It is a simple thing but the PCS has been triggered 4 times in the last 5 years and never incorrectly. I think I would have stopped soon enough without it (as I've never hit anything in my 20+ years of driving), but it was always in those unexpected situations like a car rapidly slowing down in the middle of the highway for something I can not even see.
It feels like initializing values to 0 automatically. You shouldn't need it if everything else goes perfectly, but it doesn't hurt to have it.
My car (not a toyota) does it too and I've never had it actually brake but the very audible + visual warning signs definitely makes you act tiny fraction sooner (at least that is how it feels). I'm pretty sure it would have stopped otherwise on its own but a bit less pleasant.
edit: it also triggers when you go down a steep parking lot onto a flat surface a bit too fast which is interesting but at least valid (with respect to suspension compression and hitting the ground).
Yup, the fact it chimes in at a lower confidence reduces the negative effects of any false positive. It needs to be very confident to start applying braking, but it also primes your brakes before that so if you slam on the brakes from the chime it gets them to 100% instantly.
>it also triggers when you go down a steep parking lot onto a flat surface a bit too fast
that's a great feature, I always have to remind friends and relatives to slow down when going down an incline onto the road (they invariably scrape the underside of the car)
We have it our 2016 Forester and I won't buy a new car without it. I'm a pretty careful driver most of the time but I had one incident where I went into a road trance right as the car in front of me braked very abruptly to make a turn and I didn't register it in time. Was going about 35mph and there were a few car lengths in front of me. Automatic braking kicked in along with a loud chime and I slammed on the brake and stopped within inches.
> You shouldn't need it if everything else goes perfectly, but it doesn't hurt to have it.
That's not how I see it. Computers react faster than humans even setting aside the mechanical delay of lifting your foot, moving it, and pressing it down again.
It's more like running a linter on your code. 99.99% of the time it isn't necessary and you already knew what it was going to say, but the one time it does catch something important it's a life saver.
There is very little reason to be in a state where the advantage is the difference between a collision and not, is I think what they were referring to.
Adequate following distance, conservative driving, etc.
Not like that happens on freeways in any city, of course, but the point is - it shouldn’t matter, but should be nice to have.
Unfortunately, I’ve had numerous false triggers (highway construction barriers coming in rapidly from the side, while other traffic merged in), which made me disable mine. It’s almost caused several accidents in the last few years.
Headline claim only pertains to rear end collisions (which to be fair, are a large portion of collisions on our modern cell-phone filled roads). AEB won't save you from losing your shit in the woods trying to dodge that deer or road debris you couldn't see until last minute nor will it save you from entering a corner too hot.
True, but the latest generation of electronic stability control systems with brake-based torque vectoring are pretty good at handling those situations. Many cars already include that feature and it will probably be universal in a few years.
Nothing will save you from physics. The tires can only apply so much force to the vehicle in order to change direction or speed. A stability control system fundamentally trades distance traveled forward in exchange for not getting sideways.
ESC is good at preventing people who don't know how hard their vehicle can actually turn from going "all in" with the brakes and winding up off the road because they robbed the car of all the tractive force it was using to turn. For example, if you whip around a turn at a high rate of speed and there's a deer there ESC will keep you on the road, you're still gonna hit the deer though.
I think all these technologies are beneficial because they bridge the gap between the hapless dolt and the driver who can get the most out of their vehicle but no amount of breathless hand wringing and low effort internet comments will ever change the rules of physics.
I think you missed the point. Adding brake-based torque vectoring to ESC does more for crash avoidance than just ESC alone. It allows the vehicle to rotate faster by maximizing use of the available traction at all four wheels. Even drivers who know how to get the most out of their vehicles aren't able to selectively brake the inside wheels while turning. This isn't magic and won't prevent all crashes, but will prevent some.
I wonder how many extra crashes will something like this trigger and who will pay when accidents happen because the car decided to break for no apparent reason.
I've seen PCS working well at slow speeds and, arguably, they would be more helpful at higher speeds. But would you trust such system with your life at high speed on a busy motorway ?
The person hitting you from behind would be at fault anyway, at least where I live you are required to keep enough distance to stop even for no apparent reason, if driving in a lane and not moving to another.
If you do it whilst moving in front of another car as it could be on you as you are required to yield and leave enough space to not hinder or endanger the driving of the other vehicle. This also includes brake-checks as your obligation to yield does not stop after you have merged into another highway lane and continues for an unspecified amount of time.
So there should not be an issue there, only problem is people can and will not understand the stopping distance of a car driving 100+kph and do not leave enough space. YMMV with respect to the laws involved as it's entirely possible you could be at fault at the place you are living.
The rules for accident liability aren't as rigid and naive as you are implying.
The rear ender having to pay is just the base case that is used in the absence of other facts.
If you drive "in an asinine manner" (the definition of asinine is subject to discretion and negotiation between the relevant insurance companies) and manage to make the front of someone else's care meet the rear of yours in the process AND there are witnesses, dashcam footage or other evidince you will almost certainly wind up having to pay up.
Everybody knows that traffic doesn't follow the rules. Pretending like it does is a convenient legal fiction we use in order to make rule making easier.
There is intentionally tons of redundancy baked into the rules to cover for all the edge cases where people routinely don't follow the rules. Hence why other people's obligation to not crash into stuff isn't a blank check to do whatever. In cases where two people are breaking the rules usually whoever's breaking them in the more typical and predicable manner is the one given a pass (e.g. someone speeding "a normal amount" will likely not be found at fault if you roll a stop and get t-boned).
Sure, if driving like a maniac, but you would argue the driver stopping for a dog on the road is at fault for the person crashing into him/her from behind?
Maybe it's different in the states, I'm not up to date with all traffic rules everywhere.
The challenge is that our tailgating rules aren’t sufficient for extreme cases. Two seconds behind someone is sufficient for most cases, but if the person in front of you, say, hits a wall and comes to an immediate stop, it won’t be enough.
So if autonomous systems hit the brakes much more severely than conditions warrant, it’s not obvious that the drivers behind you are going to have time to react.
It’s been my experience/understanding that in the US someone hitting a car from behind is almost always at fault. The onus is on everybody to avoid an accident. But that doesn’t include forcing a car to continue forward.
Also people commenting here are likely from widely disparate parts of the world with different driving laws. Those differences are more than enough to preclude useful discussion here at the extremes.
It probably varies by state, but people I know who've rear ended someone else have said that no one is interested in how it happened. The cops didn't care, and the insurance didn't care. The rule is it's your responsibility to maintain a safe distance.
So sure - the guy in front of you may have been extremely reckless, but no one involved is even going to want to hear that narrative.
>So sure - the guy in front of you may have been extremely reckless, but no one involved is even going to want to hear that narrative.
Nobody cares about talk. Everybody lies when they have financial motive to do so and everyone who deals with accidents professionally knows this. That said, insurance companies care deeply about hard to falsify (i.e. anything better than heresay) evidince that show that their customer was not the cause of the loss (dashcam video, surveillance footage, 3rd party witness statements, etc) because the profitability of their business depends in large part on claims payouts.
For other accidents, yes - I've found they want to listen. Rear ending: Not really: They just want to know who was driving the car that rear ended the other car.
I got rear ended once. I spoke to the other party's insurance. Trust me - they didn't want to know why I had gotten hit. It's to their benefit to know, but for them it was an open and shut case. All they wanted to confirm was that it was their insured who had rear ended me.
It isn't as black and white as you make it out to be.
I have a dashcam, if someone cuts me off and slams on their brakes I may not have time to react. The party in front could be responsible if you can prove it with a video. The insurance company WILL CARE if you have footage.
However, if someone seems to brake no reason, it is on the driver behind to stop.
>The person hitting you from behind would be at fault anyway
Where is this place where drivers just magically pay for damages? Where I live in the US, the person who hits you from behind is probably going to back up and just drive away.
Most other brands seem pretty good. My 2019 Subaru has zero phantom braking events so far. (Although the adaptive cruise control does get confused when driving in the slow lane on freeways and slows down when the car ahead turns onto an offramp.)
Automatic emergency braking changes nothing from a crash liability standpoint. Generally the leading vehicle has the right of way, and the following driver must leave enough space to avoid a crash even if the leading vehicle brakes inappropriately.
Fuck no. I had to deal with a rental that had driver assist technology and it damn near killed me. There was a boulder on the road around a blind corner and the car fought me trying to swerve out of the way, I barely avoided it.
Imagine auto braking on black ice or because of a faulty sensor. We're giving immature technology too much control of the vehicle.
AEB is absolute magic for preventing rear endings by distracted drivers in stop and go traffic. People who's behavior doesn't tend to come with much risk of this will experience mostly false positives from AEB hence why "everyone" has a story.
Many of us are quite familiar with the reliability of software, and have serious concerns about trusting it to make the right decisions in a complex real-world situation.
Many of us are quite familiar with the reliability of humans and have serious concerns about trusting them to make the right decisions in a complex real-world situation.
There are almost 2 million rear end collisions in the US every year. Humans just don't have the reaction times to handle many situations. That is also best case. Many people are distracted while driving.
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 where the four corners of the vehicle are - I don't need the computer slamming on the brakes when I am reversing in a tight spot. It feels _more_ dangerous and I fear that one day, my knee-jerk reaction will be to fight the machine (press the gas harder, or get distracted looking at the console which emits lights and sounds every single time auto-brake kicks in) and wind up wrecking with even more force than I might have otherwise.
Also, in traffic, I'll often take my foot off the gas and coast/idle, letting the vehicle slow down naturally. I try to do this instead of braking sometimes as I believe it assists with keeping the flow of traffic predictable for others. Usually this is no problem because I follow the next person at a safe distance.
Sometimes, while decelerating as described above, I will allow the distance between myself and the next car to close, for example, if they're turning and will be gone in a second anyway. The Subaru then ruins my slowdown maneuver by slamming on the brakes because it thinks I'm approaching the vehicle ahead of me too quickly. Well, yes, maybe, but they're also halfway out of the lane already so it's not terribly significant that I'm closing the distance. Another half-second and they'll be gone, restoring my follow distance. (This has only happened once or twice but I imagine it gives the person behind me quite the unnecessary shock.)
I wish there was a way to fine-tune the sensitivity, or at least an option to say "I am an attentive driver, please switch auto-brake to a lower sensitivity level." Currently the only option is to disable it each time the engine starts, which feels wrong to do...
I just bought a 2023 Crosstrek and haven't really noticed it kicking on too aggressively, it does beep sometimes. The only time I get annoyed is when its in adaptive cruise control and someone is merging off the highway it will think they are slowing a lot but its clear they will be out of the way.
Same experience. ACC doesn't brake anywhere near as hard as the emergency auto-brake, but when ACC is enabled and the car in front flips their blinker on and starts moving, I have to proactively feather the gas, otherwise ACC will ride the brakes until they have completely exited the lane.
Past that, ACC is a godsend, should be standard everywhere. Lane keep assist also works impressively well (the proactive one that steers for you, there's another "emergency" lane keep system that will haul you back onto the road if you start to veer off, which I've never had the pleasure of using)
Emergency auto-brake is _scary_ though. When it kicks in, the brakes make this horrible grinding sound, and you can tell the vehicle is stopping with all its might. You feel like you've done something wrong even if it's clear that the maneuver was safe.
I have a 2022 BMW X4 and it handles it really well. It actually prevented me from rear-ending someone earlier this year. I have never had it kick in "accidentally".
The lane departure can be slightly more aggressive. It generally works very well, but I have had a few cases where old road lines (think construction zone) caused it to veer into oncoming traffic. It has happened twice. Luckily I keep my hands on the steering wheel and it feels the resistance and submits to my judgement. But for all those people that drive with their knees or text while driving, it could be problematic.
I'm comparing this to a 2020 F-150 Platinum that I had previously. It's automatic braking was awful. It had false alarms constantly. The lane departure was equally horrible. I find it interesting that the article pointed out how specifically terrible pickup trucks are with automatic braking technology and I thought back to my F-150. Since the F150 is the most common truck on the road (actually the most common vehicle in America period), I wonder how much of that statistic is being dragged down by Ford's terrible technology alone. Everyone I know with that on an F150 has turned it off because its so bad.
I think the brand and implementation of this technology is very brand-specific. I have driven my parent's 2021 VW Atlas quite a bit which is equipped with both technologies and it is "fine". Not great and not bad. I've seen a few false alarms already in the shorter amount of time I have been in it. They were constant in the Ford and I have yet to experience one after 12 months of daily driving in the BMW.
Pickups are hard to get right. If you’re larping with an empty truck, the tail end is likely to come unglued if you brake too hard. If you tune it for normies, then loaded trucks will have longer stopping distances.
Or just leave more space on the highway when someone is turning?
Auto brake isn't just for "inattentive" drivers. It's also for self proclaimed "attentive" drivers that can still lose focus at a bad instant.
A turning car can still slam in their brakes when they're not completely out of your lane. Its rare, so your maneuver will be fine most of the time. But sometimes other drivers do unexpected things.
Fair enough, could definitely happen. I figure I _do_ still leave enough space even when closing though. I've never wrecked a car yet, so I tend to doubt the machine when it challenges a what I'm pretty sure is a well-refined heuristic.
Totally fair. If (when!) the day comes, hopefully it will have been for some other reason instead of a maneuver I incorrectly thought was safe. I trust myself enough to think this will be the case.
And if someone is following you too closely, but the lane to your left is clear, so it is in your interest to absorb the slack from someone in front of you turning because you can swerve left if they do something unexpected?
I don't think anyone would complain about these systems if they had all of the context and made good decisions. But it is a problem when either humans or automated systems stand on the brakes based solely on what is in front, without regard for sides or rear.
I do believe these systems are a net win. But they have rough edges that at least cause a lot of near-accidents because they don't behave the way drivers expect each other to.
I've never had a false alarm from the system on my car. But then, I actually follow the recommended minimum following distances and generally drive safely.
Well, it is either your superior driving behaviors, your car manufacturer's superior implementation, or just the way statistics work that not everyone sees every bug.
My car auto-brakes at 5mph for parked cars that are backed into spaces, which I am sure reflects poorly on my driving in some way, if we're adopting the "bad things only happen to bad people" model.
I've had the additive cruise control do some fairly hash braking in situations which didn't call for it. One I remember was when passing someone who had pulled into a layby (a rest area just off to the side of the road) and was stopping. Once you grow to expect it it's not really a problem, you just put your foot on the accelerator until you pass something which you know the car might not like.
I've also had it activate in normal driving due to someone else doing something dangerous. I'm pretty sure I was on top of those situations but I'm happy the system had my back even if I didn't need it.
Honestly, I feel like a lot of the people complaining about this feature are just bad drivers who regularly drive unsafely and are now getting called out on it. This in particular:
> Sometimes, though, I will allow the distance between myself and the next car to close, for example, if they're turning and will be gone in a second anyway. The Subaru then ruins my well-calculated slowdown maneuver by slamming on the brakes because it thinks I'm approaching the vehicle ahead of me too quickly. Well, yes, maybe, but they're also halfway out of the lane already so it's not terribly significant that I'm only one car-length away and still going 40 MPH. Another half-second and they'll be gone, restoring my follow distance.
You really shouldn't be driving like that. You don't know if the car in front of you making that turn is going to brake suddenly, like because, I dunno, they suddenly see a pedestrian crossing on the side street.
Personally, I'm a more reserved (I guess safer?) driver, and I always leave good following distance and brake predictably in order to do so, and I can't say I've had problems with these systems. And I'm 100% in favor of systems that force other drivers on the road to drive more safely as well. Now if only they could prevent tailgating entirely ...
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 actually _need_ the car to do it, by a fairly wide margin.
1-2 car lengths (not in literal units of 15-feet each, I mean one or two _seconds_ of follow distance minimum after accounting for speed/traffic/weather) going the speed limit with my foot off the gas and over the brake, paying attention ready to slow down fast in case of a contingency feels very safe to me. Again, pretty nuanced, this only lasts for a handful of seconds while the lead car completes their maneuver.
The salient point is that I already do what the machine tries to replicate, I don't need my maneuver clobbered by another system.
I’m not comfortable at all claiming that you’re a bad driver in general, like the GP proposes, and maybe I’m taking your unit of measurement too literally, but I don’t think 1-2 car lengths is a reasonable follow distance in almost any circumstances above 45mph, two lengths is kinda the minimum to not bother the person in front of you. Again, I’m making a very general statement, that might not apply to the situations you’re describing.
And I’m a young guy that is working on being a more conservative driver myself - so I’m chuckling to myself just at the idea of me taking this side of the discussion.
This is an interesting point. The Subaru's adaptive cruise control system treats a "car length" as a fairly large unit of measurement. One car length seems to be the literal length of the vehicle, plus some reasonable amount of buffer on both ends. Probably twice as large as the vehicle itself. And the faster you're going, the larger a single car length becomes. Infinite nuance :P
But in general, very good commentary on systems that provide useful feedback for the human operator versus ones that don't. ACC makes it clear what a car length should be, and if you're paying attention you can gauge how much more space it leaves when you're moving fast. So that's what I go by.
The Subaru uses two seconds per tick mark on the adaptive cruise display, so the distance changes as you go faster. At slow speeds, it's roughly exact car lengths, and at 65MPH it's considerably further.
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 could work out for you fine for 20+ years before one day you get into accident, and presumably blaming the driver who suddenly stopped mid turn.
Check out watchpeopledie or idiotsincars for plenty of videos of what could go wrong. I recall one video of exactly this issue — an idiot SUV stopped mid turn in the middle of a lane, clearly a bad driver. And then another driver t-boned her because he didn’t have enough distance to stop, also cleary partially at fault IMO.
I know people with lifelong pain from minor auto accidents. Don’t have that be you, or cause that for someone else. What do you lose by keeping some more space between you and the next car?
One car length is way more than 15 feet to my mind, probably 40 feet or more depending on speed. See my other comments about how nuanced this entire dialog will inevitably be. Don't you think it's more reasonable to assume we have different definitions of a car length? Perhaps I've used the term in a grossly incorrect manner. "One car length" to me equals "one unit of minimum safe distance taking into account road conditions, traffic conditions, and speed"
I think you are confused (either that or I am!). I’m pretty sure a car length is literally the length of a car, which for a Crosstrek is around 15 feet.
Given this confusion, it does seem like it explains the root of the disagreement here, but that said, I don’t think it’s unreasonable for people reading your comment to assume that when you said “car length” you meant the length of a car.
Sure, I'm fine with admitting that. It was an inevitable misunderstanding anyway because cars are different lengths so "car length" is largely meaningless.
The Subaru's adaptive cruise control system treats car lengths as variable units based on speed. It's much more liberal than I made it sound in the original comment. It sounded reasonable when I wrote it, but infinite nuance strikes again I suppose.
Have an upvote for the adaptive cruise control comment. It's this way on the Tesla, too - follow distance is described as car lengths, but it's actually speed-parameterized follow distances in reality.
Personally, I find it somewhat confusing, but people should probably be more aware that it's a thing and not necessarily someone mixing up terminology.
> One car length is way more than 15 feet to my mind, probably 40 feet or more
Cars in your area are on average 40 feet long?
A car length is about the length of an average car.
Either way, with a 40 foot "car length", 1-2 car lengths is then ~80 feet. The above stopping distance chart puts a 40mph stopping distance with reaction time at almost 140 feet. <80 feet away is driving way too close at 40mph! Especially for a car you know is doing a maneuver which could result in them braking suddenly such as turning into another field of traffic.
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
If you're going 40mph and approaching nearly stopped cars at <80 feet, you're absolutely tailgating people and creating extremely risky situations.
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 better action would have been for me to be going slower and approach that situation with less speed, not to just blame the car for being cautious and forcing realistic safety margins.
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_
> 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.
You can turn the wheel of a vehicle without being stopped. People change lanes at speed on the highway every day. Please try to assume good faith. "Turn" does not always imply a 90 degree turn with a full stop prior. I am not approaching cars at speed while they are stopping to make a 90 degree turn...
Changing lanes is called changing lanes, not turning. They're inherently different maneuvers.
Either way, if you are rapidly closing the distance to a car which is changing lanes, you don't know for certain they won't cancel the maneuver and go back to being in the lane. You're still assuming that, and assuming you'll be able to slow or stop fast enough to handle it.
If your AEB is constantly getting "false" alarms, maybe it is not the AEB that needs adjustment. Maybe driving in a fashion where the car's AEB doesn't constantly give "false" alarms would be a lot safer.
It is by no means a constant occurrence. I've edited my original comment to disclaim this as you seem unable to assume good faith about any of this. It has happened only twice, both times with a fairly wide margin where human intervention could have occurred should it have been needed (it wasn't).
Changing lanes is a type of turn because you _turn_ the wheel to change lanes. You also might turn 45 degrees in a roundabout, or 90 degrees at a stoplight. They are all turns.
I'd agree that it's an assumption. Though your assumption that the distance is closed _rapidly_ is also just that - an assumption, and one made in bad faith despite my efforts to correct it.
The mere act of being in a car on the road involves dozens of assumptions made every single minute about the traffic conditions. Very little is known for certain, ALL maneuvers are to some extent based on assumptions.
This conversation is no longer productive, thanks for your participation anyway though.
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.
> Teaching a young inexperienced driver “just always keep one car length” where one = safe, is meaningless.
Not if taught correctly, which I think it's important to note that we can't really do via textual communication.
In the driver's seat, during a driver's education course, you might learn that a car length is the length of an average car, but you also learn how to count the seconds of stopping distance you have in front of you. In addition, you learn that weather, traffic, and other factors can affect stopping power/distance, the point being that the whole system is incredibly dynamic and variable.
One can't reduce a dynamic traffic situation down to "X car lengths = safe." Similarly, saying "1 car length = a safe distance" doesn't really help either.
The idea is to teach people what "safety" actually looks like. How it's referred to is secondary. The proof is in how badly I was misunderstood when I said 1-2 car lengths. I _know_ I'm keeping enough distance, because I know how to judge a safe traffic situation.
I don't really care what a car length is or isn't, it's fairly irrelevant because safety is a much bigger picture than units of measurement.
Exactly; car lengths vary by model, not by velocity.
I get it. You'd prefer to use the phrase "car length" to not literally mean "length of a car" in this context. Apologies if I seemed pedantic but, as evidenced by this thread, your use of car length is going against the grain.
Safe following distance is often expressed in multiples of car length. What car? Sure, good point. Pick one; it's close enough! (If you're actually thinking about following distance in any terms at all, even roughly estimated, you're ahead of the safety curve and you clearly are!)
Ideally, following distance could be accurately estimated in metres and adjusted continuously by velocity and driving conditions. AI can do that. People just kind of eye it and say, "it was raining and I followed about four car lengths behind him" or "we were inching along and I was half a car length behind him". Good enough for meat brains!
> And then another driver t-boned her because he didn’t have enough distance to stop, also cleary partially at fault IMO.
Not partially at fault; completely and totally at fault (except if we're talking about someone deliberately trying to cause a crash in which case I'll settle for partially). The reality is there could be a hundred reasons the car stopped, the driver being an idiot is only one of them. Mechanical failure, something unseen from the following car, a door flying open, someone stepping out in front of them, a queue in front of them which is not obvious from behind etc.
If you are not leaving enough room to come to a stop when the car in front does then you are riding your luck, there are no two ways about it.
It sounds like the example was not of a car they were following, but one that pulled out infront of them and stopped in their lane. Just as you are referencing possible excuses for that driver, we could come up with possible excuses for the driver that pulled out (like pulling out suddenly without enough distance to react even if the other car was going under the speed limit).
We also need to understand that being at fault isn't 1-to-1 with who was being safe. Typically, if you pull out and get t-boned by someone who has the right of way and is generally following the law, the person being t-boned is at fault for failing to yield. Where a vehicle is impacted plays a huge role in investigators determining who is at fault. Now if you run into the back of the person in front of you, it's almost always your fault, unless the person in front was driving carelessly or recklessly (brake check, for example) but would still involve partial fault in many cases.
So really, we can't say either way without knowing a lot more.
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.
Little known fact: You can travel the exact speed of the car in front of you while also being any distance N behind them. If I'm traveling greater than 50MPH, I leave at least 3 car lengths between me and them, this is to allow for reaction time to stop at the same rate they are stopping.
I don't understand this - are you implying that the only way to safely drive on highways is to always maintain a follow distance equal or greater to your stopping distance?
I don't think it's reasonable to prepare for the car in front of you to stop in place as though it had hit a brick wall. Instead, the safe follow distance is derived from the current speed and breaking power of the vehicle I'm operating and the vehichle that's behind me, and the distance to the vehichle behind me.
I used to have a roommate (who has several accidents on his record) with the exact same model of Toyota Corolla that I had. We’d frequently go on trips together.
My driving experience: very rarely have a PCS audible warning when conditions change unexpectedly on the 10 (SoCal). Braking activated once or maybe twice in three years.
His experience: constant “false” alarms from the system, several instances of pedestrians and vehicles “coming out of nowhere” that passenger saw 10+ seconds away, several instances of slamming on the brakes, both machine and human-activated.
Some people just don’t treat driving as the life safety critical activity that it is. Most people.
I tend to agree, especially in the situation described in that comment. I have a 2020 Subaru Outback that I believe has a very similar braking system, and while I have also experienced a small handful of false positives (especially when moving very slowly in a tight parking spot), I think the system is pretty good, and I do feel good about its ability to help at least a little bit if I ever really need it.
I’m willing to ignore the false positives when moving very slowly in tight parking spaces. That’s startling and annoying, but doesn’t really bug me too much. I believe you can also turn that off independently of the forward-facing road-speed emergency braking feature (and you need to if you have a trailer or bike rack).
As for false positives while at road speed, I think the actual brakes have only kicked in once or twice, and only very briefly (certainly not enough to slow me down so much that it could cause an accident). It’s a bit more common to get a false positive on the first stage of alert, which in my car is an audible alert and some red LEDs on the primitive heads up display.
Anecdotally, I’ve found similar. Never had phantom breaking in my crosstrek. While it’s possible someone’s car could be miss calibrated, I’d guess pebkac is more likely and self reflection of driving habits is needed.
The only object warnings I’ve triggered are completely understandable and never had auto braking
A sharp turnning off-ramp to a rest stop on i5 with a sign in the middle that one drives directly at before turning has reliable triggered the object warning but never breaking. I suspect that if I went dangerously/stupidly fast in the turn it would brake.
The other other time I could reliably trigger it was pulling in faster than usual to park head on 1 ft in front of a fence, and that only ever did the warning not braking.
So far, and it’s anecdotal yes, I’ve never had it happen when actually on the road.
What I do find annoying is the cruise control starts to floor it when changing lanes if it sees the clear path down the lane line during the change.
My experience is largely the same as yours. I've had the alert (no braking) several times on the highway during sharp corners or when coming up on slower traffic (when I've been totally aware, but probably coming in hotter than I oughta be). I've also had it trigger twice when entering my apartment building's parking garage. It has a very steep uphill ramp and a couple of times I must have approached it fast enough that it thinks I'm running at a wall.
I also agree with the cruise control issue. The adaptive cruise control is very nice for highway traffic that's changing speeds a lot, except that I'll forget that it's set at 65-70 after cruising around 50 for a while, and then when it finds a clear lane it will try to accelerate very quickly. That's ultimately just a limitation in how far ahead the system looks to find cars.
"And I'm 100% in favor of systems that force other drivers on the road to drive more safely as well."
Ug. I'd rather have testing be changed so that safety is increased in all situations by having a competent driver. Most of the situations being described here are simply poor choices on the part of one or more drivers.
For real, who the hell is cutting through lanes of traffic and slamming on brakes because they will miss a turn? Best to remove these people than have them rely on a price of tech to save them in 1 situation but let them continue to be dangerous in another 9 areas.
> You don't know if the car in front of you making that turn is going to brake suddenly
More drivers need to be aware of this one. There's an intersection near me where drivers always tailgate and rush others through the (slightly greater than 90-degree) turn onto a side street, no matter how well the turn has been signaled already. There have been multiple minor accidents, but fortunately no pedestrians have been hit that I know of. When someone's turning, drivers behind need to give them more space not less.
Maybe? Few would openly admit to be a bad driver to begin with so it is hard to even get anecdata on the subject. In other words, I am not sure you can determine an answer either.
What I can say is what bothers me about it. Can I turn it off? Can toggle on/off switch be disabled by an update? Can I trust that it the off button will do what it is supposed to do? If I can do those things, can I trust this feature to work as advertised? I used to not ask questions like that with cars as there was certain level of.. expectation that this machine has to work in sometimes drastically radical conditions ( especially in some parts of US ).
Cars are software now. But that is not my main beef with it. My beef is that it is built to the detriment of the end user and to strip the user of all control.
> You really shouldn't be driving like that. You don't know if the car in front of you making that turn is going to brake suddenly, like because, I dunno, they suddenly see a pedestrian crossing on the side street.
I think that's the problem with that attitude and why I don't like my car doing excessive braking. Unlike the distance lidar, I can actually see there's nothing obstructing the turning driver, and I can see their speed of leaving the lane is simply too high for them to stop before leaving the lane even if they slam the brakes. And even if they did somehow manage to break where they are already I'd only need a little swerve to the left to drive around with no traffic there etc
I'm not here to defend every occurrence of an automated system firing. I'm pointing out that people who think they are attentive and skilled enough to not need these aids are exactly the people who should be using them.
Fair enough. I don't believe I fall into that category though, it's not so much that I consider myself skilled enough that the safety system isn't necessary, but rather that I wish I could adjust sensitivity, because I like the idea of the system in general. In this vehicle I'm only able to disable it entirely (which seems unsafe to do, so I keep it on).
Ideally I'd like to have it disabled only when reversing. Between the backup camera, mirrors, and the rear window, the safety systems are already present. The rear bumper really does not need to be triggering emergency brakes imo.
The front bumper though - yeah that one should probably stay on, even if it annoys me sometimes.
My sister got annoyed with the auto-braking on her new Subaru and turned it off. Three days later she rear ended someone, smashing up the whole front of her car. This was the third time she had rear ended someone.
If only. My grandad was a lifelong truck driver and a pretty good one AFAIK, he kept working well into his 70s with a safe driving record. But eventually as he got older he caused three minor accidents in less than a year before he agreed to stop driving. This was in the late 00's as he was approaching 90.
2020 Jeep here. I used to park in a garage where I had to go 4mph or less, because at 5mph and above auto-braking would trigger every time I got to the end of a row and a car had backed in so its headlights were facing me. Scared the bejesus out of me, over and over.
Also the same issue coming up on turning cars that will be gone momentarily. I'm ready to brake if they suddenly stop, but the system freaks the hell out and tries to get me rear-ended.
I am willing to believe that there is a net reduction in crash likelihood because it may save me one time that I would have crashed. But the cost is a constant low-level fear of surprise and terror from normal driving.
At least it's better than the 2014 Audi I had that would slam on the brakes on the freeway if there was a semi trailer going slow one lane to my right. I learned to keep one foot on the gas and ready to floor it when that happened (maybe 5-10 times a year).
> 'Sometimes, though, I will allow the distance between myself and the next car to close, for example, if they're turning and will be gone in a second...'
I often wonder what advantage in life people think they are gaining by this behaviour. Care to share?
Reducing the odds of getting rear-ended by absorbing the slack of a conservative following distance rather than braking to maintain the same following distance from 35 to 20 mph.
You can't control what the person behind you does, but you can control what you do and rushing people through turns is unsafe. If the person in front of you signaled (or did anything else to indicate) their turn in sufficient time, then you should be able to do likewise for the person behind you with a light tap on the brakes. The odds of being rear-ended probably won't change by any significant amount, and IMX people who cite those odds weren't really thinking about them at the time. It's just an excuse for prioritizing speed over safety.
These systems are imperfect. People are imperfect, too.
But please consider that not everything is evidence that everyone else is reckless driver. One day your system will fail in a surprising/dangerous way, and you'll tell someone "wow, it mistook a reflection for tail lights", and they'll say "well I am a perfectly safe driver so that could never happen with my careful driving, you must have been really reckless", and you'll have an epiphany.
> please consider that not everything is evidence that everyone else is reckless driver
Never said or implied that. I said that one specific behavior is dangerous. Maybe you're right that "my system" will fail some day, but in the meantime I'll continue doing my best to improve the odds instead of using "well, stuff happens anyway, can't do anything about it" as an excuse. After driving for ~40 years, having been in a few accidents (only one in the last ~30 and never even remotely considered to be at fault) and seen more, I don't think I'm the one who needs that epiphany here.
BTW, let me go into a bit more detail about that one accident, since it's kind of relevant. I was turning, had signaled, person behind me saw and had tapped the brakes, person behind them was on their phone and plowed right into them, pushing them into me. No injuries, amazingly. Key point: there was nothing the woman in the middle could have done. She would have been struck regardless. If she had "absorbed the slack" as you suggest, her car would have just been slammed into mine even harder - quite likely with more dire consequences. Other times, as I already mentioned in another comment, drivers "absorbing the slack" actually caused accidents themselves at an intersection near me. More than once.
You're relying on your reactions being better than those of the person behind you (if not better than humanly possible), with no justification whatsoever. "Absorbing the slack" is a stupid and dangerous habit that most people who have driven for a while learn to avoid. I'm trying to tell you here so you don't have that epiphany about defensive driving and margins of error too late.
This reminds me of the auto-correction feature on my insulin pump. Insulin dosage can be seen like braking: a certain brake pressure/duration decreases velocity over a period of time, and a specific amount of insulin decreases blood glucose over a period of time. My problem with the feature has been similar - it steps on the brakes too soon when I don’t need or expect it to. It can be adjusted, but in braking terms, one can adjust the pressure but not when it brakes. While this is touted as a cutting edge feature and many people like it, I had to turn it off.
1. Forward collision alarm goes off falsely sometimes, but never the actual braking
2. Rear collision braking is usually fine as well, but since it doesn't realize grass/bushes aren't solid it feels a little more intense in those situations.
It really feels like you're just driving recklessly.
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.
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.
You could use actual distances with speed, or seconds behind. Either one can be an appropriate measurement and are used in things like Driver Ed courses.
Car length may be variable, but is colloquially understood to be 15' give or take, but not more than 20'.
Subaru is wrong for thinking you closing on a barely-moving car at speed is dangerous, and the entire internet is wrong for thinking "car length" refers to the length of a car. Two doesn't quite make a pattern, but it suggests one. You being obviously-wrong on the second point doesn't mean you're definitely wrong on the first, but I'd be more inclined to trust the automotive company with access to crash statistics than your "never wrecked a car yet" instincts, personally.
Then again, I've known two people who both proudly proclaimed that they'd never even gotten a ticket before whose driving was so terrifyingly unsafe I wouldn't get into a car with them a second time, so maybe that's my bias.
Safe follow distance is usually measured in time, not distance. It's a function of human reaction time plus your vehicle's ability to brake, which is mostly a function of its velocity (also greatly affected by tires and weight but there's far less variance there in passenger cars compared to personal variance in velocity).
Most DOTs claim around 1.5s for reaction time, and then up to another 1.5s for braking at typical highway cruising speeds. So, 2-3s follow distance in total. Adjust down for low velocity and up for poor driving conditions.
"Always measure your safety buffer in the appropriate metric: time."
Distance is the appropriate metric when you want to keep two objects a minimum distance apart.
Your response is only half the equation, then stopping performance comes into play. So while reactions are measured in seconds, you're converting those into distance traveled.
Measuring in following time is just a convenience for eliminating distance estimation biases. That time will also fluctuate based on the road conditions and vehicle performance.
> It's too sensitive and tends to brake shockingly hard during fairly mundane maneuvers.
I've had a Crosstrek since 2018, and it has prevented accidents for me at least 4 times. It can be annoying when someone edges into your lane, or is edging out of your lane (and usually braking), but for every time it autobrakes for that, there's probably a situation where I'm glad it did. I'm sure the tech will just get better over time.
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
"Over-sensitive" or not, what's the actual harm in driving in a way that avoids triggering it?
When your driving safety system gives you feedback while driving, you have two choices:
- Learn from the system and modify your driving to be safer for yourself and those around you, or
- Ignore the system, describe it as "too sensitive," and disable it.
Before the driving safety system feedback, you might have been an unsafe driver out of ignorance. After the driving safety system feedback, you're choosing to be an unsafe driver willfully.
This is fair. I do (and have) adjusted my behavior to avoid setting off the auto-brake. Mainly I did this because disabling it entirely seemed like a bad idea, despite my misgivings.
Sometimes I still trigger it when reversing towards obstacles though. It still prompts an eyeroll and a muttered curse. Not sure if that will ever go away, somebody else mentioned that it tends to treat bushes as solid objects. Not that I'm reversing over top of the bushes, but reversing _towards_ them should not be as big of a problem as the auto-brake would have the driver believe.
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 acceleration or top speed capabilities of a car, traffic calming measures that reduce top speeds are always fought, speed limiters are way out of the overton window, just mentioning automated speed cameras cause aneurysms, ...
People have unhealthy attachment to the brand of driving, the dumb shit that they see on car advertisements.
It's primarily a male ego thing, and it's pathetic and needs to go.
Safety measures that prevent so-called spirited driving should be mandatory on cars: speed limiters, auto-braking, and lane keeping are a good start.
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.
That's a common false sentiment. People driving slower, in a safer cars cause less accidents, less deaths, and they themself die less.
On the other hand a lot of "aggressive" drivers slip up earlier or later. The risk is too high.
Also, looking at a phone is entirely your choice, not a boredom/distraction moment. Listen to audiobooks if your mind needs to do something while driving.
>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.
I'm all for them but properly tested and validated, not the tesla cowboy approach that musk espouses. I fear that he will discredit the idea before we have serious autonomous driving products.
I’ve had auto braking nearly cause collisions twice with other vehicles when it got confused in construction zones (in heavy traffic) and jammed on the brakes.
I also drive pretty carefully and provide a ton of space, but others don’t.
The title is a tiny bit misleading. Here are the stats from the article:
Automatic braking has demonstrated the ability to:
- reduce rear-end automobile crashes "in half" (technically 49%)
- reduce Rear-end crashes with injuries by 53%
- vehicles without automatic braking, but with collision warnings only cut accidents by 16% (compared to 49% with automatic braking)
- pickup trucks are less effective at preventing crashes, only preventing 43% of accidents and reducing injuries by 42% (compared to above numbers for other vehicles)
- lane departure systems reduce crashes by 8% and reduce injuries by 7%
- A consortium of 20 auto manufactures have voluntarily committed to offering automatic braking technology to 95% of their light-duty models during the 2023 model year
I don't have an automatic brake in my car, but a sensor that warns me when I'm about to crash into something. There has so far been a single incident where this was actually helpful. In >95% of the cases, it's false positives.
I can only imagine what driving would be like if the car did indeed autonomously brake in those situations.
Same here, previous generation of bmw 5 series, the warnings happen often in non-standard but completely safe situations that human can easily assess (ie full parking lane starting on the right in lane that was driving one 50m before, with very clear signs and good visibility).
Or in situation when I am already breaking ie to full stop hard with enough breaking room and it still pops up the warnings. Sometimes just warnings out of blue, in the middle of an empty road. Me and my family are very happy no automated breaking is integrated into that car, its current state would kill us sooner or later.
Someone recently opined that the boffins should have started with collision avoidance. Then build up to FSD.
Facepalm slap. Seems so obvious once said out loud.
That'd be like a Rodney Brooks inspired actionist strategy, right? Our vehicles as boids, with implicit coordinated action, like flocking, herding, pacing, station keeping, etc.
Maybe a bottom-up emergent behavior strategy has potential. Or a hybrid strategy.
When it comes to AI, FDS, etc. I obviously know nothing about nothing, so please chime in.
I always thought Tesla should have both. When I had a Toyota with automatic braking, it only kicked in in very rare circumstances; truly an emergency feature rather than a driver assist you rely on.
It would have, as a separate system, probably saved several of the Tesla drivers who drove directly into obstacles at highway speeds, which for whatever reason a purely optical system will screw up. Similar to how it saves human drivers that rely on sight.
In my experience, I only had my car activate this once in 8 years. I was on the M6, and it was slowing down, I changed lane and start slowing, and somehow just miscalculated, and was still going 10 mph when the other car was stopped. I was just too relaxed, and it kicked in and braked for me. Saved me a rear end, and became worth the money.
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.
Such a great feature, both of my last cars had this "presense" breaking. I was never really in a situation where it was critical, but the feeling that the breaks are already in a ready state (touch it slightly and you knew a little bit more will do hard breaking instead of going all the way) when I was touching it felt pretty reassuring and a little magic at the same time.
There's also a more basic version of something like this in older cars, "emergency brake assist", which senses a hard application of the brakes (determining from the nature of how the pedal is pressed) and applies full brakes.
Apparently most drivers don't actually apply the brakes fully when emergency braking, so this helps with that.
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.
Yeah I think so, I've gotten the warning as well when someone cut in at a slower speed but this time it definitely felt like it saved the situation because it knew it needed to.
I have a 2017 Outback and there exists a cluster of switches on the dash for easily toggling all the EyeSight features.
They actually recommend to disable the "pre-collision braking" feature before driving through an automated carwash. Apart from that situation, I also disable it when I'm facing highly congested traffic for the reasons indicated in the other comments. It's very easy to do. I don't understand why this is a big deal.
I think the system works very well and has saved me several times over the years while approaching intersections and on the highway.
It's more startling but dangerous, but also, disabled the Reverse Automatic Braking when pulling a trailer. If you try to back into a parking spot with it engaged, the car will freak TF out and make an awful noise as it jams on the brakes. Or so I've heard.
Again I have one on my 2017 Forester, and never turned its safety features including AEB off. All it does when reversing is beep because the sonar sensor is confused. It never behaved unpredictably.
(and yes the AEB did save me from backing into things at least twice in these years, so I know it works)
I was just making a joke about how you basically can't back up a trailer with AEB turned on since it sees the trailer behind you and senses an imminent collision. I've got a 2020 Outback and the only other safety feature I turn off is the driver detection or whatever it's called so it doesn't constantly beep at me when I'm looking at cornfields or whatever on road trips.
Super satisfied with the system otherwise though. Lane keeping and adaptive cruise control are good enough to ease the burden on longer trips but just bad enough that I never "fully" trust them and completely divert my attention.
I think, quite literally, one's mileage may vary. Not all stop-and-go traffic is the same.
It's not always safe to keep the huge distances apart at the speeds the system wants (other drivers will cut in). The system can also have a difficult time with motorcycles lane-splitting.
Anyway the way I see this is the switches are there for the driver to use at their discretion. I would hate for the industry to move towards full automation. I love the system as it works right now. Just my two cents.
Implementation matters. The automatic braking on my compact SUV has falsely triggered hundreds of times over the course of 3 years, usually when transitioning from a moderately-pitched-down driveway into a roadway. The result of this scenario is the car coming to a dead stop with its front end halfway into a traffic lane, putting me and my passengers at greater risk of a collision from oncoming traffic approaching from the left hand side. It’s happened so often I’ve made a habit of disabling it whenever I exit certain commonly used driveways know to trigger the behavior.
Toyota has a good one: it gives me a beep and turns the screen red, but I have to start braking by myself, at which point it takes over and adjusts braking force so as to not hit whatever is in front of me.
False positives usually happen when there are cars parked along a turn, but I ignore this completely.
Over the course of the five years I had this car it prevented a collision twice this way.
> Toyota has a good one: it gives me a beep and turns the screen red, but I have to start braking by myself, at which point it takes over and adjusts braking force so as to not hit whatever is in front of me.
This way takes away the biggest advantage of this systems - that they can react before you do.
Thing is it does react before I do - in those two situations I would have probably continued on my path for too long and brake too late to avoid a collision.
Wow, I've had the same thing in two different cars (Ford & Mazda), and it is awful.
Always false alarms, never in time that I could brake at a time that I wouldn't otherwise, and distracting enough to be a real worry. The only situation I can conceive of it being useful is if the driver is falling asleep on the highway.
What were the situations where yours triggered and actually helped?
First was my first day with glasses - I didn't anticipate that my depth perception would be so different so the sensor beeped when traffic in front of me stopped due to a changing light.
Second was the car in front of me hitting the brakes when I was looking in the rearview mirror because both of us wanted to overtake the truck in front of us - that other person in the last moment decided not to do it.
Or perhaps they weren't planning on that and just didn't see the truck - I didn't see them indicate.
Interesting thanks - could see how it could have helped in those situations. And in both, you managed to see/hear the warning and brake in time - impressive!
This is my gripe with the safety of self-driving cars generally. The net crashes are much lower (very good thing) but the crashes that do happen take place under different circumstances. A good driver paying close attention will probably be better than the computer for a long time. The crashes being avoided are dumb read end collisions where the crash happened because the driver didn’t realize someone was stopped at the red light in front of them (just one example of an unfortunately common crash).
Still looking forward to it when I’m older and a bad driver anyway. Can’t wait to have a personal vehicle that takes me everywhere.
Yup. Our cars don't have auto-braking, but the "Pre-Collision Warning" or "Collision Alert" in the Ford Ranger and Mazda MX5 are both very annoying. They create enough of a distraction that I'm concerned that it could lead me into an accident. Yet it triggers too late to do anything about it, unless I simply train myself to reflexively hard brake whenever it goes off, which would almost surely get me rear-ended, especially since it's always a false alarm.
They both mis-trigger fairly reliably if I'm in a bend in the road and there is a car or object on the outside of the bend, so it seems that they don't take into consideration that I've turned the wheel, or the steering angle. I've also had total mystery alerts, seemingly from spots or a shovelfull of dirt on the road surface.
OTOH, the distance-keeping cruise control on the Mazda is very good, and I've used it for dozens of miles at a time on country roads, with and without traffic.
These emergency auto-braking systems are clearly not ready for prime-time, except maybe for highway use, which is where they can do the most good anyway. I sure as heck don't want my car to auto-brake in any of the situations I've seen the "Collision alert" triggered. Some would have definitely caused accidents.
The features most related to this article are: FCW, AEB, CAEB, HAEB, and PD. Note that some manufacturers have much better implementations than others, so after you settle on a few models, investigate how good their implementations actually are.
One time my car decided that I was going to crash into one of those water tank things at a fork in a highway (actually, this was at a merge, on a curve, which is odd because you don't expect that) and it started doing it's alerting thing, and I had to swerve just so it would stop thinking I was going to crash into it. It was a curving merge, so briefly the car thought that I was driving towards an obstacle, but as long as I stayed in my lane that was never going to happen.
That incident gave pause. If the brakes had engaged, might that have caused a crash?
I have to back out of my driveway in a 2021 Ford Explorer on a fairly busy street. I am typically very cautious because there are parked cars along the street obstructing visibility and you have to be real careful backing out. Even with this heightened caution level, one time I missed a small, gray car that happened to be perfectly obstructed by the rear left pillar as I elected to back out. The "collision avoidance autobraking" kicked on and definitely saved an accident. I may get false positives now and then, but that one instance of a saved accident makes up for all the random quirks as the manufacturers work to improve these systems. I'm a believer.
I have a 2018 VW Atlas and its automated braking system has done the right thing 99.9% of the time. It's definitely saved me from 5-6 accidents -- being cut off a number of times, a racoon jumping in front of my car, and that one time my attention waned.
My Tesla, on the other hand, get's it right about 10% of the time. I wanted to type a higher percentage, but phantom breaking happens so often. The number of times I've seen the red X on the atlas in the entire time owning it is about the number of times the M3 loses its mind on a monthly basis.
The other interesting thing: I could probably write the algorithm for the adaptive cruise control on the Atlas. It's so predictable that I know exactly what it's going to do in reaction to traffic around me. If a car ahead of me slows down, I slow down at a constant rate. If the car speeds up, I know exactly how much it's going to speed up. Same with people changing lanes ahead of me, etc.
The M3 OTOH feels like a buggy machine learning model. I have no idea why it's at the current speed it's at. If I set it to 120KM/H and there's no car in front of me the chances of it being 120KM/H is about 30%. If a car pulls away from and my car should speed up there is no rhyme or reason to when and how quickly it speeds up.
All that being said, I'd still take the Tesla automated braking over nothing at this point. Reading the other posts, it sounds like VW is doing something right.
Anecdote here: 2015 Chevrolet SS was slightly aggressive, but overall I'd say tuned extremely well and saved me once when someone drove through a stop sign without looking onto my freeway offramp and then stopped dead. I was already on the brakes but it went into full panic stop a touch faster than I would have and that made the difference. A few times I noticed it preapplying the brakes when someone cut me off, but it never kicked them in during those situations.
> The group found front-to-rear crashes were cut 49% when the striking vehicle had forward collision alert plus automatic braking, when compared with vehicles that didn’t have either system.
I wonder about front-to-rear crashes when the struck vehicle has automatic braking when the rear one doesn't.
I worry about people with automatic braking not paying attention and being on their phone and letting the automatic braking keep them from hitting people in front of them, while coming to abrupt stops and getting hit more from behind.
Automatic braking on my Mazda almost caused me 2 accidents.... because it breaks to almost a full stop on the highway for almost no reason sometimes (and someone was right behind me)
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[ 2.4 ms ] story [ 229 ms ] threadWe have automatic braking (fixed: breaking) on my Toyota Rav4:
https://www.youtube.com/watch?v=gbnoFbb8G8Q
It is a simple thing but the PCS has been triggered 4 times in the last 5 years and never incorrectly. I think I would have stopped soon enough without it (as I've never hit anything in my 20+ years of driving), but it was always in those unexpected situations like a car rapidly slowing down in the middle of the highway for something I can not even see.
It feels like initializing values to 0 automatically. You shouldn't need it if everything else goes perfectly, but it doesn't hurt to have it.
edit: it also triggers when you go down a steep parking lot onto a flat surface a bit too fast which is interesting but at least valid (with respect to suspension compression and hitting the ground).
that's a great feature, I always have to remind friends and relatives to slow down when going down an incline onto the road (they invariably scrape the underside of the car)
Amazing technology that saved my ass and my car.
That's not how I see it. Computers react faster than humans even setting aside the mechanical delay of lifting your foot, moving it, and pressing it down again.
It's more like running a linter on your code. 99.99% of the time it isn't necessary and you already knew what it was going to say, but the one time it does catch something important it's a life saver.
Adequate following distance, conservative driving, etc.
Not like that happens on freeways in any city, of course, but the point is - it shouldn’t matter, but should be nice to have.
Unfortunately, I’ve had numerous false triggers (highway construction barriers coming in rapidly from the side, while other traffic merged in), which made me disable mine. It’s almost caused several accidents in the last few years.
https://www.motorbiscuit.com/do-you-know-what-torque-vectori...
ESC is good at preventing people who don't know how hard their vehicle can actually turn from going "all in" with the brakes and winding up off the road because they robbed the car of all the tractive force it was using to turn. For example, if you whip around a turn at a high rate of speed and there's a deer there ESC will keep you on the road, you're still gonna hit the deer though.
I think all these technologies are beneficial because they bridge the gap between the hapless dolt and the driver who can get the most out of their vehicle but no amount of breathless hand wringing and low effort internet comments will ever change the rules of physics.
The person hitting you from behind would be at fault anyway, at least where I live you are required to keep enough distance to stop even for no apparent reason, if driving in a lane and not moving to another.
If you do it whilst moving in front of another car as it could be on you as you are required to yield and leave enough space to not hinder or endanger the driving of the other vehicle. This also includes brake-checks as your obligation to yield does not stop after you have merged into another highway lane and continues for an unspecified amount of time.
So there should not be an issue there, only problem is people can and will not understand the stopping distance of a car driving 100+kph and do not leave enough space. YMMV with respect to the laws involved as it's entirely possible you could be at fault at the place you are living.
The rear ender having to pay is just the base case that is used in the absence of other facts.
If you drive "in an asinine manner" (the definition of asinine is subject to discretion and negotiation between the relevant insurance companies) and manage to make the front of someone else's care meet the rear of yours in the process AND there are witnesses, dashcam footage or other evidince you will almost certainly wind up having to pay up.
Everybody knows that traffic doesn't follow the rules. Pretending like it does is a convenient legal fiction we use in order to make rule making easier.
There is intentionally tons of redundancy baked into the rules to cover for all the edge cases where people routinely don't follow the rules. Hence why other people's obligation to not crash into stuff isn't a blank check to do whatever. In cases where two people are breaking the rules usually whoever's breaking them in the more typical and predicable manner is the one given a pass (e.g. someone speeding "a normal amount" will likely not be found at fault if you roll a stop and get t-boned).
Maybe it's different in the states, I'm not up to date with all traffic rules everywhere.
So if autonomous systems hit the brakes much more severely than conditions warrant, it’s not obvious that the drivers behind you are going to have time to react.
Also people commenting here are likely from widely disparate parts of the world with different driving laws. Those differences are more than enough to preclude useful discussion here at the extremes.
So sure - the guy in front of you may have been extremely reckless, but no one involved is even going to want to hear that narrative.
Nobody cares about talk. Everybody lies when they have financial motive to do so and everyone who deals with accidents professionally knows this. That said, insurance companies care deeply about hard to falsify (i.e. anything better than heresay) evidince that show that their customer was not the cause of the loss (dashcam video, surveillance footage, 3rd party witness statements, etc) because the profitability of their business depends in large part on claims payouts.
For other accidents, yes - I've found they want to listen. Rear ending: Not really: They just want to know who was driving the car that rear ended the other car.
I got rear ended once. I spoke to the other party's insurance. Trust me - they didn't want to know why I had gotten hit. It's to their benefit to know, but for them it was an open and shut case. All they wanted to confirm was that it was their insured who had rear ended me.
I have a dashcam, if someone cuts me off and slams on their brakes I may not have time to react. The party in front could be responsible if you can prove it with a video. The insurance company WILL CARE if you have footage.
However, if someone seems to brake no reason, it is on the driver behind to stop.
Where is this place where drivers just magically pay for damages? Where I live in the US, the person who hits you from behind is probably going to back up and just drive away.
https://electrek.co/2022/08/30/tesla-faces-class-action-laws...
https://jalopnik.com/the-honda-cr-v-and-honda-accord-are-bei...
Most other brands seem pretty good. My 2019 Subaru has zero phantom braking events so far. (Although the adaptive cruise control does get confused when driving in the slow lane on freeways and slows down when the car ahead turns onto an offramp.)
Automatic emergency braking changes nothing from a crash liability standpoint. Generally the leading vehicle has the right of way, and the following driver must leave enough space to avoid a crash even if the leading vehicle brakes inappropriately.
Imagine auto braking on black ice or because of a faulty sensor. We're giving immature technology too much control of the vehicle.
I remember back in the day when seatbelts were controversial because someone was thrown free from a car.
We really should work on software reliability.
As for humans, 35,000 Americans die every year on the roads and 6 million accidents occur.
I think we should be able to get software reliable enough to reduce that by 10x
There are almost 2 million rear end collisions in the US every year. Humans just don't have the reaction times to handle many situations. That is also best case. Many people are distracted while driving.
Wrt. black ice, if there's a stopped car in front of you, black ice or no you want to try to stop.
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 where the four corners of the vehicle are - I don't need the computer slamming on the brakes when I am reversing in a tight spot. It feels _more_ dangerous and I fear that one day, my knee-jerk reaction will be to fight the machine (press the gas harder, or get distracted looking at the console which emits lights and sounds every single time auto-brake kicks in) and wind up wrecking with even more force than I might have otherwise.
Also, in traffic, I'll often take my foot off the gas and coast/idle, letting the vehicle slow down naturally. I try to do this instead of braking sometimes as I believe it assists with keeping the flow of traffic predictable for others. Usually this is no problem because I follow the next person at a safe distance.
Sometimes, while decelerating as described above, I will allow the distance between myself and the next car to close, for example, if they're turning and will be gone in a second anyway. The Subaru then ruins my slowdown maneuver by slamming on the brakes because it thinks I'm approaching the vehicle ahead of me too quickly. Well, yes, maybe, but they're also halfway out of the lane already so it's not terribly significant that I'm closing the distance. Another half-second and they'll be gone, restoring my follow distance. (This has only happened once or twice but I imagine it gives the person behind me quite the unnecessary shock.)
I wish there was a way to fine-tune the sensitivity, or at least an option to say "I am an attentive driver, please switch auto-brake to a lower sensitivity level." Currently the only option is to disable it each time the engine starts, which feels wrong to do...
Past that, ACC is a godsend, should be standard everywhere. Lane keep assist also works impressively well (the proactive one that steers for you, there's another "emergency" lane keep system that will haul you back onto the road if you start to veer off, which I've never had the pleasure of using)
Emergency auto-brake is _scary_ though. When it kicks in, the brakes make this horrible grinding sound, and you can tell the vehicle is stopping with all its might. You feel like you've done something wrong even if it's clear that the maneuver was safe.
The lane departure can be slightly more aggressive. It generally works very well, but I have had a few cases where old road lines (think construction zone) caused it to veer into oncoming traffic. It has happened twice. Luckily I keep my hands on the steering wheel and it feels the resistance and submits to my judgement. But for all those people that drive with their knees or text while driving, it could be problematic.
I'm comparing this to a 2020 F-150 Platinum that I had previously. It's automatic braking was awful. It had false alarms constantly. The lane departure was equally horrible. I find it interesting that the article pointed out how specifically terrible pickup trucks are with automatic braking technology and I thought back to my F-150. Since the F150 is the most common truck on the road (actually the most common vehicle in America period), I wonder how much of that statistic is being dragged down by Ford's terrible technology alone. Everyone I know with that on an F150 has turned it off because its so bad.
I think the brand and implementation of this technology is very brand-specific. I have driven my parent's 2021 VW Atlas quite a bit which is equipped with both technologies and it is "fine". Not great and not bad. I've seen a few false alarms already in the shorter amount of time I have been in it. They were constant in the Ford and I have yet to experience one after 12 months of daily driving in the BMW.
Auto brake isn't just for "inattentive" drivers. It's also for self proclaimed "attentive" drivers that can still lose focus at a bad instant.
A turning car can still slam in their brakes when they're not completely out of your lane. Its rare, so your maneuver will be fine most of the time. But sometimes other drivers do unexpected things.
I don't think anyone would complain about these systems if they had all of the context and made good decisions. But it is a problem when either humans or automated systems stand on the brakes based solely on what is in front, without regard for sides or rear.
I do believe these systems are a net win. But they have rough edges that at least cause a lot of near-accidents because they don't behave the way drivers expect each other to.
My car auto-brakes at 5mph for parked cars that are backed into spaces, which I am sure reflects poorly on my driving in some way, if we're adopting the "bad things only happen to bad people" model.
I've also had it activate in normal driving due to someone else doing something dangerous. I'm pretty sure I was on top of those situations but I'm happy the system had my back even if I didn't need it.
> Sometimes, though, I will allow the distance between myself and the next car to close, for example, if they're turning and will be gone in a second anyway. The Subaru then ruins my well-calculated slowdown maneuver by slamming on the brakes because it thinks I'm approaching the vehicle ahead of me too quickly. Well, yes, maybe, but they're also halfway out of the lane already so it's not terribly significant that I'm only one car-length away and still going 40 MPH. Another half-second and they'll be gone, restoring my follow distance.
You really shouldn't be driving like that. You don't know if the car in front of you making that turn is going to brake suddenly, like because, I dunno, they suddenly see a pedestrian crossing on the side street.
Personally, I'm a more reserved (I guess safer?) driver, and I always leave good following distance and brake predictably in order to do so, and I can't say I've had problems with these systems. And I'm 100% in favor of systems that force other drivers on the road to drive more safely as well. Now if only they could prevent tailgating entirely ...
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 actually _need_ the car to do it, by a fairly wide margin.
1-2 car lengths (not in literal units of 15-feet each, I mean one or two _seconds_ of follow distance minimum after accounting for speed/traffic/weather) going the speed limit with my foot off the gas and over the brake, paying attention ready to slow down fast in case of a contingency feels very safe to me. Again, pretty nuanced, this only lasts for a handful of seconds while the lead car completes their maneuver.
The salient point is that I already do what the machine tries to replicate, I don't need my maneuver clobbered by another system.
And I’m a young guy that is working on being a more conservative driver myself - so I’m chuckling to myself just at the idea of me taking this side of the discussion.
But in general, very good commentary on systems that provide useful feedback for the human operator versus ones that don't. ACC makes it clear what a car length should be, and if you're paying attention you can gauge how much more space it leaves when you're moving fast. So that's what I go by.
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 could work out for you fine for 20+ years before one day you get into accident, and presumably blaming the driver who suddenly stopped mid turn.
Check out watchpeopledie or idiotsincars for plenty of videos of what could go wrong. I recall one video of exactly this issue — an idiot SUV stopped mid turn in the middle of a lane, clearly a bad driver. And then another driver t-boned her because he didn’t have enough distance to stop, also cleary partially at fault IMO.
I know people with lifelong pain from minor auto accidents. Don’t have that be you, or cause that for someone else. What do you lose by keeping some more space between you and the next car?
Not just 15 feet, that'd be insane!
Given this confusion, it does seem like it explains the root of the disagreement here, but that said, I don’t think it’s unreasonable for people reading your comment to assume that when you said “car length” you meant the length of a car.
The Subaru's adaptive cruise control system treats car lengths as variable units based on speed. It's much more liberal than I made it sound in the original comment. It sounded reasonable when I wrote it, but infinite nuance strikes again I suppose.
Personally, I find it somewhat confusing, but people should probably be more aware that it's a thing and not necessarily someone mixing up terminology.
Cars in your area are on average 40 feet long?
A car length is about the length of an average car.
Either way, with a 40 foot "car length", 1-2 car lengths is then ~80 feet. The above stopping distance chart puts a 40mph stopping distance with reaction time at almost 140 feet. <80 feet away is driving way too close at 40mph! Especially for a car you know is doing a maneuver which could result in them braking suddenly such as turning into another field of traffic.
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
If you're going 40mph and approaching nearly stopped cars at <80 feet, you're absolutely tailgating people and creating extremely risky situations.
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 better action would have been for me to be going slower and approach that situation with less speed, not to just blame the car for being cautious and forcing realistic safety margins.
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.
Either way, if you are rapidly closing the distance to a car which is changing lanes, you don't know for certain they won't cancel the maneuver and go back to being in the lane. You're still assuming that, and assuming you'll be able to slow or stop fast enough to handle it.
If your AEB is constantly getting "false" alarms, maybe it is not the AEB that needs adjustment. Maybe driving in a fashion where the car's AEB doesn't constantly give "false" alarms would be a lot safer.
Changing lanes is a type of turn because you _turn_ the wheel to change lanes. You also might turn 45 degrees in a roundabout, or 90 degrees at a stoplight. They are all turns.
I'd agree that it's an assumption. Though your assumption that the distance is closed _rapidly_ is also just that - an assumption, and one made in bad faith despite my efforts to correct it.
The mere act of being in a car on the road involves dozens of assumptions made every single minute about the traffic conditions. Very little is known for certain, ALL maneuvers are to some extent based on assumptions.
This conversation is no longer productive, thanks for your participation anyway though.
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)
To me, a car length should simply mean the minimum safe _length_ at which to follow the car in front of you.
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.
Not if taught correctly, which I think it's important to note that we can't really do via textual communication.
In the driver's seat, during a driver's education course, you might learn that a car length is the length of an average car, but you also learn how to count the seconds of stopping distance you have in front of you. In addition, you learn that weather, traffic, and other factors can affect stopping power/distance, the point being that the whole system is incredibly dynamic and variable.
One can't reduce a dynamic traffic situation down to "X car lengths = safe." Similarly, saying "1 car length = a safe distance" doesn't really help either.
The idea is to teach people what "safety" actually looks like. How it's referred to is secondary. The proof is in how badly I was misunderstood when I said 1-2 car lengths. I _know_ I'm keeping enough distance, because I know how to judge a safe traffic situation.
I don't really care what a car length is or isn't, it's fairly irrelevant because safety is a much bigger picture than units of measurement.
I get it. You'd prefer to use the phrase "car length" to not literally mean "length of a car" in this context. Apologies if I seemed pedantic but, as evidenced by this thread, your use of car length is going against the grain.
Safe following distance is often expressed in multiples of car length. What car? Sure, good point. Pick one; it's close enough! (If you're actually thinking about following distance in any terms at all, even roughly estimated, you're ahead of the safety curve and you clearly are!)
Ideally, following distance could be accurately estimated in metres and adjusted continuously by velocity and driving conditions. AI can do that. People just kind of eye it and say, "it was raining and I followed about four car lengths behind him" or "we were inching along and I was half a car length behind him". Good enough for meat brains!
Safe driving!
Not partially at fault; completely and totally at fault (except if we're talking about someone deliberately trying to cause a crash in which case I'll settle for partially). The reality is there could be a hundred reasons the car stopped, the driver being an idiot is only one of them. Mechanical failure, something unseen from the following car, a door flying open, someone stepping out in front of them, a queue in front of them which is not obvious from behind etc.
If you are not leaving enough room to come to a stop when the car in front does then you are riding your luck, there are no two ways about it.
We also need to understand that being at fault isn't 1-to-1 with who was being safe. Typically, if you pull out and get t-boned by someone who has the right of way and is generally following the law, the person being t-boned is at fault for failing to yield. Where a vehicle is impacted plays a huge role in investigators determining who is at fault. Now if you run into the back of the person in front of you, it's almost always your fault, unless the person in front was driving carelessly or recklessly (brake check, for example) but would still involve partial fault in many cases.
So really, we can't say either way without knowing a lot more.
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.
I don't think it's reasonable to prepare for the car in front of you to stop in place as though it had hit a brick wall. Instead, the safe follow distance is derived from the current speed and breaking power of the vehicle I'm operating and the vehichle that's behind me, and the distance to the vehichle behind me.
My driving experience: very rarely have a PCS audible warning when conditions change unexpectedly on the 10 (SoCal). Braking activated once or maybe twice in three years.
His experience: constant “false” alarms from the system, several instances of pedestrians and vehicles “coming out of nowhere” that passenger saw 10+ seconds away, several instances of slamming on the brakes, both machine and human-activated.
Some people just don’t treat driving as the life safety critical activity that it is. Most people.
I’m willing to ignore the false positives when moving very slowly in tight parking spaces. That’s startling and annoying, but doesn’t really bug me too much. I believe you can also turn that off independently of the forward-facing road-speed emergency braking feature (and you need to if you have a trailer or bike rack).
As for false positives while at road speed, I think the actual brakes have only kicked in once or twice, and only very briefly (certainly not enough to slow me down so much that it could cause an accident). It’s a bit more common to get a false positive on the first stage of alert, which in my car is an audible alert and some red LEDs on the primitive heads up display.
The only object warnings I’ve triggered are completely understandable and never had auto braking
A sharp turnning off-ramp to a rest stop on i5 with a sign in the middle that one drives directly at before turning has reliable triggered the object warning but never breaking. I suspect that if I went dangerously/stupidly fast in the turn it would brake.
The other other time I could reliably trigger it was pulling in faster than usual to park head on 1 ft in front of a fence, and that only ever did the warning not braking.
So far, and it’s anecdotal yes, I’ve never had it happen when actually on the road.
What I do find annoying is the cruise control starts to floor it when changing lanes if it sees the clear path down the lane line during the change.
I also agree with the cruise control issue. The adaptive cruise control is very nice for highway traffic that's changing speeds a lot, except that I'll forget that it's set at 65-70 after cruising around 50 for a while, and then when it finds a clear lane it will try to accelerate very quickly. That's ultimately just a limitation in how far ahead the system looks to find cars.
Ug. I'd rather have testing be changed so that safety is increased in all situations by having a competent driver. Most of the situations being described here are simply poor choices on the part of one or more drivers.
For real, who the hell is cutting through lanes of traffic and slamming on brakes because they will miss a turn? Best to remove these people than have them rely on a price of tech to save them in 1 situation but let them continue to be dangerous in another 9 areas.
This follows to taking driving license from them.
You'd have to change USA more than Lincoln and Roosevelt together to remove critical dependency on cars there.
More drivers need to be aware of this one. There's an intersection near me where drivers always tailgate and rush others through the (slightly greater than 90-degree) turn onto a side street, no matter how well the turn has been signaled already. There have been multiple minor accidents, but fortunately no pedestrians have been hit that I know of. When someone's turning, drivers behind need to give them more space not less.
What I can say is what bothers me about it. Can I turn it off? Can toggle on/off switch be disabled by an update? Can I trust that it the off button will do what it is supposed to do? If I can do those things, can I trust this feature to work as advertised? I used to not ask questions like that with cars as there was certain level of.. expectation that this machine has to work in sometimes drastically radical conditions ( especially in some parts of US ).
Cars are software now. But that is not my main beef with it. My beef is that it is built to the detriment of the end user and to strip the user of all control.
I think that's the problem with that attitude and why I don't like my car doing excessive braking. Unlike the distance lidar, I can actually see there's nothing obstructing the turning driver, and I can see their speed of leaving the lane is simply too high for them to stop before leaving the lane even if they slam the brakes. And even if they did somehow manage to break where they are already I'd only need a little swerve to the left to drive around with no traffic there etc
The autobraking isn't getting in your way and you don't need it, it's exactly for you lmao.
Ideally I'd like to have it disabled only when reversing. Between the backup camera, mirrors, and the rear window, the safety systems are already present. The rear bumper really does not need to be triggering emergency brakes imo.
The front bumper though - yeah that one should probably stay on, even if it annoys me sometimes.
My sister got annoyed with the auto-braking on her new Subaru and turned it off. Three days later she rear ended someone, smashing up the whole front of her car. This was the third time she had rear ended someone.
She keeps it on now.
Pretty wild. Seems like license suspension or retraining should be required.
Also the same issue coming up on turning cars that will be gone momentarily. I'm ready to brake if they suddenly stop, but the system freaks the hell out and tries to get me rear-ended.
I am willing to believe that there is a net reduction in crash likelihood because it may save me one time that I would have crashed. But the cost is a constant low-level fear of surprise and terror from normal driving.
At least it's better than the 2014 Audi I had that would slam on the brakes on the freeway if there was a semi trailer going slow one lane to my right. I learned to keep one foot on the gas and ready to floor it when that happened (maybe 5-10 times a year).
I often wonder what advantage in life people think they are gaining by this behaviour. Care to share?
https://www.abi.org.uk/products-and-issues/topics-and-issues...
But please consider that not everything is evidence that everyone else is reckless driver. One day your system will fail in a surprising/dangerous way, and you'll tell someone "wow, it mistook a reflection for tail lights", and they'll say "well I am a perfectly safe driver so that could never happen with my careful driving, you must have been really reckless", and you'll have an epiphany.
Never said or implied that. I said that one specific behavior is dangerous. Maybe you're right that "my system" will fail some day, but in the meantime I'll continue doing my best to improve the odds instead of using "well, stuff happens anyway, can't do anything about it" as an excuse. After driving for ~40 years, having been in a few accidents (only one in the last ~30 and never even remotely considered to be at fault) and seen more, I don't think I'm the one who needs that epiphany here.
BTW, let me go into a bit more detail about that one accident, since it's kind of relevant. I was turning, had signaled, person behind me saw and had tapped the brakes, person behind them was on their phone and plowed right into them, pushing them into me. No injuries, amazingly. Key point: there was nothing the woman in the middle could have done. She would have been struck regardless. If she had "absorbed the slack" as you suggest, her car would have just been slammed into mine even harder - quite likely with more dire consequences. Other times, as I already mentioned in another comment, drivers "absorbing the slack" actually caused accidents themselves at an intersection near me. More than once.
You're relying on your reactions being better than those of the person behind you (if not better than humanly possible), with no justification whatsoever. "Absorbing the slack" is a stupid and dangerous habit that most people who have driven for a while learn to avoid. I'm trying to tell you here so you don't have that epiphany about defensive driving and margins of error too late.
Just that bit from my original comment. The other child comment worded it better than I did though.
1. Forward collision alarm goes off falsely sometimes, but never the actual braking
2. Rear collision braking is usually fine as well, but since it doesn't realize grass/bushes aren't solid it feels a little more intense in those situations.
It really feels like you're just driving recklessly.
These numbers must be wrong, and are terribly unsafe.
Just off the top of my head, that's like travelling 60fps for .5 seconds is 30 feet, which exceeds 1 car length, even for my truck.
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.
Car length may be variable, but is colloquially understood to be 15' give or take, but not more than 20'.
Then again, I've known two people who both proudly proclaimed that they'd never even gotten a ticket before whose driving was so terrifyingly unsafe I wouldn't get into a car with them a second time, so maybe that's my bias.
Most DOTs claim around 1.5s for reaction time, and then up to another 1.5s for braking at typical highway cruising speeds. So, 2-3s follow distance in total. Adjust down for low velocity and up for poor driving conditions.
Your reactions don't correlate in distance (car-lengths), they're measured in time response (seconds).
Always measure your safety buffer in the appropriate metric: time.
Distance is the appropriate metric when you want to keep two objects a minimum distance apart.
Your response is only half the equation, then stopping performance comes into play. So while reactions are measured in seconds, you're converting those into distance traveled.
Measuring in following time is just a convenience for eliminating distance estimation biases. That time will also fluctuate based on the road conditions and vehicle performance.
I've had a Crosstrek since 2018, and it has prevented accidents for me at least 4 times. It can be annoying when someone edges into your lane, or is edging out of your lane (and usually braking), but for every time it autobrakes for that, there's probably a situation where I'm glad it did. I'm sure the tech will just get better over time.
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
When your driving safety system gives you feedback while driving, you have two choices:
- Learn from the system and modify your driving to be safer for yourself and those around you, or
- Ignore the system, describe it as "too sensitive," and disable it.
Before the driving safety system feedback, you might have been an unsafe driver out of ignorance. After the driving safety system feedback, you're choosing to be an unsafe driver willfully.
Sometimes I still trigger it when reversing towards obstacles though. It still prompts an eyeroll and a muttered curse. Not sure if that will ever go away, somebody else mentioned that it tends to treat bushes as solid objects. Not that I'm reversing over top of the bushes, but reversing _towards_ them should not be as big of a problem as the auto-brake would have the driver believe.
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 acceleration or top speed capabilities of a car, traffic calming measures that reduce top speeds are always fought, speed limiters are way out of the overton window, just mentioning automated speed cameras cause aneurysms, ...
People have unhealthy attachment to the brand of driving, the dumb shit that they see on car advertisements.
It's primarily a male ego thing, and it's pathetic and needs to go.
Safety measures that prevent so-called spirited driving should be mandatory on cars: speed limiters, auto-braking, and lane keeping are a good start.
On the other hand a lot of "aggressive" drivers slip up earlier or later. The risk is too high.
Also, looking at a phone is entirely your choice, not a boredom/distraction moment. Listen to audiobooks if your mind needs to do something while driving.
>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.
I'm all for them but properly tested and validated, not the tesla cowboy approach that musk espouses. I fear that he will discredit the idea before we have serious autonomous driving products.
I also drive pretty carefully and provide a ton of space, but others don’t.
Also see Tesla phantom braking.
It isn’t just diesel bros.
Automatic braking has demonstrated the ability to:
- reduce rear-end automobile crashes "in half" (technically 49%)
- reduce Rear-end crashes with injuries by 53%
- vehicles without automatic braking, but with collision warnings only cut accidents by 16% (compared to 49% with automatic braking)
- pickup trucks are less effective at preventing crashes, only preventing 43% of accidents and reducing injuries by 42% (compared to above numbers for other vehicles)
- lane departure systems reduce crashes by 8% and reduce injuries by 7%
- A consortium of 20 auto manufactures have voluntarily committed to offering automatic braking technology to 95% of their light-duty models during the 2023 model year
I can only imagine what driving would be like if the car did indeed autonomously brake in those situations.
Or in situation when I am already breaking ie to full stop hard with enough breaking room and it still pops up the warnings. Sometimes just warnings out of blue, in the middle of an empty road. Me and my family are very happy no automated breaking is integrated into that car, its current state would kill us sooner or later.
Facepalm slap. Seems so obvious once said out loud.
That'd be like a Rodney Brooks inspired actionist strategy, right? Our vehicles as boids, with implicit coordinated action, like flocking, herding, pacing, station keeping, etc.
Maybe a bottom-up emergent behavior strategy has potential. Or a hybrid strategy.
When it comes to AI, FDS, etc. I obviously know nothing about nothing, so please chime in.
It would have, as a separate system, probably saved several of the Tesla drivers who drove directly into obstacles at highway speeds, which for whatever reason a purely optical system will screw up. Similar to how it saves human drivers that rely on sight.
Apparently most drivers don't actually apply the brakes fully when emergency braking, so this helps with that.
https://en.wikipedia.org/wiki/Emergency_brake_assist
They actually recommend to disable the "pre-collision braking" feature before driving through an automated carwash. Apart from that situation, I also disable it when I'm facing highly congested traffic for the reasons indicated in the other comments. It's very easy to do. I don't understand why this is a big deal.
I think the system works very well and has saved me several times over the years while approaching intersections and on the highway.
(and yes the AEB did save me from backing into things at least twice in these years, so I know it works)
Super satisfied with the system otherwise though. Lane keeping and adaptive cruise control are good enough to ease the burden on longer trips but just bad enough that I never "fully" trust them and completely divert my attention.
It's not always safe to keep the huge distances apart at the speeds the system wants (other drivers will cut in). The system can also have a difficult time with motorcycles lane-splitting.
Anyway the way I see this is the switches are there for the driver to use at their discretion. I would hate for the industry to move towards full automation. I love the system as it works right now. Just my two cents.
False positives usually happen when there are cars parked along a turn, but I ignore this completely.
Over the course of the five years I had this car it prevented a collision twice this way.
This way takes away the biggest advantage of this systems - that they can react before you do.
Always false alarms, never in time that I could brake at a time that I wouldn't otherwise, and distracting enough to be a real worry. The only situation I can conceive of it being useful is if the driver is falling asleep on the highway.
What were the situations where yours triggered and actually helped?
Second was the car in front of me hitting the brakes when I was looking in the rearview mirror because both of us wanted to overtake the truck in front of us - that other person in the last moment decided not to do it.
Or perhaps they weren't planning on that and just didn't see the truck - I didn't see them indicate.
Still looking forward to it when I’m older and a bad driver anyway. Can’t wait to have a personal vehicle that takes me everywhere.
They both mis-trigger fairly reliably if I'm in a bend in the road and there is a car or object on the outside of the bend, so it seems that they don't take into consideration that I've turned the wheel, or the steering angle. I've also had total mystery alerts, seemingly from spots or a shovelfull of dirt on the road surface.
OTOH, the distance-keeping cruise control on the Mazda is very good, and I've used it for dozens of miles at a time on country roads, with and without traffic.
These emergency auto-braking systems are clearly not ready for prime-time, except maybe for highway use, which is where they can do the most good anyway. I sure as heck don't want my car to auto-brake in any of the situations I've seen the "Collision alert" triggered. Some would have definitely caused accidents.
The features most related to this article are: FCW, AEB, CAEB, HAEB, and PD. Note that some manufacturers have much better implementations than others, so after you settle on a few models, investigate how good their implementations actually are.
That incident gave pause. If the brakes had engaged, might that have caused a crash?
My Tesla, on the other hand, get's it right about 10% of the time. I wanted to type a higher percentage, but phantom breaking happens so often. The number of times I've seen the red X on the atlas in the entire time owning it is about the number of times the M3 loses its mind on a monthly basis.
The other interesting thing: I could probably write the algorithm for the adaptive cruise control on the Atlas. It's so predictable that I know exactly what it's going to do in reaction to traffic around me. If a car ahead of me slows down, I slow down at a constant rate. If the car speeds up, I know exactly how much it's going to speed up. Same with people changing lanes ahead of me, etc.
The M3 OTOH feels like a buggy machine learning model. I have no idea why it's at the current speed it's at. If I set it to 120KM/H and there's no car in front of me the chances of it being 120KM/H is about 30%. If a car pulls away from and my car should speed up there is no rhyme or reason to when and how quickly it speeds up.
All that being said, I'd still take the Tesla automated braking over nothing at this point. Reading the other posts, it sounds like VW is doing something right.
Side note, that car has astoundingly good brakes.
I wonder about front-to-rear crashes when the struck vehicle has automatic braking when the rear one doesn't.
I worry about people with automatic braking not paying attention and being on their phone and letting the automatic braking keep them from hitting people in front of them, while coming to abrupt stops and getting hit more from behind.