Hi vis discussion thread (read post #1)

magicbastarder

well done for quote mining my post and finding the study that showed the negative correlation, but not the two others which showed the positive correlation.

Stark

https://www.boards.ie/discussion/comment/122714862#Comment_122714862

"If it saves just one life..."

magicbastarder

oh yeah - i'd forgotten about that Danish study - that was the one which reported a significant decrease in single vehicle accidents, for cyclists wearing hi vis - which throws the entire study into doubt; how would wearing a hi vis jacket reduce the chances of the cyclist themselves crashing?

thebullkf

https://www.boards.ie/discussion/comment/122714862#Comment_122714862

Really ?

Seth Brundle

https://www.boards.ie/discussion/comment/122715219#Comment_122715219

Really what? Would it not work and if not why?

thebullkf

https://www.boards.ie/discussion/comment/122715041#Comment_122715041

Even including the bias , it was shown that redu tion was significant. Thereby supporting the usage ?

Interestingly in Netherlands the number of single crashes NOT involving any motorized vehicles increased by 50% .

more than 90 % of the crashes resulting in serious injuries not involving motorised vehicles were bicycle crashes and the majority of these crashes were single-bicycle crashes.

So a layered approach is definitely better. Safe systems of transport/awareness and proactive measures needed. Worth noting that overall bike crashes with serious injuries have decreased overall which is a good thing👍

thebullkf

Not sure what quote mining is referring to tbh

thebullkf

https://www.boards.ie/discussion/comment/122715260#Comment_122715260

I think we both know the answer to that.

Swiss cheese method / layered approach is probably the best option tbh.

magicbastarder

https://www.boards.ie/discussion/comment/122715266#Comment_122715266

you ignored the parts of my post which didn't support your conclusions (the other studies from wikipedia) and took the one part that did in isolation. but even that, it's a study which appears to be flawed and which stands on its own in terms of results, compared to other studies.

one piece of data which would have been interesting to see was to ask the participants who were involved in a multi-vehicle collision, whether they believed their visibility was a factor. which would help sanity test the conclusions.

as a corollary, i would like to see the data sanity tested against collision data in general. for example; lets say in general, in bicycle/car collisions, it was determined that the motorist is at fault 50% of the time, and the cyclist 50% of the time (figures chosen to make the maths easy, i don't know what they are for denmark). to see that ~50% in reduction in collisions in my hypothetical scenario, would require the jackets to be so effective as to totally eliminate motorist-caused collisions.

also worth noting, the study was in denmark, which is on a par with NL in terms of cycle infrastructure so probably hard to 'port' the conclusions to expectations in other countries. fewer than 1 in 20 people reported collisions, and only one in every 53 people who took part reported colliding with a vehicle, which over the course of a year, would seem low to me? basically means for every 53 years of cycling, you'd expect one collision with another vehicle.

thebullkf

https://www.boards.ie/discussion/comment/122715420#Comment_122715420

I didn't ignore nor conclude, there are lots of apparently conflicting studies, but at least they are there. I'm guessing by your porting comment that you would agree our cycling infrastructure is poorer, ? Which would indicate an even greater need for a multi modal approach, which is what I advocate for.

As I said, context matters. Risk awareness, risk compensation too. ( I remember reading about motorbike accidents occuring within 5km of the riders home for example)

Awareness/ Lights + hi vis + competency= a good thing.

Mocking folks for wearing hi vis is a not a good thing.

We have RLJ's on every mode of transport, cars / vans / trucks are ultimately more hazardous to all other road users, but even with good infrastructure accidents can and do happen, no matter how many lights and hi vis you have .

Have seen some low ball comments on this thread ( over a sustained period) equating hi vis with looking like a bin man or Xmas tree. - victim blaming etc it's unhelpful.

Education and enforcement are key too. I'll find the link to the other study from Netherlands which has some interesting data. Demographics ref older riders vs younger ones etc

Ultimately not wearing a hi vis ( definition tbd) can negatively affect our projection and ultimately exposure.

thebullkf

https://www.sciencedirect.com/science/article/pii/S0001457523004438#b0355

According to Dutch hospital data, over 80 % of all seriously injured cyclists (MAIS3+) were involved in crashes without motorized vehicles, most of these being single-bicycle crashes (Aarts et al., 2022). According to two international reviews, the proportion of single-bicycle crashes among cyclist casualties treated at emergency departments or having been admitted to hospital after a crash ranges from 50 % to 95 % across countries. This range has remained fairly constant over time (Schepers et al., 2015, Utriainen et al., 2023).

It is important to understand that fatal bicycle crashes differ from bicycle crashes resulting in (serious) injury. Some data from the Netherlands illustrate this (Aarts et al., 2022): 55 % of all fatalities amongst cyclists in 2021 were in a collision with a motorized vehicle and 45 % were not. However, 18 % of seriously injured casualties were in a collision with a motorized vehicle and 82 % in other crash types.

To conclude: measured by the number of bicycles per capita or the modal share of cycling and the number of kilometres travelled we may conclude that worldwide the Netherlands is a cycling champion. However, this is also reflected in the official crash data. While the cyclist fatality rate is low by international standards, the high amount of bicycle use results in a considerable share of cyclists in road fatalities (40 %) and extremely high share in serious injuries (71 %). Cycling safety is mainly a problem of older cyclists (85 % of all cyclist fatalities are over 50 years old, 51 % are older than 75 years).

magicbastarder

if you're referring to Paddigol's mention of christmas trees, you need to reread that because it's not victim blaming in the slightest. it's blaming drivers, not cyclists.

and if you hang around the cycling forum long enough, you'll see that lights are pretty sarosanct here; they're proactive rather than reactive, and as i mentioned earlier, work without the headlights of a car needing to be shone on them. you'll get excellent advice on lights if you ask here.

i'm obviously not going to speak for everyone here, but many of us here are fed up with the RSA's attitude to making cyclists safer is to get us to wear PPE - which is victim blaming in a sense. i'm sceptical of the effectiveness, i think driver inattention is a major factor which hi-vis does not address. i usually would wear bright clothing while commuting, but as much so it can't be used against me if i'm taken off the bike in a context where it would have been irrelevant anyway.

CramCycle

https://www.boards.ie/discussion/comment/122714871#Comment_122714871

BINGO in that you made a lot of one line statements without reference or regard or even general flow, which read like a collection of snippets from Irish Times letters blaming cyclists for whatever the flavour of the month us. Ironically it is also how my post reads when trying to respond.

There are a number of false assumptions, and belief that your opinion must be fact, an error routinely made by the RSA, from my reading of your post.

It might be easier to reference your claim to avoid confusion, as the only one I could figure out doesn't say what you think it says if I have read your and MBs post correctly.

AndrewJRenko

https://www.boards.ie/discussion/comment/122715219#Comment_122715219

Yes really. Safe systems of transport/awareness and proactive measures needed, right?

AndrewJRenko

https://www.boards.ie/discussion/comment/122715487#Comment_122715487

Are your 'Really' comments helpful? With all those RLJs going on, surely hiviz for all cars will help make dark cars less dangerous? Do motorists not deserve to be saved with hiviz too?

tomasrojo

https://www.boards.ie/discussion/comment/122715041#Comment_122715041

Yeah, they acknowledged that the respondents seemed to be keen to try to tell them what they the survey creators wanted to hear (the jackets were great), so calculated a correction factor that would reduce the collision protection appearance for solo crashes to zero, and then applied it to everything else. Of course, among other things they were assuming that the underreporting of collisions was the same for people involved in multi-party collisions, which seems unwarranted to me.

But when Ian Walker commented on it, he didn't take issue with their correction factor. He said the apparent protective effect they had seen (in some scenarios, by no means all) was in the general scheme of things a small effect that could only be visible in a place like Copenhagen, that had engineered out the most serious sources of collision already. (Which is like what MB already said)

tomasrojo

https://www.boards.ie/discussion/comment/122715508#Comment_122715508

The Netherlands has high *numbers* (rather than rates) of injuries because it has very many cyclists, including in two categories likely to have collisions or falls; the very young and the very old. This isn't really a HV thing.

If you're referring back to the apparent protective effect against solo collisions in the Copenhagen study and think the NL needs to take advantage of this effect because of its large number of solo collisions, the authors don't claim HV prevents solo falls or collisions; they acknowledge that the lower rate for that scenario is due to response bias: the participants want the jacket to work and underreport incidents that they feel undermine the study.

magicbastarder

https://www.boards.ie/discussion/comment/122715883#Comment_122715883

yeah, they seem to assume underreporting of 'single' PIAs would happen at the same rate as underreporting of 'multiple' PIAs, which is a bold assumption.

from the paper:

"This study as well as the study of the effect of bicycle lights (Madsen et al., 2013) suggest a bias in the two groups’ reporting which could be prompted by the fact that the experiment was non-blinded. Thus, test group participants seem to under-report PIAs, whereas participants in the control group seem to over-report PIAs. Similar effects are known from both marketing and psychology and are often referred to as demand characteristics (Nichols and Maner, 2008, Orne, 1962) or response bias (Furnham, 1986). There seems to be a response bias in our data which results in 96 single PIAs in the control group and only 80 in the test group. This difference was unexpected, as the bicycle jacket is supposed to have no effect on single PIAs.

Madsen et al. (2013) suggested a correction method to adjust for this bias, and this correction method was applied in this study."

magicbastarder

going back to the point i was making about sanity testing the stats - let's say 75% of cyclist/motorist collisions were the fault of motorists (i vaguely remember a TfL study that looked into this, with more complex conclusions, but IIRC something like 60-70% is more accurate).

the uncorrected near 50% effectiveness claim would require the 75 out of 100 collisions being the fault of the motorist, to drop to ~25 out of 100 - in short, suggesting that hi vis was actually 66% effective, and that's without taking collisions where the motorist is at fault but visibility not an issue, which would drive that figure higher. i just find that hard to swallow.

TL;DR - i reckon it's pure fantasy to think that hi-vis could nearly halve the number of collisions.

FWIW, i've been involved in two collisions with motorists where i sustained minor injury. one was my fault, and the second had nothing to do with hi vis.

Paddigol

https://www.boards.ie/discussion/comment/122713418#Comment_122713418

Very valid point on the hi viz in the countryside during the day time - almost all builders vests I see handed out by 'road safety' groups are yellow. Which camouflages nicely against any countryside hedge, bank or ditch. And of course it being day time, any reflective qualities will probably be less than the discarded can of coke on the road throws up. At night - wear as much hi viz as you like, but for the love of god wear a proper head torch.

Paddigol

https://www.boards.ie/discussion/comment/122715487#Comment_122715487

Nobody is mocking anyone for the simple fact of wearing hi viz. That's an important point to make. Wearing hi viz is one thing, but it's a personal choice and there's a real danger of both exacerbating the problem and also discouraging active travel in holding hi viz out as being the only way to be responsible. Which is what much of the talk around hi viz ends up being - hence the reason the "if it saves just one life" gets people's backs up, because that logic is conveniently only applied to suit the narrative of putting the onus on the non-driver to reduce accidents.

zell12

Near RSA HQ, builders vests abound

https://www.rte.ie/news/connacht/2024/1017/1476059-mayo-school-footpath/

Macy0161

How many lives would be saved by mandatory full face helmets for those in cars, along with proper rally style harnesses and roll cages? "if it saves one life" just became impractical, as it's discommoding car users.

Markcheese

Is anyone actually arguing that a hi-viz jacket should be mandatory for any group ?

Recommended, yeah sure , encouraged probably,

Personally I would have argued it for electric scooter riders to have to wear hi-viz , along with a helmet with a red light in the back of the helmet ,14 year olds to be allowed ride , and compulsory scooter equivalent of a kids bike safety course ,with an id card to be carried to say you have completed the course, but then I still think electric scooters could be a transport game changer. .

zell12

🙄 🙄

https://www.echolive.ie/corknews/arid-41490854.html

AndrewJRenko

https://www.boards.ie/discussion/comment/122734651#Comment_122734651

Is that really a good priority area to focus on, given the nature of deaths on our roads?

https://www.boards.ie/discussion/comment/122740038#Comment_122740038

Selling less booze would be more effective.

zell12

RPU Chief Supt Humphries on Radio1 reminding pedestrians to wear hi-vis and to walk facing traffic (so they can be blinded by headlights)

Markcheese

Wasnt that always the recommendation?

( The walk facing traffic bit ? )

It was reflective armbands that were recommended when I was a kid ,

Any recommendation for drivers to slow down

Wasn't there a recommendation recently to reduce speed limits on rural roads ?

Markcheese

Who are the rpu ?

Seth Brundle

RPU = Roads Policing Unit