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.

>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.

Exactly. Nissan and FCA will finance anyone with a pulse and they make cars at low price points. The Juke is just about the cheapest AWD crossover so you get a statistically unflattering clientele driving it. You can see the reverse situation with the Dodge Journey. It is known for being the cheapest people hauler on a per-seat basis and also has a very unflattering set of customers. The 2wd is statistically more dangerous than the 4wd presumably because the riskiest buyers don't care how many driven wheels it has they just need something with a lot of seats for cheap to haul around their massive family.

I think it's more relevant how much each group drives. Everyone I know who drives a lot espouses how important 4WD/AWD is, whereas the people who barely drive at all aren't willing to pay so much more for it.

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 to about it (admittedly a small subset of people who use AWD) greatly overestimate its safety benefits.

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 time:

I have a fleet of several identical station wagons. There is one of them that's FWD. They all use the same brand of tires. It's as close to scientific experiment as you can get. The FWD one sucks in the wet/snow/anything but dry. Forcing all the horsepower to go through just two tires that also have to do double duty and steer the vehicle make it peel-out city. The AWD ones are much more tame. But the FWD one gets a couple more mpg so we keep it around. Given the choice between snow tires on the FWD wagon and driving one of the AWD wagons on all season tires I will pick the AWD one every time. Having a marginally shorter minimum stopping distance and being able to corner better is less of an improvement than having a substantially reduced likelihood of peeling out on an uphill.

The above opinion is shared by the other four people who have to drive the vehicles in question which is why I'm the one who gets stuck driving the FWD one when it snows.

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.

edit: "a matter of preference and consensus"

The likelihood to oversteer depends on whether the 2WD alternative is front or rear wheel drive. RWD is more likely to oversteer on acceleration in slippery, turning conditions.

No argument here. That was my regional bias slipping in -- RWD is incredibly uncommon in the cold places I've lived except for pickups, and most people are aware of the potential dangers of RWD.

I daily-drove a rear-drive Alfa Romeo Spider for 5 Boston winters. Then drove a rear-drive Mercedes E300TD for another 4 Boston winters (though that one I at least put snow tires on). You learn pretty quickly what the car can and can't do; even on summer tires (and a limited-slip differential), the Alfa would go until it got high-centered on the snowpack. Either would handily out-perform my current Nissan LEAF (FWD) in the snow. LEAF factory tires are designed for economy, not winter traction.

The same discrepancy appears in the 2014 data as well so it's probably not a statistical fluke. Maybe there's a real design flaw in the Juke 4WD model?

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.

> People tend to overestimate what their 4wd is going to do for them and aren't sufficiently cautious.

Or because when it snows the ones who can afford to do so take the "winter beater" 2002 Trailblazer instead of the car they usually drive.

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

It can go the other way too, they don't buy it to drive in inclement conditions, but once they have it they increase their driving in inclement conditions because "4x4s can go in any conditions".

4x4 drivers might do offroading: so the figures could be much lower than if those people had 4x2 (2wd) vehicles.

I think recreational 4x4 is niche enough that it is probably not significantly represented in the data (and those accidents are mostly single-vehicle and probably less likely to be reported)

I have been watching this chart for as long as it has been on the internet -- it's great for finding vehicles which are cheap on insurance.

That being said, I see obvious self-selection issues show up in that chart all the time. Looking at the extremes usually points it out -- 'old man' sports cars usually have very low accident rates. Vehicles sold with deep discounts or aggressive financing deals usually have high accident rates. These are likely bought by very different buyers with very different life circumstances who use their cars very differently.