That's a pretty common reason people cite for buying big SUVs. A belief that being the bigger car in an accident makes you safer.

It's more than a belief... the statistics bear it out. "The lowest 2015 death rate by vehicle type is for very large SUVs: 13 deaths per million registered vehicles. The highest is for mini cars: 64 deaths per million registered vehicles." https://www.edmunds.com/car-safety/are-smaller-cars-as-safe-...

That could just mean SUV drivers drive less, or a myriad of other things. PG posted on Twitter a while back a study that showed SUVs were _less_ safe (per mile driven? I think).

This is a very simple matter of physics. Do you know what typically kills in a car crash? Extreme G-forces generated by near instantaneous deceleration. Big, heavy things have to expend more energy to decelerate, so they tend to do so at a relatively slower rate. Small things can be stopped very quickly. Therefore, someone in a big, heavy SUV is going to have much higher chances of survival than someone in a Mini.

You're completely ignoring higher center of gravity and rollovers.

But more importantly, "deaths per registered car" is meaningless to an individual make a purchase.

Ah, I found it: https://www.nytimes.com/2004/08/17/business/safety-gap-grows...

But the article was from 2003, unfortunately. Searching online I can't find statistics per mile driven, which is what you need to made the claims the replies to my posts are making.

It means that F=ma - the bigger you are, the safer you are. The driver of a small 2 seater car is going to be worse off than a huge semi if they both collide.

What you're talking about is "which is safer in a collision", which is an entirely different question from "which car is safer per mile to drive?"

Would really have to be a myriad of other things if that’s supposed to explain a 5x difference without the obvious reason for it.

What's the reason? That's it's bigger? But what if bigger cars crash more often? So yes, it does have to be thought about with clarity.

I think a perception of additional personal safety is definitely a reason people like SUVs.

But you can be super safe while still helping protect your crash partners. You can often improve both your and your crash partner's safety with more crumple zones.

I don't think the patrons of this thing are going to be thinking about this much.

"crash partner"? That's a really weird and indirect term. If I'm in a collision with another driver, he's not my "partner".

I'm not in the field; I just picked it up from the wikipedia page. They call it the "crash partner vehicle". Searching reveals that's what it's sometimes called in the vehicle safety industry.

Maybe he should be.

A lot of problems with driving come with people treating it as adversarial situation, instead of cooperative one.

Adversary?

More mass = less acceleration when the same force is applied, and acceleration is what really kills you. You can't argue with physics.

There's also strain in an inelastic collision. More strain = less acceleration = more living. Super rigid structure = less train = more acceleration = less living. No doubt the airbags and whatnot will make this very safe from the inside. I'm just worried about from the outside. But whatever. Not too worried. Plus, who knows, maybe they did design in strategic crumple zones. They never said they didn't. Just got me worried with the sledge.

At least in principle, modern cars should be getting better at not running into things to begin with. The most survivable crash is one that didn't happen because HAL stepped in at the last minute to apply the brakes or stabilize the vehicle.

Disagree? Why? Active crash-avoidance aids seem to be getting pretty impressive.

Yep, if you're going to crash, better to be in as big a vehicle as possible. There is an argument to be made that smaller, more nimble, faster braking vehicles have a better chance of avoiding the crash in the first place, but the statistics do still show SUVs are safer overall, not just on a per-crash basis.

That works until you encounter a concrete wall or solid telegraph pole.

It also is unfair to those you share the road with to embark on an arms race “who can afford the heaviest car”, if only because pedestrians and cyclists will always lose that race.

Unfortunately, a vehicle can only be as nimble as its driver is. Most vehicles out there are driven by average, distracted, exhausted humans.

About this time last year, I skidded and lost control of my car for a fraction of a second while changing lanes on a busy highway at 60mph. I'm alive and typing this not because I was nimble enough to recover from that situation, but because my car had electronic stability control -- a feature that is often not available in smaller models -- and a good set of winter tires.

Don’t think I’ve driven a car without ESC, it’s been mandatory in new cars for almost a decade now.

It depends on the country. ESC became mandatory in most large markets since sometime between 2012 and 2014, but lots of cars are older than that. Unlike phones, automobiles can easily last 15 years or more if well cared for. Which is great in one respect but also a nightmare when it comes to safety and emissions.

I was going to make a comment about the hood not being soft enough for pedestrians hitting it, but maybe the computer would prevent such a collision.

That is a poor, poor substitute for passive safety measures...

Why? In principle, it should be possible to build a car that couldn't be used to mow down a pedestrian or cyclist if the driver tried.

Broadly speaking, active safety systems in any industry are generally considered less reliable than passive ones due to things like software bugs, unforeseen circumstances, malicious tampering, power outages, etc.

But hey, that's why we're both here, right, shooting the shit on a site called "Hacker News." Because we believe there are -- and will continue to be -- better ways to do things through the appropriate application of technology.

Right? If your bio isn't a joke, you'd better darned well have that attitude. Otherwise I don't see how you'd get through a typical workday.

Bio's not a joke, I actually design nuclear reactors. In fact, my experience in that field is why I believe what I said above.

The SL-1 nuclear reactor accident (possibly murder-suicide) happened because a human was actively actuating a control rod by hand and pulled it out too fast. Passive systems that limit rod withdrawal rate are better.

The Three Mile Island accident happened because a sensor mislead the human operators, who then did the wrong thing and ended up dropping the coolant level below the core, which subsequently partially melted. Passive safety systems like a pool of low-pressure coolant preclude this entire class of accidents.

Chernobyl happened because humans could and did manually disable all the automatic safety systems that told them the reactor was in an unstable configuration. Passively safe reactors can't physically get into unstable configurations.

Fukushima had active cooling systems powered by diesel generators. After the earthquake, they started up and worked fine. But when the tsunami came, it flooded the basement. The operators for god knows what reason put the fuel supply and electric switches in the basement, which flooded. The active safety systems failed, the coolant boiled, and the cores melted. As with TMI, passively safe reactors with low-pressure coolant and/or natural-circulation driven decay heat removal (i.e. no diesel backup power needed) would preclude this condition.

The nuclear industry is very into passive safety features, from experience. The first true passive safety demos happened in Idaho in April 1986 (weeks before Chernobyl) at a reactor called the EBR-II.

In summary, making a system safer with active systems is one approach. It's often both more elegant, more reliable, and cheaper to improve a system passively via design ingenuity. Thus, passive safety has a place here at Hacker News.

Passive safety sounds like exactly the kind of thing you'd want to focus on when designing nuclear reactors.

Ha, the comment right above yours, 7 hours after it, is someone that designs nuclear reactors stating just that https://news.ycombinator.com/item?id=21606744

That was Boeing's approach for safety on 737 MAX.