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Automatic braking doesn't get much attention, but it seems like something that could be incredibly valuable if it got to the "clearly better than human" level.

by lacker 5y ago

Automatic braking doesn't get much attention, but it seems like something that could be incredibly valuable if it got to the "clearly better than human" level. This is purely anecdotal, but I find the automatic braking system on my Mazda CX-9 to be fairly annoying. Once every couple months or so, it has a false alarm and brakes while blaring out alerts, in an urban environment where I don't observe anything out of the ordinary at all. And it's never activated in a situation where I found it to be helpful. That said, it's possible that an annoyance every two months is just the cost of a system that really would help me if I got into bigger trouble. It's hard to say from purely my own anecdotes.

ajross 5y ago
> Automatic braking doesn't get much attention, but it seems like something that could be incredibly valuable if it got to the "clearly better than human" level. It's important to point out here that a handful of back of the envelope analyses are out there that show that Tesla's autopilot is already "clearly better than human" level at avoiding emergency vehicles. These are very common accidents. Emergency vehicles in travel lanes get hit all the time, crews are carefully trained to avoid that situation if at all practical, and taught how to reduce personal risk when that's not possible. In fact (and I don't have a link handy) if you extrapolate out from a few different data sources it looks like Tesla's on AP get in these crashes about half as much as vehicles in the general fleet. Now, that doesn't mean that these 13 events don't constitute a cluster worth investigating. And it doesn't mean that there can't be a bug worth fixing. It doesn't even mean that the media shouldn't write about it. It does mean that we should be very careful with pronouncements about safety from a sample set of this size, though.
- lacker 5y ago
  I think the problem here is calling something "better than human" because it manages to avoid some accidents. If a car avoids one accident for every 100,000 times it intervenes, that isn't really a good thing. It just means that drivers start to ignore flashing lights and warnings because they are always meaningless. Maybe it even causes some accidents by distracting the driver, and they don't get categorized as "caused by the automatic braking system" because nothing really tracks that. Every time I start my car, about 15 seconds into the drive a popup appears on the screen, saying something like "Warning: automated driving assistance system can cause distraction. Select OK to dismiss". Thanks, you have reduced your own liability in exchange for further distracting the driver.
- syrrim 5y ago
  >In fact (and I don't have a link handy) if you extrapolate out from a few different data sources it looks like Tesla's on AP get in these crashes about half as much as vehicles in the general fleet. Why use that as a comparison? The obvious confounder would be that people would disable autopilot in poor conditions, making such crashes a priori more likely. The relevant comparison would be Teslas (with and without AP) against a similar class of cars, maybe BMWs.
  - ajross 5y ago
    That's nitpicking. There's an initial contention: "Teslas hit emergency vehicles frequently", and a simple refutation: "No, they don't, here are some numbers[1]". Your response only makes it "not impossible" that the initial contention is correct, but you have to show numbers to prove that. All we have is a cluster of 13 accidents over 3-4 years, and there are something like thousands of such accidents in the US every year. That's not proof that this is noise and not signal, but the obvious hypothesis is that it's probably noise[2] [1] Which I don't have, though I suppose I could track it down. [2] For the record: I believe it's probably a real bug, but in a product that on the whole is clearly better, so it's well hidden in the noise.
    - syrrim 5y ago
      The initial contention was that tesla's autopilot was superior to humans, at a specific task. If this were true, it would be very interesting, and represent real progress in the self driving space. Thus I'm interested in whether it's true, and proposed a method by which that might actually be determined.
- emn13 5y ago
  What's the source for this claim? Are you accounting for the fact different classes of vehicle have differing accident statistics (e.g. comparing teslas to similarly old and expensive alternatives), and that autopilot's miles are not a random sample of all driven miles?
  - ajross 5y ago
    No, because it's enough that it exists as an existence proof refuting the hypothesis. The burden is on people contending that e.g. AP can't stop for emergency vehicles (or the related point in the linked article that emergency braking doesn't work) to show that it is unsafe. That analysis doesn't hold for obvious interpretations of the data we have. That doesn't mean it's wrong, it means you need to come to the table with more work. It's not enough to argue with me on HN.
    - emn13 5y ago
      If you're merely questioning whether Tesla's really do crash into emergency vehicles more often that would be expected, I get it. But "Tesla's on AP get in these crashes about half as much as vehicles in the general fleet" is unsupported; even in Tesla's own figures from https://www.tesla.com/VehicleSafetyReport https://www.tesla.com/VehicleSafetyReport the difference between AP and non-AP Tesla's isn't large enough (for me anyhow) to actually draw any conclusions from, since AP usage is obviously correlated with road conditions. To be clear: I'm not saying it's at all obvious that AP does worse than a human driver, but it's neither is that possibility ruled out by anything they've posted there - Tesla simply choose to present statistics without the context required to interpret them, likely because it suits their marketing aims. News at 11. The human instinct to retain control even when that's not to their advantage gives me the hunch that it's more plausible that the apparent numerical benefits of AP are simply due to selection bias; people turn it on in situations that are less messy, and therefore it's involved in fewer accidents. Perhaps these investigations will reveal more. Put it this way: if autopilot actually were better than a human driver, and humans choose to use it in less dangerous situations, and those drivers at least sometimes pay enough attention to catch the occasional AP oversight (better isn't perfect!) - well, then I'd expect the AP crash numbers to be dramatically lower than the human crash numbers. They're not. I do think the Tesla AP numbers look less bad than they did a few years ago anyhow, to be fair. I just don't think it paints a clear picture yet.
jacquesm 5y ago
The one on my 2016 C-class Mercedes was so bad that it almost caused two accidents. If not for years of pingpong... I got rid of it after having it checked out and declared healthy, if that system wasn't broken it might as well be. Worse than useless. Don't get a MB with automatic emergency braking unless you want to covertly commit suicide.
- dazbradbury 5y ago
  "The one on my 2016 C-class Mercedes was so bad that it almost caused two accidents. If not for years of pingpong..." Care to elaborate? Both how it nearly caused an accident, and how you avoided one seem interesting!
  - jacquesm 5y ago
    There were two instances that were particularly memorable, the first was when passing through a steel bridge with fairly narrow spacing, the car - without any warning - slammed on the brakes just as I was passing the entrance to the bridge. The road surface was wet from recent rain and the car immediately started to spin due to uneven grip. I managed to avoid the posts :) This happened once more in the same spot but then I was already more alert to this kind of nonsense so that time it was pretty uneventful even if the car - again - slammed on the brakes. The other situation was when in a tight right hand turn a large advertising sign caused the car to believe I was about to have a head on collision (when in fact the object was merely passing right-to-left through my field of view). This caused me to end up on the wrong side of the road, if there had been opposing traffic it would have been a head on collision, exactly the thing it was trying to avoid. I brought the car to the local dealership, they checked it over and pronounced it sound, I sold it a week later. Murderous beta grade - or not even beta grade, proof of concept - software in that car. I was pretty loyal to the brand but I don't think I'll ever have another one, besides the plastic bling interior the fact that they shipped that junk has made the brand worthless to me. Now I drive a 24 year old car that was re-built end-to-end. It has an ECU, ABS, an aftermarket mp3 player / navigation combo and that's it.
    - deleted 5y ago
seoaeu 5y ago
How would you define "clearly better than human" for a driver assist technology? Like if 'driver + automatic breaking' gets into fewer crashes than 'driver', is that a success? What if the assist is constantly doing phantom breaking, but never hits anything?
- lacker 5y ago
  If it's a lot fewer crashes, and phantom braking happens rarely, that would be pretty strong evidence. After some brief looking around the internet, I didn't really find any good evidence, or any weak evidence, it seems like we don't really know. I wouldn't be surprised if some of these systems perform far better than others and the general lack of data and transparency makes it hard to figure out whether they are better than human, or not, or it's a mix.
tidbits 5y ago
Toyota's safety sense system has saved me from minor accidents a few times. It has never auto applied the brakes, but the alarms and brake assist have been really helpful on freeways during abrupt stops. My girlfriend, on the other hand, hates her Honda's auto braking system, as it triggers too easily, even on the lowest setting. I've seen it regularly trigger when pulling up to sensor controlled gates.
- browningstreet 5y ago
  I have a Toyota and my auto-braking alarm thing has only gone off a few times... all very clearly my fault for losing attention for a brief moment. To be honest, I have no idea if it's gone into applying-brake-mode. I'm guessing yes, but... it hasn't been often nor can I even remember really what happened. I do know that it prevented crashes, whether it applied the brakes or alerted/scared me into doing so. There has never, ever been a false alarm though. Not even once.
29083011397778 5y ago
Just as another point of reference, my (2021) Mazda 3 AEB has only ever activated when another driver stopped short in front of me. I believe it's configurable in settings, though your experience may be worse due to environmental concerns (bugs, rain, dust), different model year, or simply being a bigger vehicle (with a different bumper height or more mass requiring more time to stop).
brokenmachine 5y ago
What happens when the auto braking engages? Does it just slam the brakes on and stop dead? Wouldn't that be a big risk of you getting rear ended by someone behind you (especially if it's a false alarm)?
- kbos87 5y ago
  Yes, it goes into full anti-lock braking, but it only does this at the very last possible second it can be done without a collision - the driver usually gets enough time hearing an audible alarm to stop, provided there is enough time. I haven’t heard of any rear end accidents due to false alarms with AEB, though that doesn’t mean they don’t exist. I’d guess the system is tuned to need enough confidence that a forward collision is likely to engage braking, knowing of the potential consequences of suddenly and dramatically stopping.
- willcipriano 5y ago
  In my Passat it just barely taps the brakes rapidly to get your attention, I've never had it go further then that but in theory it will lock them up if you don't respond. If it detects someone in the lane you are about to merge into, it cuts off the power steering for a millisecond, just long enough for you to notice the car in your blind spot but not long enough to prevent you from going into the lane if you really want to. It's pretty close to perfect in my opinion.
- SkyPuncher 5y ago
  Depends on the vehicle. My 2014 Chevy pretensions the brakes, but doesn't apply meaningful force. My 2021 Hyundai alerts and pretensions as well. The two situations it's come on, I've been aware of the situation and actively moving to brake. Had I not actually applied braking, I believe the vehicle would have in my place. I somewhat suspect AEB on the Hyundai will lead to a collision, but at a significantly reduced speed. In other words, a fender bender instead of mangled mess.
kbos87 5y ago
Automatic Emergency Braking is amazing and it never gets talked about. I’ve logged 40k miles in my 2019 Subaru with Eyesight and it very reliably notices dangerous situations. Other vehicles hard stopping in front of me is the most common occurrence, and it always hits that sweet spot of me being glad it alerted me so I could brake before it had to. I’ve had one instance where it went straight to braking - I took a right turn at low speed onto a neighborhood street and encountered a cyclist in my lane coming quickly and directly towards me, about 20 feet away. The car stopped itself. It was jarring but I wouldn’t say it was an overreaction. I can only think of 1-2 cases where it’s truly given a false alarm - both at low speed on a city street with thick steam coming from a manhole in front of me, which Subaru says in the manual is a difficult situation. Both times I only got a momentary audible alarm; tap the brakes and it stops. The reliability of AEB definitely varies by manufacturer, but I’m impressed by it.
- rameshs 5y ago
  Second this. Really impressed with Subaru's eyesight system. No false alarms till date. Twice in 3 years it alarmed when cars were turning in front of me and it was too close for the car to stay comfortable but i would have been okay with it. 3 times it has saved me from frontal crash at highway speeds by applying AEB.
- SkyPuncher 5y ago
  I have a Hyundai with a similar system. In urban highway traffic, I've found it exceptionally good at reacting to drivers going from "barely braking" to "stopping hard" before I can physically react. Pretty incredible system.
- fingerlocks 5y ago
  > Other vehicles hard stopping in front of me is the most common occurrence Wow, is mine defective? I have the same vehicle. My most common occurrence is backing out of my steep driveway at faster than 1 mph. We made a habit of disabling it as soon as we start the engine. The second most common occurrence is driving past the narrow neighborhood roundabouts everywhere in Seattle.
MichaelZuo 5y ago
It’s really the type of safety system consumers cannot reliably judge from first hand experiences since preventing a near accident will never be as vivid or memorable of an experience as it malfunctioning and nearly causing an accident.
gmac 5y ago
My 2018 SEAT (VW group tech) has twice saved me from an expensive mistake by slamming on the brakes rather than reverse into an obstacle. The first time I'd only had the car a couple of days and had accidentally engaged reverse when I thought I was in first (the previous car had a different gear layout). Another couple of times it's squeaked at me at low speed for no obvious reason. On balance, I'm extremely pleased with it.

by lacker 5y ago

ajross 5y ago

> Automatic braking doesn't get much attention, but it seems like something that could be incredibly valuable if it got to the "clearly better than human" level. It's important to point out here that a handful of back of the envelope analyses are out there that show that Tesla's autopilot is already "clearly better than human" level at avoiding emergency vehicles. These are very common accidents. Emergency vehicles in travel lanes get hit all the time, crews are carefully trained to avoid that situation if at all practical, and taught how to reduce personal risk when that's not possible. In fact (and I don't have a link handy) if you extrapolate out from a few different data sources it looks like Tesla's on AP get in these crashes about half as much as vehicles in the general fleet. Now, that doesn't mean that these 13 events don't constitute a cluster worth investigating. And it doesn't mean that there can't be a bug worth fixing. It doesn't even mean that the media shouldn't write about it. It does mean that we should be very careful with pronouncements about safety from a sample set of this size, though.

lacker 5y ago
I think the problem here is calling something "better than human" because it manages to avoid some accidents. If a car avoids one accident for every 100,000 times it intervenes, that isn't really a good thing. It just means that drivers start to ignore flashing lights and warnings because they are always meaningless. Maybe it even causes some accidents by distracting the driver, and they don't get categorized as "caused by the automatic braking system" because nothing really tracks that. Every time I start my car, about 15 seconds into the drive a popup appears on the screen, saying something like "Warning: automated driving assistance system can cause distraction. Select OK to dismiss". Thanks, you have reduced your own liability in exchange for further distracting the driver.
syrrim 5y ago
>In fact (and I don't have a link handy) if you extrapolate out from a few different data sources it looks like Tesla's on AP get in these crashes about half as much as vehicles in the general fleet. Why use that as a comparison? The obvious confounder would be that people would disable autopilot in poor conditions, making such crashes a priori more likely. The relevant comparison would be Teslas (with and without AP) against a similar class of cars, maybe BMWs.
- ajross 5y ago
  That's nitpicking. There's an initial contention: "Teslas hit emergency vehicles frequently", and a simple refutation: "No, they don't, here are some numbers[1]". Your response only makes it "not impossible" that the initial contention is correct, but you have to show numbers to prove that. All we have is a cluster of 13 accidents over 3-4 years, and there are something like thousands of such accidents in the US every year. That's not proof that this is noise and not signal, but the obvious hypothesis is that it's probably noise[2] [1] Which I don't have, though I suppose I could track it down. [2] For the record: I believe it's probably a real bug, but in a product that on the whole is clearly better, so it's well hidden in the noise.
  - syrrim 5y ago
    The initial contention was that tesla's autopilot was superior to humans, at a specific task. If this were true, it would be very interesting, and represent real progress in the self driving space. Thus I'm interested in whether it's true, and proposed a method by which that might actually be determined.
emn13 5y ago
What's the source for this claim? Are you accounting for the fact different classes of vehicle have differing accident statistics (e.g. comparing teslas to similarly old and expensive alternatives), and that autopilot's miles are not a random sample of all driven miles?
- ajross 5y ago
  No, because it's enough that it exists as an existence proof refuting the hypothesis. The burden is on people contending that e.g. AP can't stop for emergency vehicles (or the related point in the linked article that emergency braking doesn't work) to show that it is unsafe. That analysis doesn't hold for obvious interpretations of the data we have. That doesn't mean it's wrong, it means you need to come to the table with more work. It's not enough to argue with me on HN.
  - emn13 5y ago
    If you're merely questioning whether Tesla's really do crash into emergency vehicles more often that would be expected, I get it. But "Tesla's on AP get in these crashes about half as much as vehicles in the general fleet" is unsupported; even in Tesla's own figures from https://www.tesla.com/VehicleSafetyReport https://www.tesla.com/VehicleSafetyReport the difference between AP and non-AP Tesla's isn't large enough (for me anyhow) to actually draw any conclusions from, since AP usage is obviously correlated with road conditions. To be clear: I'm not saying it's at all obvious that AP does worse than a human driver, but it's neither is that possibility ruled out by anything they've posted there - Tesla simply choose to present statistics without the context required to interpret them, likely because it suits their marketing aims. News at 11. The human instinct to retain control even when that's not to their advantage gives me the hunch that it's more plausible that the apparent numerical benefits of AP are simply due to selection bias; people turn it on in situations that are less messy, and therefore it's involved in fewer accidents. Perhaps these investigations will reveal more. Put it this way: if autopilot actually were better than a human driver, and humans choose to use it in less dangerous situations, and those drivers at least sometimes pay enough attention to catch the occasional AP oversight (better isn't perfect!) - well, then I'd expect the AP crash numbers to be dramatically lower than the human crash numbers. They're not. I do think the Tesla AP numbers look less bad than they did a few years ago anyhow, to be fair. I just don't think it paints a clear picture yet.

jacquesm 5y ago

The one on my 2016 C-class Mercedes was so bad that it almost caused two accidents. If not for years of pingpong... I got rid of it after having it checked out and declared healthy, if that system wasn't broken it might as well be. Worse than useless. Don't get a MB with automatic emergency braking unless you want to covertly commit suicide.

dazbradbury 5y ago
"The one on my 2016 C-class Mercedes was so bad that it almost caused two accidents. If not for years of pingpong..." Care to elaborate? Both how it nearly caused an accident, and how you avoided one seem interesting!
- jacquesm 5y ago
  There were two instances that were particularly memorable, the first was when passing through a steel bridge with fairly narrow spacing, the car - without any warning - slammed on the brakes just as I was passing the entrance to the bridge. The road surface was wet from recent rain and the car immediately started to spin due to uneven grip. I managed to avoid the posts :) This happened once more in the same spot but then I was already more alert to this kind of nonsense so that time it was pretty uneventful even if the car - again - slammed on the brakes. The other situation was when in a tight right hand turn a large advertising sign caused the car to believe I was about to have a head on collision (when in fact the object was merely passing right-to-left through my field of view). This caused me to end up on the wrong side of the road, if there had been opposing traffic it would have been a head on collision, exactly the thing it was trying to avoid. I brought the car to the local dealership, they checked it over and pronounced it sound, I sold it a week later. Murderous beta grade - or not even beta grade, proof of concept - software in that car. I was pretty loyal to the brand but I don't think I'll ever have another one, besides the plastic bling interior the fact that they shipped that junk has made the brand worthless to me. Now I drive a 24 year old car that was re-built end-to-end. It has an ECU, ABS, an aftermarket mp3 player / navigation combo and that's it.
  - deleted 5y ago

seoaeu 5y ago

How would you define "clearly better than human" for a driver assist technology? Like if 'driver + automatic breaking' gets into fewer crashes than 'driver', is that a success? What if the assist is constantly doing phantom breaking, but never hits anything?

lacker 5y ago
If it's a lot fewer crashes, and phantom braking happens rarely, that would be pretty strong evidence. After some brief looking around the internet, I didn't really find any good evidence, or any weak evidence, it seems like we don't really know. I wouldn't be surprised if some of these systems perform far better than others and the general lack of data and transparency makes it hard to figure out whether they are better than human, or not, or it's a mix.

tidbits 5y ago

Toyota's safety sense system has saved me from minor accidents a few times. It has never auto applied the brakes, but the alarms and brake assist have been really helpful on freeways during abrupt stops. My girlfriend, on the other hand, hates her Honda's auto braking system, as it triggers too easily, even on the lowest setting. I've seen it regularly trigger when pulling up to sensor controlled gates.

browningstreet 5y ago
I have a Toyota and my auto-braking alarm thing has only gone off a few times... all very clearly my fault for losing attention for a brief moment. To be honest, I have no idea if it's gone into applying-brake-mode. I'm guessing yes, but... it hasn't been often nor can I even remember really what happened. I do know that it prevented crashes, whether it applied the brakes or alerted/scared me into doing so. There has never, ever been a false alarm though. Not even once.

29083011397778 5y ago

Just as another point of reference, my (2021) Mazda 3 AEB has only ever activated when another driver stopped short in front of me. I believe it's configurable in settings, though your experience may be worse due to environmental concerns (bugs, rain, dust), different model year, or simply being a bigger vehicle (with a different bumper height or more mass requiring more time to stop).

brokenmachine 5y ago

What happens when the auto braking engages? Does it just slam the brakes on and stop dead? Wouldn't that be a big risk of you getting rear ended by someone behind you (especially if it's a false alarm)?

kbos87 5y ago
Yes, it goes into full anti-lock braking, but it only does this at the very last possible second it can be done without a collision - the driver usually gets enough time hearing an audible alarm to stop, provided there is enough time. I haven’t heard of any rear end accidents due to false alarms with AEB, though that doesn’t mean they don’t exist. I’d guess the system is tuned to need enough confidence that a forward collision is likely to engage braking, knowing of the potential consequences of suddenly and dramatically stopping.
willcipriano 5y ago
In my Passat it just barely taps the brakes rapidly to get your attention, I've never had it go further then that but in theory it will lock them up if you don't respond. If it detects someone in the lane you are about to merge into, it cuts off the power steering for a millisecond, just long enough for you to notice the car in your blind spot but not long enough to prevent you from going into the lane if you really want to. It's pretty close to perfect in my opinion.
SkyPuncher 5y ago
Depends on the vehicle. My 2014 Chevy pretensions the brakes, but doesn't apply meaningful force. My 2021 Hyundai alerts and pretensions as well. The two situations it's come on, I've been aware of the situation and actively moving to brake. Had I not actually applied braking, I believe the vehicle would have in my place. I somewhat suspect AEB on the Hyundai will lead to a collision, but at a significantly reduced speed. In other words, a fender bender instead of mangled mess.

kbos87 5y ago

Automatic Emergency Braking is amazing and it never gets talked about. I’ve logged 40k miles in my 2019 Subaru with Eyesight and it very reliably notices dangerous situations. Other vehicles hard stopping in front of me is the most common occurrence, and it always hits that sweet spot of me being glad it alerted me so I could brake before it had to. I’ve had one instance where it went straight to braking - I took a right turn at low speed onto a neighborhood street and encountered a cyclist in my lane coming quickly and directly towards me, about 20 feet away. The car stopped itself. It was jarring but I wouldn’t say it was an overreaction. I can only think of 1-2 cases where it’s truly given a false alarm - both at low speed on a city street with thick steam coming from a manhole in front of me, which Subaru says in the manual is a difficult situation. Both times I only got a momentary audible alarm; tap the brakes and it stops. The reliability of AEB definitely varies by manufacturer, but I’m impressed by it.

rameshs 5y ago
Second this. Really impressed with Subaru's eyesight system. No false alarms till date. Twice in 3 years it alarmed when cars were turning in front of me and it was too close for the car to stay comfortable but i would have been okay with it. 3 times it has saved me from frontal crash at highway speeds by applying AEB.
SkyPuncher 5y ago
I have a Hyundai with a similar system. In urban highway traffic, I've found it exceptionally good at reacting to drivers going from "barely braking" to "stopping hard" before I can physically react. Pretty incredible system.
fingerlocks 5y ago
> Other vehicles hard stopping in front of me is the most common occurrence Wow, is mine defective? I have the same vehicle. My most common occurrence is backing out of my steep driveway at faster than 1 mph. We made a habit of disabling it as soon as we start the engine. The second most common occurrence is driving past the narrow neighborhood roundabouts everywhere in Seattle.

MichaelZuo 5y ago

It’s really the type of safety system consumers cannot reliably judge from first hand experiences since preventing a near accident will never be as vivid or memorable of an experience as it malfunctioning and nearly causing an accident.

gmac 5y ago

My 2018 SEAT (VW group tech) has twice saved me from an expensive mistake by slamming on the brakes rather than reverse into an obstacle. The first time I'd only had the car a couple of days and had accidentally engaged reverse when I thought I was in first (the previous car had a different gear layout). Another couple of times it's squeaked at me at low speed for no obvious reason. On balance, I'm extremely pleased with it.