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While true, self-driving vehicles should be able to optimize the flow of traffic more efficiently than humans do. There are known methods for improving the flow

by cosmie 9y ago

While true, self-driving vehicles should be able to optimize the flow of traffic more efficiently than humans do. There are known methods for improving the flow of traffic, such as the zipper merge, that are really hard to get humans to do consistently. As well as the cascading effect of different reaction times to going and stopping, delays caused by too aggressive or too conservative lane changing behavior, etc. Once you remove the inconsistent skill level, distractedness, irrationality, and emotional reactions that accompany human drivers, you can increase road utilization considerably without a noticeable increase in congestion.

tempestn 9y ago
That's true, but most of those measures require near 100% adoption, which obviously will lag significantly behind introduction of fully autonomous vehicles. It is possible the reduced need for downtown parking could significantly reduce congestion in cities though.
- adrianN 9y ago
  There is some reason to believe that even a small percentage of "good" drivers can reduce traffic problems such as standing waves on highways: http://trafficwaves.org/trafexp.html http://trafficwaves.org/trafexp.html
- ensignavenger 9y ago
  Lanes dedicated to self driving vehicles could get many of those benefits with relativly low adoption. As adoption increases, more lanes can be dedicated to autonomous mode.
- cosmie 9y ago
  Will it though? A lot of resistance to more efficient driving patterns is due to emotional reactions (or the fear of emotional reactions). The zipper/delayed merge being the quintessential case[1][2][3]. It works better, a lot of people know it works better, and the only argument against it seem to be "it's dangerous because people are irrational assholes and road rage is a thing"[4]. Once you have self-driving cars around, it might break some of those irrational fears and habits. A self-driving car isn't going to get mad at you if you merge late, it's just going to react to your merging and be done with it. So you're no longer the asshole cutting someone off at the last second, you're just another car that's merging at the point where you have to merge. Road etiquette shifts from emotionally driven to pragmatic, since the self-driving cars around you will also be acting pragmatically. It's not going to slam on the gas and brakes to ride the person in front of them in order to be an asshole to the guy next to them trying to "unfairly get ahead", it's going to maintain a safe driving distance and accelerate and decelerate in a controlled manner to optimize for wear and tear, ride smoothness, fuel economy, and maintaining a safe distance. Self-driving cars will not only be better drivers on the whole, but also allow human drivers to break through inhibitions related to "proper road etiquette", since it's a whole lot easier to do something subjectively rude to a machine than a human. [1] http://transportation.ky.gov/zippermerge/Pages/default.aspx http://transportation.ky.gov/zippermerge/Pages/default.aspx [2] https://arstechnica.com/cars/2014/07/the-beauty-of-zipper-merging-or-why-you-should-drive-ruder/ https://arstechnica.com/cars/2014/07/the-beauty-of-zipper-me... [3] https://www.nytimes.com/2016/10/13/us/why-last-second-lane-mergers-are-good-for-traffic.html https://www.nytimes.com/2016/10/13/us/why-last-second-lane-m... [4] http://jalopnik.com/stop-trying-to-make-the-zipper-merge-happen-1785205684 http://jalopnik.com/stop-trying-to-make-the-zipper-merge-hap...
  - hueving 9y ago
    That's a pretty big claim with no evidence. Even if people can easily identify self-driving cars and use that to decide to merge, it may just increase their aggressive driving behavior to the point where they cut off self-driving cars at dangerous times. A cutoff that forces the self-driving car to slam on the brakes will propagate backwards and cause more of the fabled phantom traffic jams.
    - cosmie 9y ago
      It's conjecture, provided as a counterpoint to the conjecture in the parent post about requiring near 100% adoption of autonomous vehicles in order to see the benefits. You're completely right that it could cause an increase in aggressive driving behavior. But it's just as possible that it'll decrease aggressive driving behavior. My conjecture's based off of three personal observations: 1) A lot of the aggressive drivers I know that have road rage-like tendencies take it as a personal affront when another driver does something like turn in front of them or using a less congested lane of traffic to get as far ahead as possible before getting over. 2) One of the most effective strategies I had available as a retail manager to diffuse a situation with an irrational/irate customer was to pass blame on to "the system/corporate policy" if they couldn't see reason. They'd still be irate, but they'd redirect their behavior towards something other than the immediate situation. The same principle applies when you go from blaming a specific driver to blaming "those damn autonomous Nissans. They always <insert some peculiar trait of Nissan's self driving implementation>". 3) Aggressive driving is hard to escalate into full-blown road rage when one participant is a computer. As you said, it'll react to the situation by potentially braking aggressively, but it won't then try to tailgate the individual and escalate the situation. It'll back off appropriately and assure that it's not put into that position again and be done with it. Aggressive drivers will get bored with antagonizing autonomous cars when they get used to them and to the fact that you can't get a rise out of them. As well, autonomous cars can likely get better at identifying indicators/patterns of an aggressive driver and account for that.
    - boznz 9y ago
      At least there will be lots of factual and camera evidence from the self driving car computer to make a case against the arseholes who do this.
saosebastiao 9y ago
> There are known methods for improving the flow of traffic, such as the zipper merge, that are really hard to get humans to do consistently. I know a few traffic engineers and one of the things they regularly laugh about are zipper merge advocates (as well as traffic circle advocates, but that's a discussion for another time). It's not that they don't recommend the zipper merge, it's that the advocates think they are magical and ascribe magical effects to them that don't exist in reality. Want an example of the perfect zipper merge? Look at an hourglass. Thousands of tiny grains of sand perfectly zipper merging at the last instant. And yet there is still a traffic jam. Inflows and outflows still dominate traffic congestion. Now imagine what would happen if you early merged those grains of sand. Your hourglass is now 6 miles tall. Interestingly enough, the early merge is more efficient for flow, but not by enough of a margin (1-2%) to overcome the drawback of the terrible space efficiency. What the zipper merge is really good at isn't improving flow, it is improving space efficiency. The bottleneck uses far less of the highway when people merge last instant. This allows people to reroute or exit the highway before the traffic jam, reducing the burden on the bottleneck. That's it, nothing more. The idea that traffic would suddenly get so much better if people zipper merged perfectly is not rooted in reality...traffic volume is still the more important factor by several fold.
- tempestn 9y ago
  True, but I think you undersell the benefit of this: > This allows people to reroute or exit the highway before the traffic jam, reducing the burden on the bottleneck. Many of those people could have already been intending to exit the highway earlier. Because of the back-up, their journeys are slowed way down unnecessarily. And then you get compounded effects - the highway backs up past another entrance, causing that feeder road to back up past an intersection... In the worst case you end up with gridlock. I'm not arguing that zipper merges are magical either, but they can definitely have a significant impact.
- cosmie 9y ago
  I don't disagree that it's overhyped, it's just the most recognizable example for me to mention. > reducing the burden on the bottleneck. That's it, nothing more. That's precisely it though. By reducing the burden of the bottleneck on the greater traffic network, it localizes the congestion to a smaller area and reduces the disruption the rest of the traffic network has to feel. Overall improving congestion, even if locally the congestion still occurs. > What the zipper merge is really good at isn't improving flow, it is improving space efficiency. This is based on the human execution of a zipper merge. Ideally, the continuing lane of traffic will be going at a consistent speed with enough space between vehicles to allow the merging traffic to merge without causing a disruption in the flow of traffic. Theoretically you'd get this benefit from merging earlier as well, but as you mentioned the space efficiency causes cascading impacts to other aspects of the traffic network. That being said, I only mentioned that as a recognizable example. However, a lot of congestion isn't due to a specific trigger such as a lane ending. It's due to bad human driving habits, and suboptimal human reactions to that behavior. Which create phantom traffic jams[1][2]. Self-driving cars will drive more consistently than human drivers, introducing a level of calm in a sea of inconsistent human reactions. Effectively buffering traffic in a way that will improve overall traffic flow, even before we have majority adoption of self-driving cars. [1] http://topyaps.com/how-traffic-jams-are-created http://topyaps.com/how-traffic-jams-are-created [2] http://imgur.com/gallery/CIhYAiv http://imgur.com/gallery/CIhYAiv
pishpash 9y ago
That's going to be a little bit of optimization on top of a magnitude difference in demand. The overwhelming effect is still more congestion.
deleted 9y ago
[deleted]

by cosmie 9y ago

tempestn 9y ago

That's true, but most of those measures require near 100% adoption, which obviously will lag significantly behind introduction of fully autonomous vehicles. It is possible the reduced need for downtown parking could significantly reduce congestion in cities though.

adrianN 9y ago
There is some reason to believe that even a small percentage of "good" drivers can reduce traffic problems such as standing waves on highways: http://trafficwaves.org/trafexp.html http://trafficwaves.org/trafexp.html
ensignavenger 9y ago
Lanes dedicated to self driving vehicles could get many of those benefits with relativly low adoption. As adoption increases, more lanes can be dedicated to autonomous mode.
cosmie 9y ago
Will it though? A lot of resistance to more efficient driving patterns is due to emotional reactions (or the fear of emotional reactions). The zipper/delayed merge being the quintessential case[1][2][3]. It works better, a lot of people know it works better, and the only argument against it seem to be "it's dangerous because people are irrational assholes and road rage is a thing"[4]. Once you have self-driving cars around, it might break some of those irrational fears and habits. A self-driving car isn't going to get mad at you if you merge late, it's just going to react to your merging and be done with it. So you're no longer the asshole cutting someone off at the last second, you're just another car that's merging at the point where you have to merge. Road etiquette shifts from emotionally driven to pragmatic, since the self-driving cars around you will also be acting pragmatically. It's not going to slam on the gas and brakes to ride the person in front of them in order to be an asshole to the guy next to them trying to "unfairly get ahead", it's going to maintain a safe driving distance and accelerate and decelerate in a controlled manner to optimize for wear and tear, ride smoothness, fuel economy, and maintaining a safe distance. Self-driving cars will not only be better drivers on the whole, but also allow human drivers to break through inhibitions related to "proper road etiquette", since it's a whole lot easier to do something subjectively rude to a machine than a human. [1] http://transportation.ky.gov/zippermerge/Pages/default.aspx http://transportation.ky.gov/zippermerge/Pages/default.aspx [2] https://arstechnica.com/cars/2014/07/the-beauty-of-zipper-merging-or-why-you-should-drive-ruder/ https://arstechnica.com/cars/2014/07/the-beauty-of-zipper-me... [3] https://www.nytimes.com/2016/10/13/us/why-last-second-lane-mergers-are-good-for-traffic.html https://www.nytimes.com/2016/10/13/us/why-last-second-lane-m... [4] http://jalopnik.com/stop-trying-to-make-the-zipper-merge-happen-1785205684 http://jalopnik.com/stop-trying-to-make-the-zipper-merge-hap...
- hueving 9y ago
  That's a pretty big claim with no evidence. Even if people can easily identify self-driving cars and use that to decide to merge, it may just increase their aggressive driving behavior to the point where they cut off self-driving cars at dangerous times. A cutoff that forces the self-driving car to slam on the brakes will propagate backwards and cause more of the fabled phantom traffic jams.
  - cosmie 9y ago
    It's conjecture, provided as a counterpoint to the conjecture in the parent post about requiring near 100% adoption of autonomous vehicles in order to see the benefits. You're completely right that it could cause an increase in aggressive driving behavior. But it's just as possible that it'll decrease aggressive driving behavior. My conjecture's based off of three personal observations: 1) A lot of the aggressive drivers I know that have road rage-like tendencies take it as a personal affront when another driver does something like turn in front of them or using a less congested lane of traffic to get as far ahead as possible before getting over. 2) One of the most effective strategies I had available as a retail manager to diffuse a situation with an irrational/irate customer was to pass blame on to "the system/corporate policy" if they couldn't see reason. They'd still be irate, but they'd redirect their behavior towards something other than the immediate situation. The same principle applies when you go from blaming a specific driver to blaming "those damn autonomous Nissans. They always <insert some peculiar trait of Nissan's self driving implementation>". 3) Aggressive driving is hard to escalate into full-blown road rage when one participant is a computer. As you said, it'll react to the situation by potentially braking aggressively, but it won't then try to tailgate the individual and escalate the situation. It'll back off appropriately and assure that it's not put into that position again and be done with it. Aggressive drivers will get bored with antagonizing autonomous cars when they get used to them and to the fact that you can't get a rise out of them. As well, autonomous cars can likely get better at identifying indicators/patterns of an aggressive driver and account for that.
  - boznz 9y ago
    At least there will be lots of factual and camera evidence from the self driving car computer to make a case against the arseholes who do this.

saosebastiao 9y ago

> There are known methods for improving the flow of traffic, such as the zipper merge, that are really hard to get humans to do consistently. I know a few traffic engineers and one of the things they regularly laugh about are zipper merge advocates (as well as traffic circle advocates, but that's a discussion for another time). It's not that they don't recommend the zipper merge, it's that the advocates think they are magical and ascribe magical effects to them that don't exist in reality. Want an example of the perfect zipper merge? Look at an hourglass. Thousands of tiny grains of sand perfectly zipper merging at the last instant. And yet there is still a traffic jam. Inflows and outflows still dominate traffic congestion. Now imagine what would happen if you early merged those grains of sand. Your hourglass is now 6 miles tall. Interestingly enough, the early merge is more efficient for flow, but not by enough of a margin (1-2%) to overcome the drawback of the terrible space efficiency. What the zipper merge is really good at isn't improving flow, it is improving space efficiency. The bottleneck uses far less of the highway when people merge last instant. This allows people to reroute or exit the highway before the traffic jam, reducing the burden on the bottleneck. That's it, nothing more. The idea that traffic would suddenly get so much better if people zipper merged perfectly is not rooted in reality...traffic volume is still the more important factor by several fold.

tempestn 9y ago
True, but I think you undersell the benefit of this: > This allows people to reroute or exit the highway before the traffic jam, reducing the burden on the bottleneck. Many of those people could have already been intending to exit the highway earlier. Because of the back-up, their journeys are slowed way down unnecessarily. And then you get compounded effects - the highway backs up past another entrance, causing that feeder road to back up past an intersection... In the worst case you end up with gridlock. I'm not arguing that zipper merges are magical either, but they can definitely have a significant impact.
cosmie 9y ago
I don't disagree that it's overhyped, it's just the most recognizable example for me to mention. > reducing the burden on the bottleneck. That's it, nothing more. That's precisely it though. By reducing the burden of the bottleneck on the greater traffic network, it localizes the congestion to a smaller area and reduces the disruption the rest of the traffic network has to feel. Overall improving congestion, even if locally the congestion still occurs. > What the zipper merge is really good at isn't improving flow, it is improving space efficiency. This is based on the human execution of a zipper merge. Ideally, the continuing lane of traffic will be going at a consistent speed with enough space between vehicles to allow the merging traffic to merge without causing a disruption in the flow of traffic. Theoretically you'd get this benefit from merging earlier as well, but as you mentioned the space efficiency causes cascading impacts to other aspects of the traffic network. That being said, I only mentioned that as a recognizable example. However, a lot of congestion isn't due to a specific trigger such as a lane ending. It's due to bad human driving habits, and suboptimal human reactions to that behavior. Which create phantom traffic jams[1][2]. Self-driving cars will drive more consistently than human drivers, introducing a level of calm in a sea of inconsistent human reactions. Effectively buffering traffic in a way that will improve overall traffic flow, even before we have majority adoption of self-driving cars. [1] http://topyaps.com/how-traffic-jams-are-created http://topyaps.com/how-traffic-jams-are-created [2] http://imgur.com/gallery/CIhYAiv http://imgur.com/gallery/CIhYAiv

pishpash 9y ago

That's going to be a little bit of optimization on top of a magnitude difference in demand. The overwhelming effect is still more congestion.

deleted 9y ago

[deleted]