

Study: Hybrid cars hit more pedestrians - vrobancho
http://green.venturebeat.com/2009/11/25/blood-in-the-streets/

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patio11
I think the study is likely detecting "hybrids are disproportionately used in
big cities and blue states", where pedestrian/bicycle traffic is
disproportionately likely to be close to cars and thus gets hit more often
(versus, say, rural Kansas where cars generally hit stationary objects or each
other).

You would probably also find that hybrids strike proportionately more
vegetarians than non-hybrid cars. This does not mean meat scares Priuses away.

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vomjom
There's also the possibility that hybrid drivers simply drive more often
because their cost per mile is cheaper.

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patio11
I suppose that is possible, but consumer gas consumption is mostly non-elastic
(i.e. does not change with the price). We saw this during the price spikes a
few years ago. It doesn't strike me as likely that it would suddenly get
elastic when moving downwards.

This is assuming for the sake of argument that hybrids are cheaper per mile.
The thing that makes that claim difficult to evaluate is "Cheaper than what".
There are several plausible candidates for a yardstick which make the claim
catastrophically false. (Gas is a fraction of the cost per mile. People notice
it because they don't remember ever not having a $350 car payment and don't
consider the cost-per-mile that was rolled into that.)

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jsz0
Modern gasoline compacts with small engines are very quiet at city speeds.
Even on an empty street you wouldn't hear a huge difference. Tires on pavement
would be an audible constant for both. On a busy street with other background
noise it would be nearly impossible to distinguish the two. Certainly there's
an audible difference between a hybrid and a diesel truck but you'd assume
people stopped relying on audible warnings with the advent of quiet gasoline
cars.

I think it's more likely that hybrids change the way some people drive. The
peppy stop & go performance, combined with good braking performance, might
make people more daring, more likely to accelerate quickly, more likely to
rely on short stopping. This is exactly why insurance rates on sporty or high
performance cars is higher than an under powered station wagon. Your choice of
car changes the way you drive. If this is true it's likely that quiet gasoline
compacts with good acceleration would also cause a higher number of accidents
involving pedestrians.

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tumult
8,387 were hybrids, of which 77 had struck a pedestrian — this works out to a
0.9 percent incidence rate

559,703 vehicles were traditional gas-burners, which struck 3,578 pedestrians,
which works out to a 0.6 percent incidence rate

The article says "nearly twice as likely", which is not even really close at
all. Also, the sample size is much smaller for the hybrids.

I understand that cars which are running on electricity are harder to hear
coming. For the blind, I can see that as being troubling. That being said, I
can hear a hybrid or a full electric fairly easily. I might have trouble
hearing one coming if it were going over 20mph, since I'd have less time to
react. The point is moot, though, since I actually look both ways when I'm
crossing a street, like you are told when you're a child.

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foulmouthboy
They may have edited the article, but it reads, "up to twice as likely" and
that observation is based on the incidents of bicyclists hit by hybrids vs
standards (.6 to .3 percent respectively).

Also, to say that one can avoid being hit by a car by simply looking both ways
when crossing a street is a little crass. I'm sure the thousands of
pedestrians actually injured and killed by cars every year never thought to
"look both ways".

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tumult
I'm sure they are. But I suspect the difference between a gas engine and a
hybrid one would not have made a difference in cases like those.

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foulmouthboy
Why not?

I don't think the initial hypothesis is so bad: If you can't hear something
coming, you're more likely to get hit by it. A gas engine is significantly
noisier than a hybrid one.

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tumult
It's just a hypothesis. The burden of proof rests on gathering evidence. So
far, I don't think there is any.

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makecheck
Correlation does not equal causation, of course. And we lack information on
the conditions of the pedestrian accidents (e.g. were the drivers not paying
attention, and did each pedestrian specifically say "didn't hear the car
coming" as the reason for the accident?).

