Forum Index Register Members List Events Mark Forums Read Help

 International Skeptics Forum Self-Driving Uber Car Kills Arizona Pedestrian

 Welcome to the International Skeptics Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.
 22nd April 2018, 01:45 AM #601 rjh01 Gentleman of leisure Tagger     Join Date: May 2005 Location: Flying around in the sky Posts: 23,535 Originally Posted by GlennB As has been mentioned, one problem is for vehicles trying to join the motorway. If the convoy is long and a number of cars want to merge then the convoy not only has to split, but it has to split in a number of places. To do this by slowing, the rearmost vehicles creating a gap for merging have to slow more than those creating gaps further forward. It's a cumulative thing. To create (say) 3 gaps in a convoy doing 60mph by slowing by (say) 10mph for x seconds then the rearmost chunk of convoy will be down to 30mph by the time all the merging is done, as will the traffic behind them in that lane. Convoys are a pain in the arse. Better to spread out, allowing some flexibility in spacing and speed to accommodate general maneouvering. This contains an error in logic. The lead vehicle would not change speed at all. If three vehicles joined the convoy by the convoy creating three gaps to allow the vehicles to join the convoy and then reform the single convoy then the end of the process the trailing vehicle would be three vehicles further away from the lead vehicle, which has not changed speed at all. One complication in this is that the trailing vehicles would need to go faster than the leading vehicles for a short time to catch up to the rest of the convoy. Originally Posted by The Great Zaganza The argument from fuel economy is no longer as strong as it once was: energy, especially electric, is no limiting factor anymore: off-peak energy production is plenty-full. Even if energy was free you conveys would be a good idea as a energy saving measure. They would extend the range of a vehicle. Or make it faster to recharge as less electricity would be needed. __________________ https://conservationcouncil.org.au/ https://www.2xxfm.org.au/
 22nd April 2018, 03:24 AM #602 GlennB Loggerheaded, earth-vexing fustilarian     Join Date: Sep 2006 Location: Pie City, Arcadia Posts: 22,408 Originally Posted by rjh01 This contains an error in logic. The lead vehicle would not change speed at all. If three vehicles joined the convoy by the convoy creating three gaps to allow the vehicles to join the convoy and then reform the single convoy then the end of the process the trailing vehicle would be three vehicles further away from the lead vehicle, which has not changed speed at all. One complication in this is that the trailing vehicles would need to go faster than the leading vehicles for a short time to catch up to the rest of the convoy. I didn't suggest the lead vehicle needs to slow down. It doesn't - in fact it would scupper the whole manoeuvre if it did. __________________ "Even a broken clock is right twice a day. 9/11 truth is a clock with no hands." - Beachnut
 22nd April 2018, 03:01 PM #603 arthwollipot Observer of Phenomena     Join Date: Feb 2005 Location: Location, Location Posts: 56,749 Originally Posted by GlennB As has been mentioned, one problem is for vehicles trying to join the motorway. If the convoy is long and a number of cars want to merge then the convoy not only has to split, but it has to split in a number of places. To do this by slowing, the rearmost vehicles creating a gap for merging have to slow more than those creating gaps further forward. It's a cumulative thing. To create (say) 3 gaps in a convoy doing 60mph by slowing by (say) 10mph for x seconds then the rearmost chunk of convoy will be down to 30mph by the time all the merging is done, as will the traffic behind them in that lane. And why would this not be taken into account in the programming? If you've thought of it, surely others have as well. A convoy would intentionally be prepared to divide as needed, whenever needed. An autonomous vehicle, in this admittedly idealised vision of the future, is aware of all the other autonomous vehicles on the road through direct communication, and all non-linked vehicles through 360 degree awareness, and not just those vehicles that are already part of the convoy. Originally Posted by GlennB Convoys are a pain in the arse. Better to spread out, allowing some flexibility in spacing and speed to accommodate general maneouvering. And again, what's to stop the vehicles to be programmed to move in convoy when it is appropriate to do so, and not when it is not? This isn't a problem. At the very least it is a programming issue. Ideally, the software would deep-learn the most efficient and effective safe ways of managing traffic by itself. If a computer can deep-learn how to beat the best human Go players in a week, it can deep-learn traffic management in years. __________________ "This quote was taken out of context." - Randall Munroe
 Yesterday, 12:04 AM #605 GlennB Loggerheaded, earth-vexing fustilarian     Join Date: Sep 2006 Location: Pie City, Arcadia Posts: 22,408 Originally Posted by arthwollipot And why would this not be taken into account in the programming? If you've thought of it, surely others have as well. A convoy would intentionally be prepared to divide as needed, whenever needed. An autonomous vehicle, in this admittedly idealised vision of the future, is aware of all the other autonomous vehicles on the road through direct communication, and all non-linked vehicles through 360 degree awareness, and not just those vehicles that are already part of the convoy. The problem isn't one of programming difficulty or awareness, it's the degree of slowing required. In this (purely theoretical) case the rearmost lorry slows from 60 to 30 in a relatively short time, which can be a problem in heavy traffic. Shockwave traffic jam. __________________ "Even a broken clock is right twice a day. 9/11 truth is a clock with no hands." - Beachnut
 Yesterday, 05:05 AM #606 rjh01 Gentleman of leisure Tagger     Join Date: May 2005 Location: Flying around in the sky Posts: 23,535 Originally Posted by bruto I think you are minimizing the difficulty and unevenness of a convoy opening up "as needed." If a convoy of vehicles is close together, and must separate to allow others to enter, every single member of that convoy behind the opening must immediately slow down to avoid colliding with the one that opens the gap. Unless on-ramp is very very long, this all must either be done well in advance of the event, or the ramp must be very long. And this expansion must be done for every vehicle that enters the line. This would be true no matter how automated the entering vehicles are. By comparison, if the vehicles already on the highway were evenly spaced with a distance between them enough for safe entry at speed, cars could merge into the line easily, the job of anticipation would be much less, and the re-establishment of safe distances could be done with less urgency. A large number of vehicles could alternately merge at a high density intersection and readjustment could be done gradually before the next intersection. If the next intersection is some miles down the road, the adjustment would be barely noticeable, involving slight throttle modulation rather than the fairly drastic moves required of a close convoy in which even the slightest malfunction or mis-coordination could cause a massive pileup. After all, remember that this entire thread begins with the discussion of an automated car that did not stop for a pedestrian. What if it had, and it had been at the head of a long, bumper to bumper convoy? I think this issue of breaking a convoy multiple times to allow other vehicles in is a bit of a waste. If several vehicles are waiting they can join together and act as one. Maybe join at the start or rear of the convoy where it would be lot simpler to do. What would be complex would be when one vehicle wants to leave the convoy. Then there needs to be a split, the vehicle can leave and then the convoy can rejoin. __________________ https://conservationcouncil.org.au/ https://www.2xxfm.org.au/
 Yesterday, 06:00 AM #607 bruto Penultimate Amazing     Join Date: Jun 2005 Location: Way way north of Diddy Wah Diddy Posts: 22,381 Originally Posted by rjh01 I think this issue of breaking a convoy multiple times to allow other vehicles in is a bit of a waste. If several vehicles are waiting they can join together and act as one. Maybe join at the start or rear of the convoy where it would be lot simpler to do. What would be complex would be when one vehicle wants to leave the convoy. Then there needs to be a split, the vehicle can leave and then the convoy can rejoin. Indeed, breaking a convoy mulitiple times is a waste, which is why I suggest it makes the idea a poor one. But now if you presume that a new convoy will join only at the end of the existing one, you have re-invented the rail crossing. A large number of vehicles must, in this scenario, wait for a time until the entire train has crossed, and then join the end. At the next entrance, the wait will be that much longer, since the convoy is now longer. They can't join at the start unless there is either a very long anticipation period programmed in, and only if, at the entrance, a long wait is automatically programmed in so as to make sure that the entering group is large enough to be granted entrance. Leaving such a convoy should, by contrast, be trivially easy, assuming that there is no rule that space be made up instantly. A vehicle exits the group, and vehicles behind briefly add a little bit of speed to close the gap. The gap will, just as in a coupled train, close progressively, and it will take a little time, but it will require very little adjustment - a little stab of the accelerator passed on down the line, with no horrific consequence for a little loss of coordination. Of course it would not actually be so easy in a congested environment, because nearly every place an exiting vehicle will want to go, it will be faced with a traffic jam, as other queues of vehicles wait their turns to join other convoys. If traffic with no spaces between vehicles becomes backed up, exit into a new lane will be impossible. I sincerely urge you, if you are going to advocate this kind of thing, to take a drive on the interstate system, and to do it through a big urban interchange - say on one of the main arterial routes through the American South, where during a busy time the highway is dense with vehicles, and exits occur within a mile or two of each other- and where many of those exits are on to the entrances of other superhighways. Imagine traffic here being arranged into a number of unspaced multi-vehicle trains operating as units. I think the result would be nearly instant gridlock. By contrast, I think a completely automated system might actually work in such an environment if a part of the system is engineered specifically to avoid that very thing and to maintain safe, even spacing between vehicles so as to allow them to act with initial autonomy and subsequent coordination. __________________ I love this world, but not for its answers. (Mary Oliver) Quand il dit "cuic" le moineau croit tout dire. (When he's tweeted the sparrow thinks he's said it all. (Jules Renard)
 Yesterday, 02:52 PM #608 arthwollipot Observer of Phenomena     Join Date: Feb 2005 Location: Location, Location Posts: 56,749 Originally Posted by GlennB The problem isn't one of programming difficulty or awareness, it's the degree of slowing required. In this (purely theoretical) case the rearmost lorry slows from 60 to 30 in a relatively short time, which can be a problem in heavy traffic. Shockwave traffic jam. It's much more of a problem for a human driver than it is for a robot, which after all can draw almost instantly upon a potentially vast database of statistics and models that predict the behaviour of traffic in this and other situations. In short, an autonomous truck will know about the situation and will take steps to anticipate it - either by slowing earlier and more gradually, or more likely by manoeuvring to avoid it entirely well before it occurs. __________________ "This quote was taken out of context." - Randall Munroe
 Yesterday, 02:54 PM #609 arthwollipot Observer of Phenomena     Join Date: Feb 2005 Location: Location, Location Posts: 56,749 I want to point out again that I am speaking of a hypothetical idealistic future. I am not intending to suggest that what I am describing is possible now. I just want to make that very clear. __________________ "This quote was taken out of context." - Randall Munroe
 Yesterday, 03:20 PM #610 bruto Penultimate Amazing     Join Date: Jun 2005 Location: Way way north of Diddy Wah Diddy Posts: 22,381 Originally Posted by arthwollipot I want to point out again that I am speaking of a hypothetical idealistic future. I am not intending to suggest that what I am describing is possible now. I just want to make that very clear. I realize that this is all theoretical and not descriptive of current possibilities. What I believe, though, is that within any reasonable set of conditions your idea of convoys and their operation is actually theoretically impracticable, and that within a somewhat nearer future less hypothetical other arrangements would be more practicable and less likely to result in occasional catastrophic accidents. __________________ I love this world, but not for its answers. (Mary Oliver) Quand il dit "cuic" le moineau croit tout dire. (When he's tweeted the sparrow thinks he's said it all. (Jules Renard)
 Yesterday, 03:33 PM #611 rjh01 Gentleman of leisure Tagger     Join Date: May 2005 Location: Flying around in the sky Posts: 23,535 Originally Posted by bruto By contrast, I think a completely automated system might actually work in such an environment if a part of the system is engineered specifically to avoid that very thing and to maintain safe, even spacing between vehicles so as to allow them to act with initial autonomy and subsequent coordination. Leaving spaces between vehicles would drastically reduce the capacity of a road. Nor do I see the convoys being very long*. So delays in joining the end of one would not be long. *On busy highways cars would be banned. People would travel in buses. So you can replace 40 cars with one standard bus. So the number of lanes this alone saves is huge. Then add in the fact that there is no distance between vehicles then you only need one lane which would be underutilised. __________________ https://conservationcouncil.org.au/ https://www.2xxfm.org.au/
 Yesterday, 05:47 PM #612 bruto Penultimate Amazing     Join Date: Jun 2005 Location: Way way north of Diddy Wah Diddy Posts: 22,381 Originally Posted by rjh01 Leaving spaces between vehicles would drastically reduce the capacity of a road. Nor do I see the convoys being very long*. So delays in joining the end of one would not be long. *On busy highways cars would be banned. People would travel in buses. So you can replace 40 cars with one standard bus. So the number of lanes this alone saves is huge. Then add in the fact that there is no distance between vehicles then you only need one lane which would be underutilised. Of course if you're now speaking of no cars at all it's a different matter, no doubt, and I've been arguing from the start that the idea of simply automating the fleet is silly compared to improving public transit, but that's a different matter from simply banning cars from large areas of the country. But I think you exaggerate the idea of road capacity. The road is a conduit, not a container, and if the convoy is spread out thinner, the difference in arrival time that spacing vehicles makes will be trivial. The longer the distance, the less important the tailgating becomes. If you leave on a long trip and average 60 miles an hour, and I leave on the same trip at the same speed a mile behind you, I'll arrive a minute after you do, even if we drive across the country. If, as originally suggested, the vehicles waiting to join a convoy are appended as a group to the end as it passes by an entrance, the convoy will end up becoming longer with every entrance no matter how short it is at the start. I'm not sure just where all this business is going to take place, either. Will there be separate highways for the cars Let us say, for example, that (as I have many times) I am driving from Vermont to Georgia, a journey that passes through a number of urban areas where traffic becomes very dense, and on and off ramps come quite close together. If cars are banned on such a highway, what happens to through traffic? Does one park at one end, get on the bus, baggage, bicycles, canoe and all, and then find another car at the other end? Who is going to pay for all this? __________________ I love this world, but not for its answers. (Mary Oliver) Quand il dit "cuic" le moineau croit tout dire. (When he's tweeted the sparrow thinks he's said it all. (Jules Renard)
 Yesterday, 05:54 PM #613 crescent Master Poster     Join Date: Jul 2011 Posts: 2,232 I swear reading some years back that much of the very early work with autonomous vehicles was specifically geared towards military convoys. Pack the convoy together bumper to bumper as fast as the road surface allows, ram through a whole bunch of supplies as quickly as possible. Convoy traffic may be one of the simpler issues for self driving, being the first part to have been worked on.
 Yesterday, 07:10 PM #614 bruto Penultimate Amazing     Join Date: Jun 2005 Location: Way way north of Diddy Wah Diddy Posts: 22,381 Originally Posted by crescent I swear reading some years back that much of the very early work with autonomous vehicles was specifically geared towards military convoys. Pack the convoy together bumper to bumper as fast as the road surface allows, ram through a whole bunch of supplies as quickly as possible. Convoy traffic may be one of the simpler issues for self driving, being the first part to have been worked on. I imagine it would work pretty well for military convoys. A human driver at the head could essentially control a huge string of vehicles behind, for example. I'd be sorry to run into that kind of operation on the public highway though. __________________ I love this world, but not for its answers. (Mary Oliver) Quand il dit "cuic" le moineau croit tout dire. (When he's tweeted the sparrow thinks he's said it all. (Jules Renard)
Yesterday, 11:46 PM   #615
GlennB

Join Date: Sep 2006
Posts: 22,408
Originally Posted by arthwollipot
I want to point out again that I am speaking of a hypothetical idealistic future. I am not intending to suggest that what I am describing is possible now. I just want to make that very clear.
Understood, but the technical considerations are still interesting. For example, vehicles will need to 'publish' their intended route even before it becomes physically obvious what route they're taking. The point being that a convoy on the motorway might need to begin slowing even before a vehicle that intends to join the motorway gets onto the entry ramp.

Consider the interchange below, with a vehicle approaching from 12 o'clock. It might be aiming to swing around the gyratory and exit that at 6 o'clock, or peel off and join the motorway at 9 o'clock. If the latter, then the convoy might need to start slowing even before that becomes visually apparent. Technically manageable perhaps, but not in the transition period where AVs are mixed with meat drivers. It adds a layer of technology (therefore expense) that might take decades to be of any real use.
Attached Images
 interchange.jpg (9.1 KB, 12 views)
__________________
"Even a broken clock is right twice a day. 9/11 truth is a clock with no hands." - Beachnut

 Today, 12:18 AM #616 Pixel42 Schrödinger's cat     Join Date: May 2004 Location: Malmesbury, UK Posts: 10,231 One potentially workable possibility is a future in which motorways are reserved for autonomous lorries and coaches, with a car park and bus station at every junction. __________________ "If you trust in yourself ... and believe in your dreams ... and follow your star ... you'll still get beaten by people who spent their time working hard and learning things" - Terry Pratchett
 Today, 12:22 AM #617 rjh01 Gentleman of leisure Tagger     Join Date: May 2005 Location: Flying around in the sky Posts: 23,535 Originally Posted by bruto Of course if you're now speaking of no cars at all it's a different matter, no doubt, and I've been arguing from the start that the idea of simply automating the fleet is silly compared to improving public transit, but that's a different matter from simply banning cars from large areas of the country. But I think you exaggerate the idea of road capacity. The road is a conduit, not a container, and if the convoy is spread out thinner, the difference in arrival time that spacing vehicles makes will be trivial. The longer the distance, the less important the tailgating becomes. If you leave on a long trip and average 60 miles an hour, and I leave on the same trip at the same speed a mile behind you, I'll arrive a minute after you do, even if we drive across the country. If, as originally suggested, the vehicles waiting to join a convoy are appended as a group to the end as it passes by an entrance, the convoy will end up becoming longer with every entrance no matter how short it is at the start. I'm not sure just where all this business is going to take place, either. Will there be separate highways for the cars Let us say, for example, that (as I have many times) I am driving from Vermont to Georgia, a journey that passes through a number of urban areas where traffic becomes very dense, and on and off ramps come quite close together. If cars are banned on such a highway, what happens to through traffic? Does one park at one end, get on the bus, baggage, bicycles, canoe and all, and then find another car at the other end? Who is going to pay for all this? It is one option to take a car or minibus to the highway then catch a bus to wherever. The car or minibus can then go elsewhere. The reverse procedure on the other end. Convoys may not get longer at every intersection. There would be ideally some vehicles leaving there. Unless it is a highway where everyone wants to go from somewhere to one end. This could be true if one end is work or a major sporting event. This sort of thing will take decades to arrive. Will have to redesign entire cities. For example not many people will want garages or driveways. This takes up a significant % of a block of land with one house or even a block of flats. Who pays for it is another question. Not going there. __________________ https://conservationcouncil.org.au/ https://www.2xxfm.org.au/
 Today, 06:07 AM #618 bruto Penultimate Amazing     Join Date: Jun 2005 Location: Way way north of Diddy Wah Diddy Posts: 22,381 Of course if you're heading for a city, having a car park and switching to public transit makes sense, but having the system here described inherently bans through traffic. To design a separate set of highways for through traffic would require, I think, a rather complex set of new highways and rearrangements of old ones. Of course all this stuff is possible in the abstract. All it requires is that everything be redesigned. Different cities, different housing, different ways of life, a different way of getting places, a different idea of ownership, not only of vehicles but of everything else. Get on an interstate highway and look around. Sure, a great many people are just commuting, and could, and probably should, be using public transit. But many are passing through, and a small but significant number are pulling campers, toting bicycles and boats, lawn maintenance trailers, etc. A system that makes it impossible to do this means that one would not only have to give up the individual ownership of cars, but of all those things as well. If you can't get it from one place to another you can't use it. While you're at it, look at the trucks. Sure, a fair number are going to exit into the city, but far more are passing through. That's what interstate highways are for. Trucks cross the entire country. A long convoy may shorten a little from time to time, but it will stay long and will get longer over a distance. Part of the problem now is the lack of good public transit. Somehow the solutions being put forth seem bass-ackwards. Instead of addressing the current problems by improving public transit, they first create new and expensive problems, and then end up solving them by improving public transit. __________________ I love this world, but not for its answers. (Mary Oliver) Quand il dit "cuic" le moineau croit tout dire. (When he's tweeted the sparrow thinks he's said it all. (Jules Renard)

International Skeptics Forum

 Bookmarks Digg del.icio.us StumbleUpon Google Reddit