Mobility

quote of the week: hopeful intentions of the u.s. federal transit administration

[In reading this, recall that mobility means "how far you can go" or "how much area you can cover" in a given time.  "Accessibility" or "access" means "how many economic, social, and recreational opportunites that you can reach" in a given time.]

"[The U.S. Federal Transit Administration (FTA)] believes improvements to both access and mobility are key features of a good transit investment. FTA agrees a measure that defines accessibility instead of mobility might be a better representation of the kind of benefits transit projects are intended to produce. As noted, however, it has proven very difficult to measure. Although it is relatively easy to specify a measure such as number of jobs within a specified travel time of a single location, creating a broader corridor or regional measure including calculations to and from multiple locations is more difficult and complex. FTA believes a measure focusing on project ridership will indirectly address access improvements since more people will ride a project that has enhanced access to jobs or other important activity centers. Focusing on the way a transit project can enhance an individual’s ability to get places, rather than just travel faster, is a desirable outcome of the evaluation process. FTA intends to continue to explore how best to do so."

The FTA's Notice of Proposed Rule Making [pdf] that
proposes to shift the criteria for funding
new transit projects from travel time to ridership,
a move that Socrates* had some questions about.
Hat tip to Susan Pantell for reminding me
of this passage. 

This is indeed hopeful.  I'll lay out a fuller argument on how this agenda might move forward in a coming post.

Question: When FTA refers to the difficulty of aggregating accessibility measures for everyone in a region, do you think they're referring to a logical problem (i.e. the stated task is logically or philophically incoherent), or a data availability problem, or some other kind of problem?  It certainly shouldn't be a processing power problem anymore.

* To anyone who suggests that I'm being grandiose in assigning my own thoughts to Socrates, I can only reply that (a) the dialogue in question is broadly consistent with Socratic method, which is Socrates's primary legacy, and (b) Plato made quite a successful career of ascribing his own ideas to Socrates, including many that were not at all consistent with Socratic method, and he doesn't seem to have come to much moral/karmic harm.  As long as a fiction is obviously a fiction, it's not lying, it's metaphor.  

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:

6a00d83454714d69e2011571e07ffe970b-800wi
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.

imagining cities without mobility

Philips Corporation, like everyone, is running a livable cities program, in this case a set of awards for individual projects rather than big-picture rankings of cities.  I just stumbled on it, and got a rude shock.

There are eight categories: Neighborhood, Mobility, Care, Education, Water, Shade, Sport, and Regeneration — all excellent things.  Obviously, I'm professionally interested in mobility, so I looked to see who was winning there. 

The leading candidate for the Mobility award is Plaza Movil Street Park, a proposal (for Buenos Aires, Argentina) for temporary street closures to create community park space.  Its benefits are described like this:

Creating recreational spaces for local communities to relax, play, meet, and chat.

That's wonderful.  It's glorious.  I'm all for it.  To use Philips's terms, it's great for Neighborhood, and probably also for Shade.  But it's not mobility

The only relationship that this plan has to mobility is that it takes space normally used for mobility and uses it for something else.

St. Augustine observed that we are always either being or becoming.  In urbanism, "being" corresponds to placehood, and "becoming" corresponds to movement or mobility.  The late 20th Century car-centered model led to the massive conversion of land area from placehood functions to mobility functions.  Transit's great virtue is that it provides a lot of mobility using relatively little space, so that more area can be devoted to places, both public and private.

And yes, a great street provides an experience that integrates placehood and mobility to a degree.  And yes, good urban redevelopment also reduces our need for mobility up to a point. 

Bravo for well-designed street closures.  But to give a street closure a mobility award seems to imply that mobility — our ability to get to places we want to go to — just no longer matters. 

There is a strong current in New Urbanism, not without detractors, that does seem interested in abolishing mobility.  Patrick Condon's idea for Vancouver, for example, would cancel a single proposed subway line and instead replace all of the city's electric trolleybuses with streetcars that go the same speed as the buses do.  He would cancel a mobility-improving project and instead spend money in way that that may do great urban things but doesn't increase mobility at all.  Once his network was complete, nobody could get anywhere any faster than they can now. 

This makes sense only in a context where going places (even under renewable elecric power) is an objective evil.  Streetcars, in this vision, supposedly cause greater urban density to be built at livable neighborhood scales, so that people meet more of their needs close to home.  People spend most of their time in their own "villages" and others nearby.  They simply do not travel far across the city, and had better not be in a hurry when they do.

It's understandable that "urban village" is a winning concept right now.  We do need to increase the self-reliance of each part of a city, so that travel demand for many of life's needs can met closer to home.  The pendulum swung far the other way in the late 20th century, toward surrendering placehood to movement.  I support and eagerly participate in efforts to help it swing back.

But I think we can see what it might look like to swing too far in the new direction.  We stay close to home, and thus evolve transport systems that are useful for going short distances and useless for going long ones.  And the obvious retort to this is:  In that case, why live in a city?  Why not just live in a country village, or in a small city? 

The whole point of living in a city is to have access to unusual things that are only possible at a large scale.  If you want major league sports or a good symphony orchestra or a world-class major university, you need to be in some kind of urban area.  If you have a very unusual interest, only a place with lots of people will have a few people who share that interest.  If you want choices, you need redundancy, also known as competition.  You need there to be two or more sources for whatever service or product or experience you're looking for, readily available from where you live.   For those things, you need a certain amount of urban mass, and some options for moving around within it.

The great irony of anti-mobility village-first thinking is that it inevitably leads to monotony — less choice and therefore less opportunity for people to form specalized communities where unusual thought and creativity can flourish.  More disturbingly, it leads to a world where only the internet offers those things, which leads in turn to nightmare images of a world of plugged-in couch potatoes, people who never go outside anymore because their social and intellectual needs simply aren't met by the 500 people who happen to be within walking distance.

The antidote to conformity and monotony is the city.  For a city to function as a city, you need mobility.  Streetcars are fun to ride, but not if you're in a hurry.  Closing a street on Sundays so people can dance is a great thing.  But you can't run an economy that way, nor can your citizens feel free. 

basics: expertise vs. activism

The planning professions work in a grey zone between expertise and activism, and managing these competing impulses is one of our hardest tasks.

As a transit planning consultant, I don’t worry much about being perceived as an advocate of transit in general.  Experts in any field are expected to believe in its importance.  But I do try to keep a little distance between my knowledge about transit and the impulse to say “You should do this.”  A good consultant must know how to marry his own knowledge to his client’s values, which may lead him to make different recommendations than he would do as a citizen, expressing his own values. Continue Reading →

transit’s product: mobility or access?

This post is an important early section in the book I'm working on.  Longtime readers will recognize the primordial muck from which it arose.  I thought I would share it because it's a key conceptual marking-point and I know it will be controversial.  In brief, I argue that while "mobility" is problematic as a goal of a whole transportation system, we can't abandon it as a descriptor of transit's primary purpose and function, because to do so makes it impossible to understand how and why transit does what it does.  If anyone has a better word for what I'm calling mobility, I'd love to hear it. 

 

Because transit debates so often lose track of transit’s defining product – which I’ve called personal mobility – it’s worth pausing to clear some weeds around this concept.

In contemporary urbanist thinking, the world mobility is profoundly out of fashion. Todd Litman of the Victoria Transport Policy Institute defines mobility this way:

Mobility refers to the movement of people or goods. It assumes that “travel” means person- or ton-miles, “trip” means person- or freight-vehicle trip.   It assumes that any increase in travel mileage or speed benefits society. (Litman, 2008)

By this definition the output of transit that matters is passenger-miles or passenger-km.  A passenger-mile is one passenger carried for one mile.  (Ten passenger miles, for example, could mean one passenger carried for ten miles or ten passengers each carried for one mile.)

Defined this way, the concept of mobility can be misleading because it doesn’t measure how readily people got to where they were going; it just measures how far they were moved.  Most of the time, though, our travel isn’t motivated by a sheer desire for movement; it’s motivated by the need to do something – make some kind of economic or personal contact – that is too far away to walk to.

Suppose that your favorite grocery store is reachable from your house only via a circuitous bus route.  When you ride this bus to the store, you only want to go about 3 miles, but the bus takes you 5 miles in the course of getting there, and the bus company will claim to have delivered 5 passenger-miles of mobility as a result of your trip.  Obviously, that’s unfair, because you only wanted to go 3 miles. 

But really, you didn’t even want that.  What you wanted was your favorite grocery store.  You wanted access to your grocery store, not 3 miles worth of mobility.

So there are two problems with mobility, defined and measured this way.  First, it measures how far you were moved, even if some of that movement wasn’t necessary.  Second, more fundamentally, it implies that a greater good was delivered by taking you to shops three miles away than would have been delivered if the same shops were close enough to walk to. 

Transit that participates in reshaping the city, by encouraging greater density and walkability so that the basic needs of life are available with less travel, has the effect of increasing access even as it reduces our need for mobility.   From the perspective of almost all of transit’s goals, replacing long trips with short trips that achieve the same outcome is a good thing.  If shops identical to the ones you have three miles away were to open next to your house, you wouldn’t travel as far. In fact, you wouldn’t make a transit trip at all.  The bus company would lose a customer and its ridership would fall as a result.  Yet clearly, the ability to do something via a short trip rather than a long trip is better for you, better for the energy-efficiency in your city, and better for the environment. 

That’s why Litman suggests we should care more about what he calls access:

Accessibility (or just access) refers to the ability to reach desired goods, services, activities and destinations …   Access is the ultimate goal of most transportation, except a small portion of travel in which movement is an end in itself (jogging, horseback riding, pleasure drives), with no destination. This perspective assumes that there may be many ways of improving transportation, including improved mobility, improved land use accessibility (which reduce the distance between destinations), or improved mobility substitutes such as telecommunications or delivery services.  (Litman, 2008)

Mobility is how far you can go in a given time.  Access is how many useful or valuable things you can do.  If a new grocery store opens near your house, that doesn't improve your mobility but it does improve your access.  You can now get your groceries closer to home, so you don't need as much mobility as you did before.  You can also improve your access by working at home instead of commuting, downloading music instead of going to a CD store, and moving in with your romantic partner.  In other words, a lot of the work of access is simply about eliminating the need to move your body around the city in order to complete the economic and personal transactions that make up a happy life.

But before we dismiss mobility as a distraction, let’s look again at the three ways of improving access, as Litman lists them:

  • “Improved mobility”
  • “Improved land use accessibility (which reduces the distance between destinations)”
  • “improved mobility substitutes such as telecommunications or delivery services”

When I say that transit’s product is personal mobility, I’m emphasizing the first of these three ways of improving access.  I’m not implying that the others are unimportant, only that the first of these – improving access by improving mobility – is transit’s primary job, just as firefighting is the fire company’s primary job.

Transit does have side effects, though, that affect the second kind of access, and we’ll return to these in Part II.  If an especially popular or exciting form of transit, such a streetcar or monorail, is built in an area, this may raise the land value of the area in a way that encourages denser development, and denser development often improves access by putting shops and other destinations that you value closer to your house. 

Designing transit to trigger desirable development is one of the core ideas of the New Urbanism, but like many new ideas it’s really an old one.  In 1900, when public transit was the primary form of urban transport for distances too far to walk, the public transit infrastructure determined the shape of the city’s growth.  In fact, many transit lines were created and owned by developers whose real goal was to build and sell houses along the line.

So transit can improve access two ways: (a) by providing personal mobility and (b) by influencing development to create denser communities where less mobility is required to do the same things. 

The second of these, however, is obviously an indirect impact.  Transit may lead to access-improving development, but only via several intermediate and unreliable steps.  You can build a rapid transit line and still not get more density if several other things don’t fall into place – including zoning, economic growth, cooperative neighbors, and bankers willing to lend to developers.  In that case, the new transit project doesn’t improve access at all, unless it has improved the first kind of access: mobility.

What is more, the ability of transit to stimulate development is clearly related to how well that transit seems to promise good mobility to the people who will live, work, or play there.  We don’t pay more for an apartment over a transit station because the station is a nice community amenity, like brick paving and planter boxes.  A transit station adds value to development precisely because buyers think it will make it easier for them, or their tenants, to get around.  So if transit isn’t credible in offering mobility, or at least appearing to do so, it’s unlikely to stimulate development.

In 2009, we began to see web-based tools that allow you to enter an address and see where you can go, in a fixed amount of time, from that address.  Here, for example, is the output from WalkScore.com's travel time tool, when queried by someone near the San Francisco Civic Center at 9:00 AM:

 GoogEarth walkscore

These tools aren’t for planning a trip, they’re for visualizing your freedom.  Not your freedom in some improved city of the future, but your freedom now.  That’s what mobility is: your freedom to move right now.

But the genius of these tools is that they let us see how choices we might make would affect that freedom.  Imagine that you’re deciding where in a city to live.  For each house or apartment you’re considering, you can check one of these sites and see quickly where you’ll be able to get to easily on transit.  And you won't get just an abstract "transit score."  You can look at this map and see how easy it will be to get to the places that matter to you.

The tool might save you a fortune.  If you’ve decided that you can only afford a house in a distant suburb, enter that address and you’ll get a clear map of just how far away things that you care about will be.  You might run the numbers on the cost of commuting and decide you’ll save money by spending more to live in a better location, closer to rapid transit and/or closer to the city, where you’ll spend less on transportation. 

In other words, you might make a decision that requires less mobility, because it has better access.  That access will consist not just in being closer to things you value, but also in having better transit options for the trips that are still too far to walk or cycle.

Mobility and access aren’t opposites, and mobility isn’t some tired doctrine worshipped only by blinkered traffic engineers.  If we want cities to be built in ways that require less travel, cities with better access, we will do that by ensuring that those cities still have generous transit mobility.  We need to show that if you locate in a transit-intensive place, you will be able to get to lots of places that matter to you, on transit; indeed, that you’ll have full access to all the riches of your city, or at least those that you care about. 

So in a book on transit, I’m going to insist, unfashionably, that in the transit business mobility is still our primary product.  Mobility is only one dimension of access.  The other two, as Litman defines them, are urban redevelopment and telecommunications, both of which can reduce the need for travel.  But mobility is the kind of access that most people expect transit, in particular, to deliver.

One of the major hazards of urban planning is that planners and theorists can get so excited by their visions of the future that they lose track of the present.  We can imagine futures in which transit systems help us to build denser cities, where we can have more access because things are closer.  But if we want today’s voters to support our vision, we have to care equally about what their needs are right now. 

In the short term, most of us are stuck with the current geography of our lives.  Our homes, jobs, relatives, friends, and favorite shops are wherever they are, and we’ve accepted, consciously or not, the need to travel the distances between these important things.  We can try to relocate some of these things in the months or years ahead, but we can’t relocate any of them today. 

This book will look more at urban form and all the ways we can change it, but we can’t use transit to create better cities unless we first understand how transit does its primary task of providing mobility.  Meanwhile, though, transit needs to focus on the shorter-term perspective: the perspective of someone who needs to go somewhere, and get there soon, to address a need that they have right now.  This person isn’t thinking about how better transit might help transform her city.  She’s thinking: “I just need to be there!”  We need to figure out whether transit can help her, and if so, how.

Beyond “Transit Scores”: an Exchange with Matt Lerner

Matt Lerner of WalkScore.com and I recently exchanged emails about WalkScore’s “Transit Score” product, which provides a two-digit score supposedly capturing the usefulness of transit at any address in the USA.  It’s designed on analogy to the successful (if still controversial) Walk Score, a similar tool for summarizing how friendly a place is to walking.  For example, 300 Turk Street, San Francisco is scored 100 (perfect) on both Walk Score and Transit Score.

Transit score 300 turk

Toward another extreme, here’s 7000 Lake Mead Blvd in the far east of Las Vegas.  Walkscore is 52, Transit Score is 33.

Las vegas walkscore

Tools like these have huge potential relevance to the real estate industry, and more broadly to anyone who makes locational decisions about anything.  To the extent that we encourage people who value transit to locate where good transit is viable, everyone wins.

Earlier, Matt’s team had created a “transit travel time tool” which can be used to show you the actual area you can get to in a specified amount of time.  I used this tool as the core of my definition of mobility, in one of this blog’s earliest posts.

GoogEarth walkscore

So which is more useful, the simple two-digit Transit Score, or an actual map of where you can get to in a given time?

Here’s what I wrote to Matt:

Dear Matt,

About a year ago I mentioned your transit [travel time] tool as a useful way to visualize mobility …

The first draft of the book I’m writing … praises this WalkScore tool in some detail, as a way for people to understand the degree of freedom that transit will offer them.  I think it may be a crucial tool for helping people see beyond modal fetishes to understand how transit actually works and how to determine if transit can actually get you where you’re going.

…  Transit Score is useless to me because it encodes an intrinsic bias toward rail modes, as though rail is intrinsically faster, which is utterly misleading in a world of 6.5 mph streetcars and 60 mph busways.  [I’m referring to the Transit Score methodology’s use of a “mode weight” defined as “(heavy/light rail is weighted 2X, ferry/cable car/other are 1.5X, and bus is 1X)”.  Note that unlike the travel time tool, Transit Score lacks a way to capture how far you can get how fast, so it uses mode as a proxy for speed, fatally in my view.]

In short, whereas the earlier tool presented raw information in a compelling way that the user could use for her own purposes, Transit Score contains value judgments (“we know you’d rather ride a slow streetcar than an express bus”) which the user may not share, and thus may be an obstacle to her ability to make transit meet her needs.

So I guess I will praise mapnificent.net instead.

This issue sits at the very foundation of my current book, so as an admirer of your work, I’d like a better understanding of why you abandoned the original accessbility tool. Was it a matter of the processing required to do what’s basically a massive search of trip planners?  I can see that Transit Score is a much faster calculation, but wonder if that was the key issue.

All the best for ’11,

Jarrett Walker

Matt replied:

HI Jarrett,

Good to hear from you.

You’re right that we are promoting Transit Score over Transit Time Maps — but we haven’t abandoned the transit time maps.  We are working on new ways to use them and they are still available here: http://www.walkscore.com/transit-map.php).

Here’s why we’ve been promoting Transit Score more heavily.  Our mission is to promote walkable/transit friendly neighborhoods and we think the best way to do this is to have Walk Score / Transit Score on real estate listings.

As we developed Transit Score we looked at a few methods of calculating a Transit Score.  The two finalists were our current method (detailed here) and a method where we summed the Walk Score under the area of the transit shed in our Transit Time Maps.  In practice, the scores were very similar between the two methods so we chose the current method which is much easier to scale (we show millions of scores per day).

We want to boil down transit access into a score so that it can appear on real estate listings and people can compare locations.  ZipRealty.com has added our Transit Score to millions of listings and we have some more partners on the way.

We did not see a lot of consumer/partner interest in the transit time maps — which is unfortunate because of course I love them.  One scenario I’m hoping to promote with our Transit Time Maps (we just need a partner) is to allow people on real estate sites to search by transit time.  E.G. find me an apartment within 30 minutes of work on transit.  I’d also like to integrate the transit sheds into the standard Walk Score experience.

I like the simplification Mapnificent made which was to not include walking time in their transit sheds — this makes it much easier to compute.

So to sum up, I like your suggestion of avoiding any mode weight value judgments — it just turns out that in practice our current method was very similar and easier to scale. Anyway, would love to hear your thoughts on this.

Also, we’re launching a beta of “Street Smart” Walk Score later this month and we’d love your feedback on that too.

Happy New Year!
Matt

To which I replied:

Matt

Thanks!  … Suppose, hypothetically, that you had the processing power and datasets to run a purely mobility-based Transit Score.  Let’s call it a Transit Mobility Score.  The algorithm would be something like:  Identify the area reachable in 30 minutes on transit from the selected point (I choose this because it seems to have a long history as an acceptable commute time).  Then, grab the MPO’s database of population and jobs by small zone and calculate the percentage of the region’s jobs and population that are in that 30 minute band.

That also gives you a 2-digit number, but now it’s a fact rather than a score.  You’re saying: “If you locate here, you’ll have convenient transit access to __% of the region’s activity.”  And that strikes me as something that a realtor could value, understand and explain.  How far are you (or someone) from being able to do that kind of algorithm?  Obviously you’d need to have the MPO on your side, so start with somewhere like Portland where they generally are.

Frankly, you’d probably want to do two such scores, one based on your mobility at 8:00 AM and another for your all-day mobility — say, at 1:00 PM.  But I think a realtor could make sense of those too.  Everyone understands that transit in the peak is different from midday, and that both matter.  Suburban areas, especially those under the influence of commuter rail and commuter express buses would show quite a difference between the two.

I think this could be huge.  Because the output is a fact, not a judgment. …

All the best, Jarrett

Matt replies that this “sounds like an awesome planning tool and one we could potentially pursue if we had a grant or something to fund it.”

I still think this could be huge.  What if everyone making a locational decision could go to something like the WalkScore travel time tool or Mapnificent and see a map of where they’ll be able to get to in 30 mintues on transit?  It would finally make our mobility visible.

And if we could measure our mobility so accurately, for so many hypothetical cases, we just might value actual mobility more, and be less distracted by unreliable symbols of mobility — like, say, whether there are rails in the street.  Technophiles shouldn’t be too alarmed; many people will still have modal preferences.  But meanwhile, those of us who just want mobility would be able to measure it, fast, for anywhere that we might be locating something, including our homes.

redundancy in transit networks: a good thing?

Transit planning consultant Bob Bourne is thinking about the Brisbane flood's impact, and wondering whether building more redundancy into transit networks is a good idea:

My heart goes out to everyone affected by the floods.  It can be devastating on so many levels, individual lives lost; extensive property damage to individual residences, and infrastructure damage.  I managed the system in Ames, IA during our floods in 1990, 1993, 1998, and 2005 and I have been assisting the Cedar Rapids, IA transit system in recovering from their 2008 floods.  I worked in Chicago during the blizzard winters of 1977-78 and 1978-79 where the city and suburbs experienced several weeks of paralysis due to the continuous heavy snows as well as way too many blizzards in Iowa over the years.
 
In the U.S. buses typically operate without a lot of redunancy in the route network.  Your commentary on numbering overlapping bus routes and make them understandable to the riding public is interesting and implies that there are lots of routes serving several corridors.  In the U.S. that may be true, but usually the headways are pretty well trimmed to provide the absolute minimal level of service.  When you add demand due to adjacent services becoming inoperative, the existing routes are overwhelmed.  Overloading causes extended travel times and buses cannot make their normal cycle times which exacerbates the problem.  Throw in a street network in chaos and the bus system will be criticized as not meeting the needs of the citizens in the time of crisis.  No easy way to explain the problem.
 
The other problem that we had in Ames, Chicago, and Cedar Rapids was that some of the drivers lived in areas that were flooded or had immediate family in those areas.  They needed to tend to their family/housing priorities and this decreased the number of people available when the workload  of more passengers and longer travel times increases.
 
At some time in the future, after everything settles, perhaps you could solicit comments on building redundancy into your transit system.  Sometimes, it is good to have lightly used routes that can be cancelled in a crisis allowing redeployment of drivers and vehicles.  Sometimes it is good to have headways with a loading standard of less than 125% of seats at the peak point on the route instead of cramming buses with 150% or 175% of seated load.   Your 10 or 12 minute frequent headway concept can provide additional resources if you need to cut it back to 15 to 20 minutes during a crisis.
 
After the September 11, 2001 disaster in New York, the subway system was able to recover quickly because the lower end of Manhattan was one of the few places in the subway system where there was some redundancy.   Multiple routes close to each other and at the end of some routes made it easy for commuters to resume their normal lives long before the reconstruction of the subway damage.
 
Redundancy is not favored by policy makers and can add to costs.  However, a system with excess capacity will perform well in times of crisis and will provide addtional service during normal times.
 
Our prayers are with everyone who is suffering through this disaster and we hope that good luck will shine on Australia again.

The kind of redundancy that Bob praises is something transit planners spend much of their time trying to get rid of, because on typical days when we don't need it as redundancy, we call it duplication and waste.

Transit agencies work on such tight budgets that it doesn't make sense to run, say, a bus line next to a rail line, doing the same thing, just for the redundancy.  If the rail line is serving the market, the bus should be off somewhere else, providing unique mobility rather than duplicating the rail.

This is especially true in small cities like Bob's hometown of Ames, Iowa, or Great Falls, Montana.  These networks' resources are stretched tightly to create the maximum amount of mobility for the budget.

Having said that, there are a few situations where an efficient network is also a redundant one.

Classic high-frequency grids provide redundancy for transit in the same way they do for cars.  If one segment in a grid goes down, there's a parallel line 800m away that you can walk to in a pinch.  It will probably allow you to complete the same L-shaped trip that you intended to make on the disabled line.  

Grid with trip

Ferries are more complicated.  The long cross-city run of the CityCats mostly connects stations that are also connected by bus.  The bus trip generally runs a shorter distance at a higher frequency, though it may require a connection.  So there's no question that the intrinisic attraction of the ferry is part of what keeps it busy.  There may also be secondary issues, like the legibility problems of much of the bus system in downtown Brisbane, where most connections occur.  But there are also situations where CityCat and the smaller CityFerry does a link that's simply impossible by road, or much, much longer, and in these cases the ferry wins on pure mobility grounds. 

Of course, bus operators generally have backup fleets in case they need to suddenly replace a non-redundant train or ferry line that goes down.  In Australia, there are often standing agreements between government and private operators to shift buses into this role, and given a day's warning — which Brisbane had — it's not hard to replace a failed network segment with buses even while running the rest of the bus network.

So is redundacy a good thing in disasters?  Of course it is.  Is it a reason to design networks that are redundant all the time, at the expense of more mobility that could be provided at the same cost?  No, probably not, because you're weighing a rare disaster against daily inefficiency.  Are there styles of network design that are both efficient and redundant?  Yes, the high-frequency grid comes to mind. 

In really big and dense cities, you can also get both redundancy and efficiency, because there will tend to be overlaps of service just to provide capacity into dense centers like Lower Manhattan, and in these cases, as Bob notes, redundancy is often possible.  The key there, however, is that the duplication of services isn't justified by the need for redundancy, but rather for the sheer capacity need, and providing necessary capacity, of course, is part of efficiency.

 

new year’s resolution: no more coercion

PC310069 If you want to find vigorous attacks on urbanism and sustainable transport by car-and-highway advocates, just Google for forms of the verb to coerce.  The most recent one you'll find is from the reliable Fred Barnes of the Weekly Standard.  Called "Coercing people out of their cars," it exploits an unfortunate comment by Secretary of Transportation Ray LaHood.  As Barnes puts it:

Last year, George Will zinged LaHood as the “Secretary of Behavior Modification” for his fervent opposition to cars. LaHood all but pleaded guilty. Steering funds from highways to bike and walking paths and streetcars, he said, “is a way to coerce people out of their cars.” His word, coerce.

Here's the source, reported on conservative blogs but not much elsewhere.  CNS News:

On May 21, [2009?] LaHood told reporters at the National Press Club that the “Partnership for Sustainable Communities’ his department had formed with the Environmental Protection Agency and the Department of Housing—sometimes known as the “livability initiative”–was designed to “coerce” people out of their cars.

If LaHood did describe the sustainable transportation project as coercion, even in jest, he should be more careful. Just as one doesn't joke about terrorism at airport security checkpoints, we shouldn't even joke about coercion in urban and transportation policy.  The word is a primitive grenade that can blow up any and all parties present.

The idea that urbanists and transit advocates are trying to coerce people to give up cars is one of the most treasured bits of pro-car rhetoric, because it feeds the association of cars with liberty.  Because so much urbanist work necessarily happens through government, the image of coercion also helps people think of government as intrinsically an oppressor, always a convenient refuge for the lazier kind of libertarian.

Google assembles a convenient list of definitions of to coerceWikipedia's is typical of the range:

Coercion (pronounced /koʊˈɜrʃən/) is the practice of forcing another party to behave in an involuntary manner (whether through action or inaction) by use of threats, intimidation or some other form of pressure or force.

Almost all of the definitions refer to actual or threatened force.  

By those definitions, I can't think of anything that I have done, in 20 years in this business, that would qualify as coercion.  Certainly, I've never threatened any motorist with force, or advised anyone else to do so.  No, Barnes would respond, but I have advised governments to adopt policies that are coercive toward motorists.  For example, I advised the City of Minneapolis to restrict traffic on certain streets to create a functional transit mall, which they did in 2009.  They even changed the direction of certain lanes.  Something that used to be legal is now prohibited.  If someone drives his private car through the bus lanes (especially in their pre-2009 direction!) police might show up and, if all else fails, might even shoot at him.  Force!  Coercion!  Rhetorically, the coercion-victim wins.  Of course, the vehicle he was driving was also a deadly weapon, so he too was threatening force, but he's already declared victory, paid his citation with an air of martyrdom, written his angry article, and gone home.

In the new year, let us all resolve not to be coerced by the rhetoric of coercion, and never to use the term, even in jest, to describe our own project. 

In its impact on motorists, sustainable urbanism is all about accurate pricing.  We care about pricing in two separate and non-convertible currencies: money, and the limited road space of our cities. 

We experience urban congestion, and parking shortages, when road-space is inaccurately priced.  As I explored here, it's as though we were giving out free tickets to a concert; when you do that, you get lots of people waiting in line, spending time to save money.  Today's approach to pricing forces everyone to act like those frugal concertgoers, when in fact many could easily afford to spend some money to save time, and would prefer to do so if asked.  High Occupancy Toll (HOT) lanes are one experiment in that direction, while the downtown congestion charges of London, Stockholm, and Singapore are another.  On the pricing front, San Francisco's free-market approach, which may finally liberate motorists from endlessly circling the block seeking a space, is another breakthrough. 

The absurdity of underpricing scarce urban road space, and thus causing congestion and parking shortages, is simply this: It forces us all to save money, a renewable resource, by wasting time, the least renewable resource of all.

Of course, when a price goes up, some who could afford it now can't, and may blame the government.  This happens when the price of anything goes up; it will always happen as long as people hold exaggerated notions about the power of government over the economy.  To meet the needs of people who are dissuaded from driving by price, and ensure that they continue participating in the economy, road-pricing and parking-pricing strategies work only in the context of abundant and attractive travel alternatives, including transit.  This is part of the free-market justification for transit subsidies, in a big-city context, so long as there continue to be equal or greater subsidies for the motorist.

Reduction of government subsidies is not coercion.  Fred Barnes is the socialist in this debate, demanding government subsidy for his own chosen lifestyle but not for that of others.  As for those of us who support more accurate pricing — of road space, parking, and all the other incremental costs of transport, including transit fares — we are the libertarians!

“Mapnificent”: Your Freedom to Roam

Long ago I highlighted an early product by WalkScore.com which enabled you to select a location and time of day, and then showed you a map of all the places you can get to on transit within a specified time.  Reader Tom West points me to a new effort along similar lines, called Mapnificent, by Stefan Wehrmeyer.  He describes the product on his blog in both geeky and practical detail. Continue Reading →

Dissent of the Week: My Alleged “Bias” Against Rail

I’m relieved to report that commenters who actually saw me give the presentation “A Field Guide to Transit Quarrels” seem to agree that I wasn’t displaying a bias toward or against particular projects, except perhaps for projects that were based on misunderstanding or ignoring some basic geometry.

However, finally I have a comment that attacks me full-on, which gives me yet another opportunity to think about whether I do have a “modal bias.”  It’s from commenter Carl, who I believe saw the presentation in Seattle: Continue Reading →