down from that. And the way that it is creeping, nay - racing - into normal everyday wear for kids, walkers, cyclists, old people, road workers, John Key ... the end result again is a sea of dayglo yellow/orange that no-one sees anymore.
Using seatbelts as an analogy, SD, only works when compared to helmets. They are both there as injury mitigation only AFTER it has all turned tits up. Neither prevent crashes. Well, a visor on a helmet might, by keeping bugs 'n shit out of one's eyes...

I still maintain that a rider's best defence is their own awareness.
And that is advice that our fathers/grandfathers told us...watch out for the idiots out there, son, for they are indeed trying to kill you.