[email protected] wrote, regarding what's a "serious" injury:
>
>
> > > Oh jeez. People do not 'smash' their derailers when
> > > falling over at a traffic light! Ride much? A $50 wreck
> > > is also likely to result in injury to the rider, as is
> > > reflected in that study.
> >
> > Oh jeez, indeed! I gave that as one example! Check Nashbar for the
> > price of a Gore-tex jacket.
> > http://tinyurl.com/avj6h
> > If a person falls and rips his jacket but suffers no injury, that's a
> > "serious accident" by Moritz's standard. If a person tries to ride
> > through a narrow space between buildings and hooks and rips a pannier,
> > that's a "serious accident." If a person slips and trashes his right
> > STI lever, that too is "serious", even if the person isn't hurt at all.
>
> And if a person goes to the hospital and incurs $250,000 worth
> of medical expenses, that doesn't count at all! Because it's
> an 'outlier.' Great stuff.
Do you understand what "outlier" means in statistics? Are you aware of
"Student's t-test," a mathematical rule for excluding outlying data,
and why it's used? Are you aware that a $250,000 data point among a
$150 median data set is almost always excluded as spurious? And are
you aware that this would _certainly_ be done if (as in the case of
Moritz's data) there was no explanation for that point?
This is standard statistical treatment of data, Robert, using
well-established rules. You may not be familiar with this, but that
does _not_ mean it's somehow cheating!
> In any case, the estimates show that cycling is
> ... relatively likely to cause injury.
> That's injury, as in both serious and minor.
"Relatively likely" compared to what? Playing basketball? And by what
measure - emergency room visits per year, or per hour?
If you claim it's per hour, you'll need to find per hour data on
basketball. I'm curious how you'll do that, and what methodology will
have been used, and how valid you'll claim it is.
If it's per year, you're simply wrong. Basketball causes quite a few
more ER visits per year in the US than does cycling. (That's from the
National Safety Council, using NEISS data, IIRC.)
If you're talking minor injuries, I recently cited a paper that showed
that gardening, weighlifting, aerobics and walking for exercise all
cause more injuries per month than cycling does. (Do you want that
citation again?)
>
> > > I guess it depends on how you define 'serious injury,'
> > > doesn't it?
> >
> > Of course. One of the problems with this sort of work is defining
> > various types and levels of injury. (Recall that Thompson and Rivara
> > called a cut hear a "head injury" to pump up fear.)
Sorry for the typo. That was supposed to be "called a cut _ear_ a
"head injury"...
>
> The medical terminology also classifies many
> injuries which laypeople do not typically think
> of as head injuries as head injuries.
The point is, people hear "head injury" and they think "debilitating
brain injury, drooling in a wheelchair." T&R's classification of cut
ears as head injury was, I believe, deliberately deceptive.
> > > .01% is 100-per-million population, or what
> > > about 40,000 every year in the US.
> >
> > Remember, that figure was for San Diego county. The proportion for all
> > America is likely to be signficantly less. Not much cycling in Fargo
> > during the winter.
>
> Maybe, maybe not.
I'll just let that stand, thanks.
> > The threshold Moritz used was simply wrong. It was too low. And yet,
> > even with that, his paper shows cycling to be acceptably safe.
>
> One of the most serious injuries I have ever suffered
> caused absolutely no damage to the bike, and I never
> went to the doctor because I had no insurance at the
> time. Thus this rather debilitating injury cost exactly
> $0 on the Moritz scale. I'm sure there is a lot of
> that, but you only see the other side of it, the
> minor injuries that make it into the 'real' column.
I'm sure that there are serious injuries that don't get reported.
Nothing is perfect. But your rationale, that any imperfection
(specified or not) requires completely discarding all information, is
completely silly.
One of the things I got some training in is called "error propagation."
In my field, it's a technique for estimating a variety of errors in a
series of related measurements, and computing how they are likely to
affect the overall outcome. It involves a little advanced math - that
is, at least partial derivatives. But briefly, a 10% error in a
certain measurement does not mean the entire result will be off by 10%.
Depending on the situation, you can still get very good overall
results.
> I see you using the term 'acceptably safe' now.
> Is it no longer 'relatively safe?'
Oh, quit looking for boogeymen! Bicycling is both "relatively safe,"
and "acceptably safe."
> No, Frank. It is you who continually insist that I
> am referring to minor injuries. I am concerned
> with 'real injuries.' Not skinned knees, as you
> continually insist.
Perhaps you and I should agree on the exact level of injuries to term
"serious," and promise to never mention lesser ones. Where would you
agree on a limit?
FWIW, I don't like "ER visit" as a threshold. Too low, because many ER
trips are for injuries and ailments that would never lead to problems
if untreated. As examples, we took my daughter to the ER once, because
of a bad cold on a weekend. I went to the ER once for a half-inch cut
on my foot, and was told I should have just used a butterfly bandaid.
How about hospital admission? There are decent records for that, I
believe.
>
> > If all that time, you were talking about _serious_ injuries per mile,
> > then I suppose you are not lying in your paragraph just above. But,
> > OTOH, you are absolutely mad!
>
> Absolutely mad, huh? Okay. Takes one to know one I guess.
> Kifer and Moritz both reported roughly 10% of their very
> experienced respondents suffered a 'real' or a 'serious'
> injury in the past year....
>
> That is your cue to repeat your unsubstantiated claim
> that the 'real' and 'serious' crashes reported in these
> surveys are actually 'minor' injuries.
That is my clue to tell anyone else to read the original documents.
I'll let them decide.
But since I'm perhaps not understanding you: Are you claiming that
there are lots of _serious_ injuries per hour cycling, or lots of
_minor_ injuries per hour?
>
> There you go again.
Was that your Ronald Reagan impression?
> Insisting that the 'real' and
> 'serious' injuries reported by cyclists are actually
> all minor and consequential...
No, I'm insisting that the vast majority of injuries reported by
cyclists are minor. And that even those are rare.
> What the hell are you talking about? I have
> never written any such thing. There are literally
> millions of cases of road rash every year that never
> see a doctor and are not reported in any way.
So is road rash serious? How much does it take to be serious? A
square inch? Six square inches? A square foot?
Is it serious only when it happens on a bike? How much should we wring
our hands if the same amount happens in a playground game of tag? Is
tag dangerous, too?
> > Tell us: Does your typical bike messenger head for the ER for his
> > typical case of road rash?
>
> The typical bike messenger does not
> go to the ER unless a bone is sticking out.
I suppose they all die of road rash, eh? Because, golly, road rash
really is dangerous!!!
> > Awareness is good. I've never said otherwise. But fear is not needed.
> >
> > I understand your motives are good - that you think scaring people
> > about cycling will make them better riders.
> >
> > But I disagree that such a thing is necessary or justifiable. I'll
> > note that the people most respected in cycling education also disagree
> > with you.
>
> Really? This is interesting. Who are these 'people most
> respected in cycling education,' and what do they
> say?
What they do NOT say is "Cycling in traffic is dangerous, and 'traffic'
is any time there's any other vehicle on the road" - which is, I think,
a pretty accurate quote of what you've said.
I'd say the most respected people in cycling education include John
Allen, Fred Meredith, John Schubert and John Forester, among others.
(I don't wish to slight any I'm omitting.)
I'm not aware of _any_ of these people stating, as you have done, that
cycling is dangerous.
What these people do is tell people how to ride competently and safely
- yes, even in traffic. They feel no need to frighten people. Quite
the opposite.
Any other readers may wish to read some of John Allen's qualifications
at
http://www.bikemaps.com/bss.htm
and see his recommendations on riding in traffic at the excellent
http://www.bikexprt.com/streetsmarts/usa/index.htm
Note the absence of fear-mongering.
- Frank Krygowski