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The technology that asdf is asking about already exists. It's called a "trolleycar", that is a trolleybus with a car form factor.

That would be a way for electrical cars to refuel in transit.

Asdf's transducing car has no "freedom" advantage over trains in that it still needs to run on a dedicated road. The real advantage of cars in that respect is that it allows off-roading. There's also the individual freedom aspect of "this is my own vehicle I'm riding".

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman

by Migeru (migeru at eurotrib dot com) on Mon Feb 6th, 2006 at 10:12:38 AM EST
[ Parent ]
I sort of assumed a system where all the roads we have now are turned into induction roads. I wouldn't see the point otherwise.
by Colman (colman at eurotrib.com) on Mon Feb 6th, 2006 at 10:25:54 AM EST
[ Parent ]
Most roads do have electrical transmission lines running along them, especially in rural areas.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Migeru (migeru at eurotrib dot com) on Mon Feb 6th, 2006 at 10:28:17 AM EST
[ Parent ]
It doesn't take exotic materials (http://www.wampfler.com/INDEX.asp?lang=2&page=31,1,32&zuf=0.5012981482920433), but even if it did, that's not the point. The point is that the car-like thing delivers freedom of origin, destination, and schedule that you don't get with train-like things.

A better idea, in my opinion, is for government to say "ok, we're going to put a tax of x% on the CO2 equivalent of each energy source, based on our understanding of the social (environmental) costs, and let the market choose whether to implement car-like or train-like things."

The energy efficiency of trains versus cars is a very complex thing to analyze, and it's not obvious that trains are actually better than cars--even after allowing for their routing and scheduling inflexibility.

by asdf on Mon Feb 6th, 2006 at 10:29:11 AM EST
[ Parent ]
The point is that the car-like thing delivers freedom of origin, destination, and schedule that you don't get with train-like things

and congestion. You can't awoid that.

The energy efficiency of trains versus cars is a very complex thing to analyze

Really? Could you elaborate on this? From everything I read, trains are much more energy-efficient than cars, primarily because of economies of scale. Even for high-speed trains, I recall equivalent figures at average seating in the range of the PSA diesel hybrid Jérôme blogged about.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Mon Feb 6th, 2006 at 10:34:53 AM EST
[ Parent ]
Not only economies of scale. The amount of energy lost to friction differs by orders of magnitude.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Migeru (migeru at eurotrib dot com) on Mon Feb 6th, 2006 at 10:38:24 AM EST
[ Parent ]
The freedom of origin, destination and schedule that you stress come from private ownership of the vehicles, which is the primary source of energy inefficiency when measured not in distance/energy but in payload*distance/energy (e.g., miles-person per gallon instead of miles per gallon).

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Migeru (migeru at eurotrib dot com) on Mon Feb 6th, 2006 at 10:40:57 AM EST
[ Parent ]
I'm not sure about the congestion point. There has not been a railroad system that supported anything like the volume of travel that is currently supported by the automobile.

I think one must be careful about the train versus car efficiency argument. Trains, for example, are big. You get a dining car, aisles to walk around in, lots of extra space that you don't get in a car--and that needs to be carried around with the people. Also, the fixed A-to-B routing with intermediate stops means that at the ends of the run the train may be mostly empty--something every tram or train commuter is familiar with. And it's true that steel wheels on steel rails have very low friction, but low rolling resistance car tires have low friction--and it's a space that has not been fully explored by the technologists.

But again, the point is that perhaps trains ARE more energy-efficient than cars, but even so, if people are willing to pay more to have the flexibility of the car, it is worthwhile to allow that--if in both cases they meet the broad social objectives.

by asdf on Mon Feb 6th, 2006 at 11:05:03 AM EST
[ Parent ]
In the end the point is that energy is not properly priced, but in many cases subsidized. And in the case of nonrenewable energy sources, the cost of depletion is something that can hardly even be estimated. Just because a cost cannot be estimated doesn't mean it's not zero.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Migeru (migeru at eurotrib dot com) on Mon Feb 6th, 2006 at 11:08:39 AM EST
[ Parent ]
Sorry, I mean just because a cost cannot be estimated doesn't mean it's zero.

A society committed to the notion that government is always bad will have bad government. And it doesn't have to be that way. — Paul Krugman
by Migeru (migeru at eurotrib dot com) on Mon Feb 6th, 2006 at 11:09:51 AM EST
[ Parent ]
I'm not sure about the congestion point. There has not been a railroad system that supported anything like the volume of travel that is currently supported by the automobile.

Really? I think that you didn't read the linked resources carefully enough. Between 1964 and 1976, the Shinkansen managed about a hundred million passengers a year. By 2004, the segment of the Shinkansen between Tokyo and Osaka has carried 4.16 billion passengers. This is for long-distance inter-city transport, remember, so we're not competing with all car use, merely a subset of it combined with inter-city busses and continental airline flights. Intra-city transport is better accomplished by metros, light rail, or even bus networks.

I think one must be careful about the train versus car efficiency argument. Trains, for example, are big. You get a dining car, aisles to walk around in, lots of extra space that you don't get in a car--and that needs to be carried around with the people.

No, actually, you don't need any of the above. And in fact, hauling that stuff around is still plenty efficient. Remember, cars are subject to a massive inefficiency because they have to haul their fuel around with them. Trains don't have this problem, which gives them a lot of wiggle room, especially on long journeys.

Also, the fixed A-to-B routing with intermediate stops means that at the ends of the run the train may be mostly empty--something every tram or train commuter is familiar with. And it's true that steel wheels on steel rails have very low friction, but low rolling resistance car tires have low friction--and it's a space that has not been fully explored by the technologists.

Most of the passengers on most trains for a fixed, long-distance A-to-B route will be travelling between A and B. Moot point. The friction is also a moot point - even if the car's wheels can achieve the same efficiency as rail wheels, it'll still be worse than a maglev, and the car will still have to haul its fuel around with it. You can't just wave the magical technologist wand and say "cars will be better".

But again, the point is that perhaps trains ARE more energy-efficient than cars, but even so, if people are willing to pay more to have the flexibility of the car, it is worthwhile to allow that--if in both cases they meet the broad social objectives.

They don't. Cars rely on oil. Oil is limited in quantity. Oil is really dirty. We need - and have - a reliable alternative.

by Egarwaen on Mon Feb 6th, 2006 at 02:39:07 PM EST
[ Parent ]
I think one must be careful about the train versus car efficiency argument. Trains, for example, are big. You get a dining car, aisles to walk around in, lots of extra space that you don't get in a car--and that needs to be carried around with the people.

Let me turn this into a point that actually carries weight (because, carrying empty space, cost nothing). Indeed it is true that while on a modern train with average filling (40-50%), you have roughly 1 ton for 1 passenger, while for a car (a car not a SUV), you have that when just the driver sits in it.

However, mass is the main factor only when you accelerate. At constant speed, friction is the factor, and trains rule. But even acceleration doesn't really make them worse. On one hand, trains typically gain speed/brake with much lower accelerations (no 100 km/h in ten seconds). On the other hand, modern electric trains (especially those using a lower-than-grid-frequency separate railway AC system, say the 16.7 Hz in Germanic and Scandinavian countries) have regenerative electric brakes, and send much of the braking energy back to the catenary - which can have a greater efficiency than even hybrid cars that recharge themselves while braking. (There are also experiments with adding gyros to diesels for similar short-term energy conservation.)

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Mon Feb 6th, 2006 at 03:04:24 PM EST
[ Parent ]
trains typically gain speed/brake with much lower accelerations

Sorry about that, of course that is irrelevant - the energy input is the same. However, there is a further pointof how often acceleration/deceleration takes place - with street lights and tunrs at corners, I think cars are ahead even if trains have many stops.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Mon Feb 6th, 2006 at 03:08:21 PM EST
[ Parent ]

Yes. The main killer for cars, even on highway driving, is the frequency of acceleration. Trains have very smooth acceleration/deceleration profiles, which makes them easy to optimize. When they don't, something has generally gone very wrong.

With cars... Well, think about how you drive on the highway. Your speed's usually about the speed limit. Sometimes you drift a little higher, sometimes a little lower. Sometimes you make really sharp changes in speed, like when you come over that hill and see Granny McBloggs putting along at a positively mind-boggling 50 km/h, and again when you pull out to try and pass her. It's better than city driving, but it's still pretty nasty compared to a good train system.

by Egarwaen on Mon Feb 6th, 2006 at 04:01:02 PM EST
[ Parent ]
With cars... Well, think about how you drive on the highway.

I know this is a rhetorical "you", but let it be noted that I don't drive a car :-)

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Mon Feb 6th, 2006 at 04:25:23 PM EST
[ Parent ]

How one drives on the highway. Happy?

I don't either, though I do know how to drive. So I do sort of know what I'm talking about when I talk about relying on public transportation. ;)

by Egarwaen on Mon Feb 6th, 2006 at 04:54:03 PM EST
[ Parent ]
I hear the arguments pro and con, but still we are missing the point, which is that the anti-car sentiment must be separated from the anti-CO2 emissions argument.

  • Cars need not carry their fuel with them, as already discussed. Even if they do, battery technology improves constantly. According to this article batteries on the brink of commercial availability are five times better than the best ones available right now. That translates into about a 500 mile range for a GM EV-1 car.
  • "Think about the way you drive" doesn't prove anything, because we shouldn't be talking about future perfect trains compared to today's cars. If slow acceleration is important--and as a hybrid driver I assure you that it is, because of hysterisis loss in the rubber of the tires--then change the way cars accelerate. That's why the 2CV can pass me in the morning.
  • No particularly good statistic about long distance car travel leaps immediately to mind, but the seven lane Tappan Zee bridge in New York, on a route perhaps comparable to the sort that a high speed interstate railroad might take, carries 135,000 cars per day. If there are perhaps 1.2 people per car average, that's about 60 million passengers per year--a favorable comparison to a train running in Japan's heaviest traffic corridor.
  • Also, I don't see what's wrong with waving a technological wand around. Is there some problem with thinking that technology--of both cars and trains--will change in years to come?

Jerome is correct in saying that one of the big problems is the subsidy of oil. One might work on that problem and then find out whether cars are still undesireable. In the meantime, nobody can prove which will be better in the long run, so making a political pro-train decision based on rough comparisons of today's technology is not going to give the best answer.

Incidently, here is a pretty long list of American cities where the use of mass transit has increased recently: http://www.apta.com/media/releases/050926gas_prices.cfm

by asdf on Mon Feb 6th, 2006 at 09:59:05 PM EST
[ Parent ]
Cars need not carry their fuel with them, as already discussed. Even if they do, battery technology improves constantly.

Great. And they're still more wasteful than a train. Which means more load on the grid, something that can't be tolerated on a green grid. And carrying a battery means that it still has to carry its fuel with it - batteries aren't weightless, you know. I'm willing to bet they still can't even come close to oil in terms of energy density. And then there's all the problems with disposing of batteries that've exceeded their lifespan...

And you still haven't dealt with the congestion and safety issues.

"Think about the way you drive" doesn't prove anything, because we shouldn't be talking about future perfect trains compared to today's cars.

Actually, we're talking about modern trains compared to near-future cars. And the way one drives is very relevant - cars are inherently human-controlled free-route vehicles. This introduces certain inherent inefficiencies that trains don't share because they travel a closed, fixed route.

Also, I don't see what's wrong with waving a technological wand around. Is there some problem with thinking that technology--of both cars and trains--will change in years to come?

Yes, there is. We're running out of oil. We need to develop replacements for oil-dependent methods. In most cases, this means drastic changes to the way we do things, because our current oil-centric methods are inherently wasteful in many ways. All of the alternatives have a significantly lower energy density. One can't just wave the magic technology wand and say "cars will continue to be viable". There's only so much technological developments can do before you start running into limits caused by the basic characteristics of the mode of transport.

This is not a political statement, nor is it a decision. The purpose of this diary series is not to "decide" anything, but to examine the options available to a post-oil society (which ours will be in about fifty years) based on current technology. Any subsequent technological developments, except possibly the development of economically viable fusion power, will only shift things further in favour of the alternatives presented here.

by Egarwaen on Mon Feb 6th, 2006 at 11:10:03 PM EST
[ Parent ]
No particularly good statistic about long distance car travel leaps immediately to mind, but the seven lane Tappan Zee bridge in New York, on a route perhaps comparable to the sort that a high speed interstate railroad might take, carries 135,000 cars per day. If there are perhaps 1.2 people per car average, that's about 60 million passengers per year--a favorable comparison to a train running in Japan's heaviest traffic corridor.

The Shinkansen Tokyo-Osaka line has carried an average of 104 million people per year, is much safer, is more environmentally friendly, and is more sustainable. That's over the Tokyo-Osaka line's entire lifespan - when one considers that passengers/year will only have increased since the line opened, the figure becomes even more favourible. I'm willing to bet that your 1.2 people per car average is a little on the high side - that means one in five cars has two passengers, on average.

by Egarwaen on Mon Feb 6th, 2006 at 11:22:27 PM EST
[ Parent ]

Having done some Googling on A123Systems, I'm suspicious. Most of the stuff I've found is carbon copies of press releases, and their site is woefully short on method details. They make a lot of claims, but back none of them up. And I feel compelled to note that if their batteries use copper or palladium, there are serious and unresolvable sustainability and volume problems.

by Egarwaen on Mon Feb 6th, 2006 at 11:27:35 PM EST
[ Parent ]

Doing some more reading, those batteries you list still have a significantly lower energy density than petrolium. For starters, I think that measuring energy density in W/kg is misleading - the standard measure for that appears to be joules/kg. Even leaving that aside, they're still significantly inferior to gasoline. They provide 3000 joules/kilogram. Gasoline provides over 40 megajoules/kilogram.

So unless I'm missing some implication of their chosen metric, there's still a big gap here.

by Egarwaen on Tue Feb 7th, 2006 at 04:41:50 PM EST
[ Parent ]
In that particular context they are talking about power density, which is W/kg. Energy density is another issue, and I probably confused them above.

With gasoline in a modern car getting 50 MPG you can go over 500 miles without stopping. But so what? You still have to stop to relieve yourself once in a while--in my case about once an hour, say 100 miles. Increasing the range beyond 100 miles is decreasingly important. The EV-1 had a practical range in bad conditions of about 100 miles, and batteries continue to improve...

by asdf on Tue Feb 7th, 2006 at 08:23:17 PM EST
[ Parent ]
Increasing the range beyond 100 miles is decreasingly important.

Actually, it is pretty important. It directly affects the necessary frequency of charging stations.

by Egarwaen on Tue Feb 7th, 2006 at 10:20:16 PM EST
[ Parent ]

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