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?

#21

Post by dangus » Tue, Jun 30, 2020, 3:32 PM UTC

blakesterz wrote: post #6

gorgoiler wrote: post #4

Volvo was always marketed as a safety product years ago. Seatbelts, seatbelt warning lights, airbags, and daytime lights — a requirement in Sweden — all spring to mind. I had assumed that Volvo lost that edge this century so it’s good to see them at the top of the list.

I just took a quick look at Consumer Reports for Vovlo's reliability and they're not great. A couple were even bad. If my memory is right, this has been the case for a while. It looks like maybe Volvos are safe, but not super reliable I guess?

On the other hand, all car makes have become much more reliable than they were in the past.

Mostly, what you're looking out for is cost of parts and difficulty of labor. For example, a lot of Audi/Volkswagen products suffer from simple repairs being made more complicated by the need to pull things apart for the mechanic to reach them.

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

#22

Post by preinheimer » Tue, Jun 30, 2020, 3:32 PM UTC

czzr wrote: post #2

Optimizing for a test is an issue if the test is not well correlated with the desired outcome. By and large that doesn’t seem to be a big issue for crash tests.

The problem is that they're optimizing for a very specific crash tests. Optimizing for those alone may involve trade offs for other tests. Doing super well for an offset head on collision at 30mph may involve adding weight and supports that make things worse for a collision at an angle.

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

#23

Post by globular-toast » Tue, Jun 30, 2020, 3:33 PM UTC

JoeAltmaier wrote: post #17

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…

Drive the largest vehicle you can. When in a collision the momentum is converted to crushing force, you want to be in the less-crushable vehicle. Hey this may be an unpopular choice, but it is the one with the biggest safety impact! And that was the question.

Presumably downvoted because people don't like it. But it's the truth.

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

#24

Post by yboris » Tue, Jun 30, 2020, 3:33 PM UTC

JoeAltmaier wrote: post #17

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…

Drive the largest vehicle you can. When in a collision the momentum is converted to crushing force, you want to be in the less-crushable vehicle. Hey this may be an unpopular choice, but it is the one with the biggest safety impact! And that was the question.

Rather immoral. Not just offloading, but also exacerbating the burden onto others.

Vehicles and Crashes: Why is this Moral Issue Overlooked? by Douglas Husak

https://www.jstor.org/stable/23562447?seq=1

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

#25

Post by bcrosby95 » Tue, Jun 30, 2020, 3:33 PM 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…

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.

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

#26

Post by andykellr » Tue, Jun 30, 2020, 3:33 PM 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…

This reminds me of the fact that my grandmother who recently passed away at 96 refused to make left turns. She stopped driving years ago, but before she did, my father would always help her find a way to get to the pharmacy, the grocery store, church, and family and friends houses making only right turns. Sometimes she went miles out of her way.

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

#27

Post by dangus » Tue, Jun 30, 2020, 3:36 PM 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…

The way to make yourself safer is to move to one of the few American cities and towns with walking and transit-oriented development.

Seriously!

You'll spend a fewer hours in the car risking car accident death. A family can easily downsize to one car or less.

You'll also spend more time getting light exercise by walking to the bus/train, walking to the store, walking for enjoyment.

You'll also save from no longer buying an expensive, depreciating asset. Sure, maybe your housing cost is higher in a city like this - but your house doesn't lose value like a car.

It's also more pleasant to live in. I love the rural areas, and I love the cities, but the suburbs are just the worst of both worlds.

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

#28

Post by baxtr » Tue, Jun 30, 2020, 3:36 PM UTC

bcrosby95 wrote: post #25

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…

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.

I wonder what happens if you compare driving to other activities, by stretching them out to the 3-4 trillion miles - but in time and then compare death rates. E.g. taking swimming 2hrs per day (maybe equivalent to the 2-3 hrs spent in cars daily). Higher or lower death rates?

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

#29

Post by nostrademons » Tue, Jun 30, 2020, 3:37 PM UTC

nradov wrote: post #11

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…

The most relevant research on car brands and models is probably the IIHS driver death rate data. It's not perfect since the populations are self selecting (cars aren't assigned to drivers at random) but within a particular vehicle class if you see a huge difference in death rates then that's probably meaningful. https://www.iihs.org/ratings/driver-death-rates-by-make-and-...

An interesting instance of the self-selection problem seems to show up if you select small 4-door 2017 cars. The Nissan Juke 2WD has a death rate of 12; the 4WD version of the same car has a death rate of 65. I have trouble believing that there's a significant difference in the cars themselves, so it seems likely that people who would buy a 2WD small SUV are a significantly different demographic than those who would buy a 4WD small SUV.

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

#30

Post by wscott » Tue, Jun 30, 2020, 3:39 PM UTC

The article reminds me of a story from a friend that was an engineer at a major water heater company. Modern electric water heaters are already fairly efficient, but every model gets tested by the government to be given an efficiency rating.

The test consists of replacing the anode with a rod that has a series of temperature probes to measure the water at different levels in the water heater. Since water would form layers of different temperatures you needed measure at multiple locations to know the overall energy in the water. Then a series of water draws are performed with pauses between them and the total energy used is compared to the energy delivered.

Our engineer realized that if he could put the temperature layers at just the right locations then the calculations with the limited number of probes could be skewed. And this can be done by tweaking the height of the 2 heating elements. Just moving them a few inches.

The first time he tried this, an internal test came back at 101% efficiency. At little more tweaking and the test returns a consistent 99.x% that was respectable.