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?

#131

Post by hansvm » Tue, Jun 30, 2020, 5:37 PM UTC

fractionalhare wrote: post #110

YetAnotherMatt wrote: post #83

Earlier quoted context omitted.

For almost everyone 18-40 year old, driving less is one of the healthiest decisions you can make. A little nitpick: Motorcycling, cycling, and walking are all significantly worse than traveling by car. If this interests you, it's possible to find a lot more interesting research by searching for "microlife" and "micromort".

Is that a typo, or do you teally mean cycling and walking are significantly worse than traveling by car? Are both of those activities actually more dangerous? I would have thought cycling and walking - even in urban settings! - are safer activities than driving, statistically.

I doubt it was a typo. As a ballpark, cycling has 10x the deaths per mile as driving.

Here in the Bay nobody stops at stop signs (3-10mph is typical), and they don't even really slow down to look both ways till after the white line and after the sign -- plowing straight into sidsewalks and bike lanes. I'm honestly shocked it doesn't cause more deaths.

Cyclists themselves usually aren't much better -- not even bothering to slow down for a 4-way stop, failing to signal before turning, etc....

As a personal anecdote, I was biking home down a pretty steep hill (I had lights, a helmet, etc) last fall on a road without any shoulder or bike lanes whatsoever. It was a short stretch, there were plenty of signs warning cars of cyclists, and I thought it would be fine, but shortly after I started the descent I had an SUV tailgate me the entire way down the mountain (again, nowhere for me to pull over, no way to get out of the way). If I'd hit a rock or anything and lost control I would've been toast.

When I checked my GPS after the fact I had been going a minimum of 10 over the limit, but that wasn't enough for somebody in a hurry and apparently not aware they were risking my life.

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

#132

Post by mumblemumble » Tue, Jun 30, 2020, 5:38 PM UTC

Somewhat related anecdote, related to me by an acquaintance who works at a major US crash testing facility:

I don't know about now, but, once upon a time, not too long ago, US safety standards included crash tests where the dummies were not wearing seat belts. This naturally leads to cars sold in the US having air bags that are tuned slightly differently, so that they are less likely to cause injuries to people not wearing seat belts. Unfortunately, doing this decreases their ability to protect the vast majority (nowadays) of people who do use their seat belts.

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

#133

Post by sterwill » Tue, Jun 30, 2020, 5:39 PM UTC

hpkuarg wrote: post #57

Merrill wrote: post #53

>For a long time, adult NHSTA and IIHS tests used a 1970s 50%-ile male dummy, which is 5'9" and 171lbs. ... >For reference, in 2019, the average weight of a U.S. adult male was 198 lbs and the average weight of a U.S. adult female was 171 lbs. So the average mass of the American male has increased 15% in 50 years! No data on whether he is taller, but I'd bet the BMI has gone up.

Over 70% of adult Americans are overweight or obese, according to BMI. Of course, BMI is an imperfect measure, but you're quite right to bet on the average American male having gotten fatter, not taller.

At 5'9" and 171 lb, the old 1970s dummy has a BMI of 25.2 and is already "overweight" (probably because of the heavy steel they have to build it around).

My main takeaway from Dan's article is that we have a lot of blind spots in our view of car crash safety, mostly for lack of samples, and also because the American consumer just doesn't care enough about safety during the buying process to demand better information.

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

#134

Post by ebg13 » Tue, Jun 30, 2020, 5:39 PM UTC

henryfjordan wrote: post #121

ebg13 wrote: post #95

Earlier quoted context omitted.

So they _intentionally_ set themselves up to lie to regulatory agencies and consumers about real world efficiency. That honestly sounds basically the same to me. In both cases the tests are poor approximations, and in both cases someone could accidentally optimize the test, and in both cases someone did it intentionally to deceive people.

Imagine the water heater company didn't know they were gaming the test. They first design a water heater and it gets a B- on the test. Being overachievers, they work hard and submit a second design that gets an A+. They might not realize that both heaters are basically the same with the only difference being some heating element spacing that works better for the test. Both times they submitted a legit design that was…

> Imagine the water heater company didn't know they were gaming the test.

We don't have to. In this case we have clear admission of intent. The intent to deceive is what makes it fraud and not just being wrong.

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

#135

Post by [deleted] » Tue, Jun 30, 2020, 5:39 PM UTC

jhardy54 wrote: post #111

shoes_for_thee wrote: post #43

Earlier quoted context omitted.

This might have some useful info for you... https://www.cyclehelmets.org/1026.html death rates per million hours of activity

Do you know what 'residential fire' means? I'm imagining a scenario where my residence is on fire, which would seem to be high-risk (but is somehow the lowest risk).

[deleted]

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

#136

Post by kube-system » Tue, Jun 30, 2020, 5:40 PM UTC

gav wrote: post #126

kube-system wrote: post #59

Earlier quoted context omitted.

The person is not suggesting it's a statistical flaw -- but that it's a self-selection bias. Hypothesis: The people who opt to spend more for a 4wd version are people who know they will use it because they operate the vehicle in inclement conditions, and/or they are uncomfortable with their ability to operate a 2wd vehicle in those conditions and/or they do not have the option to stay home when the weather is bad.

Living in Vermont for five years taught me that while a 4wd is a better choice for bad conditions, it's because they are less likely to get stuck with spinning wheels, but they don't stop any faster than a 2wd. I would see way more SUVs in ditches than sedans. People tend to overestimate what their 4wd is going to do for them and aren't sufficiently cautious. The first snow/ice of the year was particularly bad.

Good point, can't crash a car if you can't get it to move.

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

#137

Post by WWLink » Tue, Jun 30, 2020, 5:41 PM UTC

komali2 wrote: post #61

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…

Riding motorcycles means I'm often playing the percentages game. When we turn we're sacrificing our finite amount of traction for either more speed or a more aggressive turn. If I lean off the bike, I get some traction back. So how much am I willing to sacrifice in the name of fun, while still leaving wiggle room for suddenly encountering a tar snake or something in the middle of my turn? Little things. Motorcyclists…

"if you have to think about it for a second, just don't do it. Thinking about that narrow pass on the freeway? Let it go, you can pass in a couple seconds after the gap widens. Thinking about gunning through the yellow? Relax. Just stop. Etc."

That totally applies to driving a car as well!

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

#138

Post by tialaramex » Tue, Jun 30, 2020, 5:41 PM UTC

SkyBelow wrote: post #127

ebg13 wrote: post #95

Earlier quoted context omitted.

So they _intentionally_ set themselves up to lie to regulatory agencies and consumers about real world efficiency. That honestly sounds basically the same to me. In both cases the tests are poor approximations, and in both cases someone could accidentally optimize the test, and in both cases someone did it intentionally to deceive people.

There is a difference between memorizing enough information to ace a test and sneaking in notes that aren't allowed to ace a test. And people would also say it is wrong to steal a copy of a test and then memorize the answers to it to ace a test. But what if a professor uses the same test every year (maybe changing a few numbers but in a way that only impacts the calculations, not the way to solve it) and people study…

If you cheat in most such tests it just means you miss out on actually learning what you were supposed to. If it wasn't your intention to learn anyway I guess that's fine.

Rarely the purpose of tests is to assure the public of your fitness (e.g. a driving test) and cheating those might be a problem, but if you cheat my CS 101 course and then struggle because you needed remedial classes but the cheated test means you don't get them that's your problem.

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

#139

Post by nimih » Tue, Jun 30, 2020, 5:43 PM UTC

Daneel_ wrote: post #117

fractionalhare wrote: post #110

Earlier quoted context omitted.

Is that a typo, or do you teally mean cycling and walking are significantly worse than traveling by car? Are both of those activities actually more dangerous? I would have thought cycling and walking - even in urban settings! - are safer activities than driving, statistically.

I would imagine that it’s not a typo. In a car you have a big shell around you to protect against the environment. While walking or cycling you’re far more prone to be injured by the world - a branch could fall on you, a car could hit you, another person could hit you, you could trip, slip or lose balance, etc. Being inside a big metal shell that can’t fall over and with active safety measures is a great place to be,…

On the other hand, when I'm cycling, I'm typically not moving at >15 mph or so. When I'm walking, reduce that to 3mph. That seems like it would do a lot to counteract the car's crumple zones and airbags in terms of severity of injury.

In fact, once you take into account severity, the GP's claim seems extremely suspect: maybe the chance of any injury on a bike or by foot is higher, but I'd be skeptical of claims that the same applies to death, or even chance of serious injury (since that's what I, personally, care about), without serious backing evidence.

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

#140

Post by ReactiveJelly » Tue, Jun 30, 2020, 5:47 PM UTC

ebg13 wrote: post #99

ivanbakel wrote: post #93

Earlier quoted context omitted.

What was more heinous about the VW case IIRC is that the cleanliness gains the cars made on the treadmill setup were enough to push them into compliance with regulations, which the engines normally didn't meet. "Cheating" a better efficiency rating is significantly less reprehensible than cheating a legal obligation which was legislated for public health and environmental reasons.

But the efficiency ratings also exist for public health and environmental reasons. Why does it matter to you that one is a mandate? They're both intentionally deceiving regulators and consumers (vs accidentally acing the test without cheating). Both are fraud.

One is polluting at the tailpipe, the other is only polluting at a power plant.