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Old 16th April 2018, 11:11 AM   #561
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Originally Posted by shuttlt View Post
One would have to do the maths of course, but I wonder whether there would be any point in doing this, given the fuel cost of slowing down and catching up again. On UK motorways this would be happening every few minutes. Maybe the need to do this would be an upper bound on the length.

I agree/ It wouldn't take much to eliminate any fuel savings benefits gained from 'drafting'. But traditionally there have been other reasons.

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Old 16th April 2018, 01:42 PM   #562
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As you have correctly surmised, I haven't done the math on whether it would be economical or not. I was merely arguing that it would be possible.
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Old 16th April 2018, 03:34 PM   #563
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Originally Posted by shuttlt View Post
One would have to do the maths of course, but I wonder whether there would be any point in doing this, given the fuel cost of slowing down and catching up again. On UK motorways this would be happening every few minutes. Maybe the need to do this would be an upper bound on the length.
Aren’t convoys illegal in most countries, mostly due to traffic impedance concerns caused by a long “block” of trucks. They would interfere with other vehicles trying to enter and exit high/freeways and to me sound like they would cause a number of road safety issues.
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Old 17th April 2018, 01:12 AM   #564
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Originally Posted by EHocking View Post
Aren’t convoys illegal in most countries, mostly due to traffic impedance concerns caused by a long “block” of trucks. They would interfere with other vehicles trying to enter and exit high/freeways and to me sound like they would cause a number of road safety issues.
I do not see the problem with trying to enter a road when there is a convoy of trucks. They would be highly visible so the other cars would know to wait. In fact it could improve things as the convoy of trucks would take up far less room than trucks travelling independently so increasing the capacity of the highway.
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Old 17th April 2018, 01:26 AM   #565
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Originally Posted by rjh01 View Post
I do not see the problem with trying to enter a road when there is a convoy of trucks. They would be highly visible so the other cars would know to wait. In fact it could improve things as the convoy of trucks would take up far less room than trucks travelling independently so increasing the capacity of the highway.
Are trucks the major source of congestion? My experience is that it is cars.
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Old 17th April 2018, 01:42 AM   #566
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Originally Posted by rjh01 View Post
I do not see the problem with trying to enter a road when there is a convoy of trucks. They would be highly visible so the other cars would know to wait. In fact it could improve things as the convoy of trucks would take up far less room than trucks travelling independently so increasing the capacity of the highway.
You can't 'wait' when merging onto a motorway. You synch your speed with the moving traffic and drive on into a gap.
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Old 17th April 2018, 06:39 AM   #567
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Originally Posted by GlennB View Post
You can't 'wait' when merging onto a motorway. You synch your speed with the moving traffic and drive on into a gap.

There would be two simple solutions to this. One would be that the trucks moving in convoy stay in the far lane from merging traffic. (I know of very few instances of merge lanes merging into a single lane road of high speed traffic). The other would be for the individual trucks in the convoy to be programmed to slow down for merging traffic at the appropriate point to permit the merge.

Neither of which, it should be noted, are behaviors which can be depended upon from human drivers in the same circumstances.
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Old 17th April 2018, 06:53 AM   #568
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Originally Posted by GlennB View Post
You can't 'wait' when merging onto a motorway. You synch your speed with the moving traffic and drive on into a gap.
This. Now of course, it's clear if you've driven many years on American highways that many people do not know how to use an acceleration ramp, but this is how it's supposed to work. You use the ramp to accelerate to the speed the rest of the traffic is going, and because there are gaps, you simply merge with them at speed. If nobody opens up, you must either stop at the end of the ramp or crash. Most of the time, the cars and trucks have enough space between them that it's possible to merge, and a vehicle can slow enough to facilitate it, or can merge into the next lane to provide more room. This would be impossible if the vehicles were too close together.

"Simply wait" does not work if traffic is heavy and the convoy long, because at many times it would result in a traffic jam on the inbound ramp, which would work its way back to whatever highway the ramp comes off of, and so forth. I have been in many places where, in rush hour, there is already a degree of congestion. If the traffic on the ramp is forced to stop completely, the result would be a chain reaction of gridlock.

If you've ever driven during peak times on an old expressway such as the Merrit Parkway or the Taconic Parkway, which were built in the 1930's without acceleration ramps, you'll have a better grasp of what sort of chain reaction gridlock is possible. And those are highways that are closed to trucks.

Trucks may not be a major source of congestion now, but that is, in part, owing to the fact that they do not draft and convoy, at least in congested areas, and to the fact that they are driven, for the most part, by skilled human drivers.

A truck is a big object and no matter what is driving it, it takes some time to stop and slow down. Even if it takes only a split second to react to an event ahead, the delay down the line becomes significant. EVer watched a long train stop?

Even if it's possible for automated trucks to operate in unison, I think that the only way it would be practical would be to insure that they operate far enough apart to allow for merging and for reaction time.
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Old 17th April 2018, 08:18 AM   #569
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Originally Posted by GlennB View Post
You can't 'wait' when merging onto a motorway. You synch your speed with the moving traffic and drive on into a gap.
You've never been to Pittsburgh.

If I recall correctly, there's an asinine on ramp with a stop sign. Near Squirrel Hill, I think. It's a bitch.

And lots of folks slow down to get on the highway there. Totally frustrating.
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Old 17th April 2018, 09:53 AM   #570
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Originally Posted by phiwum View Post
You've never been to Pittsburgh.

If I recall correctly, there's an asinine on ramp with a stop sign. Near Squirrel Hill, I think. It's a bitch.

And lots of folks slow down to get on the highway there. Totally frustrating.
There's a beauty in M60 around Manchester where for some reason, the traffic merges with the fast lane. Nobody seems to know why - but a lot of the junctions are rather odd on that road.
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Old 17th April 2018, 03:50 PM   #571
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Originally Posted by jimbob View Post
There's a beauty in M60 around Manchester where for some reason, the traffic merges with the fast lane. Nobody seems to know why - but a lot of the junctions are rather odd on that road.

There are a lot of those in the more complicated interchanges in large cities around here. Even the ones that aren't so large. The 'fast lane' concept is supposed to be held in abeyance in these instances. Apparently this is a closely held and rarely shared piece of information.

Not far from here there is a merge from the left (our fast lane side) from an eastbound multi-lane, limited access highway into another eastbound multi-lane, limited access highway, the latter an interstate with four lanes in that direction.

Both are heavily traveled commuter arteries with a posted speed limit of 65mph, which is generally considered to be a minimum by the drivers.

That one can be something of a nail biter at times. Depending a lot on how much of a hurry the interstate commuters are to get to work. For some reason this seems to affect their grasp of the whole 'fast lane' thing, as well as of the posted speed limit.

Also, that 'drafting' idea seems popular at such times, although I don't think they're doing it to save fuel. The idea of somebody getting in front of them appears to be unacceptable.
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Old 17th April 2018, 09:04 PM   #572
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I think you'll find drafting really does save a bucket of fuel, but of course only for the followers. In bicycle racing it's considered courteous to switch over from time to time, and I don't know how trucks do that.

There's a stretch of I-84 in southern Connecticut that was built in the late 60's or early 70's, in which some entries and exits are on the fast lane side, but also in which lanes change from travel to ramp and back without warning, so that if you don't pay attention and change lanes you'll end up exiting. A nice big, smooth, modern stretch of interstate and one of the worst bits of engineering ever!
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Old 17th April 2018, 10:39 PM   #573
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Originally Posted by bruto View Post
I think you'll find drafting really does save a bucket of fuel, but of course only for the followers.

<snip>

Oh, I don't question that it does. I just don't think that was why they were doing it.
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Old 18th April 2018, 01:25 PM   #574
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Do single-lane highways in America usually have a large number of onramps in a small space? Seems to me that a phalanx of trucks would be programmed to use the inside lane, or the centre lane where there are three or more lanes available. Most of the highways here in Australia have multiple lanes in places where a lot of onramping traffic is a concern. But I haven't driven in America so I don't know what it's like.
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Old 18th April 2018, 02:16 PM   #575
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Originally Posted by arthwollipot View Post
Do single-lane highways in America usually have a large number of onramps in a small space? Seems to me that a phalanx of trucks would be programmed to use the inside lane, or the centre lane where there are three or more lanes available. Most of the highways here in Australia have multiple lanes in places where a lot of onramping traffic is a concern. But I haven't driven in America so I don't know what it's like.
I expect examples could be found but it's not the norm.

I've been thinking two days about the "center lane" preference.
A convoy couldn't (or shouldn't) be allowed in the slow lane.
In the center it becomes an issue as drivers slow to get behind and move left (not supposed to pass on the right)... backing up traffic flow, and those who want to pass on the right anyway.

And the fast lane (if there are three) just leads to everyone passing on the right, making it problematic when one or more need to drop out of the group to exit.

It's a quandry, eh?

We do have the occasional carpool/HOV/express lane(s) physically separated by "Jersey Curbs"/K-Rails (I experienced one on the West side of the ring road highway around D.C., I expect there are a few others).
One downside is some spots can for six, seven (more?) miles between spots to get in and out of the express... guess where I got caught?
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Old 18th April 2018, 02:32 PM   #576
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Originally Posted by shuttlt View Post
Are trucks the major source of congestion? My experience is that it is cars.
My experience in the UK is that lane-hoggers are a major cause of congestion. if a slower vehicle is hogging a centre lane, overtaking traffic has to (legally) concentrate in the offside lane to pass them, this can reach critical densities causing slower speeds and tail backs. I've not even tied to keep count of the number of times when I've experienced a chock-full outer lane, moderately busy centre lane and an absolutely empty inside lane. Really frustrating!
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Old 19th April 2018, 05:58 PM   #577
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Originally Posted by Mikemcc View Post
My experience in the UK is that lane-hoggers are a major cause of congestion. if a slower vehicle is hogging a centre lane, overtaking traffic has to (legally) concentrate in the offside lane to pass them, this can reach critical densities causing slower speeds and tail backs. I've not even tied to keep count of the number of times when I've experienced a chock-full outer lane, moderately busy centre lane and an absolutely empty inside lane. Really frustrating!
Should be a rule that says if the left lane is empty then you need to move to the left lane.
Originally Posted by bruto View Post
This. Now of course, it's clear if you've driven many years on American highways that many people do not know how to use an acceleration ramp, but this is how it's supposed to work. You use the ramp to accelerate to the speed the rest of the traffic is going, and because there are gaps, you simply merge with them at speed. If nobody opens up, you must either stop at the end of the ramp or crash. Most of the time, the cars and trucks have enough space between them that it's possible to merge, and a vehicle can slow enough to facilitate it, or can merge into the next lane to provide more room. This would be impossible if the vehicles were too close together.

"Simply wait" does not work if traffic is heavy and the convoy long, because at many times it would result in a traffic jam on the inbound ramp, which would work its way back to whatever highway the ramp comes off of, and so forth. I have been in many places where, in rush hour, there is already a degree of congestion. If the traffic on the ramp is forced to stop completely, the result would be a chain reaction of gridlock.

<snip>.
What you are saying is that the highways are already clogged with cars. Having trucks travel together rather than leaving a gap between them would reduce this issue a little. Though the only real solution is to get rid of the cars totally. And fix everything else that causes so many people to have cars. Self driving vehicles is part of the solution. These would not carry one person, but several.
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Old 19th April 2018, 07:26 PM   #578
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Originally Posted by rjh01 View Post
Should be a rule that says if the left lane is empty then you need to move to the left lane.


What you are saying is that the highways are already clogged with cars. Having trucks travel together rather than leaving a gap between them would reduce this issue a little. Though the only real solution is to get rid of the cars totally. And fix everything else that causes so many people to have cars. Self driving vehicles is part of the solution. These would not carry one person, but several.
No, that's actually not what I'm saying primarily, though there is a truth to that also. The rails are not "clogged" with trains, but if a 100 car freight train crosses the road, there will be a traffic jam and delays. If only one such train crosses in a day, statistically traffic may be faster, but for a percentage of the population it is a long wait, and during that time traffic will pile up far back. If long convoys of trucks pass on a highway, there will be traffic jams even if the flow of traffic is smooth and fast when they are spaced apart., and even if the times between such convoys are free of truck traffic.


The idea that closing the gap makes any other difference is only true if the highways are so clogged for such a long distance that some are prevented from getting where they need to go.

A common and often fatal, as well as fatally stupid, mistake made by many on relatively congested roads is to presume that any time at all is saved by tailgating. It's not. Following at an unsafe distance gains you the same couple of car lengths, and ultimately the time it takes for you to travel them at the road's prevailing speed, whether you travel a mile or a hundred.

e.t.a. here in Vermont where many main arterial roads are two lane only, I've seen people make repeated hazardous maneuvers, passing recklessly, harassing drivers ahead, even driving oncoming traffic off the road, only to be a few cars ahead at a stop light after 50 miles. Every year there are people who die in head-on collisions while passing and are hurt in tailgating collisions, all to gain half a minute in a hundred miles.

If you want efficient, smooth flowing traffic as a result of automation, I think you'll get it by maintaining safe and consistent space between the vehicles, with a margin for reaction time, error, and merging.
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Old 19th April 2018, 11:35 PM   #579
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Bruto, assuming that one needs 2 seconds between vehicles, you can get somewhat* less than 30 vehicles a minute per lane past any one loint. If a convoy of self-driving vehicles can safely reduce the separation to one second, you have nearly doubled the lane capacity at speed*


*vehicles are not zero-length, and at slow speeds are a significant fraction of the distance travelled in 2 seconds. At 80kph (50mph) it's 44m.
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Old 19th April 2018, 11:53 PM   #580
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Originally Posted by jimbob View Post
Bruto, assuming that one needs 2 seconds between vehicles, you can get somewhat* less than 30 vehicles a minute per lane past any one loint. If a convoy of self-driving vehicles can safely reduce the separation to one second, you have nearly doubled the lane capacity at speed*


*vehicles are not zero-length, and at slow speeds are a significant fraction of the distance travelled in 2 seconds. At 80kph (50mph) it's 44m.
I think queuing theory may be worth considering here. The busier the road gets, the slower any individual driver will generally go.
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Old 20th April 2018, 12:54 AM   #581
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Originally Posted by jimbob View Post
Bruto, assuming that one needs 2 seconds between vehicles, you can get somewhat* less than 30 vehicles a minute per lane past any one loint. If a convoy of self-driving vehicles can safely reduce the separation to one second, you have nearly doubled the lane capacity at speed*


*vehicles are not zero-length, and at slow speeds are a significant fraction of the distance travelled in 2 seconds. At 80kph (50mph) it's 44m.
Then decrease that time to 0 seconds and allow any vehicle to join the convoy then you can get a huge increase in the number of vehicles that can use a road. They would all need to be self driving vehicles with standard interfaces, like what trains have between carriages. But I mentioned that above.
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Old 20th April 2018, 01:09 AM   #582
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Originally Posted by rjh01 View Post
Then decrease that time to 0 seconds and allow any vehicle to join the convoy then you can get a huge increase in the number of vehicles that can use a road. They would all need to be self driving vehicles with standard interfaces, like what trains have between carriages. But I mentioned that above.
The closer everyone drives, the further back the ripples from any event that causes a single vehicle to slow down go. The higher the utilization of the road, the slower any given driver will be able to travel along the road.
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Old 20th April 2018, 02:18 AM   #583
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Originally Posted by shuttlt View Post
The closer everyone drives, the further back the ripples from any event that causes a single vehicle to slow down go. The higher the utilization of the road, the slower any given driver will be able to travel along the road.
Actually if vehicles can travel together than this would no longer be true. All what would happen, at worst, is that the convoy gets longer. The convoy behaves like one vehicle.

If most people traveled by bus then you probably only need one lane each way. Plus, optionally, an exit and entry lane.
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Old 20th April 2018, 05:19 AM   #584
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Originally Posted by bruto View Post
I think you'll find drafting really does save a bucket of fuel, but of course only for the followers.
Maybe a smaller bucket, but drafting can also benefit the truck in front by reducing the base drag behind it. NASCAR drivers often encourage drafting even when leading the race.

And, drafting can help a bicycle in front also.

"Even the lead rider’s drag is reduced by the presence of the drafting rider, with a drag reduction of 10.9W (4.4%). The leading rider continues to benefit from a drag reduction due to the drafting rider up to 5m offset.": https://www.swissside.com/blogs/news...with-drafting?

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Old 20th April 2018, 05:33 AM   #585
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Driverless cars, especially if they make up all the cars in the road, would allow for all kinds of interesting things.

A major one is that we could get rid of parking lots and garages because a car could meet you at home, drive you to work, then take off to drive someone else. It would not need to park. After work, a car meets you and takes you home.

I think it'll take more of a change in the way people think and act than technology changes to get to that point - especially in most of the US where cars are a big part of many people's lives and identities. In cities, though, I can see it catching on pretty quickly.
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Old 20th April 2018, 05:50 AM   #586
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Imagine the filth, food and trash inside a "community car". Unlike a taxi with a human driver, the automatic car will just accumulate disgustingness until a human cleans it.

These cars won't have vomit sensors so when it arrives to pick up you and your dinner date it just might contain a gallon of puke. Or maybe even some poop or pee.
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Old 20th April 2018, 07:36 AM   #587
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Community cars will certainly solve some problems but I suspect they will introduce others. One, of course, would be how the costs of running them will be apportioned and billed. Another would be how priorities of use are apportioned. Not everyone every time knows when he'll need the car again. Imagine getting out for an appointment, finding that it's been cancelled, or is shorter than expected, but your car won't be back for an hour. There will always be accidents and mishaps, road construction and diversions. What if you need your car back for another important appointment, and it's held up? Of course one could, perhaps, call for another car, but owning a share of a pool of cars is not the same as owning a car. Another would be what one does with the contents. One of the advantages of a car is that you can leave stuff in it. If it's going to be shared with others, especially strangers, that will be a problem. It seem what we've invented is an expensive and inefficient bus.

I still think that in practical terms the convoying of trucks would turn out to be a bad idea. I think you'd find that trying to interject other traffic into an unspaced queue would be very difficult and dangerous, and would ultimately be no more efficient than spacing them well to begin with.

Of course there's already a system whereby large loads can be carried without interjection with no space between, along a specified path. It''s called a "train." Trains are very efficient. It's also, however, instructive to watch how a long train stops and starts. The time it takes for a change of motion at the front to hit the back is surprising.

Of course I realize that all those problems could, at least in theory, be solved by massive and expensive technology. Sure, someday we could have computerized cars on computerized highways, and change the way we live and the way we get places and the way we approach transportation, and we'd end up with something that still resembles cars and still in some degree satisfies the illusion of individual freedom that cars provide, but what we'd mostly be doing is finding a hugely complex and insanely expensive substitute for public transportation.
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Old 20th April 2018, 11:28 AM   #588
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Originally Posted by shuttlt View Post
I think queuing theory may be worth considering here. The busier the road gets, the slower any individual driver will generally go.
That only happens if each vehicle is autonomously controlled (i.e. by a driver. People are notoriously bad at station keeping in dense traffic, leading to a small response at the start of the packet of vehicles (a military term for a group of vehicle moving together with 'fixed' distances between them, but useful for thinking of vehicle bunching and platooning) becoming exaggerated as it propagates back from the packet. This can end up with stop-start traffic purely due to traffic density.

If the lead vehicle can telegraph that it is responding to a situation to the other vehicles early enough the effects can be minimised (earlier braking at the rear, passage of information to trailing packets, and faster recovery after the action). This should reduce the effects that you mention.
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Old 20th April 2018, 03:20 PM   #589
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Originally Posted by shuttlt View Post
One would have to do the maths of course, but I wonder whether there would be any point in doing this, given the fuel cost of slowing down and catching up again. On UK motorways this would be happening every few minutes. Maybe the need to do this would be an upper bound on the length.


The thing it, drafting can improve your gas mileage a lot. Mythbusters did a test of this, and the results were surprising:

https://www.autoblog.com/2007/10/28/...-improve-mile/

Drafting 50 feet back improved gas mileage by 20%. Even at 100 feet, it was 11% better. I doubt slowing by a few miles per hour every few miles would offset that gain which would be applied for almost the entire length of the trip.
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Old 20th April 2018, 06:21 PM   #590
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Originally Posted by Horatius View Post
The thing it, drafting can improve your gas mileage a lot. Mythbusters did a test of this, and the results were surprising:

https://www.autoblog.com/2007/10/28/...-improve-mile/

Drafting 50 feet back improved gas mileage by 20%. Even at 100 feet, it was 11% better. I doubt slowing by a few miles per hour every few miles would offset that gain which would be applied for almost the entire length of the trip.

An article prefaced by this;
Quote:
Warning: Don't try this! The safest distance to drive behind a big rig at 55 miles per hour is 150 feet. Driving any closer is insane because it puts you in the driver's blind spot and also does not give you enough time to respond if the big rig's driver changes speed. This post is for informational purposes only.
Which is based, I assume, on the premise that 2 seconds is a minimum time interval distance for a safe response time. (And at 55mph 150' would take slightly less than 2 seconds to travel.)

That would be under the very best road conditions and for an unimpaired driver. (I'm thinking wakefulness and attention diversion here, not drug impairment, which would just make things worse.)

So from a safety perspective drafting is not a viable fuel saving alternative for human drivers on public roads.

As mikemcc points out, communication between the various traffic elements could address this problem. That's one of the really big potentials I see coming in the autonomously operated vehicle field. Not just the potential of drafting for fuel savings, but that could certainly be part of it.
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Old 20th April 2018, 08:09 PM   #591
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Originally Posted by jadebox View Post
... A major one is that we could get rid of parking lots and garages because a car could meet you at home, drive you to work, then take off to drive someone else. It would not need to park. After work, a car meets you and takes you home.
...
While this is true, it's not necessarily as good as it sounds.

There's nothing to stop everyone from catching taxis to work now, except the price, and the hideous inconvenience of having to wait for the taxi.

If we have a fleet of autonomous cars big enough to take everyone to work at peak hour, those cars are going to sit idle for most of the day.

This will be factored into the price of the trip.

Even if people use their own autonomous vehicle to drive to and from work, sending it back home after being dropped off at work, this is still a bad outcome, because it doubles the amount of vehicle miles during peak hour.

You also have to deal with what happens at the end of the work day, when all those vehicles try to stop outside your place of work to pick you up (no car-park, remember?).

There's one thousand people in the building where I work, good luck putting 1,000 vehicles outside the front at 5pm.

This is the traffic modeller's nightmare. Any kind of event with a "finish time" will result in thousands of vehicles trying to converge on the same spot. At that time.

Expect to spend a lot of time standing around in mobs of tired angry people when this future arrives.

Even if you try to walk somewhere else and meet your vehicle there, you'll be dealing with a grid-locked city.
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Old 20th April 2018, 09:31 PM   #592
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Originally Posted by novaphile View Post
While this is true, it's not necessarily as good as it sounds.

There's nothing to stop everyone from catching taxis to work now, except the price, and the hideous inconvenience of having to wait for the taxi.

If we have a fleet of autonomous cars big enough to take everyone to work at peak hour, those cars are going to sit idle for most of the day.

This will be factored into the price of the trip.

Even if people use their own autonomous vehicle to drive to and from work, sending it back home after being dropped off at work, this is still a bad outcome, because it doubles the amount of vehicle miles during peak hour.

You also have to deal with what happens at the end of the work day, when all those vehicles try to stop outside your place of work to pick you up (no car-park, remember?).

There's one thousand people in the building where I work, good luck putting 1,000 vehicles outside the front at 5pm.

This is the traffic modeller's nightmare. Any kind of event with a "finish time" will result in thousands of vehicles trying to converge on the same spot. At that time.

Expect to spend a lot of time standing around in mobs of tired angry people when this future arrives.

Even if you try to walk somewhere else and meet your vehicle there, you'll be dealing with a grid-locked city.

We already have that. People walk (or ride) to wherever their cars are parked and leave through gridlock (AKA "rush hour").

A few more options and alternatives aren't necessarily going to make things worse.

Many of the arguments against autonomous vehicles seen in these sorts of discussions seem to be based on restricting everything to certain exclusive uses. It isn't going to happen that way. Some folks will keep and use their private vehicles, others won't, or some combination of the two. Some will use them for door-to-door transportation to work and back, others might use them for less exclusive destinations, or only use them from time to time.

Many of the objections I've read seem to overlook that they are describing problems we already have, without wondering what new options might become available with the technology.

I was struck by one paragraph only a few posts up-thread when I realized the criticisms being made would have just as easily been uttered by someone at the turn of the last century, explaining why those new-fangled automobiles would never replace trusty, dependable horses and carriages.

I expect acceptance to be gradual at first, and then, as systems become more dependable and flexible and people start to see and take advantage of possibilities which had not been possible before, the use of autonomous vehicles would explode.

When Henry Ford first started producing the Model T in 1908 there wasn't really even a road network to use them on. They were built more like jeeps, so they could handle the cart rutted single lanes which comprised most of the country's transportation network that wasn't on water or rails. Less than two decades later, when he quit making it, entire towns and cities were being transformed by new social and work patterns and transportation infrastructure.

I expect (Well, hope ... if I last another two decades.) to see change very much like that with the development of autonomous vehicles. Both in the way vehicles are used, and the infrastructure we use them on.
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Old 20th April 2018, 09:56 PM   #593
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So... we will keep the car-parks then?
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Old 20th April 2018, 10:01 PM   #594
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Originally Posted by novaphile View Post
So... we will keep the car-parks then?

I expect that there will probably be car-parks, yes. Maybe not as many, or as conspicuous.

I expect that they will gradually become noticeably different, both in form and usage, compared to the ones we are accustomed to today.
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Old 21st April 2018, 06:24 AM   #595
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Indeed, I at least am often referring to problems we already have, because I think automating cars will not correct them.

Speaking as an American of the age, I'm a car nut and gearhead to a great degree, but realistically, if cars themselves are a problem, that problem will not be ideally addressed by making the cars different.
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Old 21st April 2018, 06:52 AM   #596
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Originally Posted by bruto View Post
Indeed, I at least am often referring to problems we already have, because I think automating cars will not correct them.

Speaking as an American of the age, I'm a car nut and gearhead to a great degree, but realistically, if cars themselves are a problem, that problem will not be ideally addressed by making the cars different.

This doesn't make sense.

If cars are the the problem, then why can't fundamentally changing the available alternatives to the way we use cars be a possible approach to a solution?

The need for personal transportation isn't going to go away. Cars as personal transportation isn't going to go away very soon, either. "If cars themselves are the problem", then changing how we use them is at its most basic a way to address that problem.

"Ideally" is not a very good metric to use. "Ideally" isn't ever going to happen. It seems a bit contradictory to use "realistically" in the same sentence as "ideally". You might want to go with one or the other.
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Old 21st April 2018, 05:43 PM   #597
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Originally Posted by Jim_MDP View Post
I expect examples could be found but it's not the norm.

I've been thinking two days about the "center lane" preference.
A convoy couldn't (or shouldn't) be allowed in the slow lane.
In the center it becomes an issue as drivers slow to get behind and move left (not supposed to pass on the right)... backing up traffic flow, and those who want to pass on the right anyway.

And the fast lane (if there are three) just leads to everyone passing on the right, making it problematic when one or more need to drop out of the group to exit.

It's a quandry, eh?
If all traffic, including the convoy, is travelling at the speed limit, where's the problem? Autonomous vehicles - presumably - won't be programmed to break the law, so the only people who are being inconvenienced are people who want to break the law and are intending to break the law, but are being prevented from doing so by the presence of the convoy. I'm okay with that.

Originally Posted by William Parcher View Post
Imagine the filth, food and trash inside a "community car". Unlike a taxi with a human driver, the automatic car will just accumulate disgustingness until a human cleans it.

These cars won't have vomit sensors...
Won't they? Why won't they? Real-time continuous monitoring is becoming the norm even in taxis.

Anyway, if I owned a fleet of autonomous vehicles that is intended to be used as an autonomous taxi service, I'd be an idiot if I didn't program them to return to base for maintenance and cleaning at least once a day, and on demand if an... "incident" occurs. Furthermore, customers who intentionally mess up the car will be blacklisted from using the service.
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Old 21st April 2018, 07:10 PM   #598
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Originally Posted by arthwollipot View Post
<snip> Furthermore, customers who intentionally mess up the car will be blacklisted from using the service.
This would be one option. It would be a severe punishment as it would stop them getting around. True buses would be much better than at present, but I doubt if they would go everywhere. Like out of town to a small town.
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Old 22nd April 2018, 12:36 AM   #599
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Originally Posted by arthwollipot View Post
If all traffic, including the convoy, is travelling at the speed limit, where's the problem?
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.
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Old 22nd April 2018, 01:28 AM   #600
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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.
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