That is, of course, correct. However, it seems to me the more important question is whether it’s theoretically possible to develop computers which are a lot better than people. Which is a different question, in my opinion.
No, you didn’t understand. As the cars move faster, the distance between them increases. A lot. Read about Bernoulli’s principle. Flow-of-traffic equals density-of-traffic times velocity. If flow of traffic stays constant (same number of cars going down the street), as velocity increases density decreases!
Traffic jams should not exist. They exist because higway traffic flow is often super-critical. If people slow down, density increases. As density increases, people slow down further. The lower the speed, the lower the carrying capacity. And then you’re stuck in the new state. All you need is a way out, and you don’t need AI.
No, that’s what happens when people drive normally. Under the scenario presented, everyone would stay exactly equal in distance (eexcept that due to then not being perfectly identical, would wreck).
…
Anyway, the only possibility I even remotely see with the mostoptimistic technology assumptions is a Shadowrun-like Grid-Guide system. It would be a smart car which could follow a highway network even in tight traffic conditions. It would only work on the interstate, basically, and would have to have many warnings to get the driver to take back control. And probably a lot of people willget themselves killed when they decide to nap in their cars.
Ad hoc platooning would allow vehicles to follow each other closely enough to significantly lower the average vehicle’s Cd and such that greater traffic density could be handled as safely at usual speed limits. All that needs to happen for that to occur is that the response time be better than human reactions in the real world. Between communication to the platoon of road hazards immediately ahead, intervehicle communication of previously unidentified changes in conditions, and proximity detectors that immediately alter velocity within each vehicle, such is a very achievable goal. Decreasing accident risk to a point that vehicle weight could be lowered siginificantly at no additional risk in case of accident by virtue of this communication seems a bit much though.
Individuals could only join the platoon after ceding control of their car to the platoon and could only be releases after giving advance notice or at an previously designated release point and having the system safely release them from the platoon. It only could become effective with adequate market penetrance however.
A first market segment might be interstate trucking. Imagine the advantage of being able to put a truck on platoon piloting for the many hours of any trip, and the fuel savings from being able to safely convoy at inter-truck distances smaller than normal interstate driving human reaction times can allow. Trucks could be retrofitted with such technology fairly easily.
??? Wtf are you talking about? You’re here advocating cars that drive themselves, and then your response to my suggestion is, “well, the cars would all accelerate at different rates and crash into eachother.” Obviously they’d have a a radar to keep their distance… You know, like the ones that you can already buy?
I thought your suggestion was just to have a bunch of otherwise normal cars accelerating simultaneously. Be more clear if you want people to understand you.
All I can say here is: forget about automation of road traffic, mainly because of the:
[ol]
[li]millions of level crossings in urban areas[/li][li]building-up of ever longer files of cars leading to ever smaller end-of-file reaction time tolerances[/li][li]extremely small path deviation tolerances due to the uni-dimensional character of the road network (on a water surface, which is two-dimensional, this tolerance is already much larger)[/li][/ol]
But in the three-dimensional airspace the path-following tolerances are just huge, no pilot being bound to ever level-cross or follow any other pilot’s flight path.
Sam Stone writes in post #13:
Definitely true for road traffic, but definitely not for air traffic.
If you have kids and plan to come to Switzerland, would you deny them a ride in the front compartment of the M2 Lausanne Metro, where there is no conductor… only the amazing view through the windscreen?
Ask an IT/electronics engineer: he will confirm that state of the art technology will soon allow for the projection of thousands of virtual rail tracks into the airspace (as calculated in real-time and with quintuple redundancy from the data issued by a set of external references, i.e. the GPS, Galileo, Glonass, Indian, and Chinese satellite navigation systems) by the on-board computer of every aircraft automatically following its own dedicated aerial highway as safely as if it were flying along hardened-steel rails… (with further, autonomous, redundancy warranted by a 3-axis laser inertial platform and a TCAS (Traffic and Collision Alert System).
All of these navigation instruments are commercially available solid state products, (although partly not yet mass-produced, except the already pocket-sized GPS), and therefore bound to become light-weight, small, and low-priced as soon as they will be manufactured by millions.
With increasing standard of life, road safety, which is roughly proportional to vehicle weight/height and front crash volume, leads to ever heavier vehicles, whereas safety in the air will lead to the exact opposite: small-size and light-weight flying vehicles with maximum reactivity (swiftness) for last-second collision avoidance capacity at high cruising speeds.
So just think of the overall economic bargain, not to mention the fact that these aircraft will be mostly single-seated (taking into account that 95% of car-drivers are driving with three empty passenger seats serving mainly as an alibi for security related volume and weight).
The massive popularization of individual aeromobility will at last solve the main problems of the automobile, which are neither pollution nor noise (as being virtually solved), but:
[ul]
[li]the gigantic footprint of the road networks on the landscapes[/li][li]the astronomic construction and maintenance costs of these networks (think for example of Russia)[/li][li]the horrifying (and largely downplayed) number of dead and severely injured in road accidents[/li][li]the loss of work-hours and the stress generated during travel/commuting[/li][/ul]
However, there is no publicly known aircraft concept to date, eligible as a PA (Personal Aircraft).
You should indeed forget about:
[ul]
[li]the helicopter, with its multiple redhibitory snags and weak-points in this respect[/li][li]the tilt-rotor aircraft (as for civil certification), since it cannot autorotate[/li][li]the Groen Brothers’ notoriously far too noisy and too slow Rotodyne[/li][li]and even Sikorsky’s X-wing, which suffers much the same handicaps as the helicopter, except for its cruising speed[/li][/ul]
A more detailed explanation of the shortcomings of these state of the art concepts will follow in a further comment, where I would also be ready to circumscribe (without disclosure) and compare my own concept of a PA invented in 1982, versus the above concepts generally and wrongly believed to be predestined to take up the challenge of the future transfert of road traffic into the airspace.
President Bush may enter history as a pioneer, as he just gave the green light to ADS-B (Automatic Dependant Surveillance-Broadcast), which is the so called New Generation air traffic management system no more relying on ground-based radar, but GPS-based radio-tracking of all aircraft. The system is potentially independent of any ground-based control, as it can project onto each pilot’s LCD screen all the information only available to air-traffic controllers to date.
Hence, alas, the term ‘Dependant’ (in the acronym ADS-B), which stands for the several hundred ground-based control stations planned within the next three years to cover North-America and Canada, merely betrays the deep concern of the authorities with the prospect of loosing control over the (private) pilots community in the longer run…
Some of these problems could be solved if perhaps if the roads were replaced with some kind of parallel metal bars. It’s a crazy idea, but it might work.
Yes, with some kind of “switching” system to change how the bars link up to one another! Brilliant!
And electrified so the vehicles wouldn’t need to carry their own fuel!
(No seriously… what if we take the concept of railroads and scale them down for personal vehicles. Smaller, thinner, cheaper tracks, etc. Create wheels or wheel-changing mechanisms that lets cars go off-track too. I don’t see how it’d be more expensive than putting down pavement. Pavement is complex stuff that doesn’t last long.)
This is completely wrong. The limiting factor in controlling aircraft is not the guidance systems. Those are already quite advanced. The limitation is that an airplane is NOT on steel rails - it’s flying through a roiling, twisting air mass. The reason airplanes are separated vertically by 1000 ft (2000 in the flight levels) and by large horizontal distances is because it’s really hard to brake and accelerate in an airplane, and the airplane can be tossed around like a cork in a bottle inside it’s exclusion space.
This is the thing that those who think we will have crowded highways in the sky just don’t seem to understand. Despite there being three dimensions in the sky, the amount of air traffic you could safely put over a city is nowhere near the amount of traffic you can handle on roads. Not by orders of magnitude. Even if they were controlled by a perfect guidance system that knew the exact position of every aircraft.
Sorry, but it’s a pipe dream, and will never happen.
Yes, they’d certainly be relatively light, but not THAT light. We’re talking at least a thousand pounds here, and often two or three times that weight. And kinetic energy goes up with the square of the speed. The average traffic accident in a city probably has an impact speed of 10-40 mph. The average impact speed of two airplanes in the sky would be 200-600 mph. And of course, after the impact there is the long fall to a certain death.
And there’s no such thing as ‘last second collision avoidance’ in the sky. You need far more than a second to make an airplane seriously change direction, unless you’re flying a Pitts Special. And the high rate of closure means that if an air current throws you into the path of another airplane, you’re not going to have much time to respond.
Then there’s the fact that every time a thunderstorm passed over a city somehow the thousands of vehicles would have to get on the ground very quickly, or it would begin to rain metal along with the water.
And just think of the energy they will use climbing to altitude and back down again for short hops.
will never happen.
Sam Stone should be sentenced to lapidation for attempting to steal our children’s future!
But rather than wasting my time arguing against his kind of stubborn comment – alas, only too often heard even from technically highly educated people – or simply telling him to get stoned, I’ll continue awaiting some expert comments.
In the meantime, I’ll continue to post additional information relevant to my vision of the future of individual mobility.
In the science section of my Yahoo!, I found an article under the heading: “Bees, starlings and locusts unite for more power”, and here’s the translation of the comment I posted in French:
Man too has often successfully challenged his predators by uniting, as witnessed by all revolutions. However, the street-level strategy has become definitely obsolete, as the tenants of power have learned to cope with it efficiently.
The next revolution will therefore deploy in the airspace, once everybody will be able to move individually therein with a flying apparatus equipped with a small machine or laser gun or one or several mini-missiles… all weapons which might be considered as akin to the bee’s sting (or to the personal fire-arm every American is deemed to carry on him or her).
The civil society will then be able to take possession of the airspace to challenge the global air superiority detained to day by a single nation. The said PA (Personal Aircraft) will have to comply to the four following basic specifications:
[ol]
[li]Ability to hold a definite spatial position.[/li][li]Ability to hover in any attitude (the helicopter being able to do so in the horizontal attitude only)[/li][li]Same reactivity in all spatial directions (as the helicopter has only in the vertical axis).[/li][li]Ability to attain high supersonic speeds (the helicopter being theoretically limited to less than 200 mph).[/li][/ol]
Only if these fundamental requirements are met, will it become possible to grant a revolution without violence. Here’s why: the aim is to be able to catch by surprise whoever is committing fraud against man, animals or the nature, through massive concentration of fire power of hundreds of interceptors onto the culprit, who will then be left with the sole option of unconditional capitulation.
Greenpeace made a first step in this direction with their ship, the Rainbow Warier, embarking a host of Zodiacs (inflatable outboard-motor boats) to intercede between the harpooners and the whales, with notorious success and without bloodshed.
Franz Weber and Brigitte Bardot were similarly successful against the baby seal killers by surprising them on the ice-bank with a helicopter.
The next revolution is in the air…
Unless we build domes around cities, to eliminate high altitude air fluctuations caused by wind ! Which… would leave convection movements inside the dome. And, y’know, trap the air inside and kill all inhabitants slowly. Still : flying cars ! 
Traffic jams will always be possible, even with a perfect routing system and maximum car density.
Although, a clever routing system may make you feel like you haven’t been in a jam (e.g. your car drives itself at 30mph for 30mins instead of 60mph for 15mins and being stuck in stationary traffic for 15mins).
What makes you think you didn’t just get one? Other than that it’s not what you want to hear, that is?
Everyone’s entitled to ‘their vision’, as long as they are science fiction writers. Engineers and scientists are unfortunately bound by the laws of physics.
<Lovely story about bees follows>
Huh? That may be one of the weirder things I’ve ever seen posted on this topic. Will these personal aeromachines be required to gather honey as well? We have to keep the metaphor going, after all.
Is that all we have to do? No problem!
I’ve got news for you - the military’s latest $150 million dollar VTOL jet can’t match those requirements.
I guess we’ll just have to keep having the violent kind. I remember the old Cessna/Piper wars, fought with our laser guns and bee stingers.
Wow. I’m trying to decide if this is a joke post or not. Maybe we should get an expert opinion. Until then, I’ll assume it was.
It might, repeat, MIGHT, be possible to do some kind of computer-guided auto pattern on a major highway, with essentially no stops or intersections,m just a few off-ramps. However, you’d have the take the odds that your computer willl suddenyl deicde to commit suicide and ram you into a concrete barrier. Also, you’d have people who are guided off the highway, but have fallen asleep while not doing anything in the car or something.
Now, Sam, you know better than that. Bees don’t gather honey!
I haven’t heard anywhere about hackers. This kind of thing would be a playground for hackers the likes of which the world has never seen.
Frankly, I think the way to solve most of America’s urban traffic woes is to build a two level local road system with the upper half being an express lane and the lower half dealing with the day-to-day commerce. In the middle of most roadways (I’m thinking Michigan Avenue in Chicago) there’s enough space to put two elevated lanes of traffic that will carry you from point a to b without stopping quickly. Add the electronic guidance systems, remove large trucks and busses from the mix and viola, you’ve got everything you need to lighten the traffic load. Frankly though, I wouldn’t want to live in a country where you couldn’t just get on the interstate and go for a nice long drive of your own accord without the intervention of the government or Bill Gates.
Only if it were a centrally administered system, which it would never be unless everyone on earth spontaneously lost 75 IQ points. And replaced their cebreal cortex with bananas. Local cars don’t need to accept any signal and need only use certain information.
This doesn’t make it safe, however. People could relatively easily decided to alter the system with their own transmitters. You’d just sit one down somewhere with the right signal, and the cars would do whatever the road tells them it does.
Oh, sorry, I forgot you’re an expert contradictor…
flex727 replied: “Now, Sam, you know better than that. Bees don’t gather honey!”
To flex727:
While scanning Sam’s stuff for something worth being picked up, I missed that one… (you’d deserve promotion to 747 for spotting this) … (na, Sam, still don’t see I’m an expert in aviation?).
So, without knowing my invention, you have infallible precognition that it can’t match these four requirements, just because the militaries can’t do it even for $150 million? Remember that, despite $30,000,000,000 (billion) of taxpayers’ money poured by the militaries into the V22 Osprey tilt-rotor aircraft project, it can’t even match the safe autorotation landing requirement every helicopter meets.
The expert says: “this is a joker post!”
(Thanks again for repeating this potentially historical manifest)