5 ms·

This is it. There is nothing inherent to CV that makes self driving cars unable to operate in snow. Humans already suck massively at it (and in the rain). I re

by zanny 11y ago

This is it. There is nothing inherent to CV that makes self driving cars unable to operate in snow. Humans already suck massively at it (and in the rain). I remember driving home in a massive rainstorm at night about two years ago with around 2 meter visibility and was going like 20mph because I could not see shit. I had less sensory data than a computer with extra vectors of vision beyond sight would have had, and my reaction time is a ton slower. Then a year later I'm driving in icy conditions and count five cars that either off roaded or rear ended each other in the span of 15 minutes because of the slick surfaces. I imagine self driving cars would do a much better job slowing down and budgeting for potential slippage than impatient humans. There is nothing really magical about our eyes that give us better clarity in awful driving conditions, and we don't have radar and GPS fed into our brains to give us a clue where the roads are supposed to be - we just rely on historical context and past driving experience on the same roads. How many hours would it take a networked fleet of self driving vehicles to outdo my historical context for driving on any of the roads I've driven on for a decade? Two? Maybe three? You just need to get the tunable parameters right though some good old genetic algorithm work like what Google is doing now with its test fleet and while it would be impossible to guarantee perfect performance in every scenario (because inevitably an earthquake is going to make a self driving car crash where nobody could have prevented it) it just has to be better than us, and that has almost certainly already happened.

oqnet 11y ago
The biggest thing is that people drive when they shouldn't. Sometimes your car just isn't going to do it. All season tires, 2WD, ice storm. Yeah that's when you see people sliding down hills. There's no traction and no automation is going to fix that. The best thing it will do, no joke, is just not start the car in those conditions. You do see a spike of people who don't do well to adjust to winter driving. They don't give longer gaps, make sure they have more time before crossing intersections than they do. Computers will do that much better, eventually. I can't wait to go to work or drive around the city and not have to worry about someone texting, doing makeup or making poor driving decisions. Have a nap on long trips, watch a movie, finish up some work. I can see computers having an amazing reaction time to some kid running into the street to catch a ball. An animal running in front of you at night. It's going to take awhile though. I wouldn't trust it right now to safely take me anywhere. There are just so many variables that the engineers have to account for. Weather conditions, people conditions, car conditions and on and on. It's nuts.
- ProblemFactory 11y ago
  > The biggest thing is that people drive when they shouldn't. It is extremely common to drive beyond your actual "in complete control" speed. You are supposed to drive slowly enough in snow so that you can correct for unexpected patches of black ice or rocks in the snow slush. You are supposed to leave a long enough gap to be able to react and stop if the car in front of you unexpectedly fully slams on their brakes. You are supposed to drive slowly enough to stop if a kid runs out between parked cars. Humans almost never do, because unexpected things almost never happen. Traffic flows faster and perhaps smoother, because we willingly accept driving at speeds where we can avoid most, but not all hazards. But if we expect self-driving cars to always put safety first, then we will find them to be "tediously" slow, even if they have better sensors and faster reaction speed than us.
  - msellout 11y ago
    I drive at a "correct" following distance. Way back when I took my driving test I was told to allow 1 car length for every 10 MPH speed. So on the highway I leave at least 6 car lengths. I constantly need to tap the brake and back away as a car cuts into the lane. Almost no one on the highway leaves adequate space for human reaction times.
    - sib 11y ago
      I would say that 1 car length / 10 mph is actually a very short following distance. If an average car is 15 feet in length, at 60 mph, that is only 90 feet. At 60 mph, 90 feet of following distance is only 1.02 seconds. (1 mph == 1.4667 fps) When I was taught to drive, we were told that 2 seconds of following distance was appropriate. This just reinforces your point that the typical human driver leaves insufficient following distance.
      - david-given 11y ago
        Some of the roads in the UK have chevrons painted on them at intervals. The idea is that at a normal speed for that road, if you can see two chevrons between you and the car in front, you're leaving the right distance. It's a good idea; the distance is always bigger than you think.
paganel 11y ago
> I remember driving home in a massive rainstorm at night about two years ago with around 2 meter visibility and was going like 20mph because I could not see shit. I'm a relatively new driver (1.5 years or so since taking my license) but this happened to me twice, i.e. catching a rainstorm so big that I could barely see in front of me. In both cases I decided to stop in a refuge on the right-side of the road, waiting for the weather to improve. Sure enough, after about 20 minutes of waiting the rain eased down. What I'm saying is that under some circumstances (like close to no visibility) one should just stop and wait for the external factors to improve.
- david-given 11y ago
  I'd just like to say thank-you for stopping. I have seen drivers barreling down a motorway at 80mph in pouring rain with visibility of under fifty metres. It made my skin crawl.
- danans 11y ago
  It's good that you stopped, but it would be even better to take the nearest exit and wait it out there, because if you are stopped on the side of the road in poor visibility conditions, someone might not see you and before it's too late might hit you if they aren't exactly in the lane, which can happen during poor visibility.
  - freehunter 11y ago
    Completely agree. Though there was one situation where I found everyone had stopped on the freeway and I kept going to an exit. Had I known why they had stopped, I probably would have stopped and gotten out of my car, too. Driving through a massive thunderstorm beside dozens of semi trucks, and all of them suddenly stop all at the same time. I keep going and get to a gas station because being trapped between all these completely stopped trucks made me very nervous. When I got to the gas station, I heard the attendant say that Amtrak had stopped too because of all the tornados blowing through the immediate area. Yikes.
VLM 11y ago
And this is the classic theory vs pragmatism problem in a nutshell. You've done a good job of explaining why humans SHOULD be horrifically bad drivers in theory. There is a slight problem. In practice, in actual measured statistics, we're utterly fantastic drivers despite all the reasoning. We need a baseline. How about trains? Trains in the PTC and semi-PTC era don't (can't) speed and are monitored to crazy 1984 levels, usually there are two employees in the cab (not counting subway type things, I mean real Amtrak here). Trains don't have steering wheels, usually can't spin out, etc. Still the death rate is about 1/2 per billion passenger-miles. What can I say, brakes fail, drivers have heart attacks, rails crack. Its apparently impossible to put squishy humans in a sealed box and toss that box around at 90 MPH without killing about one per two billion miles. Note that's to the moon and back 4000 times, safer than even spacecraft. The death rate for passenger cars is about 7 per billion passenger miles. A little higher for trucks/SUVs, a little lower for cars (cars are safer on the road, more stable). That's only about 14 times worse than trains. Anecdotally human drivers do dumb things, because there's 7 billion people and world wide networks every form of idiocy is known to all, yet simultaneously its very rare. Anecdotally a billion passenger miles isn't very far, so every year we stack bodies like cordwood, sadly. But even on the ultimate in safety, a train, we'd still have 10th the number of dead. By reasoning the ratio should be immensely larger than 14, like 1000 or 1000000. But its 14. That has to be answered... Even crazier to consider is the death rate has dropped by a factor of 3 since the 1970s due to better engineering and regulation. We KNOW how to lower death rates using existing techniques. Yet we also know software written by humans is basically worthless. So given a choice of strategies to further lower death rates, given the track records I'd trust the MechEng and CivEng a lot more than the CS department. A factor of 14 reduction in death rates is unfortunately far more likely to come from the MechEng/CivEng grads than the CS grads, and I say that as a CS grad.
- rfeather 11y ago
  I'm with you up until the software being inherently unsafe bit. I've seen a lot of code I wouldn't trust with anything, let alone my life, but in your own examples: trains are partly safe due to automation, warning systems, etc. and cars have gotten safer at least partly due to things like ABS and traction control which rely heavily on algorithms. However, those are relatively simple systems compared to a self driving car and a lot more "bugs" will likely show up as more AI drives more miles.
jacquesm 11y ago
The problem is that drivers don't know when to not drive. I've driven a relatively large number of kilometers over the years as a non-professional driver and it always amazes me how many people will continue to drive in conditions that are nowhere near safe. The best way to avoid accidents is knowing when not to drive. Nothing you have to do is so urgent that you're willing to risk a detour through the hospital (or the morgue).
Animats 11y ago
"because inevitably an earthquake is going to make a self driving car crash where nobody could have prevented it" Maybe not. On March 11, 2011, a magnitude 8.9 earthquake hit Japan. The first seismometer to detect it (out of 92 in the system) was on Kinkazan Island, just off the eastern coast of Japan. Each seismometer has some compute power and is constantly computing a hazard level based on the waveforms of earth movements. The Kinkazan unit did what it was supposed to, and sent an emergency shutdown signal to the Shinkansen high speed rail system. Not through the signaling system; the circuit breakers at power substations were immediately tripped and power to the trains cut. The trains treat a power cut as an emergency stop situation and apply the brakes hard. All trains stopped safely. [1] http://www.railway-technology.com/features/feature122751/ http://www.railway-technology.com/features/feature122751/
redwall_hp 11y ago
Also, Google never said the cars were incapable of driving on snow. Just that they weren't prioritizing tests and development with that in mind yet. They want to nail typical San Francisco/Mountain View driving before branching out into other road condition types. "Haven't yet attempted" isn't a "cannot."

by zanny 11y ago

oqnet 11y ago

The biggest thing is that people drive when they shouldn't. Sometimes your car just isn't going to do it. All season tires, 2WD, ice storm. Yeah that's when you see people sliding down hills. There's no traction and no automation is going to fix that. The best thing it will do, no joke, is just not start the car in those conditions. You do see a spike of people who don't do well to adjust to winter driving. They don't give longer gaps, make sure they have more time before crossing intersections than they do. Computers will do that much better, eventually. I can't wait to go to work or drive around the city and not have to worry about someone texting, doing makeup or making poor driving decisions. Have a nap on long trips, watch a movie, finish up some work. I can see computers having an amazing reaction time to some kid running into the street to catch a ball. An animal running in front of you at night. It's going to take awhile though. I wouldn't trust it right now to safely take me anywhere. There are just so many variables that the engineers have to account for. Weather conditions, people conditions, car conditions and on and on. It's nuts.

ProblemFactory 11y ago
> The biggest thing is that people drive when they shouldn't. It is extremely common to drive beyond your actual "in complete control" speed. You are supposed to drive slowly enough in snow so that you can correct for unexpected patches of black ice or rocks in the snow slush. You are supposed to leave a long enough gap to be able to react and stop if the car in front of you unexpectedly fully slams on their brakes. You are supposed to drive slowly enough to stop if a kid runs out between parked cars. Humans almost never do, because unexpected things almost never happen. Traffic flows faster and perhaps smoother, because we willingly accept driving at speeds where we can avoid most, but not all hazards. But if we expect self-driving cars to always put safety first, then we will find them to be "tediously" slow, even if they have better sensors and faster reaction speed than us.
- msellout 11y ago
  I drive at a "correct" following distance. Way back when I took my driving test I was told to allow 1 car length for every 10 MPH speed. So on the highway I leave at least 6 car lengths. I constantly need to tap the brake and back away as a car cuts into the lane. Almost no one on the highway leaves adequate space for human reaction times.
  - sib 11y ago
    I would say that 1 car length / 10 mph is actually a very short following distance. If an average car is 15 feet in length, at 60 mph, that is only 90 feet. At 60 mph, 90 feet of following distance is only 1.02 seconds. (1 mph == 1.4667 fps) When I was taught to drive, we were told that 2 seconds of following distance was appropriate. This just reinforces your point that the typical human driver leaves insufficient following distance.
    - david-given 11y ago
      Some of the roads in the UK have chevrons painted on them at intervals. The idea is that at a normal speed for that road, if you can see two chevrons between you and the car in front, you're leaving the right distance. It's a good idea; the distance is always bigger than you think.

paganel 11y ago

> I remember driving home in a massive rainstorm at night about two years ago with around 2 meter visibility and was going like 20mph because I could not see shit. I'm a relatively new driver (1.5 years or so since taking my license) but this happened to me twice, i.e. catching a rainstorm so big that I could barely see in front of me. In both cases I decided to stop in a refuge on the right-side of the road, waiting for the weather to improve. Sure enough, after about 20 minutes of waiting the rain eased down. What I'm saying is that under some circumstances (like close to no visibility) one should just stop and wait for the external factors to improve.

david-given 11y ago
I'd just like to say thank-you for stopping. I have seen drivers barreling down a motorway at 80mph in pouring rain with visibility of under fifty metres. It made my skin crawl.
danans 11y ago
It's good that you stopped, but it would be even better to take the nearest exit and wait it out there, because if you are stopped on the side of the road in poor visibility conditions, someone might not see you and before it's too late might hit you if they aren't exactly in the lane, which can happen during poor visibility.
- freehunter 11y ago
  Completely agree. Though there was one situation where I found everyone had stopped on the freeway and I kept going to an exit. Had I known why they had stopped, I probably would have stopped and gotten out of my car, too. Driving through a massive thunderstorm beside dozens of semi trucks, and all of them suddenly stop all at the same time. I keep going and get to a gas station because being trapped between all these completely stopped trucks made me very nervous. When I got to the gas station, I heard the attendant say that Amtrak had stopped too because of all the tornados blowing through the immediate area. Yikes.

VLM 11y ago

And this is the classic theory vs pragmatism problem in a nutshell. You've done a good job of explaining why humans SHOULD be horrifically bad drivers in theory. There is a slight problem. In practice, in actual measured statistics, we're utterly fantastic drivers despite all the reasoning. We need a baseline. How about trains? Trains in the PTC and semi-PTC era don't (can't) speed and are monitored to crazy 1984 levels, usually there are two employees in the cab (not counting subway type things, I mean real Amtrak here). Trains don't have steering wheels, usually can't spin out, etc. Still the death rate is about 1/2 per billion passenger-miles. What can I say, brakes fail, drivers have heart attacks, rails crack. Its apparently impossible to put squishy humans in a sealed box and toss that box around at 90 MPH without killing about one per two billion miles. Note that's to the moon and back 4000 times, safer than even spacecraft. The death rate for passenger cars is about 7 per billion passenger miles. A little higher for trucks/SUVs, a little lower for cars (cars are safer on the road, more stable). That's only about 14 times worse than trains. Anecdotally human drivers do dumb things, because there's 7 billion people and world wide networks every form of idiocy is known to all, yet simultaneously its very rare. Anecdotally a billion passenger miles isn't very far, so every year we stack bodies like cordwood, sadly. But even on the ultimate in safety, a train, we'd still have 10th the number of dead. By reasoning the ratio should be immensely larger than 14, like 1000 or 1000000. But its 14. That has to be answered... Even crazier to consider is the death rate has dropped by a factor of 3 since the 1970s due to better engineering and regulation. We KNOW how to lower death rates using existing techniques. Yet we also know software written by humans is basically worthless. So given a choice of strategies to further lower death rates, given the track records I'd trust the MechEng and CivEng a lot more than the CS department. A factor of 14 reduction in death rates is unfortunately far more likely to come from the MechEng/CivEng grads than the CS grads, and I say that as a CS grad.

rfeather 11y ago
I'm with you up until the software being inherently unsafe bit. I've seen a lot of code I wouldn't trust with anything, let alone my life, but in your own examples: trains are partly safe due to automation, warning systems, etc. and cars have gotten safer at least partly due to things like ABS and traction control which rely heavily on algorithms. However, those are relatively simple systems compared to a self driving car and a lot more "bugs" will likely show up as more AI drives more miles.

jacquesm 11y ago

The problem is that drivers don't know when to not drive. I've driven a relatively large number of kilometers over the years as a non-professional driver and it always amazes me how many people will continue to drive in conditions that are nowhere near safe. The best way to avoid accidents is knowing when not to drive. Nothing you have to do is so urgent that you're willing to risk a detour through the hospital (or the morgue).

Animats 11y ago

"because inevitably an earthquake is going to make a self driving car crash where nobody could have prevented it" Maybe not. On March 11, 2011, a magnitude 8.9 earthquake hit Japan. The first seismometer to detect it (out of 92 in the system) was on Kinkazan Island, just off the eastern coast of Japan. Each seismometer has some compute power and is constantly computing a hazard level based on the waveforms of earth movements. The Kinkazan unit did what it was supposed to, and sent an emergency shutdown signal to the Shinkansen high speed rail system. Not through the signaling system; the circuit breakers at power substations were immediately tripped and power to the trains cut. The trains treat a power cut as an emergency stop situation and apply the brakes hard. All trains stopped safely. [1] http://www.railway-technology.com/features/feature122751/ http://www.railway-technology.com/features/feature122751/

redwall_hp 11y ago

Also, Google never said the cars were incapable of driving on snow. Just that they weren't prioritizing tests and development with that in mind yet. They want to nail typical San Francisco/Mountain View driving before branching out into other road condition types. "Haven't yet attempted" isn't a "cannot."