Ontario Helmet Law being pushed through



R

Riley Geary

Guest
"Steven M. Scharf" <[email protected]> wrote in message
news:[email protected]
> b_baka wrote:
>
> > The answer would have to be that they reduced head injury but the
> > overall effect might be to make cyclists braver than they should be
> > whilst wearing a minimal helmet.

>
> Actually, we've seen the opposite assertion here from the anti-helmet
> people. They claim that the reason (or part of the reason) why the
> injury and fatality rates are statistically lower for helmet wearers, is
> not because of any protection the helmet offers, but because helmet
> wearers are also more cautious riders.
>


No, only that *voluntary* helmet wearers (i.e. those who freely chose to do
so in the absense of a MHL or other intensive social pressure) tend to be
more cautious riders. The whole point about risk compensation theory is
that coercing people into using safety equipment that they otherwise
wouldn't chose to use on their own initiative is likely to cause them (at
least at the subconscious level) to take more risks than they otherwise
would have if they weren't using that safety equipment. Something similar
may be happening with voluntary helmet wearers as well, but unless the
elicited increase in risky behaviour is greater than their inborn aversion
to taking such risks in the first place, it is doubtful we would ever see
much of an effect in the overall stats for that particular segment of the
population.

For seat belt use, the only real risks appear to be transfered to
bicyclists, pedestrians, and the unbelted passengers of drivers who
otherwise wouldn't use seat belts. For bicycle and motorcycle helmet use
though, the additional risks taken by riders who otherwise wouldn't chose to
wear a helmet appear to equal or exceed the actual safety benefit to be
derived from the use of such equipment, which is why we see so little
evidence of a net safety benefit at the whole population level (other than
that associated with depressing the total number of bicyclists or
motorcyclists of course).

Riley Geary
 
R

Riley Geary

Guest
"John_Kane" <[email protected]> wrote in message
news:[email protected]
> Can I get a cite on the Utah study ? It looks interesting
>


The relevant data is from Table 51 of NHTSA's State Data System Crash Data
Report: 1990-1999, which can be found at
http://www-nrd.nhtsa.dot.gov/pdf/nrd-30/NCSA/Rpts/2002/809_301/15safetyequip
..pdf

Utah is one of 17 states contributing data to the SDS, which is a database
similar to FARS, except that it includes *all* injury-related traffic
crashes, not just those resulting in a fatality. There is a considerable
problem with the Utah MC helmet data, in that for about 72% of both the
fatal and non-fatal cases from 1990-99, helmet use status is listed as
"unknown." Nonetheless, if the remaining 28% of the cases where helmet use
status is known are actually representative, we have 43 helmeted fatalities,
5 non-helmeted fatalities, 1561 helmeted non-fatalities, and 185
non-helmeted non-fatalities, which yields an apparent odds ratio of
(43/5)*(185/1561) = 1.02 -- or essentially a null effect (i.e. helmeted
motorcyclists being about equally likely to suffer a fatal injury relative
to non-helmeted motorcyclists). OTOH, because of the low number of
fatalities involved, the result is exceedingly unstable. For example,
changing just a single "Helmet use unknown" fatality to a "Helmet not used"
fatality reduces the apparent odds ratio to 0.85 (a 15% net safety benefit),
so these results should be treated with considerable caution.

Riley Geary
 
R

Riley Geary

Guest
<[email protected]> wrote in message
news:[email protected]
> Riley Geary wrote:
>
> > Year Reg MC Fatalities/10,000 Reg MC (NCSA)
> > 1993 38000 7.6
> > 1994 36000 7.8
> > 1995 36000 7.8
> > 1996 36000 7.8
> > 1997 37000 5.4
> > 1998 37000 9.5
> > 1999 39000 9.7
> > 2000 43000 9.3
> > 2001 48000 11.8
> > 2002 51000 12.9
> > 2003 54000 12.6
> >
> > The other problem here is that the LA-DPS data conveniently begins

> with
> > 1997, a year with an anomalously low number of motorcycle fatalities

> in
> > Louisiana. Was this simply an innocent choice of both the data range

> and
> > data source by the author of section V, or was it deliberately chosen

> to
> > mischaracterize the increase in motorcycle fatalities per 10,000

> registered
> > motorcycles as being much higher than it really was following repeal

> of
> > Louisiana's MHL?

>
> It was both innocent and deliberate.


Oh really? The more I dig into the "Evaluation of the Repeal of Motorcycle
Helmet Laws in Kentucky and Louisiana" report at
http://www.nhtsa.dot.gov/people/injury/pedbimot/motorcycle/kentuky-la03/ the
more fraudulent the whole study appears to be, so I'll have to eventually
provide a more comprehensive critique of it; but first...

> It was the year before the repeal,
> versus the year of the repeal. Totally logical. But if you want to
> average 1993-1997, then average 1998-2003, that's fine too.


And why would we want to do that when the MHL wasn't repealed until August,
1999? The 1998 data must be included on the other side of the ledger, and
the 1999 data should probably not be a part of either data set since it was
a transitional year. Now this obviously won't change the fact that
motorcycle fatality rates have indeed risen much faster in Louisiana than in
most other states recently, but your evident inability to get even the
simplest things straight is becoming increasingly annoying. Do we really
need to fact-check every piece of data you wish to bring to our attention?

>
> 7.3 per 10K with MHL versus 11.0 per 10K after the repeal. So it's only
> a 51% increase in fatalities.


And again, it's the fatality *rate* per 10K registered motorcycles we're
talking about here, not fatalities. But the real point (assuming there
really is a point, given the natural variation inherent in the statistics of
small numbers) is that the fatality rate didn't suddenly jump as a response
to the repeal of the MHL, but had already been on the upswing for the
year-and-a-half prior to repeal, and actuall *fell* during the first full
year following repeal!

Well, that last part isn't quite true either. It turns out NHTSA has not
been consistent in the presentation of its motorcycle fatality rate per 10K
registered motorcycles data. Starting with the 1996 Fact Sheet, it began
calculating the fatality rate based on registration data from the previous
year rather than the current year, with the further complication that the
1998 Fact Sheet erroneously repeated 1996 registration data instead of using
the 1997 numbers, and the 2000, 2001, and 2003 Fact Sheets apparently used
both previous year fatalities and registrations. Sorting through all this
obfuscation, and assuming for the moment that 1996 and 1997 registration
numbers are essentially equivalent (which certainly seems to be true for
Louisiana at least), we have the following corrected fatality rates for
Louisiana:

Year Reg MC Fatalities/10,000 Reg MC (NCSA)
1993 38000 7.6
1994 36000 7.8
1995 36000 7.8
1996 37000 7.6
1997 37000? 5.4
1998 39000 9.0
1999 43000 8.8
2000 48000 11.9
2001 51000 12.4
2002 54000 12.2

>
> Sorry Riley. There is just no way you can twist the data to prove what
> you're trying to prove.


No, I'm the one trying to untwist the data so you can actually understand
it, but I suspect that may be a rather hopeless cause by this point.

> And it doesn't matter anyway. The states did
> the right thing by repealing the MHLs, but don't kid yourself into
> thinking that they did it without knowing that there'd be consequences
> in the fatality rates.
>


Sure there are likely to be consequences in terms of increased fatalities
whenever a MHL is repealed, but that's primarily due to the increase in
motorcycling by aging boomers such a repeal facilitates, not to any real
change in the underlying fatality rate with respect to either registrations
or vehicle miles travelled. As a little sneak preview of my forthcoming
critique on the Kentucky/Louisiana study, I'll simply point out that
Louisiana is the *only one* of the five states repealing their MHL's to see
a significant long-term increase in fatality rates for motorcyclists thus
far. It could be argued that Kentucky (1998) and Texas (1997) still have
marginally higher fatality rates than they had in the last few years prior
to repeal, at least as of 2002, but Florida (2000) has been essentially
flat, and Arkansas (1997) actually has a substantially *lower* fatality rate
now than it had prior to repeal.

Likewise, Guy had earlier posted CDC data indicating states without a MHL
generally had lower fatality rates than states with a MHL, and my recent
research into the subject comfirms that finding--with the 25 continuously
non-MHL states experiencing a slight decline over the past decade (from
about 5.3 to 5.0) and the 20 continuously MHL states (plus DC) experiencing
a more pronounced increase since the mid-to-late-1990's (from about 5.5 to
6.5), so who is really kidding whom about fatality rates?

Riley Geary
 
R

Riley Geary

Guest
<[email protected]> wrote in message
news:[email protected]
> Riley Geary wrote:
>
> > Year Reg MC Fatalities/10,000 Reg MC (NCSA)
> > 1993 38000 7.6
> > 1994 36000 7.8
> > 1995 36000 7.8
> > 1996 36000 7.8
> > 1997 37000 5.4
> > 1998 37000 9.5
> > 1999 39000 9.7
> > 2000 43000 9.3
> > 2001 48000 11.8
> > 2002 51000 12.9
> > 2003 54000 12.6
> >
> > The other problem here is that the LA-DPS data conveniently begins

> with
> > 1997, a year with an anomalously low number of motorcycle fatalities

> in
> > Louisiana. Was this simply an innocent choice of both the data range

> and
> > data source by the author of section V, or was it deliberately chosen

> to
> > mischaracterize the increase in motorcycle fatalities per 10,000

> registered
> > motorcycles as being much higher than it really was following repeal

> of
> > Louisiana's MHL?

>
> It was both innocent and deliberate.


Oh really? The more I dig into the "Evaluation of the Repeal of Motorcycle
Helmet Laws in Kentucky and Louisiana" report at
http://www.nhtsa.dot.gov/people/injury/pedbimot/motorcycle/kentuky-la03/ the
more fraudulent the whole study appears to be, so I'll have to eventually
provide a more comprehensive critique of it; but first...

> It was the year before the repeal,
> versus the year of the repeal. Totally logical. But if you want to
> average 1993-1997, then average 1998-2003, that's fine too.


And why would we want to do that when the MHL wasn't repealed until August,
1999? The 1998 data must be included on the other side of the ledger, and
the 1999 data should probably not be a part of either data set since it was
a transitional year. Now this obviously won't change the fact that
motorcycle fatality rates have indeed risen much faster in Louisiana than in
most other states recently, but your evident inability to get even the
simplest things straight is becoming increasingly annoying. Do we really
need to fact-check every piece of data you wish to bring to our attention?

>
> 7.3 per 10K with MHL versus 11.0 per 10K after the repeal. So it's only
> a 51% increase in fatalities.


And again, it's the fatality *rate* per 10K registered motorcycles we're
talking about here, not fatalities. But the real point (assuming there
really is a point, given the natural variation inherent in the statistics of
small numbers) is that the fatality rate didn't suddenly jump as a response
to the repeal of the MHL, but had already been on the upswing for the
year-and-a-half prior to repeal, and actuall *fell* during the first full
year following repeal!

Well, that last part isn't quite true either. It turns out NHTSA has not
been consistent in the presentation of its motorcycle fatality rate per 10K
registered motorcycles data. Starting with the 1996 Fact Sheet, it began
calculating the fatality rate based on registration data from the previous
year rather than the current year, with the further complication that the
1998 Fact Sheet erroneously repeated 1996 registration data instead of using
the 1997 numbers, and the 2000, 2001, and 2003 Fact Sheets apparently used
both previous year fatalities and registrations. Sorting through all this
obfuscation, and assuming for the moment that 1996 and 1997 registration
numbers are essentially equivalent (which certainly seems to be true for
Louisiana at least), we have the following corrected fatality rates for
Louisiana:

Year Reg MC Fatalities/10,000 Reg MC (NCSA)
1993 38000 7.6
1994 36000 7.8
1995 36000 7.8
1996 37000 7.6
1997 37000? 5.4
1998 39000 9.0
1999 43000 8.8
2000 48000 11.9
2001 51000 12.4
2002 54000 12.2

>
> Sorry Riley. There is just no way you can twist the data to prove what
> you're trying to prove.


No, I'm the one trying to untwist the data so you can actually understand
it, but I suspect that may be a rather hopeless cause by this point.

> And it doesn't matter anyway. The states did
> the right thing by repealing the MHLs, but don't kid yourself into
> thinking that they did it without knowing that there'd be consequences
> in the fatality rates.
>


Sure there are likely to be consequences in terms of increased fatalities
whenever a MHL is repealed, but that's primarily due to the increase in
motorcycling by aging boomers such a repeal facilitates, not to any real
change in the underlying fatality rate with respect to either registrations
or vehicle miles travelled. As a little sneak preview of my forthcoming
critique on the Kentucky/Louisiana study, I'll simply point out that
Louisiana is the *only one* of the five states repealing their MHL's to see
a significant long-term increase in fatality rates for motorcyclists thus
far. It could be argued that Kentucky (1998) and Texas (1997) still have
marginally higher fatality rates than they had in the last few years prior
to repeal, at least as of 2002, but Florida (2000) has been essentially
flat, and Arkansas (1997) actually has a substantially *lower* fatality rate
now than it had prior to repeal.

Likewise, Guy had earlier posted CDC data indicating states without a MHL
generally had lower fatality rates than states with a MHL, and my recent
research into the subject comfirms that finding--with the 25 continuously
non-MHL states experiencing a slight decline over the past decade (from
about 5.3 to 5.0) and the 20 continuously MHL states (plus DC) experiencing
a more pronounced increase since the mid-to-late-1990's (from about 5.5 to
6.5), so who is really kidding whom about fatality rates?

Riley Geary
 

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