Author Archive | Jarrett

basic questions about “cost/benefit analysis”

Transit projects, like all government projects, have costs and benefits, so one classic way to evaluate project proposals has been the "Cost/Benefit Analysis" (CBA).  Add up all the benefits, add up all the costs, divide benefits by costs and announce the Benefit/Cost Ratio (BCR).  If the it's below 1, which means the costs exceed the benefits, you kill the project.  The higher the it is, the better the project.

In the Financial Post (part of Canada's National Post), Peter Shawn Taylor argues that the Cost/Benefit Analysis is the best way to evaluate a project, and that bad projects are being advanced by a newfangled thing called Multiple Account Evaluation (MAE).  I encourage you to be bored by this dispute, but not before you understand it.  Neither of these methods is sufficient to end a passionate argument, and it's important to know why they never will be.

The problem with Cost/Benefit analysis is that it requires you to convert all the costs, and all the benefits, to the same currency.  That means you must know, with imperial confidence, the cost in dollars of such things as:

  • each minute of each customer's time
  • a particular ecosystem to be destroyed or preserved, which may involve various degrees of endangerment (of species, and of ecosystem types)
  • historic or cultural resources to be destroyed or relocated, or preserved.
  • the redevelopment potential of a particular area with or without the project, and the various benefits and costs arising from that potential.
  • impacts of the project on affordability, and thus on the future shift of disadvantaged persons from one area to another, with a range of social impacts.
  • benefits of electrification (quiet, no on-site pollution) on a neighborhood's quality of life, which impacts the previous point.
  • a particular aesthetic impact that makes the city distinctive in a new way, such as a stunning piece of architecture or a new relationship to a unique historic artefact or feature of landscape.

Several of these items require confident prediction of the future, and there is also a vast question of who pays these costs and reaps these benefits.  I am not criticizing the vast body of research that has gone into improving the conversion factors that turn all costs and benefits into a dollar value.  But unless we really agree on what endangered ecosystems or municipal self-esteem are worth, in dollars, it's reasonable to question whether Cost/Benefit analysis can deliver the last, decisive word on whether a project deserves public investment.

One Canadian solution is the Multiple Account Evaluation (MAE).  Different types of benefits and costs are calculated differently and not converted into a common currency.  As Taylor describes it:

Developed by the [British Columbia] government in 1993 and now in widespread use, MAE dispenses with a single spreadsheet of advantages and disadvantages and adopts instead numerous separate “accounts:” a financial account, social account, environmental account and so on. In this way, the actual monetary costs and benefits of a project become just one of many issues to be considered.

A similar idea is inherent in the term "triple bottom line," which refers to economic, environmental, and social impacts — positive and negative — of a proposal.  In either case, you end up with a series of parallel analyses that give different answers from the point of view of different kinds of cost and benefit. 

So then what do you do?  Taylor quotes emeritus Professor John Shortreed of the University of Waterloo:

“The problem with MAE is that each account is given equal weight,” he observes. “This suggests the billion-dollar cost of the project is no more or less important than any of the other accounts, however trivial.”

It's easy to weight each account equally, because that sounds fair, but of course equal weighting is just as arbitrary as any other weighting, because we're talking about things that are not directly comparable to each other, such as a social cost vs an environmental one.  If you could really compare those things, we'd be able to do cost/benefit analysis.

MAE and the "triple bottom line" are useful concepts because they reveal the arbitrariness of weighting.  Weighting implies decisions, for example, about the relative importance of social vs environmental impacts.  That means the weighting is a value judgment about what matters to us as humans, as a community, as a civilization.  Surely we should argue passionately, maybe even irrationally, about that! 

The real problem here is that in the interests of consensus, we tend to allow technical analysis to make important value judgments for us, which is to say, we want technical analysis to tell us who we are. 

When you hear the terms social benefit, environmental benefit, and economic benefit, which arouses the strongest positive feelings?  The answer is an important signal about your deeply-held values and world-view.  If a technical analyis is making that decision for you, are you sure it's the analysis you want to trust?

Cost/benefit analysis and Multiple Account Evaluation (or "triple bottom line") both conceal value judgments.  Cost/benefit analysis hides value judgments in the factors used to convert various costs and benefits into dollars.  MAE or "triple bottom line," by contrast, comes up with multiple ratios — social vs environmental, for example — and ends up having to weight them, which is where the judgment appears.  I prefer the MAE or "triple bottom line" only becuase it makes the arbitrariness of weighting more visible, and hence pushes the conversation about it closer to the public sphere. 

It's understandable that we don't want to compare a billion-dollar pricetag to unquantifiable but powerful benefits that people will weight differently.  But the whole idea of the triple bottom line is that (a) we have to make these comparisons and (b) there's no technical basis for an answer.  When I'm doing evaluation frameworks of any kind, I look for guidance on the weighting based on locally adopted goals, value statements, or public discussion.  If the goals haven't been articulated, I often suggest some public discussion about the weighting itself.  (Some evaluation processes do consult the public on weighting, but the question can sound too technical at that point so not enough people pay attention; I think more can be done to make these discussions more vivid and consequential.)

As usual, I don't have the answer, only a refinement of the question.  Should communities talk about how to weigh competing values that are in conflict?  Or should they let those decisions be made inside a technical process in the guise of analysis?  There's a very powerful argument for the latter: decisions get made.  It's a lot of work to educate a community enough that it can express its values and desires in a form that a project can implement, even before you impose the other value judgments attached to various funding sources.  I don't advocate either position entirely, but have argued the "discuss the values" position because it should be visible as a choice.  In many ways, this is the "democracy vs technocracy" debate that we're hearing right now in the context of the European Union.  It's a hard question, maybe too hard, but it's one of those great debates worth caring about.

san francisco: cable cars and green lights

A traumatic memory from my old neighborhood, still exactly as I remember it:

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The California Street cable car still doesn't influence traffic signals, even in the era of GPS.  Here at California & Hyde, the car stops in the median of the street, requiring passengers to cross a traffic lane to board or alight.  Note the green traffic signal to the right, which tells motorists it's ok to speed past the cable car as people get on and off.  The man in the black coat and cap, waiting to board, must stand in a traffic lane that has the green signal.  To the motorist, he appears to be crossing illegally, yet it's the only way to get to the cable car.

This is not a high-traffic intersection.  Surely all lights should turn red when the cable car is present.

I lived a block from this point for seven years (1987-94) yet almost never used the California St. cable car.  This was why.

san francisco: the freeway spirit lives?

About 18 years ago, when I was chairing the Citizens Advisory Committee of the San Francisco County Transporation Authority, I remember a day when staff effusively advised that they'd gotten budget to put up green signs around the city to help motorists better identify the streets.  The green sign in this picture, for example.  

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This is on Jones St. northbound approaching Sacramento St., but there are many similar cases.  (Trivia note: One of these signs appears in Gus Van Sant's fine film Milk, which is set in the 1970s.  It was the film's most glaring anachronism.)

Nobody asked my committee's opinion when these signs went up.  And today, briefly touring my old neighborhood, I find that these signs are still there.  Has nobody questioned them in all this time?

Most readers will see the issue at once, but if you don't, here we go:

The motorist faces a stopsign.  That means they should be looking at the crosswalk in front of them, and the other traffic approaching.  What's more, they should be stopped, or stopping, which means that their focal length should be short; they don't need a sign that's meant to be read at high speeds.   Yet high speed is implied by the green sign's large typesize, high position, and "freeway font"; the green sign has the same color, font, and typesize typically used on California freeways.

San Francisco's standard black and white streetsigns are the most legible I've encountered anywhere in the world.  They are a global model for simplicity, clarity, and grace.  There's one right below the green sign in this pic, in front of the tree.  The text on these signs is over 1.5 inches high.  If you can't read that black-on-white sign while stopped at a stopsign, or decelerating to it, your vision is so poor that you shouldn't have a drivers license.  Only seriously dangerous drivers need the green sign.

Then there's the question of focal height.  A sign placed very high, like the green sign here, is pulling the driver's eye away from the ground plane, which is where the squishable pedestrians and cyclists are.  Extreme type size also encourages reading the sign from further away, which means focusing further away, which means a greater risk of not seeing the pedestrian in front of you.

In short, the message of the green sign ("read me from a distance, like you're on a freeway, driving fast") contradicts the message of the stopsign and crosswalks.

Motorists choose their speed and focal length based on a range of signals, not just explicit commands and prohibitions.  These signs may be appropriate on high speed multi-lane streets, where you may need to change lanes to turn once you've recognized a cross-street.  But what are they doing at stopsigns?

I'm sure there are manuals that say this is compliant to standards.  But many bad ideas are endorsed by manuals.  Does the green sign make sense?  Argue with me.

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PS:  "Wait, Jarrett didn't say he'd be in San Francisco, and he didn't call!"  Sorry, it was just two days, and I'll be back soon.

our lady in parliament

UntitledMy friend and former colleague Julie Anne Genter, an expert in sustainable transport policy, won a seat in the New Zealand parliament on Saturday, with the Green Party. 

Raised in Southern California, Julie will be the first US-NZ dual citizen to sit in the New Zealand parliament.  More important, she has done superb work for our firm in sustainable transport policy across Australia and New Zealand, including as a leading exponent of Donald Shoup's work on parking pricing.  (I featured one of her early videos on this topic here.) 

While it appears she will be sitting in opposition, I know she'll be doing great work for New Zealand and beyond.

sydney: new efforts at frequency mapping (guest post)

Kevin McClain is currently a Project Officer at Easy Transport, the Regional Coordination Office for Community Transport in Northern Sydney.  He holds a masters degree in Transport Management from the University of Sydney.

Recently there has been a lot of discussion about Frequency Mapping on Human Transit starting with this post. Here in Australia we have seen frequency maps for Melbourne and Brisbane, but other than this map, we haven’t seen one for Sydney. Inspired by the efforts so far, I set out to try and make a frequency map of the services in Northern Sydney, the region where I currently live and work.  This effort was also driven by the desire to reduce the number of resources a transport user would need to consult in order to plan a trip.  Currently there are seven different system maps for services in the Northern Sydney Area alone: five bus maps (each covering different areas), one rail map and one ferry map.  Ultimately I ended up developing two maps: One frequency map of all of the services in Northern Sydney and one map of all frequent services across all of Sydney.

I work for Easy Transport , which provides transport information for seniors and people with disabilities. We also serve as the regional coordination office for Community Transport in the Northern Sydney Region and provide travel training to residents.  Our Northern Sydney map was developed to be a tool that could be used by the travel training program and potentially help promote our service. 

One of the challenges I have struggled with is the fact that there are a variety of service types in Sydney (buses, trains, ferries, and light rail) and people seem to want to be able to tell the difference between the service types when they look at a public transport map.  This makes frequency mapping more difficult.  In the Spokane map, all services are provided by bus.  There is no need to show service types.  Creating a map that shows service types and then shows frequency within each of those service types quickly gets complicated. 

For the Northern Sydney map I started by showing bus, train and ferry frequencies at the following levels 1-15 min, 16-30 min and 31-60 minutes.  This quickly proved to be too much, therefore the train lines were modified to show only stations that had frequent services (1-15 minutes) and stations that didn’t (Click here to download high resolution PDF.)

Northern Sydney V1

One alternative is to show only frequent and infrequent services (1-15 minutes and 16-60 minutes). While this reduces the amount of information available, it also makes the map more legible.  (Click here to download high resolution PDF.)

Northern Sydney V2

The map of all frequent services across all of Sydney is less complicated.  Only the suburban train services and frequent bus services are shown.  [JW:  Sydney has no frequent all-day ferry services.]  Train frequency was again shown on a station by station basis.  This version has the same colours for the train lines as are used in the CityRail map.  (Click here to download high resolution PDF.) 

Sydney Frequent V1
While this alternative does not have the colours of the train lines.  (Click here to download high resolution PDF.)

Sydney Frequent V2

One of the main points of both maps is to show where the frequent bus services are in Sydney.  While train frequency is also important, there has been a recent expansion of frequent bus services across Sydney with the introduction of the Metro bus services (in red on the map of all frequent services).  I think that it is important to show how these new services, along with existing frequent bus services, fill in some of the gaps.

Each of the maps show the trade-off between providing more information and a clear map that emphasizes the frequent services.  Try planning a trip on one version of the map and then the other.  Does the level of information provided affect the routes you chose?  Are you able to figure out where the routes are going?  Are there areas that are particularly confusing? Which version of each of the maps do you prefer?

These maps are still in draft form and I would welcome comments and suggestions about how the maps might be improved.  And yes, there are errors on both of the maps.  Corrections or any frequent routes that I might have missed are also welcome.   You can send me feedback either by commenting on this post or by emailing me at [email protected]


 

should we criticise false claims of “innovation”?

Yesterday, twice in one day, I encountered major news articles in media I generally trust (the New York Times and the Atlantic) which described very old ideas as though they were innovations.

In the NYT (opinion section) Lisa Margonelli described basic small city bus network planning as though it were an innovative critique of big-city planning.  (It's not, it's just different tools for a different problem.)  She also seemed dazzled by the private minivans proliferating in New York — a public transit model that's almost universal in the developing world.   (Her piece was ignorant of several other important things too, and I hope I wasn't too harsh.)

Then, on the same day, a respected (by me) columnist at Atlantic Cities proclaimed the work of an academic who claimed to have just invented flexible-route or demand-responsive transit.  This is an old idea, widely used in lower-ridership places around the developed world.  Considerable academic work has been done on it for years, and I personally was desgining these services, and often ripping them out, almost 20 years ago.

(I'm not very sympathetic to Margonelli, because her rhetoric toward my profession is so hostile.  When someone writes an article that displays ignorance of the field while hurling invective at everyone who works in it, they deserve some pushback.  I feel guilty about calling out the Atlantic writer, though, because I'd probably have made the same mistake in his place, writing in an unfamiliar field and urged on by the claims of a published academic.)

So my question for discussion is:  Should we care?  Should it matter if someone claims to have invented an idea, if that helps a good idea spread?  Am I just being a curmudgeon or killjoy to point these things out?  Is there anything wrong with letting people have the idea that the great ideas were theirs? 

 

 

new york times: how to be confused about transit

Lisa Margonelli's opinion piece in today's New York Times, "Thinking Outside the Bus," is a must-read, and not just for its important stories about small-town public transit development and the private van initiatives in New York.  It's also useful as an illustration of how people often imagine false links between unrelated ideas, and the role of emotive words and images in making these falsehoods seem real.

Everyone does this, so it's important to understand how it works.  Journalists especially must understand how this works, if they want to go beyond quick "good and evil" stories and actually explain an issue fairly.

The article begins with the story of Pam Boucher, a carless woman in the small town of Brunswick, Maine who was stranded until the advent of a small, intimate bus system:

Now in a wheelchair, Boucher calls me from a bus stop, where she’s waiting with a friend. The bus has changed her life, she says, giving her independence, control over her time and the ability to socialize. “I take it at least once a day. Sometimes three times.” She meets friends on the bus, takes herself to her medical appointments, and goes shopping for groceries afterwards. A few months ago the bus extended its hours into the evening to accommodate more commuters; she can now shop for groceries in the evening if her day has been spent at medical appointments.

And this bit is important:

“Doug’s the driver. He’s really good to me. He’s knows my condition and that I sometimes forget where I am.”

Brunswick's local buses, in short, are geared to people with special needs, as small-town transit systems often are.  The emphasis is on ensuring access for these people and providing them basic mobility in their community.

These systems are absolutely laudable.  I've helped design several of them myself.  But they are intrinsically inefficient, in terms of passengers service per unit of public cost, because the effort Doug takes in making sure Pam's needs are met requires a lot of Doug's time.  Suppose that on average, he spent six minutes taking care of each customer's needs, counting the time he's driving.  That would mean he'll never be able to serve more than 12 people per pay hour, which is very, very low by urban transit standards.  Serving special needs is a good thing to do, but it requires lots of staff time per passenger, so it will always have a very high cost per passenger.  Unless: 

Unless you pay the drivers less.  Margonelli's next story is about the emerging minibuses of New York, an important private sector initiative that's generating high frequencies of service on some streets using vans on fixed routes, where the van companies can quickly invent new routes as demand seems to require.  The genius of these buses is that they tolerate lower ridership (mandated in fact by their small size) but they can do this because the drivers make much less than unionized transit agency labor.  These vans may be innovative for New York but they're actually the normal way of doing business across most of the developing world, where low prevailing wages allow for high volumes of small-bus transit.  These systems are often not organized in the way that developed-world public transit is; often they feel more like taxis with multiple passengers.  But their sheer abundance, made possible by low wages, makes up for that deficit.

(There are intermediate models, by the way.  Vancouver's transit agency runs small buses, the Community Shuttle, at 50% of the cost of running big buses.  That lets the small buses be more abundant, reaching deeper into low-density hills than big buses could afford to do.  This didn't require the private sector, just a negotiation with the union based on the obvious fact that driving a small bus with few passengers is an easier job than driving a big bus with many.)

So is Margonelli really a ferocious right-wing union-busting capitalist?  No, she's just unclear on transit's basic geometry and economics.  Note this strange move:

America’s famously car-dependent culture strands the Pam Bouchers among us: those too old, too young, or too sick to drive cars. Overall, only 5 percent of Americans use public transit to get to work and that number is somewhat distorted by the huge numbers of people in cities who commute by subway, train or bus. Outside of metropolitan areas, the number of Americans taking public transit falls to just 1.2 percent. With so few people on the bus, schedules become infrequent and inconvenient, and ridership drops further.

The "huge numbers of people in cities" are distorting the national transit data?  Margonelli is clearly interested only in small town and rural transit, where she would like to raise that 1.2 percent figure.  Personally, I'm all for small town and rural transit, but only because of my own social-democratic beliefs about an inclusive society; unless you want developing-world wage rates, it's definitely not an efficient way to raise nationwide mode share.   That goal will be served only by focusing on places that transit can serve cost-effectively, carrying many people with few drivers.  That means cities, and a few other dense transit-oriented places like university towns.

Margonelli wants to somehow tie the social-service imperative in small towns in rural areas to the national challenge of increasing ridership, but the "low hanging fruit" for huge ridership increases is in the cities.  Our cities still have many places where the development pattern creates high potential demand for transit that isn't being well served.  If we were engaged in a national struggle to increase the usage of transit overall, that's where the big wins are. 

So let's come back to the issue of images and emotive words, and the way they help sustain confusion.  One thing happening in this story is that the human interest in Pam Boucher makes the author think that solving Pam's problem is an efficient way to serve national ridership goals.  This is just mathmatically false, becuase social service needs require lots of driver time per customer and the essence of efficient transit is minimizing driver time per customer.  Neither objective is bad, but they're different objectives.  If giving every customer five minutes of attention were the key to efficiency, corporations would still have human beings answering every customer's call.

But there are also three emotive words at work in this rhetoric.  One is "bus" as used in the article's title, "Thinking outside the bus."  The other two are in this passage:

Conventional wisdom says that the way to create or improve public transit is to invest billions to engineer rails, trains and buses. But the Brunswick Explorer [the new service that Pam Boucher uses] is one of many innovators that are seeing transit as more than an engineering problem and trying to  build transit that meets the needs of its residents.

You see them:  conventional wisdom and innovator.  This tired good-and-evil frame is routinely stamped onto all kinds of journalism about sustainability issues.  I wonder how many journalists could even write an article on these topics without using it.

Look at that word innovator or innovation.  We hear it all the time.  It means "having an idea that I personally haven't heard of before."

If don't know much about transit, many old and well-tried ideas will strike you as innovative.  The Brunswick, Maine transit system is laudable, but this kind of problem-solving focused on senior-disabled needs has been going on for decades.  It's a very localized, specialized process that's different in every town.  It's beautiful to watch and be a part of.  But the basic frame of the problem: the costs of service, the patterns of service that work in a small town, North American wage expectations, the opportunities for savings through communications and through merging existing operations — all this has been worked on for decades and solutions like Brunswick's have been created in many places.  Brunswick has tread a well-researched path; locally it's an innovation, but it's not more innovative than hundreds of similar systems.  Again, the word innovation reflects the writer's ignorance about the field.

If transit professionals seem cold to "innovative" proposals, it may because they're stuck in the mud.  But it may be because they know their field, have heard this proposal twenty times already, and understand the ways it works and doesn't work.  They may also understand that the "innovation" meme is really a way to evade a real, hard question, such as the appropriate levels of wage for transit workers.  Nobody wants to talk about that; it's much more fun to praise private-sector models like the Flatbush vans.  But if you call those vans innovative, what you're really saying is:   "I've never used public transit in the developing world, where this idea is routine, so it's new to me."  (You're also saying: "Drastically lower driver wages are a great idea.")

Remember, in North America, most of what looks "efficient" and "innovative" about "private sector" transit is simply liberation from the negotiated wage rates that bind virtually all public transit operators.  Transit costs are driven by the cost of labor, so if you make labor cheaper, many things are possible.  Calling these services "innovative" is taking your eye off the ball, and needlessly slandering transit experts as purveyors conventional wisdom just because they've heard the idea before.

As for "bus" as an image of constrained thinking (in the title, "Thinking outside the bus"), it's understandable, though increasingly archaic.  The crowded, constraining, poorly ventilated bus does feel like a box and thus as a good metaphor for mental imprisonment or "conventional wisdom".  (Remember the film Speed, or the pilot of Six Feet Under?  Both used a bus that was older than most buses on the road at the time, intentionally playing to a stereotype of buses as primitive.)  Yet all the solutions Margonelli proposes are also vehicles on tires.  "Bus" is a large and diverse category, which makes it useless for talking about what matters in transit.  The word says nothing about speed, duration, frequency, and reliability, nor does it address labor cost, which determines how much of these things you can afford.   "Think outside the bus" if you must, but as Margonelli's examples show, you're still likely to end up with one.

UPDATE:  For further entertainment, see Eric Jaffe today in the Atlantic on the "entirely new transit concept flexible bus services," which have been around for decades.  I personally was designing them (and sometimes ripping them out) almost 20 years ago. 

 

walkscore’s new apartment search functions

Walk Score, an admirable Seattle company that invented the "Walk Score" now widely used in the US real estate business, now has an improved app for their transit travel time tool.  That tool, which I use in my own definition of "personal mobility," shows you how far you can travel on transit from a chosen point in a fixed amount of time.  For example, here's how far you can go in 15, 30, or 60 minutes from San Francisco Civic Center, at least on agencies that participate in Google Transit:

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You can find something similar at Mapnificent.net.

Walkscore now has a fine new set of presentation tools that combine this information with real estate listings, so that you can search available apartments based on commute time to a destination of interest.  Couples can even search for locations that optimize both of their commutes.  For example, if one of you works in downtown Seattle and the other across the lake in downtown Bellevue, Walk Score discovers that if you want to equalize your commutes, you should live in the University District, where the blobs of access from the two workplaces overlap. Walk Score will even show you available apartments there.

2 pers commute

(Of course this service needs to be expanded beyond rentals.  Some people who are buying a home may care about similar criteria.)

All this is a step toward a more universal use of this tool that allows anyone (people, businesses, institutions, government services) to see the transit access consequences of where they choose to locate.  Many places are simply inaccessible by any efficient form of transit, so people need tools for avoiding those places if they want transit to be part of their lives, or that of their employees, customers, or clients.  That's especially important because some of these places are cheap, but may not be as cheap as they look when you consider the transport costs they impose.

I'm also interested in using this tool to generate a more factual two-digit "Transit Score" than the one Walk Score currently promotes.  More on that here.