Human Transit

avoiding car-centered language: a directive

In 1996, the City Administrator of West Palm Beach, Florida, Michael J. Wright, issued a directive to his staff on how to avoid biased language in the descriptions of transportation investments and policies.  It's four pages, sharply written, and may well be the smartest bureaucratic directive you'll ever read.  Here it is in PDF.  (Thanks to Peter Bilton at the Vorhees Transportation Center at Rutgers for pointing it out.)

It pulls no punches:

Much of the current transportation language was developed in the 1950's and 1960's. This was the golden age of automobiles and accommodating them was a major priority in society. Times have changed, especially in urban areas where creating a balanced, equitable, and sustainable transportation system is the new priority. The transportation language has not evolved at the same pace as the changing priorities; much of it still carries a pro-automobile bias. Continued use of biased language is not in keeping with the goal of addressing transportation issues in an objective way in the City.

Biased words, as identifed in the directive, include improvement, upgrade, enhancement, deterioration.  The problem with these words is that they imply an idea of good or bad that may not be universally shared.  So for example:

Upgrade is a term that is currently used to describe what happens when a local street is reconstructed as a collector, or when a two-lane street is expanded to four lanes. Upgrade implies a change for the better. Though this may be the case for one constituent, others may disagree. Again, using upgrade in this way indicates that the City has a bias that favors one group over other groups. Objective language includes expansion, reconstruction, widened, or changed.

And in the spirit of my last post:

Traffic is often used synonymously with motor vehicle traffic. However, there are several types of traffic in the City: pedestrian traffic, cycle traffic, and train traffic. To be objective, if you mean motor vehicle traffic, then say motor vehicle traffic. If you mean all the types of traffic, then say traffic.

The directive even nails the widespread misleading use of the word accident. 

Accidents are events during which something harmful or unlucky happens unexpectedly or by chance.  Accident implies no fault.  It is well known that the vast majority of [vehicular traffic] accidents are preventable and that fault can be assigned.  The use of accident also reduces the degree of responsibility and severity associated with the situation and invokes a inherent degree of sympathy for the person responsible.  Objective language includes collision and crash.

(Yes, crash sounds emotive while accident sounds cool, so it's easy to assume that accident is more objective or factual.  But sometimes the facts are emotive, and only an emotive word will accurately describe them.  The directive even notices that avoiding the emotive word can constitute an emotional bias in the other direction:   "Sheila was in a car accident!"  "Oh no, I hope she's OK!"  "Well, she killed three cyclists, so she's pretty upset!"  "How terrible!  I'll send her some flowers.")

If you have seen either (a) a better explanation of these principles or (b) a coherent refutation of them by a transportation authority, please post a link.  I'm aware of Todd Litman's comments on this (here, page 5) and I know it's come up in other academic literature.  Still, the West Palm Beach document is important because it's a directive.  Many people in transport bureaucracies are not comfortable with academic thought -- especially about linguistics, which is usually outside their training. But they are very accustomed to directives; they may find that the commanding tone of the West Palm Beach directive makes it easier for them to think about and react to. 

Read this document, discuss it, and forward it!  Yes, I know you've thought about this before, and maybe even written about it.  But remember: language evolves only through relentless repeitition!  Today, repetition is a matter of quoting, forwarding and linking.  So quote, forward, and link!

if you mean "car," say "car"

Here's a simple thing that anyone can do to improve the prospects of sustainable transportation.  When you hear a phrase that makes sense only from behind the wheel of a car, notice it, point it out, and don't get drawn into saying it yourself.

I could grab an example from anywhere, so here's one from an unsigned piece from the New Urban Network, a web publication of the New Urban News:

New York's Broadway, after giving up 3.5 miles of traffic lanes to pedestrians, bicyclists, and gathering spaces, is seeing its automotive traffic significantly decline.

Some say that Broadway should never have been allowed to cut its diagonal path across the Manhattan street grid to begin with. "The resulting three-way intersections can slow down cars and tie up the broader system," The New York Times observed Sept. 6 in an article available here.

New Urban News is a New Urbanist publication, so I'm sure the author isn't biased in favor of cars.  But still, the second paragraph is suggesting that the traffic problems caused by Broadway's three-way intersections could be an intrinisic problem with the very shape of the street.  That's true only if you're behind the wheel of the car, or in the back seat of a taxi.  If you make Broadway a great pedestrian street, presto, no more nasty three-way traffic intersections.  Problem solved.  And any urbanist will tell you that diagonal interruptions in a regular grid can be important sources of visual delight.

The New York Times article cited, by Michael M. Grynbaum, is a bit more careful:

Traffic planners at the city’s Department of Transportation say that less automobile traffic on Broadway is, in fact, a symbol of success, noting that the street’s awkward three-way intersections with other avenues created gridlock. “The mayor asked us to take a look at what we could to untangle the Gordian knot of traffic in Midtown,” Ms. Sadik-Khan said. “We’re making the network work like it was supposed to.”

But even here,  a "streets are for cars" bias slips in via the phrase "the street’s awkward three-way intersections with other avenues created gridlock" -- which is presented as a paraphrase of what the officials said.  If I'd been Grynbaum's editor I'd have insisted on something more precise like: "Using Broadway for heavy car traffic required awkward three-way signals that caused cascading delays."  Again, the problem isn't the shape of Broadway, but the use of Broadway as a heavy car street. 

Why pick on these New York examples when much more egregious cases can be found in any newspaper?  Because they show how easily a "streets are for cars" bias can hide in the language, even in the writing of people who hold the opposite view.    This, by the way, is yet another reason to hire literature students!  They'll notice how unwanted attitudes hide inside our language, especially in phrases that we write quickly as journalists under deadlines do. 

How to deal with this?  When I'm speaking or writing, I try to be aware of the dangers of quick and easy phrases that may contain values I don't want to convey.  It's hard to do as a journalist under a deadline, so let's put it as a slogan that simple enough to remember even then:

If you mean "car," say "car."

If you're describing a situation from the point of view of a car, say so explicitly.  Otherwise, you're implying -- whether you mean to or not -- that the car's point of view is so universal that it's just how real people see the world. 

 

 

canberra: "they only refer to buses"

Transit debates often get stuck because the word we need doesn't exist.  And as longtime readers of this blog will know, I'd really like there to be a word that means "transit vehicle, maybe on rails and maybe on tires" or "clearly a bus right now, but with the possibility of growing rails in the future."

But there isn't such a word.  So when I'm working in a city where the short-term reality is an all-bus system, and I talk about that system and our short-term plans for it, well, it's really hard not to use the word bus.  And when I want to help people visualize it, it's hard not to draw a picture of a bus. 

And when I do, rail advocates assume that means I'm expressing an opposition to rail, or perhaps just pandering to such feelings in my clients.  Here, for example, the latest blast from the head of the main light rail lobby group in Australia's capital city, Canberra, in a comment on the Canberra news blog RiotACT:

Although Mr Walker proclaims transport mode agnosticism, he is being paid by a pro-bus department ... . What do you think would happen to future work for his firm if he came out and said, replace buses with light rail on the rapid route where the demand warrants this modal change.

I have heard the [local government] policy people report on their long term plans based on the ‘Canberra Transport Plan’. They only refer to buses.

Actually, I'm being paid (and modestly) by a department that's trying to plot a rational course into a sustainable transport future, for a city of 345,000 people who live mostly at low densities with an abundant road network.  The transit system is not yet at a scale or intensity where it needs the capacity that light rail would offer, nor is there much near-term prospect of funding for it.  Light rail could happen, and I certainly don't oppose it, but as I said over and over in Canberra's Strategic Plan process, if you wait for light rail, you will miss a lot of other opportunities to improve transit mobility, and to encourage more transit-friendly urban form.

So to improve public transit in Canberra, the government is moving forward with a plan to improve the buses.   Not because they love buses, but because (a) they have buses and (b) they need to move forward. 

And so, to talk about that, they need to say the word "bus" a lot, and even draw pictures of buses. And yes, if your conception of transit begins with an absolute division between a bus world and a rail world, then officials who do that are going to sound to you like bus advocates. 

But if you call them that, you're projecting your scheme onto them.  Not everyone lives in a bus-vs-rail world.  The experts and officials who say bus a lot may well be true bus enthusiasts, but they may also be people like me who just want to get on with the work of developing good transit, and who therefore reach for whatever tool will best do the job at hand.

the perils of average density

In his 2010 book Transport for Suburbia, Paul Mees notices a fallacy that seems to be shared by sustainable transport advocates and car advocates.  Both sides of this great debate agree that effective transit requires high density. 

Sustainability advocates want higher urban densities for a range of reasons, but viability of public transit is certainly one of them.  Meanwhile, advocates of car-dominance want to argue that existing low densities are a fact of life; since transit needs high density, they say, there’s just no point in investing in transit for those areas, so it’s best to go on planning for the dominance of cars. 

Mees calls on his fellow transit advocates to let go of the idea that good transit requires high densities:

The central argument of this book is that density is not destiny.  Transport policy itself has a bigger impact on transport patterns than urban planners have realized, and suburbs don’t have to be totally reliant on the car.  Planners who insist that car dominance can only be addressed by impossibly large increases in density may actually be entrenching the problem they are trying to solve.

Transit does depend on density, but there are three problems with saying that “transit requires high density.”   

• First, it offers no hope to places that are already built at low densities and unlikely to change. 
• Second, it gives public transit in low-density areas an excuse for descending into a cycle of underinvestment, official neglect, and lazy operations, because after all, nobody expects public transit in low density areas to be any good anyway.  
• Third, it invites sweeping claims about transit’s viability based on the overall average density of a city, claims that, as we’ll see, make no sense at all.

Mees is right that “density is not destiny.”  Cities of any density can make better or worse transit choices and achieve significantly different outcomes as a result.  But density is still an overwhelming force in determining the possibilities and outcomes of transit, and we can’t begin to make good transit decisions until we understand it.

Density is hard to talk about for two reasons:  It’s very emotional and it’s hard to define and measure. 

The emotions are inevitable: Whenever we talk about urban form, people hear us making judgments about their homes.  I can stand in front of a group of citizens and talk about how a certain kind of development pattern implies certain consequences for transit, and thus for sustainability, and thus for civilization.  As we talk, it may appear that we’re having a thoughtful and educational discussion about good and bad design.  But some people in the audience have chosen to make their homes in the very development pattern that I’m describing, and to those people, I’m saying that their home is good or bad. 

Once you hear that, you’re likely to have a strong emotional reaction that makes you deaf to rational argument.  On some level, consciously or unconsciously, you’re going to feel as though I’d walked into your own livingroom and told you that your decor is not just ugly but a threat to civilization.   We all feel defensive about home.

But emotions often hide inside things that look like facts, and density "facts" are a great example.  In transit arguments, people say things like “the net density of Toronto is ###/hectare,” because this sounds like a fact and therefore conveys some authority to their argument.  In reality, though, there are several possible meanings of “density” in that sentence, as well as several possible definitions of “net” and ”Toronto.”   Briefly:

• “Density” in an urban planning context is always some kind of quantified human presence divided by some kind of land area, but it can be residential density (residents or homes per acre) or it can be total development density -- including homes, businesses, schools etc – or it can be an economic density such as the number of jobs in an area. 
• “Net,” as opposed to “gross,” means that the human presence is being divided by a smaller unit of area instead of a larger one.  In calculating the area, for example, you might take out undevelopable land, and bodies of water, and the land taken up by streets and highways -- or you might not.  There are arguments for or against excluding each of these things from “net density,” and an opinion about each of them is hiding inside the word “net.”
• “Toronto,” of course, can be the City of Toronto, or the Toronto Transit Commission area, or the whole urban mass of greater Toronto.  These obviously have utterly different average densities.

So the statement “the net density of Toronto is ###/hectare” is really as subjective as the statement “I think that cities should have more open space, narrower streets, and should have single governments covering the entire urban area.”  Because each of those opinions can affect how you choose to define “net,” “density,” and “Toronto,” which in turn determines the number that you declare, with cold factual authority, to be the net density of Toronto. 

At the core of Mees’s book, for example, is a table[1] that compares the gross residential density of a bunch of urban areas with the transit performance in each area.  The point of the table is to show that there’s really no relationship between the two.  Before we look at some fun facts from this table, remember that definitions are everything.  So in this case:

• “Metro Area” (my term for what Mees’s table calls “City”) is the entire urbanized area around a city, regardless of government boundaries.[2]  Think of it as the continuous patch of lights that you can see from an airplane at night.
• “Density (pop/ha)” is residential density – the entire population divided by the entire area. 
• “Transit work mode share” is the percentage of trips to work that go by transit, as opposed to car, walk, bike, etc.  Trips to work are not the only ones that matter, but they are the only ones that are measured in a consistent way.

So with those cautions, here’s a taste of Mees’s scandalous numbers:

Metro Area	Density (pop/ha)	Transit mode share for work trips.
Los Angeles	27.3	4.7
New York	20.5	24.8
Las Vegas	17.7	4.1
Vancouver	17.0	16.5

The density figures are calculated to shock.  Los Angeles is denser than New York?  Yes, that’s what happens when you average over a huge contiguous metro area.  Your own impression of “New York” is probably formed by the massed and soaring towers of Manhattan, but New York is a dense city surrounded by a lot of very low-density suburbs that are all included in this concept of “metro New York.”  Likewise, your stereotype of Los Angeles may be a ranch-style house with a big pool on a cul-de-sac, which implies a very low density, but in fact much of greater Los Angeles is four-story apartment buildings lined up for mile after mile.  Obviously, our impression of the density of a city is based on the part of it we choose to remember, or that we tend to see on television.  The average density of the whole urban area may be entirely different.

To me, Mees’s table proves that average density over a whole urban area is the wrong kind of density for understanding transit.   The impression you probably have of the densities of these cities is actually closer to the kind of density that matters. 

Transit reacts mainly with the density right around its stations.  It is in the nature of transit to serve an area very unevenly, providing a concentrated value around its stops and stations and less value elsewhere.  So what matters for transit is the density right where the transit is, not the aggregate density of the whole urban area. 

Of course, what matters even more precisely is how much stuff is within walking distance of a station, so it's not just density (the amount of stuff in a fixed radius) but the completeness of the pedestrian network.  A poorly connected pedestrian network can ensure that much of the stuff that's within a 400m radius is not in a 400m walk. 

Consider Las Vegas, which Mees finds to be denser than highrise Vancouver.  The Las Vegas economy is based on hospitality and entertainment, labor-intensive industries with low average wages.  So the city needs a lot of housing suited for lower incomes.  The Las Vegas way is to build utterly car-dependent apartment buildings on a vast scale, achieving all of the disadvantages of density with none of its benefits.  Consider:

For scale, the width of this entire image is about 0.55 miles, or 0.9 km.  The arterials along the south and west edges of the image are the only streets straight and fast enough for efficient transit.  Note how these large apartment developments are soundwalled from most direct access to these arterials, and how the accesses they have tend to come out at points where there's no controlled intersection, so the arterial is dangerous to cross.  (Two-way transit trips always require stops on both sides of the street, so if you can't cross the street, you don't really have access.)

So yes, Las Vegas has massive quantities of apartment buildings, which yield a high average density.  But at two levels of scale, these are deployed in patterns that make effective transit difficult.  On a macro level, Las Vegas is mostly midrise apartments spread over a large area, requiring transit to cover more distance to serve them; this is the most obvious explanation for Las Vegas's low transit performance compared to highrise Vancouver.  But the micro explanation is important too.  In the details of street pattern and pedestrian circulation, typical Las Vegas urban fabric is designed for motorists and hostile to pedestrians.  Average urban density says nothing about either of these factors, even though they are what really determine the transit experience in each city.

It's inevitable that in comparisons between cities, we're going to hear average density figures.  These figures are better than nothing when it comes to making global comparisons.  The famous databases created by Jeffrey Kenworthy and Peter Newman, for example, are useful in showing how a range of sustainability outcomes vary with density. 

But averages are dangerous, especially in transit.  Averaging sounds like a credible way to draw a simple fact out of a huge and diverse reality, but often, averages are just not the fact that matters.  In a recent post on the perils of average success, I pointed out that no transit customer really cares about average frequency, or average lateness, or average crowding.  By the same token, transit advocates need to be suspicious of average density.  What matters is the density around the transit system.  How can we best measure that?

---

[1]   Fig 4.1 p 60

[2]   In the US, “an ‘urbanized area’ is defined for each metropolitan region, made up by combining adjacent ‘census blocks’ (the smallest units for which data are collected) with more than 1000 residents per square mile, or 386 per square kilometre. …  Canada defines “urban area” on an almost identical basis to the US, using a density threshold of 400 [residents] per square kilometre.”  The data is from 2006 census in Canada, 2000 in the US.

weekend funny: fines after death

From Failblog, thanks to reader David Matsu.

canberra: a walk to the office

In Canberra, I recently stayed at the brand-new Aria Hotel, and had occasion to walk next door to the offices of the ABC [Australian Broadcasting Corporation] to do an interview.  Like most people in a hurry, I took the most direct way.  The resulting 200m walk was so funny I thought I'd let the photos speak for themselves.

Canberra is known as the "bush capital" because of its abundant nature reserves, and bushwalking (hiking, North Americans would call it) is a popular sport.  So maybe it's apt that pedestrians are encouraged to trample fresh landscaping as they go hurriedly about the nation's business.

on privatization scares

A new television commercial in Toronto calls on voters to "vote for candidates who will keep the [Toronto Transit Commission] public." 

 

If I were one of the experts quoted I'd be a little insulted by it, though we understand that this is the nature of TV commercials. 

There are many different ways to involve private enterprise in funding providing transit services, and these are so different that vague talk of "privatization" simply doesn't illuminate what's going on. 

At one extreme, you can privatise operations, planning, fleet, public information, branding and almost everything else.   In this model, prominent in Britain (but not London) and in British-influenced countries like Australia and New Zealand, government merely subsidises services that wouldn't make a profit, but doesn't try to control the overall planning of the network.  This approach sometimes "works," in a political sense, in areas where you have low expectations for transit overall, such as rural areas.  It's been very problematic in urban areas, because it deprives government of the control that its subsidies should be buying, and makes it impossible to plan rational networks that would meet the shared goal of a city and its people, and that would use limited street space efficiently.  Sydney, Brisbane, and Auckland all went far down this path and are trying, at various speeds, to pull back from it and re-assert government control over most aspects of planning and marketing. 

At the other extreme, you can privatise operations only.  This is the model used in a number of lean North American operators such as Southern California's Foothill Transit.  In Australia, only Perth takes this approach, but it's very successful there.  A public agency answerable to voters keeps full control of planning, and also owns the fleet and facilities.  Private operating companies are hired only to provide operations and maintenance, under contracts to the agency that are periodically re-opened to competitive procurement.  This is a targeted kind of privatisation aimed at the functions that are the biggest budget-killers for all-public agencies: labor costs, labor relations, and liability related to operations and maintenance.   You can make a good case that the private sector is in a better position to handle all of these than government agencies are, and while I won't argue the whole case here, many  agencies -- especially newer agencies that don't have legacy labor commitments -- are finding this a very good model.  In Australia, Perth works this way, and other cities are moving this direction.

You can find examples anywhere on the spectrum between these extremes.  Finally, briefly, there's a whole third kind of privatisation that's about the development of major infrastructure, typically called a public-private partnership.  This seems to be what Yonah Freemark is referring to in the ad's scare-quote about Vancouver.  While the PPP that built the recent Canada Line has been deservedly controversial, Vancouver's operations aren't privatized at all; they're run mostly by subsidiary companies owned by the transit agency, Translink, and that agency is very much in control of presenting a single unified system to the public.

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?

Transport Revolutions: Moving People and Freight without Oil, is one of the most through 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.  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. 

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 htem 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 retract able connectors could prevail over plug in hybrids.  As the grid-connection expands, the needf or 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.  And 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. 

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.”

 

call for reviews: cities in motion

[This post has been removed.  The heading remains only to avoid confusion caused by broken links.]

meta: your turn to help out human transit

So here's the deal.  I have to make major headway on a book project in the next two months, while also doing a lively full-time job as a transit planning consultant, while also moving from Sydney to Canberra (temporarily), while also doing another quick US trip in late Oct.  I'm simply not going to have time to blog original material at the rate you've come to expect.

So here's how you can help:

1. Propose guest posts.  If you know something about a relevant topic, and can write about it coherently with some pictures, draft a guest post and send it to me.  Just put the text and pics in an email for now.  I will screen for writing quality and relevance to maintain a standard, but I don't have to agree with them.  I've already run guest posts with which I disagree, and will continue to do so when they're well argued, relevant, and interesting.  (I don't mind posts that I agree with, too, although the best of all are posts about things I don't have an opinion on yet.)
   
   
2. Send me ideas.  One of the recent worldwide media sensations on this blog was a simple post on new transit-themed toys by Lego.  I did it in about six minutes from a reader's email.  That kind of thing I'll have time to do. 
   
   
3. Keep reading and commenting.  Don't decide I've vanished just because I post a little less.  And as always, if you can't comment publically for some professional reason, comment via an email (link under my photo).  Policies on confidentiality are here.

There will still be a major post by me now and then, at least once a week I hope.   Some may actually be pieces that I'm thinking of using in the book, and your responses will help me sharpen them!