The Next Transport Revolution: Trolley Wire on Every Street?

Richard Gilbert and Anthony Perl.  Transport Revolutions: Moving People and Freight without Oil [2nd edition].  Earthscan and New Society Publishers, 2010. 

As you’ve probably heard by now, the world is starting to run out of readily-accessible oil, and most rational predictions are that oil prices will continue to rise to reflect the increasing difficulty and risk involved in pursuing new supplies.  How will that change our transport system?  What kinds of change are needed?  What technologies most urgently need research?  And who will lead these changes?

Grab.tiff Transport Revolutions: Moving People and Freight without Oil, is one of the most thorough analyses of this problem available to the general reader.   While plenty of frightening books on this topic are available, Transport Revolutions is an essential counterpoint: it takes the kind of gentle and optimistic tone that you’d use to coax a suicidal friend off the ledge, or for that matter to pry anyone off of long-held but doomed opinions.

But the book goes further.  The message is still that we need a revolution, but not quite the one that many of us have in mind.

Car-based thinking is so dominant in the US that attention has focused mostly on ways to solve the problem that let us still have lots of cars and not much limit on where we can drive them.  These solutions include biofuels, diesel-electric hybrids, various kinds of battery technology, and hydrogen.  One by one, Perl and Gilbert knock down all of them, predicting that each will develop but remain marginal to the real scale of the problem.

It looks pretty clear that the long-term answer is some form of electric motor, both because electricity can come from sustainable sources and because electric motors are highly efficient and give off little or no noise or pollution.   But Perl and Gilbert argue that the crux of the problem is not sustainable power generation, but rather the means of  storing energy for portable use–in other words, batteries.  The hard fact is that there just isn’t a battery, or even a sound technical basis to hope for a battery, that approaches the efficiency of internal combustion.

The crux of the crux is that petroleum has a very high energy density, which can be thought of as the energy stored divided by the mass required to store it.  Batteries, by comparison, are just too heavy compared to the amount of energy that they can deliver, so when you put them in a mobile vehicle, they lose a lot of their efficiency to the work of transporting their own weight, and don’t have much left over to transport us or our cargo.

All this is carefully explained, and leads Gilbert and Perl to a striking conclusion:  We will need to shift most of our mechanical transport to “grid-connected vehicles” (GCVs), vehicles — like trolleybuses and electric rail lines – that can draw power from the grid continuously (and increasingly, return surplus energy back to the grid as well).   At first, this may sound like a revolution in the direction of passenger transit, and much of it is.  Gilbert and Perl call for high-speed rail replacing intercity aviation, growth of urban public transit, and so on.

But their vision goes further, to a network of “grid connected” roads, and a crucial moment, this vision turns into something that looks to the authors like Personal Rapid Transit (PRT).

Here’s the transition:

One [possible pathway toward implementation of a GCV-based land transport system] is via the plug-in hybrid car … Extensive operation of such vehicles could lead drivers to want more use of their electric motors.  To facilitate this, governments or entrepreneurs could provide means of powering them along major routes, accessible by appropriately equipped vehicles while in motion.  When such en-route powering is sufficiently extensive, [electric vehicles] with only batteries and retractable connectors could prevail over plug-in hybrids.  As the grid-connection expands, the need for off-grid movement would decline.  Roads could be supplemented and even replaced by lower-cost guideway infrastructure.  At the same time, vehicles would evolve to move only on the guideways.  They would be as light as possible and, where appropriate, be assembled into trains.  They would comprise PRT.

Another pathway could involve the evolution of public transport toward supplementation of or even replacement by PRT.  This could be driven by PRT’s low energy cost and, perhaps even more, by its potentially low infrastructure cost.  … An analysis for Corby, UK, compared costs of PRT and lighter ail.  For similar initial investment, operating costs, and fare structure, PRT would carry almost twice as many passengers annually …

The second of these paths is almost certainly an illusion.  You can do all kinds of comparisons of existing transit technology with proposed PRT technology, but none of these changes the physical fact that PRT requires carrying people in more vehicles, which means hauling around more metal per passenger.   If higher oil prices caused a huge shift in demand to some form of automated transit, PRT would have to move more metal per passenger than conventional transit would do, and that would almost certainly be the decisive factor in its ultimate energy-efficiency.  (An argument against this point would need to show that PRT is so dramatically lighter in weight than lightweight conventional transit [e.g. Vancouver’s SkyTrain] that it ends up moving fewer tons of metal per passenger.  This comparison would have to be against lightweight rapid transit alternatives.  If anyone has made that argument, please point me to it.)

But the first path is probably worth contemplating at least as a thought experiment.  Suppose we keep our current levels of car use, but gradually convert to grid connected cars.  I guess we’re to imagine giant catenary systems above every street and highway, and something like trolley poles or pantographs on top of each private vehicle.   However much they might love the freedom of the open road, motorists with hybrid vehicles would be motivated to connect to these catenaries at every opportunity, because their off-wire power options would be so expensive.

At that point, all we need is an automated system to combine cars into “trains” and we have PRT.  I suppose we could arrive at that route, but this is so unlike the station-based PRT being proposed today that I’m not sure the term is even useful in understanding it.

[One nasty technical detail: grid-connected vehicles on tires need to route both directions of the electric circuit through the overhead catenary.  That’s why trolley buses have two wires, while overhead-powered rail has only one.  With two wires, you have to connect to them with poles, because the two sides of the circuit have to be kept apart.   Trains, by contrast, are grounded through the rails and therefore need only one wire above.  That means trains can meet this wire with a large horizontal structure —  called a pantograph -– which easily accommodates lateral motion.   It’s a fine joke, really, by the technology gods:  The power source that offers the most lateral flexibility works only on rails, which have the least need for it.

So grid-connected cars, if they run on tires, will need a power-supply system that supplies both current and ground from above – like the double-wire of trolleybuses.  This is a fairly delicate technology even when all the drivers using it work for the transit agency, and even then the buses can’t pass each other.  Will someone invent a system for grounding all of these private “trolley-cars” to the earth, maybe with some kind of continuous metal strip in the pavement that the car continues to touch?   That would allow for zero lateral motion as well, so doesn’t really solve the problem.  At times like these I’m so glad not to be an engineer!]

To sum up, I think we need to be reluctant to derive “PRT” from this path, because the result would be so unlike what anyone today means by PRT that we are only creating confusion by using the term.

DSCN2101 I have delved on PRT because it’s a topic of interest on the blog, but the larger import of Gilbert and Perl’s book remains fascinating and timely.  If the future lies in grid-connected vehicles, transit agencies should be getting out ahead by expanding trolleybus systems, and certainly not removing them.

Trolleybus infrastructure may be one of those investments that would make total sense in a world that correctly priced its carbon impacts, and other externalities.  So long as the market is distorted, though, government simply has to override those market considerations in its own purchasing and planning decisions.  Yet another reason that government, not just private industry, will need to drive this next “transport revolution.”


48 Responses to The Next Transport Revolution: Trolley Wire on Every Street?

  1. alexjonlin September 19, 2010 at 6:07 pm # They had awesome trucks on electric trolley wire in greater Russia.
    Also, in France they used to have trolleywire over lots of canals.
    I believe there still is one trolleyboat canal operating in France.

  2. Bradley Wentworth September 19, 2010 at 6:56 pm #

    I agree with your assessment about cars: they’re just not energy-efficient enough, and if 9 billion people each expect to have their own, there’s no space either.
    I am an optimist when it comes to everyday transport; more LRT, bike lanes, higher urban density, etc. It is intercontinental air travel which, if we don’t make drastic changes, we might have to soon give up as a society. There are a host of changes we could make RIGHT NOW but don’t have the will:
    -Ban tankering. Tankering is the practice of carrying extra fuel because the price of fuel at your next airport is high enough that you save money even though you burn a lot of fuel carrying the extra fuel
    -Allow universal fifth freedom rights. Qantas flies Sydney-Los Angeles-New York, but cannot sell LA-NY tickets due to cabotage rules (this applies to all non-US carriers). If anyone gets off in LA seats go empty to NY
    -Severely restrict or realistically price heavy, roomy business and first class seats
    -Offer more incentives to carry less weight on aircraft whether personal baggage or cargo in the hold
    -Use towing vehicles for ALL aircraft movements on the ground. I can’t fathom why this doesn’t happen already other than political inertia. Aircraft need about 30 minutes worth of fuel to taxi around airports, much of which gets carried during the flight. To run a turbofan engine AT IDLE requires about 50% of its maximum fuel burn, ie, aircraft are ridiculously inefficient at low speeds. High torque diesel engines in those big airport vehicles are much better-suited.
    Ironically, the airlines which already do some of this are the ones that make flying really cheap: Ryanair and Easyjet, but they’re doing it to save money.

  3. Jarrett at September 19, 2010 at 7:06 pm #

    @Bradley Since anyone flying SYD-NYC is tipped out at LAX to go through customs anyway, they might as well get on a different plane. 

  4. Corey Burger September 19, 2010 at 7:07 pm #

    Wow, a PRT post without all the pro/con PRT trolls. Poor Streetsblog had to close one of their posts to comments because of them.
    Regarding trolley-pole non-bus vehicles, the Soviet Union used a great deal of these, even had trucks wired up like this. See

  5. ant6n September 19, 2010 at 8:15 pm #

    PRT might not work, but demand responsive bus transit might, especially in low density areas.
    New technology could help with a new generation of trolley trucks: modern batteries could make them more independent away from the overhead wires, to connect the last couple of meters on a delivery. If there is a reasonably well setup grid, all truck traffic could be forced along a couple of corridors, except for the last mile.
    Trolley trucking looks like a very intriguing idea. It would allow overhead caternary to be used by both public transportation and freight transportation. This in turn could make public transit more affordable.

  6. Alon Levy September 19, 2010 at 9:13 pm #

    Bradley: business and first class seats are already realistically priced. Their profit margins are much higher than those of economy class seats, and their prices are far higher relative to the amount of space they consume.
    The most useful way to reduce per-passenger-km fuel consumption would be to use larger planes, flying less frequently. The frequencies on trunk routes like NY-LA are so high that it’s feasible without worsening service quality. For legacy reasons, non-Japanese airlines use 767s or narrow-bodies on intracontinental routes.

  7. J.D. Hammond September 19, 2010 at 9:36 pm #

    The most useful way to reduce per-passenger-km fuel consumption would be to use larger planes, flying less frequently.
    I keep saying this, but everyone I know in the aircraft industry works for Boeing and uses this as a springboard to bash Airbus. I don’t understand why.

  8. Joseph E September 19, 2010 at 10:28 pm #

    @Alon Levy: “The most useful way to reduce per-passenger-km fuel consumption would be to use larger planes, flying less frequently.”
    I imagine the existing infrastructure of numerous domestic carriers, with many “smaller” planes, is an expensive legacy cost. A new 747 costs US$300 million! Makes high speed rail trains sound cheap.
    Switching to high-speed rail for flights under 500 miles would also make a big difference.

  9. Mikko Särelä September 19, 2010 at 11:07 pm #

    There is a way to push towards zero lateral motion. Mandate that you have to have a computer that does the driving while the car is in the wires and the driver only takes control once you get out of the wire reach.
    Considering that such an idea is anyways 10+ years in the future, we should have good enough driving computers for that. Even today’s cars do pretty spectacular things (and the wires would make it possible to have a reliable communication link between the cars as well).

  10. anonymouse September 19, 2010 at 11:30 pm #

    Personally I think PRT is not all that interesting or productive to discuss, and if we have to talk about outlandish-seeming technologies, let’s talk about trolleyboats! Anyway, what I think will happen as gas prices rise is that a good number of vehicle miles traveled will just go away. People will move closer to work and stores, and exurbs won’t be able to grow just by providing vast expanses of residential subdivisions. People will carpool and take public transit as driving gets more expensive. In the long run, places where people live will get locally denser, so that more of the non-commute trips can be done just by walking, while commutes will likely shift to transit, especially electrified rail, but also possibly trolleybuses.
    For freight, there will be a shift back toward rail as well. Cheap trucking has meant that freight trains are generally used to transport things long distances to a distribution center from which everything is trucked the last few tens of miles across the urban area. More expensive trucking will shift the economics back in favor of local freight rail, and move the offloading point closer to the final destination. Perhaps there will even be two levels of rail service, with what we currently know as freight rail working on the scale of containers going to warehouses, where the pallets inside are removed and loaded onto streetcars or trolley-trucks for distribution to businesses.

  11. Zmapper September 20, 2010 at 12:09 am #

    anonymouse: Amsterdam was considering a cargo tram.
    I don’t know what came about it though. I think electric trucks operating on batteries would not require the streets to be dug up to install tracks and still offer the flexibility trucks have. Notice that the CityCargo proposal still requires trucks for it to function!

  12. Rhywun September 20, 2010 at 12:27 am #

    Good grief, “market distortion” is practically all that happens in Washington – from transportation to farming, housing, and banking. I have little doubt that when the time comes, the government will attempt to fund whatever technotronic fantasy that comes along and promises to rescue the transportation component of the American Dream (just as the current and previous presidents have attempted to rescue housing and banking), over any kind of existing technology that may be more economical but would have the unfortunate side-effect of angering voters at election time. Sure, it won’t work, but they’ll wring every last scrap of hope out of it (wasting who knows how many billions of dollars) before telling the voters that.

  13. Zoltán September 20, 2010 at 3:00 am #

    Re: Those commenting on aviation:
    If we’re pushing for main routes to have very large aircraft, equally we could do with an innovation that could be relevant now, and the more HSR there is around, the more relevant it will become.
    Namely, helping to eliminate the extremely inefficient “commuter planes” on very short routes that serve primarily for connections to the hubs served by these large aircraft, by changing the mode-fetishism that exists in the flight booking process. Be it on the internet or from an agent, if you try to book a flight from one city to another, your itinerary will be flights from end-to-end.
    For example, if I try to book a flight from Manchester to Baltimore, I could well be instructed to take a flight to London, another to New York and another to BWI. Before that, I will need to take a train to Manchester Airport, and at the end of the trip, I will need to take a train into Baltimore.
    Yet Manchester to London is one of the corridors where for any city-to-city trips, trains are far too quick for there to by a serious market for flights, and likewise New York to Baltimore. In fact, it would be faster for me to take a train to Gatwick with one change, take a Gatwick to Newark flight, and from Newark take a direct train to Baltimore. This is liable to be quicker than waiting on infrequent connecting flights.
    The necessary innovation to change this, a giant giant but hugely worthwhile one, would be to have the planners used by the public and tourists suggest and book trains where a trip can most conveniently include trains as part of the itinerary. This would allow a rational comparison of options for making a trip, that would lean away from connecting flights and towards connecting trains the more places built HSR.

  14. Jason September 20, 2010 at 6:24 am #

    I’m not convinced by these arguments from the original post:
    1. Batteries will eventually be removed from cars because they are heavy.
    2. PRT doesn’t make more sense than public transport because it is heavy.
    I don’t like these arguments because I live at a time when i have seen a generation or two of technologies develop, and I have observed that weight is a tertiary consideration behind convenience and comfort. And systems with a minimum of communal infrastructure get more buy in than systems with complex communal infrastructure.
    If weight and cost was a concern for most people we’d all be on bikes and buses not SUVs and trains. If we could save money by communalising the propoulsion we’d have conveyor belts not roads.
    So I suspect people will carry those batteries around.
    Comfort and convenience is king. Every morning the thousands of car drivers I pass on my bike must value their much more comfortable chair and their climate control and their privacy bubble, or else they’d be pedalling along like me. So I suspect PRT may provide value to the punter, beyond that provided by classic trains and trams.
    In summary, I think people will save their money to travel less often and more inefficiently, rather than travel in a mode they don’t like.

  15. Danny September 20, 2010 at 8:40 am #

    I don’t buy the space argument about PRT. The amount of space that PRT takes up is determined by speed. A PRT system that has an average speed of 10mph will require roughly 8x as many cars as a PRT system that has an average speed of 80mph.
    Unlike a mass transit system where you must stop at every stop, PRT speed is not limited by the number of stops on the line.

  16. joshuadf September 20, 2010 at 8:43 am #

    By the way, Seattle has a few trolley wire sidings at busy spots (3rd and University St for example) so that the buses can pass each other even without batteries.

  17. Eric Doherty September 20, 2010 at 10:15 am #

    I agree that trolley cars are probably a non-starter. However, express buses, and dual mode highway buses and trucks could be using trolley wires very soon. (or again as mentioned above for trucks.) The existing technology is good enough for many applications.
    Vancouver BC used to have express trolley buses on Hastings Street that passed the local trolley buses. Diesels replaced the trolleys when the express bus route was extended beyond the end of the wires. The second set of wires is still there, now only used for moving empty buses. The poles and support wires look to be exactly the same as on the streets with only a single set of wires. Two sets of wires probably costs about the same as one to install.
    The challenge is connecting and disconnecting the poles without getting in the way of other vehicles. But automated connection and disconnection would probably not be too far away if a government threw say $100 million into research and development. Designs already exist – such as a single pole with two contacts and sensors to locate the wires.
    Anyone on the list have $100 million sitting around, or even $20 million to start?

  18. Jeffrey Jakucyk September 20, 2010 at 10:19 am #

    I wonder if we might see something like magnetic induction systems installed on highways and perhaps major streets. Instead of having wires overhead that need to be connected to, there’s a metal strip running down the middle of each lane, and a plate underneath the length of the car. Since most travel is down the approximate center of the lane, the connection would be maintained and the car is always powered. For lane changes or exiting to a surface street, the car would switch over to internal batteries or ultracapacitors.

  19. Rational Plan September 20, 2010 at 10:23 am #

    I remember reading about experiments in the 90’s about burrowing power cables in the road and using broadcast power to move vehicles. That way pure electrics could recharge as they drive along freeways and arterials. It would solve the distance problem of electric vehicles.
    Freight consolidation centres could also help. For example Heathrow has set up a consolidation centre for all the airports retailers. By consolidating deliveries into one warehouse and then sending out their own trucks on regular delivery routes they have cut truck movements by 50%(cutting congestion) and helped improve air quality. I know several other cities want to do the same for the city centre retailers.

  20. Dave in KY September 20, 2010 at 12:00 pm #

    “These solutions include biofuels, diesel-electric hybrids, various kinds of battery technology, and hydrogen. One by one, Perl and Gilbert knock down all of them, predicting that each will develop but remain marginal to the real scale of the problem. ”
    Good grief! We had plug-in electrics in LA in the late 90s. They worked fine. Who should I believe? The author, or my own lying eyes?
    I don’t buy the limited range knock on electrics. I’ve been bicycling everywhere for a decade, which effectively gives me a 10mi radius of action. You adapt. Life goes on. It’s not a big transition.

  21. anonymouse September 20, 2010 at 12:51 pm #

    Another thing that we’ll see more of with electric cars is AutoTrains. If you want to have your car on both ends of the trip, but can’t drive it there because it’s electric and doesn’t have the range, you can just load it on the train. I think we’ll also see rail-based express shipping become more popular. I’ve found it a convenient way to move, and as driving long distances becomes more expensive, it’ll become an increasingly popular alternative to loading up your car with all your possessions and driving. And I just want to remind everyone that when you’re looking at how people will switch away from cars, you shouldn’t look at the average driver but the marginal one, that is, the one most likely to switch. The high gas prices from 2008 showed that there are quite a lot of people willing to explore alternatives if the costs of driving increase.

  22. TransitPlannerMunich September 20, 2010 at 1:14 pm #

    In Dresden the CargoTram is used by Volkswagen to deliver auto parts:
    It also gives a good impression of a nice designed ROW for a tram.

  23. Zef Wagner September 20, 2010 at 1:55 pm #

    It seems like trolley-cars could work on highways at the very least, as long as engineers could figure out the grounding issue. I could see highways becoming more automated, with cars fixed to one lane with a metal strip in the pavement. If you wanted to exit, there could be a way to signal that and the car would release from the power strip. This extra step would have another benefit of cutting down on excessive lane switching which is a major cause of congestion.
    I live in Seattle and I am a huge fan of our trolley-bus system. They are quiet, have no emissions, and have a much easier time going up hills than diesel buses. I have read about next-generation trolley-buses that can go offwire for short periods, which would help with getting through tangled intersections or around obstacles. Streetcars are another great form of electric transit that are justified in sufficiently dense areas. As the price of oil goes up it would behoove smart cities to invest in trolley-bus systems rather than diesel-hybrids, which barely get any worthwhile increase in gas mileage.
    We should certainly consider new innovations like trolley-trucks. We already have designated trucking routes–they would just need batteries sufficient to get that last mile to the final destination. Of course, wiring the interstate highways would be a massive infrastructure project, but we could certainly use the jobs at the moment!
    Trolley-boats would be useful in certain situations, like canals and rivers, or even small lakes like we have around Seattle. Especially if the boat is running alongside or under an existing bridge, the wire would not be difficult to string up. Cities should also consider aerial trams like those found in Portland and NYC. They are a great way to connect two destinations with a large grade change. I’ve always wanted Seattle to connect trams to the Space Needle and go to the top of Queen Anne and Capitol Hill. Too bad the Space Needle is a tourist trap and not public infrastructure.

  24. Zoltán September 20, 2010 at 6:56 pm #

    The problem with the idea of widespread auto trains is quite how much energy they will waste in having to drag huge amounts of dead weight for every passenger carried.

  25. Alon Levy September 20, 2010 at 9:05 pm #

    @Zoltan: trains are much more energy-efficient than cars. An American freight train can carry a 1-ton car nearly 400 miles on the emission equivalent of one gallon of gas. The car itself can drive about 50 miles on the same gallon.

  26. Joseph E September 20, 2010 at 11:24 pm #

    Trains are much more energy-efficient than cars. An American freight train can carry a 1-ton car nearly 400 miles on the emission equivalent of one gallon of gas. The car itself can drive about 50 miles on the same gallon.
    True, but you still have to provide passengers a place to sit, which reduces efficiency somewhat.
    Why not have the passengers park their cars at home, ride on the train, and rent a car at their destination? That’s what I do when I fly somewhere and need a car.
    Auto Trains would be useful mainly for people moving long distances, or taking a special car on a long trip. I can imagine having one train a day on each major corridor, but most of the demand will always be for passenger trains, especially as car rental becomes easier and more wide-spread.

  27. Alon Levy September 21, 2010 at 12:37 am #

    The space for the passengers adds less than a ton per passenger, even on overweight American coaches.
    But in response to the broader question, some people prefer to use their own car at the destination. That’s the market for auto trains.

  28. panasonic txp50vt20b September 21, 2010 at 7:04 am #

    ie9? Should Microsoft just consider the browser and let Firefox and Chrome run the show, since they are doing much better job?

  29. panasonic txp50vt20b September 21, 2010 at 7:05 am #

    ie9? Should Microsoft just consider the browser and let Firefox and Chrome run the show, since they are doing much better job?

  30. Alex B. September 21, 2010 at 7:10 am #

    We have a power solution for connecting automobiles to the grid already:

  31. anonymouse September 21, 2010 at 8:25 am #

    I’m not saying that this is what “everyone” will do, and in general it’s impossible to say what “everyone” will do. There’s lots of people with lots of preferences and there will be lots of different solutions. Electric cars will probably be part of it, even internal combustion will survive for much longer than you think, after all people still use cars in places in Alaska with no road access from outside and $8/gallon gas. Likewise, some people won’t bother with cars at all, some will still drive all the way, some people will rent a car at their destination, and others will take the auto train. Besides, what if you’re moving permanently? Assuming you want a car on both ends of the move, renting is not an option, you’d have to either take your car with you somehow or sell it. Which just goes to show that there are probably more scenarios that we haven’t thought of.

  32. David Sucher September 21, 2010 at 9:10 am #

    “And the hard fact is that there just isn’t a battery, or even a sound technical basis to hope for a battery, that approaches the efficiency of internal combustion.”
    It seems to me that there are two important facts to consider:
    1. NO ONE knows what battery efficiencies can and likely will arise.
    2. The “design distance” for urban vehicles between re-energizing/re-fueling needs be something more like 50 miles at very most. We don’t need to replace batteries with internal combustion engines for the normal and ordinary needs of a great numbers of trips — very many are much less than ten miles i.e. We don’t need all cars which are able to go 100 miles (much less 400 miles) without refueling.

  33. Stephen Schijns September 21, 2010 at 9:43 am #

    I think I’ve seen the electric car grid in action already…the last time I was at the fairgrounds and took my kids in a bumper car ride. Electified wire mesh overhead, fun and chaos down below! The future will sure be exciting!

  34. Anon256 September 21, 2010 at 2:02 pm #

    @Zoltan: It’s not just “mode-fetishism” in flight planning and booking, but the whole way that flights are priced, that would have to change. At the moment, since people prefer nonstop flights, in general airlines effectively charge a “nonstop premium”. As a result, adding a short segment to the end of a trip adds little cost or even makes it cheaper. For example I have flown Paris-London (exactly the sort of “commuter” flight that we should try to get rid of) because flying LA-Paris-London at that time was much cheaper than flying either LA-London or LA-Paris. Even more common is for NY-DC-Europe or DC-NY-Europe to be cheaper than direct NY-Europe or DC-Europe.
    Creating a Kayak-like site that also searched high-speed rail connections is a straightforward software problem, and indeed many flight booking engines already list high speed rail connections in a few limited cases, but these options are in general so much more expensive than flight-based connections that nobody notices or cares. Of course, the nosebleed-expensive price of most high-speed rail tickets doesn’t help, but even when fares are reasonable for travel between two points, they are unlikely to be competitive with the (usually tiny or negative) marginal cost of adding a flight between those two points to the end of a longer trip. Changing this would require cooperation and revenue-sharing with the airlines, which seems unlikely to happen any time soon.

  35. ant6n September 21, 2010 at 2:46 pm #

    It’s not just a matter of showing options when purchasing, but also of integrating the modes and the ticketing. I can purchase one ticket from one city to another via a third, and as you mentioned the last leg’s cost is almost negligible; you basically get the local flight for free. But also, if there is a delay, you are guaranteed to make it to your destination (eventually…)
    I have done Montreal ParisRennes, and Montreal FrankfurtBerlin. It is reasonably comfortable, because there are train stations right at the airport (in cdg and fra), but in one case I missed my train, in the other I almost missed it. Since the train tickets were bound to specific trains, I almost would’ve lost them, and would’ve had to pay full price on new tickets.
    When I flew via Frankfurt and missed my ICE, I actually purchased a new ticket, because the train people (rudely) informed me that I forfeited my previous one. The conductor on the train was more lenient and accepted my previous ticket, so I got a refund on the second ticket later (minus 15%).
    So if I were to do that again, I’d want
    a) the train leg to not be very expensive
    b) assurance that I can take the train, even if the plane is delayed

  36. anonymouse September 21, 2010 at 4:46 pm #

    ant6n: it’s not a train vs. plane problem, really, so much as whether the train counts as part of the airline’s network. Not everything marketed as, say, a United Airlines flight is really operated by United: there are code-shares with other major airlines, and there are smaller routes contracted out to regional airlines. If you’re transferring between airlines outside that framework it’s probably going to be about the same as what happened to you and the train. The key is going to be getting the rail carrier to have the status of a regional airline in terms of ticketing and connections.

  37. Kathy September 21, 2010 at 8:42 pm #

    The last time I rode Amtrak, one of the train guys started talking with my husband and I and he said they are going to re-electrify the train routes. Apparently many years ago they were electrified and they are thinking they will save money and energy by doing it again. So, if it is so good, why did they stop doing it in the first place? There had to be drawbacks severe enough to make them stop the practice.

  38. anonymouse September 22, 2010 at 1:17 am #

    There were a few drawbacks to electrification, most of them because railroad infrastructure in the US was private: apparently the increased infrastructure resulted in increased property taxes on the lines, and besides, there was lots of expensive copper in the wires (which could last at least 100 years) which the management could sell off to boost this quarter’s profits. That and oil has been fairly cheap until fairly recently, which made diesel traction comparatively more economic than electric. Also, I’m pretty sure that the routes Amtrak wants to electrify (I think they’re New Haven-Springfield, DC-Richmond, possibly NYC-Albany) have never had electrification.

  39. Alon Levy September 22, 2010 at 2:06 am #

    @Kathy: I think the only major line that was deelectrified was the Milwaukee Road; it was part of a general program of deferring maintenance, leading to bankruptcy and the line’s abandonment. The other lines were never electrified.

  40. anonymouse September 22, 2010 at 8:22 am #

    There was also the Great Northern through the Cascade Tunnel, where the electrification has been replaced with an elaborate ventilation system involving a door that closes over the tunnel portal to make the fans more effective in removing carbon monoxide. But there was also a vast network of electric railways (“interurbans”) that people seem to have forgotten about entirely. You could go from LA to Redlands or SF to Chico or, so the legend goes, almost all the way from NYC to Chicago. You could certainly go all the way across Illinois, from East St. Louis to Champaign on an electric train.

  41. R. W. Rynerson September 22, 2010 at 10:23 am #

    On the West Coast, interurban lines were snaking towards the goal of a north-south network in competition with the Southern Pacific until WWI and the subsequent highway programs put a stop to the idea. Key components included the Sacramento Northern from San Francisco Bay to Chico and the Oregon Electric heading south from Portland to Eugene. Service included lounge cars and sleeping cars, as well as handling mail and package express. —-
    One of the ironies of the endless energy debates since 1973 is that several trolleycoach networks have been abandoned since that red-flag warning. Most recently, Edmonton could afford to scrap their modern system, which included express wires, because of the gush of oil-related revenues. Seattle is inching toward debating that issue again. Future historians will be fascinated with our bi-directional policies headed in two directions at the same time.

  42. G-Man (Type-E) September 22, 2010 at 3:43 pm #

    I’ve been saying for 2 years now that electric cars need range extending charge-in-motion infrastructure built into the highway network. Glad to see others have the same thought. Calling it PRT is odd. To me that’s a totally different thing with many disadvantages, except for very particular circumstances. There clearly won’t be one technology solution to energy descent in the near future. Rather, it looks like we are in for a period of diversity, experimentation and localized solutions. Some people may desire a natural gas electric hybrid pickup truck, while others could use pure electric cars with wires on the interstates and charging stations wherever you park in town.
    Batteries will reasonably give us 100-200miles of range within the next decade. The tech already exists to let the car drive itself while maintaining speed and lane position in a highway situation. A tolled lane would charge you for the power. Charging stations in town will be operational in the next few years in ARRA funded regions. This means regional planners need to get more serious about pricing parking and limiting sprawl to combat continued auto-dependence and make the urban fabric more people friendly. Transit systems will grow again once the current fiscal troubles subside. An aging population in the “developed” economies will demand more transit and probably different kinds of transit that may be more expensive unless we can increase efficiency of demand response… HSR is expanding (though it needs to be running and built faster), certain freight rail corridors may be candidates to electrify at some distant point. Jet engines are getting more efficient and the operational strategies mentioned in other posts will play an important role in reducing energy intensity of aviation…
    Ocean shipping presents a bigger challenge, but good ideas are simmering there as well. IMO a very important component of this change is for industry and government together to fund more implementation. Research is great, but new ideas need to be tested in the real world and successful ideas need to be scaled up fast.
    I guess my point is just to be excited about the future of transportation in general. Let’s keep our chins up, plug forward to a diversified, electrified future and before you can blink, it will be the new normal!

  43. Dave September 25, 2010 at 1:15 pm #

    Sorry I didn’t get to this thread sooner. I was hoping to read some comments about swapping battery packs as proposed by Wouldn’t that approach eliminate the need for building a new power grid on the roadways and still allow long distance travel with efficient “refueling” stops every couple of hours? Yes, you’re still carrying the weight of more batteries but the infrastructure seems less costly to build and maintain and we already have it for liquid fuels.

  44. Alon Levy September 25, 2010 at 6:32 pm #

    Dave, the Better Place idea is probably not going to work, for three reasons. First, while it gets over the problem of long charging times, it does not get over the problem of low range; you’d still need to change batteries several times as often as you refuel an internal combustion engine. Second, it requires purchasing many additional batteries to act as spares, which makes the cost prohibitive. And third, the infrastructure for liquid fuels took a hundred years to construct; constructing parallel infrastructure takes time.

  45. Petre Popescu September 26, 2010 at 8:39 pm #

    I’m sorry for arriving at this thread so late, but a while ago I saw something that promises a better PRT solution at . In summary:
    1) Super-lightweight vehicles (weighing half their maximum capacity) travelling at very high speeds (~100 mph). This means the use very little energy, but it also means that they require only very light-weight infrastructure. The proposal is for a guideway supported by stadard utility poles, with a construction cost of about $1 million per mile.
    2) Vehicles placed *below* the guideway (makes them more stable at high speeds)
    3) In-vehicle switching system (makes it possible for vehicles w/ different destinations to follow each other very closely, thereby increasing the total capacity of the system)
    4) Separate “feeder” guideways that serve “stations” – this allows vehicles to slow down for boarding without also slowing down other traffic on the main guideway.
    I’m neither a physicist nor a transportation engineer, so I cannot speak to the feasibility of this system, but I’ll let the more educated guests debate that :)

  46. Alon Levy September 26, 2010 at 10:35 pm #

    Oh, God.

  47. Jarrett November 1, 2010 at 11:21 am #

    John Todd of SoundPRT ( asked me to post this comment of his:
    It sounds like you need to come up to speed on some of the less obvious benefits (and drawbacks) of PRT, including its passenger/vehicle weight ratio (and even more important factors) in comparison with other transit technologies in terms of their relative energy efficiency. This seems to be a common theme among advocates of public transit, though certainly not universal — while most people have never heard of PRT before, of those that have, many operate under assumptions that some misinformation they’ve come across is accurate.
    Sorry we weren’t able to connect on your last trip to the Seattle area. I hope we can do so in future.
    Glad to see you beginning to entertain discussion of PRT, especially given your earlier reluctance to do so, even more so now that the Heathrow PRT system has opened to the public. I look forward to the positive discussion this will surely engender among advocates of sustainable public transit.

  48. Ting Wu August 9, 2011 at 6:43 pm #

    Trolleybus infrastructure may be one of those investments that would make total sense in a world that correctly priced its carbon impacts, and other externalities. So long as the market is distorted, though, government simply has to override those market considerations in its own purchasing and planning decisions.apb cash: