The Ergosphere
Friday, February 17, 2006
 

Out of town on rails

The question

Regular readers here will remember that I've pointed to and occasionally discussed the Blade Runner road/rail truck concept.  Well, it came up again in an e-mail discussion the other day (the fruits of which might appear elsewhere).  I pointed out that even a doubling of truck fuel economy over the next 14 years would only cut total consumption by 34% if road mileage continues to increase by even 2% per year; if we could double economy AND switch 60% of mileage to modes which don't burn any fuel, we could increase the savings to 74% *.  I got the following response, which I should have anticipated:

> The question is, CAN we move 60% of that mileage to modes
> which run on electricity in 14 years?

Not having an answer ready meant that I hadn't done my homework.  Better late than never; I went directly to the BTS1 to check it out.  Here's what I came back with:

The roads

In 2003, there were 3,974,1072 miles of highway in the USA, of which about 46,500 miles was interstates3.  The total urban free/expressways (interstates and other) came to 24330 miles; rural interstates are another 32048 miles (total 56378 for all freeways), and other rural arterials come to 97039 miles.

The vehicles

The same year, combination trucks (semi-trucks and vehicles with trailers) travelled 140,160 million miles4.  I could not find the mileage breakdown for this category.

What it takes

Commercial trucking in general seems to have more detailed statistics available5.  Commercial trucks travelled 215,884 million miles in 2003; we're looking for 60% of that, or about 130,000 million vehicle-miles.  Urban and rural interstates accounted for 86,692 million vehicle-miles (almost 2/3 of the target), leaving about 43,000 to go.  Other urban streets account for 58,830 million vehicle-miles, but we probably can't convert lanes of surface roads to electrified rail (save for dual-use, like trolley cars?) so it's questionable how much of that could be electrified.  On the other hand, short hauls away from an electrified artery could be driven on power from flywheels or batteries; this may not be hopeless.  Rural arteries tend to be less heavily travelled (otherwise they wouldn't be rural) and do not account for as much fuel use per mile of road as urban ones.

Electrification of the urban arteries would be best for eliminating diesel emissions in densely populated areas.  This is a two-fer.

What it might cost

It all comes down to money.  Adding two lanes of electrified rail to all interstates and urban free/expressways means ~113,000 lane-miles of rail3; that covers about 40% of all truck vehicle-miles.  Covering the most-travelled 50% of urban truck routes means another ~59,000 lane-miles of rail (plus overhead wires) in urban areas, getting at least half of the remaining 43,000 million vehicle-miles.  Power from flywheels or batteries could make fuel-free, zero-emission jaunts from the main lines to destinations, maybe getting the balance.  It would be close regardless.

This scheme would have a total of about 172,000 miles of rail.  If we could build that out at 20,000 lane-miles per year we'd have it in about 8.5 years.  There's almost 4 million miles of road in the total system3, and rebuilding it every 20 years means at least 200,000 miles of road (much of it 4- and 6-lane) per year.  This looks feasible to start by 2010 and have finished by 2020, with time to spare.  At $2.4 million per lane-mile, the capital cost would be about $270 billion or about $35 billion per year.

Note that this does not include the simple expedient of throwing rails back onto unused rights-of-way and running trucks on it.

What it might save

"Combination trucks" burned about 27 billion gallons of fuel in 20036.  60% of this is 16.2 billion gallons.  At $2.50 per gallon, it would cost $40.5 billion per year; substitution of electricity at 1.5 kWh/mile and 10 cents/kWh (including savings from lower rolling resistance of rail) would cost 19.5 billion dollars per year, for a gross savings of $21 billion/year for energy.  The investment would pay off in about 14 years, not including lower expenditures for pollution control, health, and other external costs of petroleum consumption in general and diesel fuel in particular.  If trucks other than "combination trucks" could use the rail/electric system it would pay off faster, and any increase in fuel prices would do the same.

Note that rail moved about 1/3 more ton-miles of freight in '03 than trucks did7, while consuming only 3.8 billion gallons of fuel8 to trucks' almost 38 billion gallons9.  The more we can make trucks like rail (and efficient as rail), the more we can ship without burning fuel.

Footnotes

* A 2% per year increase in vehicle-miles compounded over 14 years comes to 32%, or 132% of the original.  If fuel per mile is cut in half, fuel consumption falls to 66%, or a 34% decrease.  Slashing another 60% off the fuel consumption by replacement with e.g. electricity cuts the net fuel consumption to 26.4% of the original, or a 74% decrease despite a 32% increase in vehicle-miles. (back)
[1] http://www.bts.gov/publications/national_transportation_statistics/2005/index.html (back)
[2] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_01_01.html (back)
[3] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_01_05.html (back)
[4] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_01_32.html (back)
[5] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_truck_profile.html (back)
[6] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_04_05.html (back)
[7] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_01_46b.html (back)
[8] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_04_17.html (back)
[9] http://www.bts.gov/publications/national_transportation_statistics/2005/html/table_04_05.html (back)
 

Comments:
I still don't get why you think that merely building the electrified railways would be enough. Europe's got them and trucks continue to be used on routes also served by electrified rail.

I also don't understand why you wouldn't start by electrifying existing railways lines in the US.
 
"Europe's got them and trucks continue to be used on routes also served by electrified rail."

Because the flexibility of the truck is worth more than the energy savings from electrified trains.  This gets rid of the need to use trains just to move freight on electrified rails.

"I also don't understand why you wouldn't start by electrifying existing railways lines in the US."

Because U.S. trucks use about ten times as much fuel overall, and thirteen times as much fuel per ton-mile.  You can't make big impacts by going after small uses.
 
If you are talking about a new kind of truck capable of directly using electrified rail and road, I think what you need to prove is that the concept is workable. It's completely unproven at this stage, I am not aware of a single such operation in the world.

Trucks aren't actually ten times less efficient than railways. I've looked at some European statistics, and the difference in fuel consumption per ton mile is also due to the kind of freight being transported.

I think, if trucks mostly carried coal, you'd find the difference would go down to something like a factor two in favour of rail.

My recollection is also that most of that difference is due to reduced wind resistance from rail cars travelling in the wake of each other.

At any rate, your post is all about the costs of building electrified rail, which is pretty irrelevant, if you are in truth trying to sell a completely new and utterly unproven transportation concept.
 
" If you are talking about a new kind of truck capable of directly using electrified rail and road, I think what you need to prove is that the concept is workable. It's completely unproven at this stage, I am not aware of a single such operation in the world."

You've never seen electric streetcars (buses on rails) such as run in Toronto?  You've never seen the rubber-tired electric buses which run in Vancouver BC, and once went through Chicago?  This is some of the best-proven technology in the world.

"I think, if trucks mostly carried coal, you'd find the difference would go down to something like a factor two in favour of rail."

I do not think that semi-trucks carrying lettuce and frozen chicken to the supermarket are likely to change places with the trains carrying coal to the powerplant.  The US's trucks still burn ten times as much fuel as its trains, and are thus ten times as attractive a target for cutting oil dependency.

This is not to say that electrified railroads are a bad idea; just eliminating the noise and particulates from the diesels on routes through urban areas would be a great benefit.
 
What exactly are you proposing then?

The BladeRunner link you provide is to a completely new design of truck capable of using both rail and road.

Streetcars need rails to run, trolley buses only use the road. I've also never seen trolley trucks operating on electrified motorways (and by the way, I've never ever set foot outside of the European Union, though I've travelled extensively within the European Union - so I haven't been to North America and I haven't got any particular desire to go there either, if it can be avoided).

Certainly the idea of hybrid trucks capable of getting their electric power from overhead cables on the motorway and running in hybrid or all electric mode where there is no overhead cable is fascinating. It's also an old idea and so far noone's made any real effort to implement it anywhere in the world.
 
"What exactly are you proposing then?"

I'm not going to repeat the post just because you didn't read it.

"The BladeRunner link you provide is to a completely new design of truck capable of using both rail and road."

Completely new?  Strange, I found a European definition of bi-modal vehicle which suggests it's been around for a while, and a cursory search turned up related patents from 1983 and 1994.

So much for "completely new"; Blade Runner is just some engineering tweaks, with the pivoting rear trailer bogie being used to get ultra-tight turning circles.  I'll bet that's intended to allow getting on and off grade crossings from narrow roads.

"It's also an old idea and so far noone's made any real effort to implement it anywhere in the world."

Are you arguing that it's useless or pointless?  What are you claiming, anyway?  You're coming darn close to trolling.
 
I don't think your post is terribly clear about what you are proposing, and I've reread it several times.

You start off by pointing to the blade runner concept and how that's inspired a recent email conversation and then quote a question from that conversation, as to whether we can switch 60% of the mileage to modes which run on electricity in 14 years.

And then you talk a lot about fuel consumption of trucks, their mileage breakdown, possible fuel savings, the costs of extra electrified railway lines. You also mention flywheels and batteries for short jaunts.

What you don't say much about is the vehicles themselves.

I would maintain that that's by far the most speculative bit of the whole scheme, which you should explain in the greatest detail. Not doing so left me with the impression that the mention of the blade runner concept was a little aside at the start and you were actually talking about tried and tested ways of moving freight to rail, eg containers that can be carried by both trucks and rail.

I know that the concept of vehicles capable of using both the rail and road network is not new, but I haven't yet heard of an actual production vehicle being built.

That doesn't mean it's a bad concept, or that it's pointless or useless. It does mean that it's unproven.

Sorry, if I've come across unnecessarily harshly. I am not interested in needlessly annoying you.
 
Some objections:

1) I don't think laying rail is a good idea. Instead of grading new lanes of traffic and laying rail, it would be better to run dual catenaries above the right lane and leave the existing tire-based roadway intact. Yes, a dual catenary system is more complicated, but the system as a whole would be less capital intensive and the conflict between the lanes of traffic non-existant. (The latter point presumes a short-term high-discharge storage system that can provide sufficent power to move the vehicle at speed until a convential diesel can be fired up.)

2) Traffic is not going to increase forever. At some point increasing transport costs will cause "demand destruction".

3) Of course, the truly low-hanging fruit is the speed limit. Reducing it to 45 MPH for trucks (and 55 for cars so the speed differences aren't too great) would make a nice dent in petroleum consumption starting immediately. Trucking companies might bite on this if triples were allowed nationwide.

4) The whole discussion is academic. There's no way Americans are going to wake up in sufficient time to prevent the huge crisis that is brewing.
 
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