3 ms·

I actually agree with your question, but allow me to play devil’s advocate, perhaps. We only have 1 side of this story - that a few people have been surprised

by dahart 5y ago

I actually agree with your question, but allow me to play devil’s advocate, perhaps. We only have 1 side of this story - that a few people have been surprised and had accidents. We don’t have the stats on how many people the active braking has saved from a collision. (BTW I have a CRV, and have experienced sudden braking myself, both with and without something in front of me, but it hasn’t caused an accident yet.) ABS is a computer between the brake and the physics, and there’s widespread agreement about the benefits of this arrangement. So maybe the problem isn’t the computer, or the idea to use them in the loop. Maybe the problem is an incomplete understanding of people, or maybe it’s just a sensor defect or manufacturing issue. (Which, I would agree, absolutely should be considered when plugging things into a computer controller.) We have lots of computers in the physics loop, and very few of them give any of us pause. ECUs are standard these days and are critical to fuel efficiency and reducing environmental impact. Self driving cars are on the way and are a whole new level of computer control. I think I’m still in favor of self-driving cars and the potential they have to reduce traffic, collisions, and environmental impact...

bob1029 5y ago
Impact is the key function in my mind. Assume you are traveling down the 405 at 80mph during rush hour. What is the worst case scenario for an ABS failure mode? What is the worst case scenario for an emergency braking failure mode?
- dahart 5y ago
  > Assume you are traveling down the 405 at 80mph during rush hour. Okay, bad driving choice there. You are 1.5x more likely to die in a collision driving 80mph than if you were driving the speed limit (65mph), since collision energy is proportional to velocity squared. ;) Worst case for ABS failure vs emergency braking failure? Seems like both can easily result in death, and I don’t see reasons yet to believe one is more likely than the other. We probably have a lot more data on the number of deaths lack of ABS has caused over the years than computer braking systems, and the good news is that we can fix computer braking systems right now and forever. The big difference here is control, not outcome. Having brakes seize suddenly is surprising, whereas going from static to dynamic friction when slamming on the brakes isn’t very surprising. Of course we strive to minimize surprise, and of course it’s preferable if cars don’t slam on the brakes without cause.
joey_bob 5y ago
> We don’t have the stats on how many people the active braking has saved from a collision. In the article, there were several links at the bottom with stats on the impact on Volvo cars in the US: https://www.iihs.org/topics/bibliography/ref/2111 https://www.iihs.org/topics/bibliography/ref/2111. The stats aren't directly equivalent, but I think it helps to support your argument.

by dahart 5y ago

bob1029 5y ago

Impact is the key function in my mind. Assume you are traveling down the 405 at 80mph during rush hour. What is the worst case scenario for an ABS failure mode? What is the worst case scenario for an emergency braking failure mode?

dahart 5y ago
> Assume you are traveling down the 405 at 80mph during rush hour. Okay, bad driving choice there. You are 1.5x more likely to die in a collision driving 80mph than if you were driving the speed limit (65mph), since collision energy is proportional to velocity squared. ;) Worst case for ABS failure vs emergency braking failure? Seems like both can easily result in death, and I don’t see reasons yet to believe one is more likely than the other. We probably have a lot more data on the number of deaths lack of ABS has caused over the years than computer braking systems, and the good news is that we can fix computer braking systems right now and forever. The big difference here is control, not outcome. Having brakes seize suddenly is surprising, whereas going from static to dynamic friction when slamming on the brakes isn’t very surprising. Of course we strive to minimize surprise, and of course it’s preferable if cars don’t slam on the brakes without cause.

joey_bob 5y ago

> We don’t have the stats on how many people the active braking has saved from a collision. In the article, there were several links at the bottom with stats on the impact on Volvo cars in the US: https://www.iihs.org/topics/bibliography/ref/2111 https://www.iihs.org/topics/bibliography/ref/2111. The stats aren't directly equivalent, but I think it helps to support your argument.