planes vs cycles

As for your sample comparison, if you're looking for passenger-flight safety
numbers then yes, the airliner is 600 times "more dangerous" than the
motorcycle when measured in fatalities per trip (I don't know where you came
up with 302, since you failed to specify your units).


There are two crew members on a jetliner. At least the hypothetical one I was
using. One jet crashes, killing all aboard (300 pax, 2 crew). This represents
half of all jet activity. One motorcycle crashes, killing all aboard (one
person). This represents half of all motorcycle activity (in my hypthetical
Oz).

So, if we "count" the fatalities, a jet is 302 times more dangerous. But if we
just count the fatals, they are equally dangerous.

If these statistics hold up for the next year (two flights, two motorcycle
rides), and I decide to fly rather than take the motorcycle, how much more
likely am I to die? Not 302 times more likely.

I never said anything about making relative comparisons.

That's what the thread's about.

As for "more likely to kill a given person" that depends on whether the person
is given before making the choice (to fly or ride), or after.

Jose

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"Teacherjh" wrote in message
...
There are two crew members on a jetliner. At least the hypothetical one I
was
using. One jet crashes, killing all aboard (300 pax, 2 crew).

I see...I misread your post, and thought you had both airplanes crashing,
not just one. Not getting enough sleep these days I guess.


If these statistics hold up for the next year (two flights, two motorcycle
rides), and I decide to fly rather than take the motorcycle, how much more
likely am I to die? Not 302 times more likely.

No. But then, that's not the calculation you'd use for making that
comparison. You seem to intentionally be mixing your units in order to
prove some point. What point you're trying to make is lost on me, but you
need to stop mixing your units. You have to use the units that address the
comparison you want to make.

If you want to compare overall transportation safety, then a measure that
accounts for the number of passengers is useful. If you want to compare
individual passenger risk, then a per-trip analysis would be more useful.

As an example of someone that might care about the former more than the
latter, consider an insurance underwriter writing policies that cover
passenger losses.

I never said anything about making relative comparisons.

That's what the thread's about.

By "relative comparison", I mean "a quantified ratio of risk". The thread
started out asking simply whether one activity was more risky than another.
The question of HOW MUCH riskier one is than the other wasn't asked, nor
should anything I wrote be construed as addressing that question.

Pete

You seem to intentionally be mixing your units in order to
prove some point. [...]

If you want to compare overall transportation safety, then a measure that
accounts for the number of passengers is useful. If you want to compare
individual passenger risk, then a per-trip analysis would be more useful.

As an example of someone that might care about [overall transportation safety
instead as opposed
to individual passenger risk] consider an insurance underwriter writing
policies that cover
passenger losses.


My point is really the same as yours - that comparing apples to hand grenades
is tricky. As for an insurance underwriter, depending on the policy, there
will be more people paying for policies in airplanes than in motorcycles, so
the costs is spread out too. However, having the state spend money to address
road safety vs airway improvements would be an example of where the raw numbers
rather than the "relative risk" is more important.

Jose


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"Teacherjh" wrote in message
...
[...] As for an insurance underwriter, depending on the policy, there
will be more people paying for policies in airplanes than in motorcycles,
so
the costs is spread out too.

How do you figure that? Generally speaking, an insurance policy goes with
an airplane or motorcycle, not specifically the driver of that vehicle.
That is, you don't wind up with more policies for airplanes just because
there are more people riding in an airplane.

However, having the state spend money to address
road safety vs airway improvements would be an example of where the raw
numbers
rather than the "relative risk" is more important.

Yes, that would be another example.

Pete

Generally speaking, an insurance policy goes with
an airplane or motorcycle, not specifically the driver of that vehicle.
That is, you don't wind up with more policies for airplanes just because
there are more people riding in an airplane.


The insurance that each person aboard buys (i.e. health insurance, life
insurance, stuff like that, which covers some of the costs) spreads the cost
out, as does the insurance the airplane owner buys (which is partly based on
number of seats).

Jose

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"Teacherjh" wrote in message
...
The insurance that each person aboard buys (i.e. health insurance, life
insurance, stuff like that, which covers some of the costs) spreads the
cost
out, as does the insurance the airplane owner buys (which is partly based
on
number of seats).

Since the owner/operator/pilot of the vehicle most often winds up being
liable for passenger damages, passenger insurance doesn't spread the risk
out nearly as much as you appaer to be claiming.

As far as the number of seats in the airplane affecting the cost of the
insurance, that's exactly the kind of "passenger" risk calculation that the
insurance companies are doing that I'm talking about. You are just making
my point with that statement.

Pete

As far as the number of seats in the airplane affecting the cost of the
insurance, that's exactly the kind of "passenger" risk calculation that the
insurance companies are doing that I'm talking about. You are just making
my point with that statement.


Maybe we're saying the same thing different ways. I thought it would go
without saying that a crash that kills 300 is 300 times worse than a crash that
kills 1. My point was that it doesn't increase the likelihood by itself.

Now, if I were going to fly a jetliner, and one airline uses 30 seat airplanes,
and the other uses 250 seat airplanes, and they fly the same number of
passengers per year, and they each have one crash per year, I'd fly the smaller
planes. But this comes right out when you look at trips per year.

Jose



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