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Studies find automatic braking can cut crashes over 40%

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Re: Studies find automatic braking can cut crashes over 40%

#101

Post by branon »

giantg2 wrote: post #92
branon wrote: post #72

Earlier quoted context omitted.

Assuming that a "car length" is always equal to the length of a car is the unsafe bit. A car length is simply the minimum safe follow distance based on weather, traffic, and speed. To my mind it has almost nothing to do with the literal length of a car.

Please provide a source for that definition. I've never seen that used anywhere.

I don't have a source, it's just what makes sense to me - which at the end of the day, is how we all drive.

As far as definitions for "car length" go, I feel that "average length of an actual car" is just as open to interpretation as "minimum safe length at which to follow a car" - really, these are both non-definitions.

Today I've learned NEVER to reference "car length" online because it's a shitty and imprecise unit of measurement. In the future I will simply say "appropriate follow distance" even though that's highly variable too.

Re: Studies find automatic braking can cut crashes over 40%

#102

Post by berberous »

branon wrote: post #98
emptybits wrote: post #95

Earlier quoted context omitted.

> One car length is way more than 15 feet to my mind, probably 40 feet or more depending on speed. A car length is, literally, the length of a car. It does not vary with speed. Exception: https://en.wikipedia.org/wiki/Length_contraction (coming soon in a software update to a Tesla near you)

Sure, but saying this is meaningless when we're actually talking about follow distance. Cars are different lengths. To me, a car length should simply mean the minimum safe _length_ at which to follow the car in front of you.

This would lose all communicative benefits. Teaching a young inexperienced driver “just always keep one car length” where one = safe, is meaningless.

I don’t know you, but I believe a majority of people underestimate safe stopping distance. That’s why the webpage I posted, which is one of many similar ones, exist. That’s also in part why there are so many accidents.

People are also bad at estimating feet, so telling someone keep 80 feet is also not helpful.

But people are pretty good at estimating how many cars can fit between them and the next car.

So telling someone, hey, you are tailgating that guy and only one car could fit in front of you, but you need 10 car lengths to be safe, has a lot more communicative power.

Re: Studies find automatic braking can cut crashes over 40%

#103

Post by branon »

vel0city wrote: post #100
branon wrote: post #96

Earlier quoted context omitted.

With the amount of semi-trucks in my area, actually yes, average length of vehicles you encounter on the road is probably close to that. I just used the term "car length" with entirely too much room for interpretation and am now getting torn apart for it, my mistake. I swear I'm not tailgating people LOL

> I swear I'm not tailgating people LOL If you're going 40mph and approaching nearly stopped cars at Don't get me wrong, I've had my emergency braking trigger for similar circumstances of someone turning into a parking lot off a feeder of a highway. But I don't blame my equipment, I acknowledge I'm not a perfect driver. The car knew it could have been quite a challenge to stop in time and so it took action. The bette…

Nobody's approaching nearly stopped cars, I think you have misunderstood some other facet of my post. I sometimes approach _decelerating_ vehicles, _while I am also decelerating_

Re: Studies find automatic braking can cut crashes over 40%

#104

Post by vinyl7 »

trgn wrote: post #36
KptMarchewa wrote: post #12

Sure, but try to convince people who are okay with accepting (other) deaths just to feel "in control" of a two ton vehicle.

Why is this downvoted? This desire to be in control of a car, or the belief one should be in control of a car, is a true curse on the public realm. People who actively think of themselves of good drivers, are invariable the ones who drive aggressively. It's never the ones that drive slow, boring, and predictable that reject safety measures. For example; seatbelts were fought, the fetishization of things like accelera…

The more boring driving is, the more likely i am to look at my phone or fall asleep, find other distractions. If I drive aggressively then i must stay focused. It wouldn't surprise me if these safety features end up increasing collisions because people start feeling safe that the blockchain ai machine learning sensors of the future will do all the work for them. We already see this happening with teslas.

Re: Studies find automatic braking can cut crashes over 40%

#105

Post by yonaguska »

berberous wrote: post #49
branon wrote: post #33

Earlier quoted context omitted.

That was just one example. I've clarified my original comment, previously I was using the term "car length" in a way that did not make sense to others. I should have said "seconds of follow distance" All of this is infinitely nuanced anyway. There might not be a side street. It can happen on the highway too when cars switch lanes to exit. And it's not like it happens every day, it's fairly rare, I just have yet to ac…

Have you ever looked up stopping distances? https://www.automotive-fleet.com/driver-care/239402/driver-c... I don’t know how accurate the above is, but it suggest that the stopping distance at 40mph is 5-9 car lengths, so I have to agree with the above poster that if you are routinely leaving one car length and your car system is freaking out, you are probably driving unsafely. Keep in my that statistically this coul…

It's effectively impossible to maintain safe stopping distances in many places. Speaking from experience in Chicago, it's just a concept that doesn't exist for many people. And if you are driving slower in order to maintain a safe stopping distance, you're creating an extra hazard on the road by maintaining a larger speed differential from the rest of traffic. Not to mention, you increase your own risk of accidents because of all the people that will aggressively cut you off.

I personally always try to maintain a safe-ish stopping distance, but I'll also ensure that I'm never in a position where I'm missing a swerve ready escape route.

Re: Studies find automatic braking can cut crashes over 40%

#107

Post by nawgz »

branon wrote: post #10

Oof, my experience with with auto-brake in a 2021 Subaru Crosstrek (anecdotal, sample size of one, all that good stuff) is much the opposite. It's too sensitive and tends to brake shockingly hard during fairly mundane maneuvers. When backing up near a wall/obstacle, the auto-brake seems to kick in when anything is closer than three or four feet away from the bumper. I use my mirrors and have an accurate impression of…

Also driving a 2021 Subaru, and I find it only rarely triggers incorrectly.

The turning example you give, in my opinion, is a prime example of something really quite risky all drivers do, but it's quite simple for that person to tap the brakes and then you'll cause an accident.

Otherwise, with the wall, maybe your system is misconfigured; I've tested mine pretty well and at low speeds like when parking or reversing it has never triggered until I'm within 1ft of walls or bushes

The worst example was when a bird flew in front of me and the car decided that was an imminent accident, but otherwise I think if you loosened the tuning it would be unlikely to be so effective.

BTW: 0 accident driver before and after this vehicle

Re: Studies find automatic braking can cut crashes over 40%

#109

Post by sidewndr46 »

WXLCKNO wrote: post #38

Got a new M340i a month ago, first day driving it I get cut off by some 90 year old in a buick who didn't want to miss his turn. Was really glad to have automatic braking, by the time my foot had lifted off the gas it was already braking.

This sounds great, except it just encourages other drivers on the road to drive even more aggressively. They begin to realize that drivers will either voluntary brake or the automatic braking will do it. The net of this becomes a loss, because roads actually become more dangerous.

Re: Studies find automatic braking can cut crashes over 40%

#110

Post by vel0city »

branon wrote: post #103
vel0city wrote: post #100

Earlier quoted context omitted.

> I swear I'm not tailgating people LOL If you're going 40mph and approaching nearly stopped cars at Don't get me wrong, I've had my emergency braking trigger for similar circumstances of someone turning into a parking lot off a feeder of a highway. But I don't blame my equipment, I acknowledge I'm not a perfect driver. The car knew it could have been quite a challenge to stop in time and so it took action. The bette…

Nobody's approaching nearly stopped cars, I think you have misunderstood some other facet of my post. I sometimes approach _decelerating_ vehicles, _while I am also decelerating_

> Nobody's approaching nearly stopped cars

Yes they are, further up this comment chain is:

> for example, if they're turning and will be gone in a second anyway

That car turning is a nearly stopped car, doing a maneuver which could result in them stopping suddenly and unexpectedly. Going 40mph less than 80 feet away from that car turning is absolutely an extremely risky manuver. You don't know they're going to be gone in a second, you're assuming it, and if your assumption is wrong its a collision because you cannot possibly stop in time. Emergency braking triggering in this scenario is 100% justified.

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