[dimaggiosghost]

Vehicle safety is a significant confounder here. It is possible that increased deaths from higher limits was more than offset by mandatory airbags, anti lock disc brakes, crumple zones, etc.

Actually it's pretty neat how much safer cars in America have gotten since then.

[u801e]

While that is true between 1995 and 2005, if you look at the data [1] between 2005 (roughly 10 years after both drivers and passenger side airbags were required equipment) and 2015, you can see the fatality rate dropped from 1.46 down to 1.08

Given the average age of a vehicle on the road is about 10 years give or take, then by 2005, the majority of vehicles had both drivers and passenger side air bags and crumple zones. Traffic speeds have also increased to some extent in the last 10 years as well.

[1] https://www-fars.nhtsa.dot.gov/Main/index.aspx

[learc83]

There are other new safety features introduced on many cars since then. Vehicle stability control is a big one.

[CWuestefeld]

Vehicle stability control is a big one.

In some situations, but in other situations it seems to be a negative (at least as implemented on my car, a '13 Hyundai Genesis Coupe).

I can see that it's helpful for low-traction situations where it's just protecting the driver from losing control.

But on my car it has a really annoying, and I think dangerous, side effect. You'll note that difference in wheel speed from left to right is what triggers the stability control behavior, and that this delta is proportionately greater for tighter-radius turns, the ultimate example of which is a right turn from a stop sign or driveway. And the effect of it is to severely limit the force applied to the wheels (whether by pulling back the throttle or by applying a brake to the affected wheel).

But that right turn, when I'm trying to merge into traffic on a road with a 60mph speed limit, is exactly where I need the power to accelerate. So I see a break in traffic, turn onto the road, a tire slips on a bit of sand, and then I'm stuck wallowing there with no power, watching my mirrors as a car barrels down on me from behind.

I've learned that I get the best results if I make the first thing I do when I get into the car, to turn off the traction control unless the pavement is wet.

[learc83]

The NHTSA and the Insurance Institute for Highway safety estimate that stability control could prevent 1/3 of fatal accidents.

Studies show it's effective. Of course it depends on the car, but I've never found it to be a problem unless I'm driving like I'm at the track.

Also where are you turning right onto a road with a 60mph speed limit with no merging lane?

[CWuestefeld]

Studies show it's effective.

I agree that it's doing a good job in keeping me from breaking my tires free, which could lead to losing control. But I'm skeptical that enforcing these tactics blindly in all cases (as my car does) is the best overall strategy.

where are you turning right onto a road with a 60mph speed limit with no merging lane?

Specifically, US 290 west of Austin TX. But this seems to be the norm in much of Texas.

[learc83]

>But I'm skeptical that enforcing these tactics blindly in all cases (as my car does) is the best overall strategy.

It's not optimal strategy in all cases. But driving 100% of the time with electronic stability control (for which traction control is required) on results in an overall safety benefit as opposed to driving with traction control off 100% of the time. Which is why it is a required feature in all new cars.

>Specifically, US 290 west of Austin TX. But this seems to be the norm in much of Texas.

That's crazy. I've seen something like that in very rural areas, but even then the speed limit was only 55.

[douche]

This is the most dangerous thing about stability control - if you've learned how to drive without it, your instincts are going to be all wrong when it tries to compensate for what it thinks is happening. It's the same problem with ABS brakes, which can be terrifying if it's a little icy and you're expecting them to lock up properly.

I also wonder what's going to happen when those sensors get a little screwed up and start to fail. Or when you put different tires on, or make any modifications to the suspension.

[CWuestefeld]

It's the same problem with ABS brakes

I get your meaning, but any difference with ABS isn't going to put you in harm's way (except some really rare cases of deep snow, where the effect of your tires pushing the snow provides extra resistance). All you have to do with ABS is trust it, but even if you don't it'll work out fine.

But in this case, you've got your mind calibrated to how you know your car can accelerate, and the safety of the maneuver is contingent on the car living up to it. But the stability control makes the car say, "no, I'm not going to do it", leaving you hanging out there in danger.

[u801e]

Vehicle stability control isn't mandated by NHTSA, and I don't think that it's a feature on a substantial portion of the vehicle fleet.

You would have to look at what vehicle safety features were mandated between 2000 and 2010 to really see if any of them played a part in the decline in the fatality rate in the 2005 to 2015 time period.

[learc83]

Electronic stability control has been mandated by the NHTSA since 2012 (they required at least 55% of 2009 models sold to be equipped with it, 75% of 2010 models, and 95% of 2011 models)

Also in 2007 about half of all new cars sold were equipped with it.

The NHTSA and the Insurance Institute for Highway safety estimate that stability control could prevent 1/3 of fatal accidents.

If a substantial portion of cars started to be equipped with it around 2005 (they did), it's a likely explanation for a decline in traffic fatalities since then.

[u801e]

> Electronic stability control has been mandated by the NHTSA since 2012 (they required at least 55% of 2009 models sold to be equipped with it, 75% of 2010 models, and 95% of 2011 models)

I should have looked that up before stating the opposite. My mistake.

> Also in 2007 about half of all new cars sold were equipped with it.

I've read that the average vehicle age is about 10 years. That means that only now are we getting to the point where the vast majority of vehicles would be equipped with electronic stability control. Looking at the FARS page I cited earlier, the decline in fatality rate is pretty clear, but how prevalent ESP was and how much it changed in that time period is not as clear (at least I don't have the data for it).

[learc83]

Some very back of the envelope math shows that each year about 7% of vehicles are replaced each year, so by 2012 we can estimate that about 35% of cars would have been 2007 models or newer.

So by 2012 we have a minimum of 17% of cars with electronic stability control (probably much higher given that by 2010 75% of cars sold were mandated to include it). If cars with electronic stability control are really involved in 1/3 few accidents, then we'd expect a very sizeable decrease in vehicle fatalities due to electronic stability control alone by 2012 and probably much earlier.