Helmets, mothers and grandfathers



On Tue, 07 Sep 2004 21:18:19 GMT, The Oldfellow
<[email protected]> () wrote:

>Helen Deborah Vecht wrote:


>> Every helmet worn is a silent vote for compulsion in today's climate.
>>

>
>That convinced me. It's in the bin. What a relief - cool at last!


<jealous>

Spring seems to have sprung here in Aotearoa. The last three days have
been bright and sunny, light breezes and perfect cycling weather. :)

I'd also forgotten how much my head sweats whilst wearing a plastic
hat in full sun. :-(

--
Matt K.
Drawing on my fine command of language, I said nothing.
 
> OK, this is one of the claims that I think needs to have some questions
> asked about it. What does it mean to say that cycling is safer than
> walking? Are we comparing accidents per time spent walking and cycling,
> or per distance?


Per distance. The only figures I can remember seeing[1] are comparing
modes of transport, so they've compared them per mile.

> Which people are we talking about? Amongst pedestrians are many people
> who can't cycle: the very young, and the infirm. Suppose we discover
> that a significant quantity of injured pedestrians are small children.
> That might lead us to say that people who walk are more likely to be a
> vulnerable kind of person, rather than to say that walking is more
> dangerous.


The figures are only valid for a population rather than for individuals.
The tables are useful mainly in arguments about compulsion. They do,
however, give a ball park figure.

It is interesting to note that cycling as transport is notorious for
being underestimated[3] so it is likely that the dangers of cycling have
been over-estimated here. I'm not sure whether the same is true of
walking or not.

It would be interesting to see figures corrected for the young, the
infirm, the just plain doddery, the drunks etc but modifying one set of
not particularly accurate figures with other even less accurate figures
is probably going to be even less accurate. Anyone care to do it?




[1] Pretty Excel version:
<URL:http://www.statistics.gov.uk/StatBase/Expodata/Spreadsheets/D7250.xl
s>
Ugly generic version:
<URL:http://www.statistics.gov.uk/StatBase/Expodata/Spreadsheets/D7250.cs
v>

[2] Well, everyone that was measured in the sample.

[3] There was a link about this on the ng a few weeks back.
--
 
RogerDodger wrote:

> Tony Raven Wrote:
>
>>PK wrote:
>>
>>>You weaken your case by setting up such falsehoods.
>>>

>>
>>Good name for helmets that - False Hoods
>>
>>Tony ;-)

>
>
> How about poly-bonnets (as in polystryrene bonnets) - although that's
> not sufficently disdainful in my opinion.
>
>


I'll stick with HGV Deflectors.

Tony
 
PK wrote:

> Ah, but that would spoil the argument. These guys like to wrong foot
> opponents by quoting raw stats that appear counter intuitive - until that
> is you start asking pertinent questions like yours.


So is this the same PK that was complaining about smear tactics
yesterday? I think we should be told!

These guys like to work out things pertinent to their actual safety.

As for "which is safer, walking or cycling", you are to some extent
comparing apples and oranges, as you can quote stats in meaningful ways
that make things appear good or bad from either perspective. Do we look
at per hour, per km, or how? The specific context of the question is
often relevant to the best way to present the answer.

Perhaps start at http://www.cyclehelmets.org/mf.html#1014 but also
follow the references for more context. The bottom line is that both
walking and cycling are, for the most part, safe.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email protected] http://www.dundee.ac.uk/~pjclinch/
 
[Not Responding] <[email protected]> wrote:

> >That might lead us to say that people who walk are more likely to be a
> >vulnerable kind of person, rather than to say that walking is more
> >dangerous.

>
> It might. But the reason I threw in the walking comparison to the
> thread was because we were targetting one particular mode of transport
> for helmet-wearing not one particular sector of society. It was said
> that "people should wear helmets when cycling" and I was just pointing
> out that for the general demographic of "people", it's actually
> walking that's more likely to get you a head injury[1].


I don't think the word "you" in that last sentence belongs there - as
soon as you say "you" in that context, it refers to an individual, and
their likelihood of being injured in each mode of transport.

The average walker may be more likely to suffer a head injury than the
average cyclist, but that's not the same as "walking is more likely to
give you a head injury".

> If we did the analysis and found, for instance, that children were the
> victims regardless of mode it wouldn't undermine my point; having
> proved that walking was dangerous for kids, would you be recommending
> walking helmets?


No - doing the analysis might be relevant when deciding whether it's
better to walk or cycle with your children to skool.

Daniele
--
Apple Juice Ltd
Chapter Arts Centre
Market Road www.apple-juice.co.uk
Cardiff CF5 1QE 029 2019 0140
 
D.M. Procida wrote:
>
> The average walker may be more likely to suffer a head injury than the
> average cyclist, but that's not the same as "walking is more likely to
> give you a head injury".
>
>


The average person is about ten times more likely to suffer a head
injury walking than cycling because of the exposure factor.

Tony
 
D.M. Procida wrote:

> No - doing the analysis might be relevant when deciding whether it's
> better to walk or cycle with your children to skool.


All of the typical methods to get kids to skool have risk factors in the
same ballpark, i.e., not actually very big. So I'd be inclined to work
from convenience rather than trying to come out with some sort of hard
risk number. Especially as you end up with very complex risk factors
when you look at things over the long term, such as early exposure to
good road sense on bikes will possibly reduce risk factors when they
cycle on their own, and so on.

I can't remember if you've already been recommended Cyclecraft by John
Franklin, Publisher: The Stationery Office Books; ISBN: 0117020516, but
if you haven't then get a copy as it's entirely likely following the
advice therein will make you and/or the sprogs far safer than putting
lids on through actively avoiding being in accidents.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email protected] http://www.dundee.ac.uk/~pjclinch/
 
Mark Thompson wrote:
> The figures are only valid for a population rather than for
> individuals. The tables are useful mainly in arguments about
> compulsion. They do, however, give a ball park figure.
>
> It is interesting to note that cycling as transport is
> notorious for being underestimated[3] so it is likely that the
> dangers of cycling have been over-estimated here. I'm not sure
> whether the same is true of walking or not.
>
> It would be interesting to see figures corrected for the young,
> the infirm, the just plain doddery, the drunks etc but
> modifying one set of not particularly accurate figures with
> other even less accurate figures is probably going to be even
> less accurate. Anyone care to do it?


No analysis but some background data:


RAC foundation; New figures reveal that more than seven out of ten of young
adult pedestrians (aged between 16 -34) killed on the UK’s roads and
included in the study had been drinking
&
A report** two years ago suggested that the risk of fatal accident
involvement for adult pedestrians starts to increase rapidly at blood
alcohol concentrations above 120mg/100ml. Australian research*** adds that
at alcohol levels of 150 mgs/100ml and above, the risk of a pedestrian
having an accident is 15 times greater. The risk of non-fatal injury is also
considerably increased by alcohol consumption

http://www.idf50.co.uk/idfmotoring2.htm
For elderly people, road accident fatalities are primarily pedestrians. For
everyone aged 60 and over, 49 percent of all fatalities are pedestrians, and
outnumber car occupants, who are 43 percent of all fatalities. For people
aged 80 and over, pedestrians are 61 percent of all fatalities.

http://www.dft.gov.uk/stellent/groups/dft_transstats/documents/graphic/dft_transstats_505588-38.gif
gives an informative plot by age
&
..15 For all casualties, including slightly injured, children accounted for
about 40 per cent of pedestrian casualties in 1997, but only 14 per cent of
fatalities. In contrast, only 10 per cent of casualties were aged 70 and
over, but 34 per cent of those killed were in this age group.

5.16 One factor in the generally higher casualty rates among men could be
higher alcohol consumption. In 1995, about a third of pedestrian fatalities
aged 16 and over who had their blood tested were found to have blood alcohol
levels over 80mg/100ml, the legal limit for drivers. For pedestrian
fatalities occurring between midnight and 4 am, over three quarters were
over this limit. The overall percentages may be lower, as only about half of
road fatalities were tested for blood alcohol levels, possibly those where
alcohol use was suspected
&
5.25 Some police forces collect data on factors which may have contributed
towards pedestrian accidents. No national data are collected, and there are
likely to be variations in these factors by area. However, in London the
three primary factors recorded most often in 1995 were:

crossing road heedless of traffic elsewhere - 45 per cent
crossing road masked by parked vehicle - 14 per cent
crossing road heedless of traffic at pedestrian crossing - 9 per cent
&
Relative risk of walking, compared to other modes
5.28 In 1996, about 1,800 car occupants were killed as a result of accidents
on the roads of Great Britain, about twice the number of pedestrian
casualties. However, per kilometre travelled, pedestrians are now up to 16
times* more likely to be killed than car occupants (Table 23). This relative
risk has nearly doubled over the last twenty years. Using this measure, the
risk of fatality is about the same for pedestrians as for pedal cyclists,
but only about half that of motorcyclists.

* The risks are calculated using unadjusted NTS data from weekly travel
diaries on distances travelled. Since the NTS is known to underestimate
these distances, the fatality risks shown in Table 23 are likely to be over
estimates. In addition, the pedestrian risk relative to that of car users is
also likely to a slight over estimate, as the NTS excludes short walks of
less than 50m, and may generally underestimate walk distances more than car
distances.

>>


The above references seem to say that pedestrian and cycling fataliies are
broadly comparable and that pedestrian fatalities are heavily weighted for:
<16, >65, high blood alcohol and being less than sensible crossing the road.

ie if I'm >16, <80 and pay proper attention to traffic when crossing the
road, I'm safer as pedestrian than cyclist

Anyone have a source for stats on cycling injuries wrt age, alcohol etc or
mode of cycling accidents


pk
 
in message <[email protected]>, PK
('[email protected]') wrote:

> D.M. Procida wrote:
>> [Not Responding] <[email protected]> wrote:
>>
>>> I don't want my daughters growing up with the idea that
>>> cycling is dangerous when in reality it's safer than walking.

>>
>> OK, this is one of the claims that I think needs to have some
>> questions asked about it. What does it mean to say that cycling
>> is safer than walking? Are we comparing accidents per time
>> spent walking and cycling, or per distance?
>>
>> Which people are we talking about? Amongst pedestrians are many
>> people who can't cycle: the very young, and the infirm. Suppose
>> we discover that a significant quantity of injured pedestrians
>> are small children. That might lead us to say that people who
>> walk are more likely to be a vulnerable kind of person, rather
>> than to say that walking is more dangerous.

>
> Ah, but that would spoil the argument. These guys like to wrong foot
> opponents by quoting raw stats that appear counter intuitive - until
> that is you start asking pertinent questions like yours.


OK, suppose (which is highly likely) that young children are more likely
than adults to sustain head injuries while walking, and that that
represents a high proportion of all walking head injuries, and that
(taking the small children out of the dataset) for adults, walking is
no more dangerous than cycling, what does that say about who should
wear helmets and when?

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; It appears that /dev/null is a conforming XSL processor.
 
On 8/9/04 10:12 am, in article [email protected], "PK"
<[email protected]> wrote:

> The above references seem to say that pedestrian and cycling fataliies are
> broadly comparable and that pedestrian fatalities are heavily weighted for:
> <16, >65, high blood alcohol and being less than sensible crossing the road.


Yes that is the case.

> ie if I'm >16, <80 and pay proper attention to traffic when crossing the
> road, I'm safer as pedestrian than cyclist


Only if and only if the cycling figures are not biased by the very young,
the very old and the drunk.


> Anyone have a source for stats on cycling injuries wrt age, alcohol etc or
> mode of cycling accidents


So you don't know whether they are or not so your conclusion is invalid.

...d
 
PK wrote:

> Anyone have a source for stats on cycling injuries wrt age, alcohol
> etc or mode of cycling accidents


No, but I do have stats on head injury rates for child cyclists and child
pedestrians (which means that they are all young and probably very few
intoxicated). They are comparable, that is to say the proportion of
pedestrians with head injuries is less than 10% different to the proportion
of cyclists with head injuries. This is consistent across all severities of
head injury.

The biggest source of head injuries in children is trips and falls. Assault
leads to more child head injuries than cycling does.

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
Just zis Guy, you know? <[email protected]> wrote:

> PK wrote:
>
> > Anyone have a source for stats on cycling injuries wrt age, alcohol
> > etc or mode of cycling accidents

>
> No, but I do have stats on head injury rates for child cyclists and child
> pedestrians (which means that they are all young and probably very few
> intoxicated). They are comparable, that is to say the proportion of
> pedestrians with head injuries is less than 10% different to the proportion
> of cyclists with head injuries. This is consistent across all severities of
> head injury.


Can you post a link to them, if they're available out there?

Daniele
--
Apple Juice Ltd
Chapter Arts Centre
Market Road www.apple-juice.co.uk
Cardiff CF5 1QE 029 2019 0140
 
D.M. Procida wrote:

>>> Anyone have a source for stats on cycling injuries wrt age, alcohol
>>> etc or mode of cycling accidents


>> No, but I do have stats on head injury rates for child cyclists and
>> child pedestrians


> Can you post a link to them, if they're available out there?


http://www.chapmancentral.co.uk/hospital-admissions.html

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University
 
"David Martin" <[email protected]> wrote in message
news:BD63686A.1FD4D%[email protected]...
>
> I had grazes on both temples, ruined a pair of sunglasses, grazes on both
> wrists and one shoulder, a large bit of road rash on one forearm and

grazes
> on *by* chin.


It sounds like you banged your nose too :)

Tom
 
On 8/9/04 7:57 pm, in article [email protected], "Tom"
<[email protected]> wrote:

>
> "David Martin" <[email protected]> wrote in message
> news:BD63686A.1FD4D%[email protected]...
>>
>> I had grazes on both temples, ruined a pair of sunglasses, grazes on both
>> wrists and one shoulder, a large bit of road rash on one forearm and

> grazes
>> on *by* chin.

>
> It sounds like you banged your nose too :)


That was a wrist problem, not a nose problem. Typing you see, not talking..

...d
 
D.M. Procida wrote:

> I have: one girlfriend, two children, two cycle helmets and one father.


I can accept that it is a good idea for children to wear helmets until
they stop falling off. Maybe the first 2 years? They are fairly likely
to have low-speed topples which the things are actually designed to cope
with, and they're not generating 1000W of waste heat like me in a time
trial.
 
On Fri, 10 Sep 2004 19:08:11 +0100, Zog The Undeniable wrote:

> and they're not generating 1000W of waste heat like me in a time trial.


Zog! Turn that waste heat to pedal power and even Eddie Merckx in his prime
would have been left in the dust!


Then the UCI would ban it of course :-((


Mike
 
Zog The Undeniable wrote:
>
> I can accept that it is a good idea for children to wear helmets until
> they stop falling off. Maybe the first 2 years? They are fairly likely
> to have low-speed topples which the things are actually designed to cope
> with, and they're not generating 1000W of waste heat like me in a time
> trial.



Yebbut helmets add a lot of weight to the child's head and their neck
muscles are just not well developed for dealing with that extra weight
in a fall. Children's heads are actually quite resilient to falls as
they fall over and hit their heads a lot as part of growing up. Nature
has taken care of it. As we grow up we learn to protect our heads in a
fall and the skull becomes less resilient in response.

Tony
 
On Fri, 10 Sep 2004 19:08:11 +0100, Zog The Undeniable
<[email protected]> wrote:

>I can accept that it is a good idea for children to wear helmets until
>they stop falling off. Maybe the first 2 years? They are fairly likely
>to have low-speed topples which the things are actually designed to cope
>with, and they're not generating 1000W of waste heat like me in a time
>trial.


But of course they are supposed to remove the helmet every time they
get off the bike and put it on again every time they get back on. This
completely removes the fun and spontaneity from cycling. Also children
in the 1st 2 years bang their heads all the time in low-speed topples.
Nature has allowed for this by giving them softer skulls.

--
Dave...

Get a bicycle. You will not regret it. If you live. - Mark Twain