Highway Code investigative paper 2020

For all discussions about this "lively" subject. All topics that are substantially about helmet usage will be moved here.
Steady rider
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Re: Highway Code investigative paper 2020

Post by Steady rider »

With regards to Jake Olivier's comments about Clarke. Both gave evidence to an Australian Senate Committee in Melbourne 2015.
https://www.aph.gov.au/Parliamentary_Bu ... rt%20d/c05

Clarke's evidence was accepted.

Olivier's evidence was challenged. He and others were trying to say cycling had not been discouraged, and Senator David Leyonhjelm reported he was not persuaded.
1.2 During the course of the hearing, and based on available data, it became clear MHL have undermined cycling participation rates. Attempts to argue to the contrary, especially given evidence from around the world, were not at all persuasive.

Olivier has published several papers but his views are not sound.

https://www.theguardian.com/lifeandstyl ... nate-hears.

The Melbourne 1992 survey included a cycle rally that increased the counts. The survey sites were known.

Senator Leyonhjelm also stated,
1.5 I also maintain, in the absence of compelling evidence demonstrating a substantial social benefit, there should be a bias in favour of individual choice and responsibility. It is especially not the role of government to protect individuals against the consequences of their own choices when the risks are small, foreseeable and borne personally.


Clearly the helmet issue does not show compelling evidence demonstrating a substantial social benefit and the advice to wear one should be reconsidered.

Regarding the NZ data for TBI.
The researchers reported,
Our analysis showed the declining trend in rates of traumatic brain injuries from 1988-91 to 1996-99. However, it is unclear whether this reflects the effectiveness of the mandatory all-age cycle helmet law implemented in January 1994 or simply reflects a general decline in all road injuries during that period.

and
The travel surveys show that from 1989/90 to 2005/08, the average time spent cycling per week decreased from 28 minutes to 8 minutes among those aged 5-12 years and from 52 minutes to 12 minutes among those aged 13-17 years [7].

and
Of particular concern are children and adolescents who have experienced the greatest increase in the risk of cycling injuries despite a substantial decline in the amount of cycling over the past two decades.


Details for NZ were not published by age group to know how much of the reduction in TBI could be due to helmets or due to reduced cycling levels.

Information from Canada shows the rates by age groups,
https://secure.cihi.ca/free_products/nt ... 2006_e.pdf
For Canada
Between 1994-1995 and 2003-2004, 61% of cycling related traumatic head injuries occurred among those between the ages of 5 to19 years.
the highest risk ratio of injury hospitalizations appeared in those aged 10 to 14 years (RR = 9.8)
The relative risk of head injury was 9.8 times higher for the 10-14 age group.

NZ data shows cycling reducing from 80 minutes to 20 minutes for the 5-17 age range

The definition of TBI can also change, so it was unclear if the reduction in TBI was due to helmet use.
tim-b
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Re: Highway Code investigative paper 2020

Post by tim-b »

Hi
axel_knutt wrote:I don't see much rigour in the helmet research itself. They selectively investigate the effect of helmets on the survivability of an impact, whilst all but neglecting the effect of a helmet on the probability of that impact occurring in the first place. Risk to the rider derives from a combination of both.

I wear a helmet and I'm firmly in the freedom of choice camp, as I've declared here many times
There is a position in official circles that helmets are good and, whether we like it or not, only rigorous arguments will change that position. To put it another way, two wrong arguments don't make it right
Regards
tim-b
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pjclinch
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Re: Highway Code investigative paper 2020

Post by pjclinch »

tim-b wrote:
axel_knutt wrote:I don't see much rigour in the helmet research itself. They selectively investigate the effect of helmets on the survivability of an impact, whilst all but neglecting the effect of a helmet on the probability of that impact occurring in the first place. Risk to the rider derives from a combination of both.
I wear a helmet and I'm firmly in the freedom of choice camp, as I've declared here many times
There is a position in official circles that helmets are good and, whether we like it or not, only rigorous arguments will change that position. To put it another way, two wrong arguments don't make it right
That is part of the problem, but it's a ridiculous part and gives us yet another wrong.

The big pile of contradictory, weak evidence that has produced no smoking gun in decades shows that we either don't have a strong effect either way or that what effects there are are systematically awkward to spot. That Ben Goldacre, who spends much time in print (articles and books) flagging up the wonders of evidence based work and especially systematic reviews, not to mention campaigning for open access to evidence, can co-pen a BMJ editorial where he says it doesn't look like anything much is going to come out of research in to it is a pretty good indication of the same.

So since we very possibly have an effect that you won't come up with a smoking gun for, the above attitude means we'd stuck with something of little positive use with negatives for cycle promotion and inclusivity because it got in under the rigorous radar and we won't let it out the same way. It is a rigorous argument that to keep pushing something controversial as a public health intervention it is necessary to properly justify it. Not requiring this means any weak evidence that's widely believed can never be put aside, and while that might be okay in a theocracy I don't think it's okay in what's meant to be a rational country.

Freedom of choice is great, but you don't actually get that unless there's no pressure. There's lots of pressure, and the Highway Code's Rule 59 is part of it.


Pete.
Often seen riding a bike around Dundee...
Steady rider
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Re: Highway Code investigative paper 2020

Post by Steady rider »

The paper refers to
Zeegers 2015 reported on two of these studies, stating:

“Three cases could be found in the literature with sufficient data to assess both risk ratios and odds ratios: the Netherlands, Victoria (Australia) and Seattle (U.S.A). In all three cases, the problem of overestimation of the effectiveness of the helmet by using odds ratios did occur. The effect ranges from small (+ 8 %) to extremely large (> + 400 %). Contrary to the original claim of these studies, in two out of three cases the risk of getting a head injury proved not to be lower for helmeted cyclists. Moreover, in all three cases the risk of getting a non-head injury proved to be higher for cyclists with a helmet.”


From about 2500 papers on helmets, most do not provide data for assessing risk, only relative injury levels, and only 3 papers are mentioned by Zeegers.
Data from NZ and NSW provide area wide estimates, from relatively good surveys and accident data. The advice in the Code needs to sound in both improving overall safety and not incur or contribute to social injustice. There is solid evidence of social injustice and reasonable evidence that helmet use may increase the accident rate, that would be disputed by some. Both Cycling UK(CTC) and Cycling Scotland in their submissions to the consultation have requested using "Consider" rather than "Should". They are correct in trying to get the advice changed and the question to be considered is should the Code advice wearing cycle helmets at all. The DfT could allow for presentations and hear evidence to see if a good way forward can be agreed.
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pjclinch
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Re: Highway Code investigative paper 2020

Post by pjclinch »

Steady rider wrote:The need is to focus on the issue and how to improve it.


Yes, though I think the technical approaches that attempt to show that helmets are objectively bad fall in to the same sorts of traps of those trying to show they're objectively good. In practice helmets are too difficult to isolate from other factors to come to a safe conclusion where people can't point to holes in the methodology and say "but..."

I also think that the lack of a safe conclusion for most of the people, most of the time, is an entirely good reason to stop promoting, recommending or requiring them, or fostering a culture where it's okay to belittle people who don't use them. With that in mind I think the main benefit of attempting overtly technical approaches has been to show that you won't get far with overtly technical approaches, and thus it makes more sense to concentrate efforts on the clear logical holes of "you should wear these just in case, though we can't say with any certainty whether you'll be better off with or without" and the similar tosh being relentlessly pedalled to millions of folk, though largely excepting those in one of the safest countries there is to cycle.

Pete.
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Steady rider
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Re: Highway Code investigative paper 2020

Post by Steady rider »

Dominic Cummings come to mind when the person becomes the story or issue and not the policy. The helmet issue needs full attention to the science or social consequences and not be diverted onto discussions about authors if possible. The issue raised was concerning Jake Olivier publishing a one sided view, not publishing the reply from Clarke, and the comments being used to discredit Clarke, who puts forward information related to the Highway Code. It was fair to highlight the Senate findings where both people gave evidence.

In 2020, a study reported on bicycle helmet use in adults (16 years and older) and traumatic brain injury (TBI) in the Netherlands. It detailed 7% of cyclists where wearing helmets, 149 from 2133. In contrast, only 1.1% were reported wearing helmets from surveys in Amsterdam.
https://cyclingindustry.news/london-has ... most-zero/

https://www.liebertpub.com/doi/pdf/10.1 ... .2020.0010
It shows helmet use being associated with a higher accident rate.
Jdsk
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Re: Highway Code investigative paper 2020

Post by Jdsk »

Steady rider wrote:With regards to Jake Olivier's comments about Clarke. Both gave evidence to an Australian Senate Committee in Melbourne 2015.
https://www.aph.gov.au/Parliamentary_Bu ... rt%20d/c05
That link isn't to the Committee's report: it's to an individual Senator's "Additional Comments".

Here's the link to the Committee's report:
https://www.aph.gov.au/Parliamentary_Bu ... m_report_d

Well worth reading.

Jonathan
Steady rider
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Re: Highway Code investigative paper 2020

Post by Steady rider »

The link provided directly shows the Senators extra findings in addition to the general findings.

Looking at the NZ paper, http://www.cycle-helmets.com/nz-clarke-2012.pdf

Serious injuries (AIS≥3)
Cyclists 377 117 138 10.27 4.86 (-53) 6.24 (-39)
and the responce

Response to ‘Evaluation of New Zealand’s bicycle helmet
law’ article https://assets-global.website-files.com ... ntent%20(1).pdf
https://assets-global.website-files.com ... ntent%20(1).pdf
link not working

NZMJ 14 February 2014, Vol 127 No 1389; ISSN 1175 8716
The 'Responce' it was very poor and misleading.

Compare Table 4 serious injury data Clarke, to figure 1 in the responce.
Last edited by Steady rider on 4 Dec 2020, 12:21am, edited 4 times in total.
Jdsk
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Re: Highway Code investigative paper 2020

Post by Jdsk »

So the Committee didn't use categories of "challenged: or "accepted" and you added those descriptions?

And in Pete's words that judgement was "made by the person reporting it" here?

Jonathan
Stevek76
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Re: Highway Code investigative paper 2020

Post by Stevek76 »

tim-b wrote:There is a position in official circles that helmets are good and, whether we like it or not, only rigorous arguments will change that position. To put it another way, two wrong arguments don't make it right


But that's just a requirement to prove the negative and with crackpots like Jake Olivier who largely has a full time job to concoct up 'evidence' in support of the Australian law on the matter then that's simply impossible to achieve. That's why the burden is supposed to rely on proving the positive.

If that's the bar then I'm happy to call a spade a spade on the matter, mercilessly mock helmet shamers (it's always entertaining to watch the mental gymnastics on 'why no pedestrian/stairs/showering/driving helmets') and otherwise carry on. The dft already has and annually publishes data showing that the highway code contents are not consistent with the relative levels of risk. Realistically this will only change with some progressive political leadership on the matter. Until that point the most, most of us can do is simply point out the same old flawed arguments from headway & co every time this comes up for consultation to ensure it doesn't get any worse.
The contents of this post, unless otherwise stated, are opinions of the author and may actually be complete codswallop
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pjclinch
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Re: Highway Code investigative paper 2020

Post by pjclinch »

Jdsk wrote:So the Committee didn't use categories of "challenged: or "accepted" and you added those descriptions?

And in Pete's words that judgement was "made by the person reporting it" here?


This seems to be devolving in to semantics.
For a bit of perspective I would note that the New England Journal of Medicine "accepted" Thompson, Rivara & Thompson's '89 paper, as presumably did their assigned peer reviewers. It doesn't really mean much. Getting in to print is only the start and being accepted by a small number of reviewers or board members, even expert ones, is no proof of merit, even if it is generally the case that rejections are a surer sign of lack of it.

Whatever the manners of online anonymity, if we stick to the content of the papers then that's the real argument and anything around how they got published is, in the bigger picture, somewhat superfluous. On the subject of bigger pictures, personally I've mostly given up trawling through every line of this sort of work because it strikes me it is looking at very selective trees when an overview of the forest is what's needed. This approach isn't one I think will find the elusive smoking gun, mainly because we seem to be dealing with water-pistols.

Pete.
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