How well do cars do in crash tests they're not optimized for? • Hacker News Board

Re: How well do cars do in crash tests they're not optimized for?

#331

Post by nsgi » Wed, Jul 01, 2020, 6:56 AM UTC

laegooose wrote: post #5

The whole car safety topic is very confusing. Car accidents is top1-top2 death reason in US for people in 20-40 age group [1]. Probably less in Europe but still one of the leading ones. I was thinking about how I can make myself safer. Which car brand/model is better? Which seat is better for passenger? How much riskier it is to drive during the night? In the rain? How dangerous is it to overtake on road with 1 lane…

Also, when people think about the risk of driving they forget the additional risk to their health from in-car air pollution

Re: How well do cars do in crash tests they're not optimized for?

#332

Post by nsgi » Wed, Jul 01, 2020, 6:58 AM UTC

ohples wrote: post #163

laegooose wrote: post #5

The whole car safety topic is very confusing. Car accidents is top1-top2 death reason in US for people in 20-40 age group [1]. Probably less in Europe but still one of the leading ones. I was thinking about how I can make myself safer. Which car brand/model is better? Which seat is better for passenger? How much riskier it is to drive during the night? In the rain? How dangerous is it to overtake on road with 1 lane…

> Car accidents is top1-top2 death reason in US for people in 20-40 age group [1] Car crashes where the top 1-2. I am willing to bet most of those involved DUI, and therefore negligence, and shouldn't be classed as "accidents" #CrashNotAccident.

Regardless of whether you call them crashes or accidents, even if you don't do anything stupid you can still be killed by someone else's poor driving or driving under the influence. Also, no one starts out as a perfect driver

Re: How well do cars do in crash tests they're not optimized for?

#333

Post by nostrademons » Wed, Jul 01, 2020, 8:11 AM UTC

throwaway0a5e wrote: post #196

hansvm wrote: post #159

Earlier quoted context omitted.

I've always found it a bit amusing how common this belief is, especially in snowier areas. Most people would be safer without 4WD/AWD -- less likely to oversteer around a curve, and less likely to drive aggressively because of a false belief that AWD will help you stop faster or have better control of your vehicle in low-traction conditions. It's still a really nice feature that has its uses, but most people I talk t…

Comments like this remind me of the Principal Skinner quote "surely I am right and it's everyone else who's wrong" or something like that. Everyone(TM) prefers AWD for it's superior go-ing abilities even if the turning and stopping abilities are unchanged. An obnoxious vocal minority tells them they're wrong. Since it's a matter of performance and consensus the overwhelming majority can't be wrong though. Anecdote ti…

The comment was actually making a point more insulting than you assumed: they're saying that AWD may or may not make cars safer, but any effect it has is dwarfed by making the owners of those cars into overconfident morons. It's a statement about drivers, not about cars.

Note that your statement could be taken as either confirmation or refutation of the OP's point, entirely depending upon whether the reader believes you're an unreliable narrator. Not knowing you nor having driven an AWD car, I'm not qualified to guess which is true. But as someone who's super interested in the distinction between reality and perceptions of reality, I thought the juxtaposition was pretty intriguing.

Re: How well do cars do in crash tests they're not optimized for?

#334

Post by himaraya » Wed, Jul 01, 2020, 9:41 AM UTC

The "Using real life crash data" section is just wrong. The IIHS confidence interval describes an empirical death rate, not an "expected fatality rate." Therefore, an interval including 0 deaths per million registered vehicle years arises due to very few deaths over a very large dataset, not from some "informative prior" bounding the interval at 0. As an empirical description, the IIHS figures should have high statistical power, after adjusting for confounding variables. Time and location could be interesting factors to consider.

For Dan's suggestions, the IIHS already breaks down death rates per 10 billion miles by vehicle class and individual vehicles, and the latter supports the original ordering by registered vehicle years. Also, incorporating data from models under the same make doesn't make sense. Since the IIHS already accounts for different vehicle platforms, any believed correlation in death rates between a manufacturer's models must derive from the original dataset, creating a meaningless statistic.

Updated IIHS doc here: https://www.iihs.org/api/datastoredocument/status-report/pdf...

Re: How well do cars do in crash tests they're not optimized for?

#335

Post by dmurray » Wed, Jul 01, 2020, 9:59 AM UTC

dionidium wrote: post #305

dmurray wrote: post #301

Earlier quoted context omitted.

Is this still true for commercial flights? The most prominent airliner losses from the last 20 years were not close to takeoff nor to (scheduled) landing. I'm thinking of Air France off Brazil, the two Malaysian planes, all four 9/11 attacks, and the Germanwings crash. The exception is the Concorde crash on takeoff which just sneaks into the last 20 years (July 2000). Of course, part of the reason these crashes were…

My information may very well be out of date! This is one of those lines I've been repeating for 20 years and it might be time to update it.

Looking at Wikipedia [0], there a a lot of incidents I never heard about and a disproportionate number are "shortly after takeoff".

I didn't count them all, but from eyeballing it a 1000-mile journey is 3x as likely to kill you as a 100-mile one, not 1x or 10x.

[0] https://en.wikipedia.org/wiki/List_of_accidents_and_incident...

Re: How well do cars do in crash tests they're not optimized for?

#336

Post by pbhjpbhj » Wed, Jul 01, 2020, 10:33 AM UTC

macleginn wrote: post #203

pbhjpbhj wrote: post #107

Earlier quoted context omitted.

People who feel safer can take greater risks, thus safety equipment can create negative returns.

This theory (known in literature as ‘risk compensation theory’) has been debunked. See some references here: https://twitter.com/whitequark/status/1264486505168482304

tl;dr I would not use that link as evidence to say risk compensation is debunked.

Interesting, I'd certainly say it applies to me - I dive more in volleyball if I have my kneepads; I tackle harder in football when wearing shin-guards, the moreso with ankle protection; drive far more cautiously on a motorbike than in the metal, crumpled-zoned protection of a car; etc. ...

That tweet leads to https://www.sciencedirect.com/science/article/pii/S136984781... "Bicycle helmets and risky behaviour: A systematic review" which concludes:

>"Although two out of the 23 studies were supportive of risk compensation, ten other studies found helmet wearing was associated with safer cycling behaviour." //

So, risk averse people wear helmets.

Some of the support in the review comes from results like helmet wearers obeying traffic laws: the issue seems much more nuanced and complicated than that.

FWIW, risk compensation doesn't require that the entire risk is negated (or even over-compensated) so statistics on accident occurrence and severity alone - for example - would not be sufficient to prove if the effect is real: take my car driving, no matter how much I exhibit riskier driving in a car - short of being a lunatic - it's not going to make it more dangerous than motorbike riding because of all the other people on the road.

[This post relies on part on past activities and experiences!]

Re: How well do cars do in crash tests they're not optimized for?

#337

Post by archi42 » Wed, Jul 01, 2020, 1:14 PM UTC

natch wrote: post #320

43920 wrote: post #216

Earlier quoted context omitted.

Most of this is based on the IIHS data; 2012 is the last time a new type of test was added (small overlap), so it's what's being used to make this comparison. Almost all the cars mentioned in the article have likely improved since then, but the issue isn't so much how safe specific models are, but rather what approaches the manufacturers are using to improve safety. What the test results indicate is that rather than…

>the issue isn't so much how safe specific models are, but rather what approaches the manufacturers are using to improve safety. How would anybody possibly be able to characterize Tesla’s approach to improve safety today based on looking only at a test of one car eight years ago? You said it yourself: “improve” — the word implies a measurable delta in the data. But if the data is a static single value, there is no de…

Selective reading?

He acknowledges Tesla to be difficult to fit, right under the "Tier Table": "[...] Tesla not really properly fitting into any category (with their category being the closest fit)".

And in the "Bonus: Reputation" section, he supplies an argument/reasoning what he doesn't like about Tesla:

[...]I find the Tesla thing interesting since their responses are basically the opposite of what you'd expect from a company that was serious about safety. [...], they often have a very quick response that's basically "everything is fine". I would expect an organization that's serious about safety or improvement to respond with "we're investigating", [...]

For example, on the driver-side small overlap test, Tesla had one model with a relevant score and it scored Acceptable (below Good, but above Poor and Marginal) even after modifications were made to improve the score. Tesla disputed the results, saying they make "the safest cars in history" and implying that IIHS should be ignored in favor of NHSTA test scores[...]

(end quote).

In that context I think it's important not to skip on Tesla and mention the above. And by giving his thoughts this allows readers to make up their own opinion (and you're free to come to your own conclusion).

Full disclosure: Safety was one of the main reasons to get a Volvo. However, I am not someone to hate on Tesla.

Re: How well do cars do in crash tests they're not optimized for?

#338

Post by JoeAltmaier » Wed, Jul 01, 2020, 1:41 PM UTC

tpmx wrote: post #231

JoeAltmaier wrote: post #187

Earlier quoted context omitted.

To an amazing degree. In the limit, the large vehicle proceeds nearly unimpeded and the small one is a ball of tinfoil.

I mean, that makes sense if we assume that cars are sphere-shaped with consistent density. Of course, they aren't. I guess what I was looking for was actual data, not assumptions.

Data? My son in his Ford F350 had a collision with a compact car that pulled out directly in front of him across the highway at speed. Small car: totalled. Truck: some scratches on bumper, loud noise.

Re: How well do cars do in crash tests they're not optimized for?

#339

Post by [deleted] » Wed, Jul 01, 2020, 1:43 PM UTC

titzer wrote: post #324

esrauch wrote: post #316

Earlier quoted context omitted.

> If the water heater engineers designed the water heater to never turn on and keep the water at room temperature while being tested I think the difference between what they did and this is only a difference in degree and not kind though, right?

It is a difference in kind: VW dynamically detected and adapted behavior to the test. It would never operate in that way under normal conditions. The water heater example was completely static: it always behaved the same way, under test or not.

[deleted]

Re: How well do cars do in crash tests they're not optimized for?

#340

Post by elboru » Wed, Jul 01, 2020, 2:09 PM UTC

mohaine wrote: post #46

bcrosby95 wrote: post #25

Earlier quoted context omitted.

Driving is already incredibly safe. Yes, it's the leading cause of death in those age categories, but there are 3-4 trillion miles driven each year in the USA. That comes out to 1 death every 100 million miles.

This. If driving was the only cause of death, and we did nothing but drive from birth we would expect to live to ~250 years old on average.

So if we find the cure for all diseases, we still need to figure out how not to drive to become immortals.