Ontario Helmet Law being pushed through

Benjamin Lewis writes:

Bill Z. wrote:

And, of course, Frank has no data ruling out the following:

1. The people who put in by far the most mileage could
have been using helmets already (quite likely, if the
U.S. is a reasonable model).
...
What does Frank's results tell us? Not much if you are interested in
how well the helmets worked: the helmets could work just fine with the
helmet law being close to useless because people who needed the
helmets the most were either already using them before the law was
passed or ignoring the law altogether.

BTW, we have at least a factor of 1000 difference in annual mileage,
with some adult cyclists riding 5 or so miles per years and others
over 5000 miles per year. There's a lot more of the later than the
former (like a number of my neighbors, who go on a 5 mile annual
bike ride as part of a block party.)

You seem to be implying that it's the high mileage cyclists who "need
helmets the most". And yet, the risk per hour of getting into an accident
is smallest for high mileage cyclists. If you believe that helmets reduce
risk of injury given that an accident occurs, shouldn't it be the low
mileage cyclists who need helmets the most?

If you check _Effective Cycling_, Forester claims that "club cyclists"
are about 5 times safer per mile than your average adult cyclist.
Meanwhile club cyclists ride up to about 1000 times further per year.

BTW, my neighbors' annual 5 mile bike ride is about 2 miles on quiet
residential streets, 1 mile on a street with somewhat higher traffic
levels, and 3 miles on a bike path that does not cross any roads for
that distance. They ride rather slowly. What do you think their risk
level is? How do you think their risk level compares to the 19/20
year old who once nearly broadsided me as he came out of nowhere on a
sidewalk (due to vegetation and the sidewalk curving), blowing through
a red light, and flipping me off when I suggested that he watch where
he was going. He wasn't wearing a helmet either. While a helmet
might not protect him from his extreme recklessness, in the sort of
studies that Frank is touting, someone like him would contribute to a
poorer "post helmet law" injury rate (the study Frank touts did not
have any data about which injured cyclists wore helmets and which
didn't.)

Curiously, nearly all my neighbors used helmets (maybe they rode so
little it didn't matter, but using one makes it easier to convince
you kids to use one.)

--
My real name backwards: nemuaZ lliB

Bill Z. wrote:

Benjamin Lewis writes:
You seem to be implying that it's the high mileage cyclists who "need
helmets the most". And yet, the risk per hour of getting into an
accident is smallest for high mileage cyclists. If you believe that
helmets reduce risk of injury given that an accident occurs, shouldn't
it be the low mileage cyclists who need helmets the most?

If you check _Effective Cycling_, Forester claims that "club cyclists"
are about 5 times safer per mile than your average adult cyclist.
Meanwhile club cyclists ride up to about 1000 times further per year.

I'm not sure what your point is here. Clearly, the only reasonable way to
measure risk is on a per-unit-time basis. Otherwise, you'd be concluding
that the low-mileage cyclists are *much* better off wearing their helmets
when they're *not* on their bicycles, even if you're correct that cycling
is dangerous enough to warrant a helmet.

--
Benjamin Lewis

Seeing is deceiving. It's eating that's believing.
-- James Thurber

Benjamin Lewis writes:

Bill Z. wrote:

Benjamin Lewis writes:
You seem to be implying that it's the high mileage cyclists who "need
helmets the most". And yet, the risk per hour of getting into an
accident is smallest for high mileage cyclists. If you believe that
helmets reduce risk of injury given that an accident occurs, shouldn't
it be the low mileage cyclists who need helmets the most?

If you check _Effective Cycling_, Forester claims that "club cyclists"
are about 5 times safer per mile than your average adult cyclist.
Meanwhile club cyclists ride up to about 1000 times further per year.

I'm not sure what your point is here. Clearly, the only reasonable way to
measure risk is on a per-unit-time basis.

Nonsense. The highest risk is at intersections, and the number you
cross is proportional to how far you go, not how long it takes you
to complete your trip.

Otherwise, you'd be concluding that the low-mileage cyclists are
*much* better off wearing their helmets when they're *not* on their
bicycles, even if you're correct that cycling is dangerous enough to
warrant a helmet.

Nope. Guess again.

--
My real name backwards: nemuaZ lliB

On Sat, 11 Dec 2004 03:15:59 GMT, (Bill Z.)
wrote:

Well, as I said ....
(and the rest of your messages are being flushed today as well, as
it sounds like you still have nothing to contribute.)

Ref! Zaumie's off again!

Still having trouble acting like an adult, as Steven just suggested?

Apparently you are, yes.

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 CHS, Puget Sound

On Sat, 11 Dec 2004 03:28:18 GMT, (Bill Z.)
wrote:

Same propaganda ... "entire populations" is Frank's code phrase for
(to give an example) New Zealand, with a population will below some
metropolitan areas in the U.S.

So we turn instead to Rodgers, who analysed all eight million serious
and fatal cycle crashes in the USA and found... no benefit, and
helmeted cyclists somewhat more likely to die.

And we see the CPSC data which shows that for the USA, risk per
cyclist increased by 40% as helmet use rose from 18% to around 50%.

Clearly, then, the USA must be too small a sample - perhaps we should
consider the entire global population of cyclists? "The Government
knows of no case where cyclist safety has improved through increasing
helmet use" - pro-helmet British road safety minister, after an
extensive review of the evidence.

Just how big does a study population have to be before you admit that
it is more relevant than 235 people in Seattle in 1989, I wonder?

And, of course, Frank has no data ruling out the following:
1. The people who put in by far the most mileage could
have been using helmets already (quite likely, if the
U.S. is a reasonable model).
2. After the helmet law went into effect, lots of low
mileage and law abiding cyclists bought helmets to
comply.
3. Cyclists who couldn't care less about the law flaunted
it (and possibly traffic laws in general) and could thus
well be in the "relatively high risk" group.


Item 1 tells us why the pro-helmet studies are vastly over-optimistic,
and the balance is post-hoc reasoning to explain away the abundantly
obvious fact that cyclist casualties turn out not to be correlated
with helmet use. Now we compare cyclist casualties with
rest-of-population casualties and find? The trends are the same!
Amazing! But what is happening must /obviously/ be that helmets work
as advertised, but there is some artifact specific to the cyclist
population which confounds that, and confounds it differentially (and
in different directions) depending how early you adopt.

Occam's Razor indicates another interpretation...

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 CHS, Puget Sound

On Sat, 11 Dec 2004 07:56:04 GMT, (Bill Z.)
wrote:

The highest risk is at intersections, and the number you
cross is proportional to how far you go, not how long it takes you
to complete your trip.

Actually the highest risk - by just about any measure - is to
pedestrians, with cyclists at about the same risk per unit exposure as
car drivers (but numerically insignificant by comparison).

I'm sure you wear your fantastic aerodynamic helmet for these other
high-risk activities as well, anything else would be entirely
inconsistent.

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 CHS, Puget Sound

Erik Freitag wrote:


In this case, I think the burden of proof would be on you to show why the
New Zealand statistics don't apply to the Bay Area.
....

I think what Frank's saying is here's study (a) which found an 85%
reduction in head injuries for subjects wearing helmets, but it has
a number of flaws,

.... and looked at only a couple hundred cases! ...

...and here's study (b) which included a really large
number of people, which doesn't have those flaws which found a (near) 0%
reduction in head injuries for subjects wearing helmets because there was
a law requiring it.

Yes. In essense, Bill Z seems to accept a tiny study that agrees with
his side of the debate, but rejects a MUCH larger (and better
constructed) study because it's too small!


You might phrase this as "subjects presumed to be
wearing helmets because there was a law requiring it".

Correction. At the time of that 1996 Scuffham study, there was no law yet!

2. After the helmet law went into effect, lots of low mileage
and law abiding cyclists bought helmets to comply.

Again, if you're talking about the paper I'm talking about, the phrase
"after the helmet law went into effect" does not apply.

The paper is "Trends in Cycle Injury in New Zealand under Voluntary
Helmet Use", Scuffham P.A. et. al, Accident Analysis & Prevention, Vol
29, No 1, pp. 1-9, 1997. Note the work "voluntary" in the title.

Helmet use had soared because of intense government promotion. True,
the promotion was due to the fact that an all-ages MHL was to start
soon; but the period of study ended before the law went into effect.


--
--------------------+
Frank Krygowski [To reply, remove rodent and vegetable dot com,
replace with cc.ysu dot edu]

Erik Freitag wrote:

I think you mean you don't trust Frank's statistics because New Zealand
doesn't have as many cyclists as the San Francisco Bay Area.

It is not just the numbers of cyclists, it is the density, the drivers,
and other factors.

like "propaganda" and "code phrase" imply that you think Frank is
deliberately trying to mislead us so we won't, what? Wear helmets?

Yes, Frank is deliberately trying to mislead you. Taking statistics and
studies out of context is one thing he is famous for. I think it comes
down to the "everyone must do what I do because this validates what I
do." It is not an uncommon form of behavior. You see this sort of thing
a lot on Usenet.

Personally I despise this sort of thing. I much prefer the "this is what
I do and why I do it, but I understand that you may have different, but
perfectly valid, reasons for your behavior." The key is to base your
decisions on facts, not myths.

On Sat, 11 Dec 2004 18:53:51 +0000, Steven M. Scharf wrote:

Erik Freitag wrote:

I think you mean you don't trust Frank's statistics because New Zealand
doesn't have as many cyclists as the San Francisco Bay Area.

It is not just the numbers of cyclists, it is the density, the drivers,
and other factors.

like "propaganda" and "code phrase" imply that you think Frank is
deliberately trying to mislead us so we won't, what? Wear helmets?

Yes, Frank is deliberately trying to mislead you. Taking statistics and
studies out of context is one thing he is famous for. I think it comes
down to the "everyone must do what I do because this validates what I
do." It is not an uncommon form of behavior. You see this sort of thing
a lot on Usenet.

Personally I despise this sort of thing. I much prefer the "this is what
I do and why I do it, but I understand that you may have different, but
perfectly valid, reasons for your behavior." The key is to base your
decisions on facts, not myths.

So do I. The trouble seems to be identifying which is which.

On Sat, 11 Dec 2004 18:53:51 GMT, "Steven M. Scharf"
wrote:

Personally I despise this sort of thing. I much prefer the "this is what
I do and why I do it, but I understand that you may have different, but
perfectly valid, reasons for your behavior."

Unless, of course, the behaviour in question is opposing helmet laws
by pointing out reasons for their failure, in which case you will
assert loudly (although without evidence) that only the Scharf way of
opposing helmet laws can work. Even when you are up against people
who have successfully opposed helmet laws in the past.

All is well with Mr Scharf unless and until the sacred cows look like
being killed. At which point all the veneer of fairness and balance
is instantly stripped away.

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 CHS, Puget Sound