Author Archive | Jarrett

“Why Isn’t the Transportation Sector More Engaged in Student Transportation?” asks Jennifer Schiess of Bellwether Education Partners in the Eno Transportation Weekly.  Schless provides a good overview of why school buses — “the largest mass transit system in the [US]” — are so frustrating, for both students and providers.

Yet the real problem is much simpler than her article suggests.  The problem is bell times.  Really, this is all you need to know.

Many, many US transit agencies are pressured to run service to schools where yellow bus service isn’t provided.  In the early 1990s, for example, when I was working in California, funding cuts wiped out almost all school-funded yellow bus service.  Suddenly one day, a regular bus passed near a high school and found 200 kids waiting, for more than a bus could handle.  The problem was dumped onto the transit agencies without any funding to address it.

What’s more, when school districts run school buses, they think about how to run them more efficiently.  This often means setting bell times — the time school begins and ends —  differently at different schools so that a single bus and driver can do multiple pieces of work.

But as soon as the schools didn’t have to think about transportation, they stopped setting their bell times with any concern for the efficient use of transit resources.  Suddenly, we transit planners were told, bell times were locked down by other priorities.  The result was a mess for both transit agencies and students.

For transit agencies, pulling out a bus to work just a brief shift is very, very expensive.  The cost lies in the short driver shift, the one-direcitonal demand, and the cost of owning a vehicle that is used only briefly.  You can pay the driver less, but expect to get what you pay for in terms of the skills required (supervising kids, intervening in conflicts, and, in your spare moments, driving.)

Deviations to get close to schools disrupt the all-day pattern for other riders, and usually can’t provide the capacity the school needs anyway if the all-day demand is low, as in most low-density suburbs.  NCTD Route 332 in Vista, California.  Source: 511sd.com

In dense cities, there is often enough all-day transit near a school, and enough walkable streets, that students can disperse at bell times using services that are running all-day anyway, though the sudden big loads are still a challenge for these services.  In network designs, I often try to keep routes a few blocks away from major schools, so that kids will tend to walk to stops on different routes instead of all ending up at one.

But in a low density suburban area, there may be almost no demand until 3:00 PM, when suddenly there are 500 kids expecting us to take them home.  Buy big buses that hold 100?  Sure, but that’s still five driver shifts that are 1-2 hours long.  And if three schools set identical bell times, we need 15 shifts, when if they staggered bell times we might still get away with five.

This is a nice example of a problem that no technology will solve, at least until we have such cheap driverless buses that it’s no problem for them to sit around until once, twice a day, we need five of them.  Like all users of transportation services, schools need to be motivated to think about the demands they place on public services.  Because without staggered bell times, these demands can eat transit agency budgets, disrupt other customers, and produce worse mobility for everyone.

When respected authorities speculate about why transit ridership is falling in the US, they usually cite a 2015 paper by the (respected) Mineta Transportation Institute, authored by Bhuiyan Alam, Hilary Nixon, and Qiong Zhang.

The paper has one blindingly obvious conclusion that we shouldn’t need statistics to prove: If you want ridership, you have to run service.  The quantity of service, measured several ways, overwhelmingly determines ridership outcomes.  My comments about the paper in no way question this conclusion.

Still, the paper has problems that are common in papers in the statistical social sciences.  To some extent, I’m not even critiquing the paper so much as the discourse from which it arises.

(And if this is tl;dr, by the way, there’s a “Conclusion” section you can scroll down to.)

Useful Findings, Misleading Interpretation

The study seeks to explain the variation in passenger boardings per capita, an imperfect but easily calculated measure of ridership.  It looks at a large set of things that could explain this variation and concludes that:

The results indicate that gas price, transit fare, transit supply, revenue hours, average headway, safety, transit coverage, and service intensity show statistically significant impacts on transit demand by bus.

All of these except gas price are internal.  In simple language, an internal variable is a thing that someone could change, while an external one (like the weather) is one that they can’t. [1]

But their interpretation of this is deeply misleading:

The results show that the internal variables, the factors that transit managers and operators control, are predominantly the significant predictors of transit travel demand by bus mode. Seven out of eight internal variables in the OLS regression model proved to be significant factors in determining travel demand by bus. [emphasis added]

It is utterly false to say that the internal variables are under the control of “transit managers and operators,” unless you think they can print money. Again, these variables are “transit fare, transit supply, revenue hours, average headway, safety, transit coverage, and service intensity.”

Transit managements can turn fares up or down, and they can be more or less careful about safety, and they can hire firms like mine to help them redesign their networks.  But the larger reality of service quantity — the most important point of the entire paper — is mostly the result of investment decisions made above their level.  Transit is mostly subsidized due to its public benefits, and the level of that subsidy is controlled by some mix of elected officials and voters.  Management has a marginal role in how efficiently that subsidy is translated into service quantity. [2]  Mostly, you get in service what you’ve paid for in subsidy.

This mistake goes to a critical problem in the way the bus ridership decline is being discussed, and why so much activism around the issue is misfiring.  More people are yelling at their transit agencies than are yelling at the elected officials who actually control service quantity   The Mineta paper’s careless language encourages that confusion.  There is no point in telling transit managers that they should run more service.  They agree with you.  You need to tell elected officials this.

What Doesn’t Matter?

The findings about what matter to transit ridership are interesting, but so are claims about what factors don’t matter. Here the authors make sweeping claims about how clueless we transit planners are:

The study found that certain variables that many transit planners view as important determinants of transit demand did not have significant impacts on transit demand. … Variables such as transit orientation pattern, median household income, percentage of college population, percentage of immigrant population, vehicles per household, and MSAs in the South … do not impart significant effects on transit demand by bus. … Population density and the percentage of households without cars show insignificant impacts on transit demand …

To which I can only say, it depends on how you measure these things.

The finding that population density doesn’t matter is based on a common mistake.  The authors measure the total density of Metropolitan Statistical Areas, which are aggregations of US counties that may contain vast expanses of rural area and even wilderness. (More on this, with photos, here.) But even average density of the truly urban area is not what matters.  What matters is density adjacent to transit service.  (The late Paul Mees made the same mistake in his book Transport for Suburbia, as I discuss here.)

This is an example of a case where some geometric thinking would have helped, which is what I tried to do in my transit ridership explainer.  The residential density that matters to transit is the number of people within a fixed radius of a transit stop.  If ridership wasn’t twice as high where density is twice as high, this would mean that individuals living at low density are more likely to use transit than those living at high density.  Such a claim would not only be wildly counterintuitive, it’s also disproven by virtually every transit agency’s stop-by-stop ridership data, as long as you focus narrowly on density near transit.

A segment of Dublin’s bus route 13, with passenger boardings as dots and residential density in the background. More density right around the route means more ridership. Makes sense, doesn’t it?

Problems with Rates

The confusion about how to measure density also affects a confusion about terms expressed in percentages, medians or averages, as most of the demographic variables are.

The authors run correlations with the percentage of people who are immigrants or college students. Vast parts of an urban area where transit isn’t abundant enough to be useful, if it exists at all, are counted in these rates.   The median income of an entire city matters less to ridership than the median income of the parts of the city served by useful transit.  These are always very different things.

That’s why our firm almost never studies or maps percentages; instead, we study densities.  We draw maps of the density of poor people, or students, or seniors, or whatever.  Because only that shows you how many people we’re really talking about, and where they are.

Conclusions

Too often, social science papers rely on correlations without thinking about what transit is spatially.  Everything I’ve said here will be blindingly obvious to any practicing transit planner —  not just because they show up in properly granular analyses but because the mathematical consequences of them not being true are so nonsensical.  That’s why I’m confident in relying on geometric claims in my own work.  They tend to win arguments in the political world because they don’t require anyone trust a black box of analysis that’s studded with assumptions, or to assume that experts always know best.

The biggest single mistake in this and most similar studies is the false confidence in aggregating data across a metro region.  It is geometrically inevitable that any remotely viable transit agency will distribute its benefits very unequally across the land area of its region — especially in response to density — and the way that transit’s benefits are distributed over a city means that total inputs and outputs at the citywide scale don’t matter very much.

But these papers are at their most exasperating when their resistance to geometric thought is coupled with unfounded claims about how clueless we practitioners were before this paper enlightened us. As a PhD myself, I have the highest respect for the work of scholarship.  But a regression analysis is only as good as the assumptions that went into it, and these need much firmer grounding in geometric reality, as well as in the reality of how transit decisions are actually made.

Nevertheless, the main point of the study, and the one for which it’s most often cited, is indisputable:  Network design projects can help improve ridership for a given amount of money, but for step-changes in ridership, you have to fund more service.

[1] The internal/external distinction, routine in the social sciences, is entirely relative in ways that should be more clearly marked in papers.  Whether a factor is internal or external depends on the selected point of view.  My reaction to seeing transit quantity described as internal is that it is not in control of the stated point of view, namely “transit managers and operators.”  Weather used to be the paradigmatic example of an external variable, but now that we know it’s partly the result of human actions, it could be internal if you take the long view of human agency.

[2] Not a zero role, but very small compared to the magnitude of cost involved.

A thing to like about Portland’s transit agency TriMet:  They don’t hire commercial drivers and train them to be friendly.  They hire friendly people and train them to drive a bus.

(English here.)

La Proyección del Elitismo es la creencia entre las personas relativamente influyentes y privilegiadas de que lo que ellos encuentran conveniente o atractivo es bueno para la sociedad en general. Una vez que se aprenda a reconocer este error común, es fácil verlo por todos lados. Es probablemente la barrera más importante para la creación de ciudades prósperas, justas y liberadoras.

Esto no es un llamado para atacar a las élites. Tampoco es una declaración sobre la correcta distribución de riqueza y oportunidad o el derecho de una persona a influenciar el discurso público. La intención es señalar un error que las élites constantemente suelen cometer. Ese error es olvidar que las élites son siempre minoría y que, comúnmente, planear una ciudad o una red de transporte a partir de sus gustos y preferencias resulta en un proyecto que no es funcional para la mayoría. De hecho, ni siquiera a la élite minoritaria le gustará el resultado final.

Hace un tiempo, cuando estaba presentando una propuesta de transporte público ante la Junta de Directores de una agencia de transporte público de un suburbio californiano, uno de los miembros, que representaba a la ciudad más adinerada del área, se inclinó hacia adelante, aclaró su garganta y dijo:

Ahora bien, Señor Walker. Si adoptamos su plan, ¿eso hará que deje mi BMW en el garaje?

Por supuesto que la respuesta es no. Pero pensar que esa es una pregunta adecuada para evaluar un sistema de transporte público es un claro ejemplo de la proyección del elitismo. Como multimillonario, este señor pertenece a una pequeña minoría, por lo cual no tiene ningún sentido diseñar un sistema de transporte público basado en sus gustos personales. Transporte público exitoso debe ser masivo y no tiene sentido buscar la masificación a través de la atracción de usuarios como él. Quizá él se sentiría atraído a un servicio que lo dejara en la puerta de su casa, le ofreciera un masaje y una copa de vino, pero muchas personas preferirían un servicio más congruente dentro de un presupuesto limitado. Que las empresas con fines de lucro le den estos lujos al señor, y asegurémonos de que él pague por los efectos negativos.

A veces entendemos el argumento que una inversión que beneficie a las élites sirve también al bien común. Por ejemplo, mejorar la vida de los ejecutivos de negocios supuestamente atraerá inversiones a la comunidad. Un proyecto de transporte público especializado supuestamente atraerá la construcción de vivienda de lujo que a su vez incrementará la recaudación de impuestos, incluso si no pudieses vivir allá. En la medida en que algunos elementos de estos argumentos fueran ciertos, el término Proyección del Elitismo no sería el correcto. Sin embargo, la mayoría de las proyecciones elitistas no hacen tales argumentos. Es únicamente el hábito inconsciente de asumir que sus propios gustos son un buen reflejo de lo que todas las personas valoran.

Al retar la Proyección del Elitismo no estoy siendo razonable. Casi todas las personas se refieren a su propia experiencia al discutir políticas públicas. ¿A quién no le gusta que su experiencia personal sea tomada en cuenta? Pero en una sociedad donde las élites tienen un poder desproporcionado, la tarea súper-humana de resistir su proyección debe ser responsabilidad de ellos. Y yo al ser parte de estas élites – no soy millonario, pero ciertamente tengo educación y privilegios – es mi tarea también. Como con cualquier intento de hacernos menos egoístas, es una tarea agotadora y que nunca lograremos hacerla completamente bien. Por lo tanto, la crítica a la Proyección del Elitismo no puede únicamente expresarse por ira. También tiene que ser un proceso empático e indulgente.

De cualquier forma, la Proyección del Elitismo es quizá la primera barrera para lograr ciudades eficientes, justas y liberadoras. La ciudad tiene una característica especial: Funciona para cualquiera solo si funciona para casi todos. Lo mismo puede argumentarse de la sociedad en general, pero sólo en las ciudades esta característica es tan obvia que es inevitable.

El tráfico, para usar el ejemplo más obvio, es el resultado de las elecciones de todos en respuesta a la situación de todos. Hasta las élites están estancadas en el tráfico. Hasta el día de hoy, no se ha encontrado una solución para liberar a las élites del tráfico y no es porque no se haya intentado. La única solución para el tráfico es solucionándolo para todos y para hacerlo, es necesario observarlo desde la perspectiva de todos, no sólo desde la de los más afortunados.

El existente menosprecio al servicio de autobús en las ciudades de Estados Unidos es un problema fundamental de Proyección del Elitismo. Los autobuses grandes en una ruta fija son la única forma en la que el transporte público puede expandirse rápidamente usando con extrema eficiencia el espacio urbano limitado de una ciudad. Pero muchas élites creen que los autobuses y el servicio que proveen no importan ya que personalmente no es útil para ellos.

Durante mis 25 años de carrera he presenciado a líderes urbanos privilegiados – la mayoría con buenas intenciones – buscar exhaustivamente la solución para el transporte público que les permita ignorar los autobuses.  Se podrían señalar algunas como los tranvías estadounidenses atascados en el tráfico, “herramientas de reurbanización,” que a veces no tenían un valor perceptible en la movilidad. Hay barquitos adorables con mercados pequeños y trenes aeroportuarios demasiado especializados.

Hoy en día, ese mismo error alimenta la ambigua promesa de la disrupción tecnológica en el transporte público, especialmente la noción matemáticamente absurda de que en zonas urbanas y densas el transporte público llegará hasta tu puerta al llamarlo. (Expertos serios han abandonado esta idea, pero sigue siendo parte de la discusión, minando el apoyo al transporte público que en realidad funciona.)

Ninguna de estas ideas tienen sentido geométrico y por lo tanto no funcionarán para liberar a todos en una ciudad densa. Sin embargo, son ideas atractivas para las élites, atraen la atención del público en general y por lo mismo ayudan a aplazar la inversión tan necesaria en transporte público que millones de personas encontrarían útil y liberador. Este descuido causa deterioro en el transporte público, generando resultados que justifican aún más su descuido y detrimento.

De nuevo, no podemos retar la Proyección del Elitismo hasta que la perdonemos en nosotros mismos. Casi todas las personas que leerán este artículo forman parte de alguna élite. Pero mientras más poder se ostente, más urgente e importante es esta tarea. Debemos preguntarnos: “¿Esta idea funcionaría para mí si estuviera en una situación típica de un ciudadano promedio en vez de la situación afortunada en la que me encuentro?” Si la respuesta es no, tampoco funcionará para la ciudad, lo que significa que al final tampoco funcionará para ti.

It’s the topic of my piece in Citylab today.

If you’re not a techie, SXSW is South by Southwest, one of the leading summits of the tech “disruptors,” held every year in Austin.

A proposed panel on New Mobility and the Future of Design would include:

• Gabe Klein, Founder of CityFi and former director of the Depts. of Transportation in Washington DC and Chicago.
• Jeff Wood, who runs the fine urban news outlet The Overhead Wire.
• Ben Holland, Sr Associate at Rocky Mountain Institute.
• … and me!

By the standards of tech conferences, this panel would be heavy on people with experience in transit agencies and government, which could be help counterbalance some of the prevailing instincts in the tech industry.

Anyway, there’s a place you can vote for this panel.  It requires a login, which many of my tech-savvy readers already have.  Feel free to state your view.