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This is sad, but it's worth noting that even with a human driver, a car that stops suddenly is not responsible for any subsequent rear end collision(s). The col

This is sad, but it's worth noting that even with a human driver, a car that stops suddenly is not responsible for any subsequent rear end collision(s). The colliding driver has the responsibility to keep a safe stopping distance at all times.

dazc 5y ago
Speaking from the UK, if you leave a safe stopping distance on a motorway then, invariably, the gap will be filled quickly with another car. The willingness of so-called intelligent beings to needlessly risk their lives (and the lives of those around them) for no gain whatsoever is truly astounding.
- lotsofpulp 5y ago
  If people drove such that they had enough stopping distance to come to a full stop on highway at 65+mph, traffic would get backed up very quickly. Road capacity is a function of number of lanes, the velocity of the vehicles traveling in those lanes, and the density of the vehicles traveling in those lanes. If you reduce the latter, you reduce road capacity. Theoretically, everyone would be safer if they drove far enough back from the front of the car to come to be able to come to a full stop. Practically, the political uproar of enforcing this would be untenable, but I would be entertained to see the forthcoming overpopulation vs pave over all the land with roads vs mass transit vs variable rate tolling conversations that ensue.
  - susodapop 5y ago
    I’m dubious that the equation is so simple. > Road capacity is a function of number of lanes, the velocity of the vehicles traveling in those lanes, and the density of the vehicles traveling in those lanes. If you reduce the latter, you reduce road capacity. And yet study after study shows that increasing the number of traffic lanes only worsens congestion.
    - lotsofpulp 5y ago
      https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand If you have 10 cars wanting to use a stretch of road capable of carrying 10 cars at 8AM at speed X with the safest distance gaps, and you add 10 more cars, then there will be some combination of congestion behind this stretch of road, the distance gaps getting smaller, or cars driving faster now that there are 20 cars. If you add a lane so that 20 cars can travel at the safest driving distance gaps at 8AM at speed X, but this then causes 10 more cars to come on the road because they see the possibility of using a road that is maybe just under maximum capacity, then you now have 30 cars on a 20 capacity road, and once again you end up with previous situation as 20 cars on a 10 car capacity road. Obviously these things are impossible to exactly predict and constantly in flux and so engineers and politicians and drivers are all crudely estimating the shifts of supply and demand curves, and the overestimating and underestimating will cause congestion, or complaints of excess road, etc.
  - dazc 5y ago
    You are correct but I'm afraid this is not an excuse to drive at speed 2cm from the rear bumper of the car in front of you. I should add this my near daily experience driving to my office in a rural area at 5am when there is just me and a random car behind me. With 2 miles or more of empty road behind him.
    - lotsofpulp 5y ago
      > You are correct but I'm afraid this is not an excuse to drive at speed 2cm from the rear bumper of the car in front of you. I anticipated this response, hence I tried to pre empt it by making my first qualifier that I am not talking about tailgating 2cm from the car in front. > If people drove such that they had enough stopping distance to come to a full stop on highway at 65+mph, This qualifying statement was supposed to convey that the theoretical safest distance to travel behind someone at 65mph, 75mph, or more is so big that I would not expect it to be followed anytime other than the dead of night.
      - dazc 5y ago
        You are correct, again, but please consider that in order to avoid killing or seriously injuring someone in a road accident you don't need to come to an absolute stop. You can actually avoid a collision at moderate speed by simply giving your brain time to react to events happening in front of you. And, even if you do hit something, doing so at a moderately low speed may not turn out so bad?
        lotsofpulp 5y ago
        For sure, I keep as much space in front of me as possible to avoid touching the car in front. I just do not expect everyone else to.
  - tremon 5y ago
    Multiple studies in The Netherlands have shown that decreasing the speed limit during rush hour increases the road throughput. So this isn't the simple equation you try to paint, there is a nonlinear interplay between the average velocity, the variance of the velocity, and the vehicle/lane density.
    - lotsofpulp 5y ago
      That will work up to a point, but I would bet there are many situations where the amount of cars that want to be on the same piece of road at the same time overwhelms those kinds of measures. And with the same result since congestion force everyone’s speed to be lower anyway. I can think of quite a few chokepoints in the US (Manhattan/SF-San Jose/LA/Seattle/Austin) where no matter what you do, the crush of cars will be too much for the roads that exist. In these cases though, I think public transit is the only real solution, but that is a different topic.
- Handytinge 5y ago
  > Speaking from the UK, if you leave a safe stopping distance on a motorway then, invariably, the gap will be filled quickly with another car. Absolutely correct. It is then your responsibility to put a safe stopping distance between yourself and _that_ car. You are in a death machine surrounded by other death machines. Sometimes you have to choose the less convinent option.
alpaca128 5y ago
Where I live that's only true if the stop was warranted. Whether the human driver or an assistance system is the cause is not relevant.
ravishi 5y ago
But isn't that the whole point? What's "safe stopping distance"? Enough to react to the vehicle in front of you slamming the breaks at what speed? It all changes based on road visibility, if there are turns, if there are other cars, etc. It's completely different to drive behind a vehicle going at 100 km/h on a empty, well maintained (yeah, 3rd world where I live has this variable too), straight, ascending, dry road; vs behind a sinuous route downhill on a mountain, with less lanes, under some weather condition, etc. If a car in front of me SLAMS the breaks in the first scenario, I'm certainly not responsible for not being 3km away from him. In the second? Totally different. "Safe stopping distance" is not a fixed number. And I doubt any car can properly calculate that because there's just too much context to be accounted for.
- xoa 5y ago
  >What's "safe stopping distance"? At least 2-3 seconds, minimum. Did you not take any driver's ed classes? >Enough to react to the vehicle in front of you slamming the breaks at what speed? Time, not speed. It will take the average person around 1.5 seconds to react, and a car at least a second to break. Time is not hard regardless of distance, you can see when somebody in front of you passes literally anything, a sign, a tree, a rock, a road market, whatever, then just count. FFS. >If a car in front of me SLAMS the breaks in the first scenario, I'm certainly not responsible for not being 3km away from him Not responsible for being 3000m away? Sure. ABSOLUTELY RESPONSIBLE for not being 50-80m way? Yes. Both legally and morally. Maintaining at least 2-3 seconds of distance just isn't a big fucking ask. And yes that's just as true if it's an "empty, well maintained" road, well why the fuck are you tailgating in that case? Shit happens. Animals suddenly leap across the road, a pothole has opened up, someone has collapsed in weird places etc. I literally was walking with a friend along an empty straight road in a rural area a few weeks ago and they suddenly just blacked out while walking and collapsed directly into the road. Scared the crap out of me. They'd had a pulmonary embolism not too long ago and their lung function was badly affected and while they're trying to build back up sometimes they just... black out. And if you're in a car you won't see someone lying down until you're fairly close. Low probability event? Absolutely. But over hundreds of millions of people it happens. People sometimes need to stop as fast as possible. It is in every single way your job not to rear end them if they do. Period.
TeeWEE 5y ago
Actually stopping on the highway is not allowed in the Netherlands. So no, you're wrong.
- tom_ 5y ago
  Same in the UK. Nevertheless, I have encountered stationary traffic on many occasions anyway, and I've had to use the brakes to bring my car to a halt as well.
lukepothier 5y ago
This isn't how driving works in practice. Suddenly stopping on a fast freeway isn't a reasonable thing to do unless it's absolutely necessary, and it's not reasonable to expect the following driver to constantly be considering the possibility that the driver in front will slam on the brakes for no reason. Insurance companies (at least in some parts of the world) have a standing agreement to just hold the following driver responsible when there's a collision like this, because in the majority of these collisions, the following driver is at fault. It's efficient for them to agree to this convention to avoid the cost of investigating each collision individually. This has led to the common misconception that the following car is necessarily responsible if there is a front-to-rear collision.
- tasha0663 5y ago
  > it's not reasonable to expect the following driver to constantly be considering the possibility that the driver in front will slam on the brakes for no reason. It's totally reasonable. It's not hard to maintain a safe following distance. Sudden braking isn't the only reason to do so, and insurance claims aren't the only motivating factor. You drive defensively so as to reduce the likelihood of death and destruction while making life easier for other drivers.
  - tremon 5y ago
    It's not hard to maintain a safe following distance. So if a car swerves into your lane 10 meters in front of you, then slams on the brakes, you're at fault because it should have been so easy to maintain a safe following distance? (This isn't hypothetical, I've had this exact scenario happen multiple times -- on/off ramps seem to bring out the worst in some drivers).
    - frumper 5y ago
      I don't think anyone is saying what you're suggesting. If you're following a car and they stop, you should be able to stop as well. If a car pulls in front of you and slams on your brakes then that is quite a different scenario.
justin66 5y ago
Not entirely true. Some states in the United States have "brake checking" traffic laws, and others that do not have such laws can issue a citation for reckless driving in a case of brake checking. Like a lot of "road rage" stuff it probably goes underreported and under-prosecuted. (brake checking is going to be a lot easier to prove in the near future when cars are littered with cameras) Neither would seem to apply to an automated system that randomly stomps on the brakes. I would think a system like that might affect fault on the civil, rather than criminal, side, however. For example, it would seem a bit mad for the insurance companies not to blame the vehicle whose screwy brakes caused a multi-car accident.

dazc 5y ago

Speaking from the UK, if you leave a safe stopping distance on a motorway then, invariably, the gap will be filled quickly with another car. The willingness of so-called intelligent beings to needlessly risk their lives (and the lives of those around them) for no gain whatsoever is truly astounding.

lotsofpulp 5y ago
If people drove such that they had enough stopping distance to come to a full stop on highway at 65+mph, traffic would get backed up very quickly. Road capacity is a function of number of lanes, the velocity of the vehicles traveling in those lanes, and the density of the vehicles traveling in those lanes. If you reduce the latter, you reduce road capacity. Theoretically, everyone would be safer if they drove far enough back from the front of the car to come to be able to come to a full stop. Practically, the political uproar of enforcing this would be untenable, but I would be entertained to see the forthcoming overpopulation vs pave over all the land with roads vs mass transit vs variable rate tolling conversations that ensue.
- susodapop 5y ago
  I’m dubious that the equation is so simple. > Road capacity is a function of number of lanes, the velocity of the vehicles traveling in those lanes, and the density of the vehicles traveling in those lanes. If you reduce the latter, you reduce road capacity. And yet study after study shows that increasing the number of traffic lanes only worsens congestion.
  - lotsofpulp 5y ago
    https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand If you have 10 cars wanting to use a stretch of road capable of carrying 10 cars at 8AM at speed X with the safest distance gaps, and you add 10 more cars, then there will be some combination of congestion behind this stretch of road, the distance gaps getting smaller, or cars driving faster now that there are 20 cars. If you add a lane so that 20 cars can travel at the safest driving distance gaps at 8AM at speed X, but this then causes 10 more cars to come on the road because they see the possibility of using a road that is maybe just under maximum capacity, then you now have 30 cars on a 20 capacity road, and once again you end up with previous situation as 20 cars on a 10 car capacity road. Obviously these things are impossible to exactly predict and constantly in flux and so engineers and politicians and drivers are all crudely estimating the shifts of supply and demand curves, and the overestimating and underestimating will cause congestion, or complaints of excess road, etc.
- dazc 5y ago
  You are correct but I'm afraid this is not an excuse to drive at speed 2cm from the rear bumper of the car in front of you. I should add this my near daily experience driving to my office in a rural area at 5am when there is just me and a random car behind me. With 2 miles or more of empty road behind him.
  - lotsofpulp 5y ago
    > You are correct but I'm afraid this is not an excuse to drive at speed 2cm from the rear bumper of the car in front of you. I anticipated this response, hence I tried to pre empt it by making my first qualifier that I am not talking about tailgating 2cm from the car in front. > If people drove such that they had enough stopping distance to come to a full stop on highway at 65+mph, This qualifying statement was supposed to convey that the theoretical safest distance to travel behind someone at 65mph, 75mph, or more is so big that I would not expect it to be followed anytime other than the dead of night.
    - dazc 5y ago
      You are correct, again, but please consider that in order to avoid killing or seriously injuring someone in a road accident you don't need to come to an absolute stop. You can actually avoid a collision at moderate speed by simply giving your brain time to react to events happening in front of you. And, even if you do hit something, doing so at a moderately low speed may not turn out so bad?
      - lotsofpulp 5y ago
        For sure, I keep as much space in front of me as possible to avoid touching the car in front. I just do not expect everyone else to.
- tremon 5y ago
  Multiple studies in The Netherlands have shown that decreasing the speed limit during rush hour increases the road throughput. So this isn't the simple equation you try to paint, there is a nonlinear interplay between the average velocity, the variance of the velocity, and the vehicle/lane density.
  - lotsofpulp 5y ago
    That will work up to a point, but I would bet there are many situations where the amount of cars that want to be on the same piece of road at the same time overwhelms those kinds of measures. And with the same result since congestion force everyone’s speed to be lower anyway. I can think of quite a few chokepoints in the US (Manhattan/SF-San Jose/LA/Seattle/Austin) where no matter what you do, the crush of cars will be too much for the roads that exist. In these cases though, I think public transit is the only real solution, but that is a different topic.
Handytinge 5y ago
> Speaking from the UK, if you leave a safe stopping distance on a motorway then, invariably, the gap will be filled quickly with another car. Absolutely correct. It is then your responsibility to put a safe stopping distance between yourself and _that_ car. You are in a death machine surrounded by other death machines. Sometimes you have to choose the less convinent option.

alpaca128 5y ago

Where I live that's only true if the stop was warranted. Whether the human driver or an assistance system is the cause is not relevant.

ravishi 5y ago

But isn't that the whole point? What's "safe stopping distance"? Enough to react to the vehicle in front of you slamming the breaks at what speed? It all changes based on road visibility, if there are turns, if there are other cars, etc. It's completely different to drive behind a vehicle going at 100 km/h on a empty, well maintained (yeah, 3rd world where I live has this variable too), straight, ascending, dry road; vs behind a sinuous route downhill on a mountain, with less lanes, under some weather condition, etc. If a car in front of me SLAMS the breaks in the first scenario, I'm certainly not responsible for not being 3km away from him. In the second? Totally different. "Safe stopping distance" is not a fixed number. And I doubt any car can properly calculate that because there's just too much context to be accounted for.

xoa 5y ago
>What's "safe stopping distance"? At least 2-3 seconds, minimum. Did you not take any driver's ed classes? >Enough to react to the vehicle in front of you slamming the breaks at what speed? Time, not speed. It will take the average person around 1.5 seconds to react, and a car at least a second to break. Time is not hard regardless of distance, you can see when somebody in front of you passes literally anything, a sign, a tree, a rock, a road market, whatever, then just count. FFS. >If a car in front of me SLAMS the breaks in the first scenario, I'm certainly not responsible for not being 3km away from him Not responsible for being 3000m away? Sure. ABSOLUTELY RESPONSIBLE for not being 50-80m way? Yes. Both legally and morally. Maintaining at least 2-3 seconds of distance just isn't a big fucking ask. And yes that's just as true if it's an "empty, well maintained" road, well why the fuck are you tailgating in that case? Shit happens. Animals suddenly leap across the road, a pothole has opened up, someone has collapsed in weird places etc. I literally was walking with a friend along an empty straight road in a rural area a few weeks ago and they suddenly just blacked out while walking and collapsed directly into the road. Scared the crap out of me. They'd had a pulmonary embolism not too long ago and their lung function was badly affected and while they're trying to build back up sometimes they just... black out. And if you're in a car you won't see someone lying down until you're fairly close. Low probability event? Absolutely. But over hundreds of millions of people it happens. People sometimes need to stop as fast as possible. It is in every single way your job not to rear end them if they do. Period.

TeeWEE 5y ago

Actually stopping on the highway is not allowed in the Netherlands. So no, you're wrong.

tom_ 5y ago
Same in the UK. Nevertheless, I have encountered stationary traffic on many occasions anyway, and I've had to use the brakes to bring my car to a halt as well.

lukepothier 5y ago

This isn't how driving works in practice. Suddenly stopping on a fast freeway isn't a reasonable thing to do unless it's absolutely necessary, and it's not reasonable to expect the following driver to constantly be considering the possibility that the driver in front will slam on the brakes for no reason. Insurance companies (at least in some parts of the world) have a standing agreement to just hold the following driver responsible when there's a collision like this, because in the majority of these collisions, the following driver is at fault. It's efficient for them to agree to this convention to avoid the cost of investigating each collision individually. This has led to the common misconception that the following car is necessarily responsible if there is a front-to-rear collision.

tasha0663 5y ago
> it's not reasonable to expect the following driver to constantly be considering the possibility that the driver in front will slam on the brakes for no reason. It's totally reasonable. It's not hard to maintain a safe following distance. Sudden braking isn't the only reason to do so, and insurance claims aren't the only motivating factor. You drive defensively so as to reduce the likelihood of death and destruction while making life easier for other drivers.
- tremon 5y ago
  It's not hard to maintain a safe following distance. So if a car swerves into your lane 10 meters in front of you, then slams on the brakes, you're at fault because it should have been so easy to maintain a safe following distance? (This isn't hypothetical, I've had this exact scenario happen multiple times -- on/off ramps seem to bring out the worst in some drivers).
  - frumper 5y ago
    I don't think anyone is saying what you're suggesting. If you're following a car and they stop, you should be able to stop as well. If a car pulls in front of you and slams on your brakes then that is quite a different scenario.

justin66 5y ago

Not entirely true. Some states in the United States have "brake checking" traffic laws, and others that do not have such laws can issue a citation for reckless driving in a case of brake checking. Like a lot of "road rage" stuff it probably goes underreported and under-prosecuted. (brake checking is going to be a lot easier to prove in the near future when cars are littered with cameras) Neither would seem to apply to an automated system that randomly stomps on the brakes. I would think a system like that might affect fault on the civil, rather than criminal, side, however. For example, it would seem a bit mad for the insurance companies not to blame the vehicle whose screwy brakes caused a multi-car accident.