3 ms·

>we'd be able to see something very special where vehicles would be able to travel at speed while maintaining very small marginal distances Braking distance al

>we'd be able to see something very special where vehicles would be able to travel at speed while maintaining very small marginal distances Braking distance alone (excluding the reaction time) is going to be over 100ft at highway speeds. Considering how often human drivers tailgate AVs will probably have more space between them on average.

computerex 9y ago
Nah. https://link.springer.com/chapter/10.1007/978-3-662-48847-8_16/fulltext.html https://link.springer.com/chapter/10.1007/978-3-662-48847-8_... The following distance for two autonomous vehicles is going to be very small, much smaller than the distance a human can maintain. There is no point in guessing, the above paper is very quantitative. Look at the section titled "effects of autonomous vehicles".
- wcummings 9y ago
  Autonomous vehicles (AV's) might allow for a smaller headway, by removing reaction time, but this benefit will be minimal at higher speeds when cars requires hundreds of feet to stop after the brake has been applied. Reaction time becomes a smaller portion of the headway as speed increases. Most human (American) drivers drive 80 MPH. That means they need 300 or 400ft to stop, without including reaction time (these distances get even higher in poor weather). Most people don't do this, as a result lots of people die, rear-end collisions are extremely common. AV's will need to leave a few hundred feet minimum between cars to operate safely at highway speeds, which is more than most human drivers on a well trafficked road where I live. This is where you see the safety benefits of AV's: conservative driving.
  - deleted 9y ago
    [deleted]
  - computerex 9y ago
    Since you couldn't bother even opening the paper I linked to you, I will post an excerpt from it: This analysis, with the help of the macroscopic traffic flow models, shows that, in principle, a significant increase in capacity can be expected from using autonomous vehicles and that this would also enable a more efficient use of the existing transport infrastructure. Along with the expected increase in capacity for existing traffic infrastructure, traffic jams and lost time are reduced, which in turn improve the quality of traffic flow. In particular, two factors are responsible for the increase in capacity: (a) One factor is the shortening of headways between autonomous vehicles. In this context, it is significant that ride comfort is maintained, despite the short time gaps, by anticipating the actions of the preceding vehicles and thereby enabling lower acceleration or deceleration. This could also be important for column stability. The intercommunication of vehicles and infrastructure appears to be an important prerequisite for this. (b) In addition to the duration of the time gap, the speed of the vehicle group is very important. The higher the speed at a constant density, the higher the traffic volume over a cross section. However, achieving high speeds while maintaining traffic density is possible only in purely autonomous traffic. A single human-driven vehicle in the column would lead to slower speeds and reduce the capacity gain. tldr; fully autonomous traffic allows for the possibility of high density high volume traffic flow.

computerex 9y ago

Nah. https://link.springer.com/chapter/10.1007/978-3-662-48847-8_16/fulltext.html https://link.springer.com/chapter/10.1007/978-3-662-48847-8_... The following distance for two autonomous vehicles is going to be very small, much smaller than the distance a human can maintain. There is no point in guessing, the above paper is very quantitative. Look at the section titled "effects of autonomous vehicles".

wcummings 9y ago
Autonomous vehicles (AV's) might allow for a smaller headway, by removing reaction time, but this benefit will be minimal at higher speeds when cars requires hundreds of feet to stop after the brake has been applied. Reaction time becomes a smaller portion of the headway as speed increases. Most human (American) drivers drive 80 MPH. That means they need 300 or 400ft to stop, without including reaction time (these distances get even higher in poor weather). Most people don't do this, as a result lots of people die, rear-end collisions are extremely common. AV's will need to leave a few hundred feet minimum between cars to operate safely at highway speeds, which is more than most human drivers on a well trafficked road where I live. This is where you see the safety benefits of AV's: conservative driving.
- deleted 9y ago
  [deleted]
- computerex 9y ago
  Since you couldn't bother even opening the paper I linked to you, I will post an excerpt from it: This analysis, with the help of the macroscopic traffic flow models, shows that, in principle, a significant increase in capacity can be expected from using autonomous vehicles and that this would also enable a more efficient use of the existing transport infrastructure. Along with the expected increase in capacity for existing traffic infrastructure, traffic jams and lost time are reduced, which in turn improve the quality of traffic flow. In particular, two factors are responsible for the increase in capacity: (a) One factor is the shortening of headways between autonomous vehicles. In this context, it is significant that ride comfort is maintained, despite the short time gaps, by anticipating the actions of the preceding vehicles and thereby enabling lower acceleration or deceleration. This could also be important for column stability. The intercommunication of vehicles and infrastructure appears to be an important prerequisite for this. (b) In addition to the duration of the time gap, the speed of the vehicle group is very important. The higher the speed at a constant density, the higher the traffic volume over a cross section. However, achieving high speeds while maintaining traffic density is possible only in purely autonomous traffic. A single human-driven vehicle in the column would lead to slower speeds and reduce the capacity gain. tldr; fully autonomous traffic allows for the possibility of high density high volume traffic flow.