Category Archives: Urban Systems

Creating Transitopolis

The City vs. Country mismatch (where we plan for transportation systems seemingly independent of the context: city or country (suburb)) is especially relevant in metropolitan areas constructing expensive medium and high capacity transit lines to presently undeveloped places, or (re-)constructing and widening freeways in the midst of core cities.

If we are building a city, that means focusing resources closer to the center than the edges, since that is where more of the growth will be.

So the question arises in Minnesota: Are we building a city in the Minneapolis-St. Paul region or not?

Some would argue the region is already a city. Clearly the downtowns and some nearby areas resemble cities. But much if not most of the population lives in single family homes with a yard. Not there is anything wrong with that, but that yard increases spacing between neighbors, lowers densities, and makes it harder to operate a successful transit system in the automobile era.

The decisions we make regarding transportation investment rest on what our collective vision is for this place. If we are building a city, going “all in” on transit is a lot more sensible than if we are not, and a lot more sensible than half-measures. If we are not, going even partly in on fixed rail transit is fairly pointless.

The evidence to date is fairly mixed. The region is growing at about 1 percent or so per year in population. That is a bit under 30,000 people or so per year. (Investing in transit will not put a measurable dent on this, as it is hard to imagine it either increasing or decreasing the birth or death rate noticeably or significantly affecting migration patterns).

Where are those people going? Most of them are not being added to the center. If all of them were added to Minneapolis and St. Paul proper, the populations of the core cities would rise from 667,000 in 2010 to about 950,000 in 2020. If more than half of them were added to the core cities, their population would be around 810,000. Current forecasts suggest the population of the core will be closer to 732,000. In other words, well more than half (around 80%) of the region’s growth remains outside the core cities, and not terribly urban. While the center is projected to grow at a faster rate than the edges, it is not growing faster in absolute numbers.

This region collectively much more resembles Broadacre City than Greenwich Village, and probably more Broadacre City than even Welwyn Garden City or Letchworth. While the density at the edges after development must (by definition) be higher than before development, the average experienced density (e.g. the population-weighted density) may continue to fall as the region expands.

In this dispersed suburban landscape, point-to-point transportation predominates.

In the not-quite-a-city urban areas, point-to-point transportation still predominates.

It is only in full-fledged dense cities (the level of density required depends on income, technology, and other factors), and dense cities that sustain, that full-fledged dense (fixed route, fixed infrastructure) transit is warranted. Loosely, the transit-city threshold is on the order of 10,000 persons per square mile, sustained over some region. This implies a Minneapolis population of 540,000 and a St. Paul population of 520,000. While those numbers are achievable in principle, they require significant changes in market demand and reduction in supply constraints to achieve. If it were to be achieved, still under 1/3 of the region would be in the transit city. The remainder would be the country, or its suburban simulacrum.

Certainly, some parts of the core cities already sustain this density, and there is no requirement that all of the core city achieves the density, just that a sufficiently large part does. Most doesn’t.

For the Metropolitan area, fixing the total space, this threshold implies a population of 63 million, or relaxing the space but fixing the  population, a shrinkage to a developed area of 345 square miles. I would consider either outcome highly unlikely.

The car-free lifestyle is sufficiently uncommon that the local newspaper does a feature on it.

In less dense cities, less transit is warranted. But if the transit is insufficiently dense (in space (coverage) and time (frequency)), anyone with a choice will anchor to the on-demand, point-to-point mode, which will be sufficiently faster to outweigh any additional expense

 

Creating Transitopolis: the Transit City

Positive (and Negative) Feedbacks in Transportation
Positive (and Negative) Feedbacks in Transportation

Building the transit city (Transit-opolis) requires most of  the region’s central city residents (20% today) to willingly abandon the automobile in the first place: creating an environment where car ownership can be voluntarily foregone because it is to the benefit of all concerned not to own the car. The more transit users there are, the better the transit service is, in a virtuous cycle. (And of course, the fewer transit users there are, the worse the service, in a vicious cycle).

This implies focusing transit investments in the central cities, and not diffusing scarce capital like peanut butter across the region.

Why can’t we have the best of both worlds? There are a variety of interim or transitional strategies

  1. Park and ride lots accessed by private car may serve  the center-working/surburban-living suburbanite, which transfer the worker to a radial transit route. This serves a small fraction of workers, since most people don’t work downtown, where these radial services terminate, and the frequencies are typically not high enough (especially mid-day) to rely on for anyone with irregularity in their life.
  2. Single Car households  with multiple workers splits the difference, where presumably at least one of the workers does not use a car for travel to work, or the two workers carpool to the same location. This is certainly the most common hybrid case.
  3. Weekend Car households  in which the work trip is conducted by walking, biking, or transit, and the car is used for the weekend and special trips.
  4. Car sharing (on-demand car rental) allows the car-less transit user to have a car when needed for the less frequent trips. Taxis (and so-called ride-sharing services) serve a similar function.

These attempts at melding can serve specific niches and are potential transitional steps to the transit city, in that it is more likely to give up a car for some trips than all trips, or portions of trips than all of the trip. They are not however the end state.

 

 Like Clue, Pick your ending

Ending

My own prediction is that we are not in fact building a transit city. The densities that will emerge in Minneapolis and St. Paul in the next 20 or 30 years are insufficient to support a transit-based city for a majority of residents of even the core cities. (And, simultaneously and not coincidentally, the transit investments are insufficient to support a city where most people are car-less).

Pale Probiscidea
Pale Probiscidea

This explains my pessimism about the use of expensive (high fixed cost) city transit tools now. The right decision if you are certain you are building a transit city (or already live in one) is different from the decision if you are not.

While it is argued that never making the investments will ensure the transit city does not emerge, we can continuously ratchet up, rather than doing it in enormous steps. Not investing now does not mean never investing. “No” is reversible (in other words, “no” does not mean “no”).

On the other hand, “yes” is irreversible for a long time. But making the investment does not guarantee the transit city will emerge, plenty of cities, including our own, have invested in rail without seeing accompanying development, leaving an enormous pale proboscidea in its place.

Alternative Ending

My own prediction is that the core cities of Minneapolis and St. Paul are on a path towards Transitopolis. The necessary population densities to support transit are within striking distance, especially in Minneapolis, and the leadership of both cities is keen on achieving that. The big question is whether the demand for higher density housing is there in the cities, and with changing demographics, preferences, and technologies, the demand for suburban lifestyle is diminishing relative to that for urban living. Most people won’t spend their entire lives in either suburban harmony or at an urban tempo, but rather migrate between the two over the years.

The investments in the cities to support transit at a level that most people can avoid the car for most trips are still too low to make this work, there is a marked lack of ambition on the part of regional transportation officials to serve the transit cities they are building with actual rapid transit. This dysfunction has several causes, not the least of which is the leadership of planning organizations that don’t use the modes they manage, which we can attribute to the strange politics of regional organizations.

Evolution vs. Plans

Evolution

Assuming we started with an undeveloped wilderness,  cities emerge at selected points (typically points with natural accessibility advantages over their neighbors, such as ports and harbors, or water falls, or railroad junctions). But they evolve from wilderness to city over time.

They do not generally evolve because someone built city-scale transportation out in the country and waited for the people to arrive.

Instead it is a ratchet: a few people, some transportation network investment; some more people, more investment; even more people, still more investment, and so on, until something resembling a city emerged.

While the infrastructure may slightly lead the development (as in the Streetcar Suburbs or London’s Underground) those developments in general contiguously extended the urban environment in appropriate steps, and were accompanied by development in the near term (failure to see development would have led to bankruptcy for the line).

Plans

Plans aim to take this chaotic, unpredictable, evolutionary process and put a sheen of order upon it.

The general problem with public sector transportation and land use plans is that they are static. They are made for one point in time. They are  snapshots in a world with 24 frames per second (for eternity), and for which we don’t know the ending (“no spoilers”).

Life-cycle of rail in the US. From The Transportation Experience, Figure 6-4
Life-cycle of rail in the US. From The Transportation Experience, Figure 6-4

 

They design for maturity and implicitly assume that the mature (built out) city sustains. The evidence from the life-cycle for every mode (or technology) is that its scope and extent are continuously changing.

The mirror of this problem is  they ignore the path that gets you there and all interim states, as well as changes in behavior and technology that may occur in the interim.

The third problem with plans is that they address future problems that don’t exist today, when there are plenty of problems today that remain unsolved. Trying to better manage how will people get around or from or to a site which might (or might not) transform from country to city, or even low density suburb to high density suburb, in 30 years when there are plenty of ways to help people get around better today is an exercise in pointlessness, whose primary objective is to transfer resources from the public to selected (and one presumes politically influential) landholders.

There is nothing wrong with having a vision. It presents a direction in which to proceed. The most important thing is the next step (or two) though. Each step you take in one direction is a step farther away from destinations in other directions. But the path on which we are walking is shrouded in smog. Our vision is simply our imagination (or consensual hallucination) of what lies down the road. We have never been there before. But we must recognize, we never will reach where we think we are going.

City vs. Country

One of the many dysfunctions in transportation and land use planning is our collective inability to recognize the difference between city and country.

It’s really not that hard. In the country  distances between buildings are large, while in the city they are short. In land use jargon, densities are lower in the country than the city.

City Mouse and Country Mouse
City Mouse and Country Mouse

The most useful form of transportation varies between city and country.

In the country, individual, point-to-point, on-demand service (foot, horse, bike, car) saves a great deal of time over feasible shared, scheduled, fixed-route services (transit). That time savings offsets the individual cost savings from sharing a vehicle with other passengers.

In the city, shared transit services are on the whole less expensive to the user and society than individual services. The small increase in time is offset by cost savings from sharing. The greater density allows more frequent service and more direct service nearer the traveler’s trip end points.

Idealizations

In idealized low-density places like Wright’s Broadacre “City”, local transportation was clearly individuated, to the point it appears everyone has a private gyrocopter.

Howard's Garden City (1902)
Howard’s Garden City (1902)

In Howard’s Garden “City”, individual transportation was used to get around town, and to the inter-municipal railway.

In Jacobs’s New York City and Toronto, walking was used to access transit for longer distance urban and inter-urban travel, while the car was not especially welcome.

From both a transportation and land use perspective, each of these works on its own terms (assuming gyrocopters actually work).

Greenwich Village, New York (wikipedia)
Greenwich Village, New York (wikipedia)
Wright's Broadacre City (1934)
Wright’s Broadacre City (1932)

Stable points

Green Routemaster Bus serving suburban and exurban London
Green Routemaster “Country Bus” the kind that used to serve suburban and exurban London

 

Routemaster Bus (from wikipedia)
Red Routemaster “City Bus” (from wikipedia)

In short, in the current technological environment, there are two stable points: one where a sufficient number of people have abandoned their personal cars and use transit daily that transit is sustainable with high frequency and ubiquity; and one where people keep their cars and use transit on special occasions (to go downtown or the State Fair for entertainment, e.g.).

Once the car is owned, the marginal cost of the additional trip to most destinations (since free parking is found for something like 99% of all destinations in the US, gas prices and taxes are low, and we don’t have road pricing) is sufficiently low it outweighs the combination of low costs of shared transit vehicles with higher travel times.

A metropolitan area is large enough to contain multitudes. There can be a center where people can live car-less because the transit (or walking or biking) is good enough for daily city-based work and non-work trips, and a countrified-edge where people can live transit-less, since living and working in the suburbs is seldom a market transit can well serve (except as an accidental spillover where people are lucky or skilled enough to have home and work aligned on the same radial transit line).

 

Traffic Jams Make Cities Splinter into Subcenters: A rule of urban expansion could guide smarter growth – SciAm

I get quoted by Sarah Fecht in Scientific American (310(2)):

Most of the world’s cities started from an important marketplace or town square. Over time, they developed multiple centers where people could work, shop and play. But why? Some economists have suggested that cities fragment because of agglomeration—businesses that spring up in clusters increase their chances of success.

Yet physicists have arrived at a slightly different explanation: traffic jams. Marc Barthelemy and Rémi Louf, both at the Institute of Theoretical Physics in France, designed a mathematical model to explain how cities and their surrounding suburbs evolve. Their research suggests that as a city grows and congested roadways make it increasingly difficult to get to the center, subcenters emerge along the outskirts. “It’s an interplay between how attractive the place is and how much time it takes to go there,” Barthelemy says. Cities with accommodating transportation networks remain centralized longer, he adds.

The physicists validated their ideas using data from 9,000 U.S. cities and towns of different sizes.

A better understanding of how metropolitan areas evolve could prove useful, considering that two thirds of the world’s population is expected to live in urban areas by 2050, notes David Levinson, a transportation engineer at the University of Minnesota. “There’s a lot of urbanization left to happen,” Levinson says. “If planners imagine a city to take a particular form, but that’s not the way the city wants to behave, we’ll be making unwise investments.”

Barthelemy believes the model could also come in handy for estimating traffic delays, gas consumption and carbon dioxide emissions. “I think that this opens up the path to some really quantitative insights about cities,” he says. “We can take simple mechanisms, simple ingredients, and in the end predict how important properties are scaling with population.”

This article was originally published with the title “The Traffic Effect.”

Peer-to-peer car sharing gains momentum within rental car industry

I was interviewed by Catherine Boardman for the article Peer-to-peer car sharing gains momentum within rental car industry:

“Transportation analyst David Levinson said although traditional car-rental companies will not fade away, there is a niche for peer-to-peer services that can offer a quicker, easier alternative.

‘Apps can erode some of the hassle, and maybe today’s companies are too sclerotic to innovate,’ Levinson said.”

Accessibility and non-work destination choice: A microscopic analysis of GPS travel data

ArthurHuang

Congratulations to Dr. Arthur Huang for successfully completing and defending his dissertation: Accessibility and non-work destination choice: A microscopic analysis of GPS travel data

The advancements of GPS and GIS technologies provide new opportunities for investigating vehicle trip generation and destination choice at the microscopic level. This research models how land use and road network structure influence non-work, non-home vehicle trip generation and non-work destination choice in the context of trip chains, using the in-vehicle GPS travel data in the Minneapolis-St. Paul Metropolitan Area. This research includes three key parts: modeling non-work vehicle trip generation, modeling non-work, single-destination choice, and modeling non-work, two-destination choice. This research contributes to methodologies in modeling single-destination choice and multiple-destination choice and tests several hypotheses which were not investigated before.

In modeling non-work vehicle trip generation, this research identifies correlation of trips made by the same individual in the trip generation models. To control for this effect, five mixed-effects models are systematically applied: mixed-effects linear model, mixed-effects log-linear model, mixed-effects negative binomial model, and mixed-effects ordered logistic model. The mixed-effects ordered logistic model produces the highest goodness of fit for our data and therefore is recommended.

In modeling non-work, single-destination choice, this research proposes a new method to build choice sets which combines survival analysis and random sampling. A systematic comparison of the goodness of fit of models with various choice set sizes is also performed to determine an appropriate choice set size. In modeling non-work, multiple-destination choice, this research proposes and compare three new approaches to build choice sets for two-destination choice in the context of trip chains. The outcomes of these approaches are empirically compared and we recommend the major/minor-destination approach for modeling two-destination choice. The modeling procedure can be expanded to trip chains with more than two destinations.

Our empirical findings reveal that:

  1. Although accessibility around home is not found to have statistically significant effects on non-work vehicle trips, the diversity of services within 10 to 15 minutes and 15 and 20 minutes from home can help reduce the number of non-work vehicle trips.
  2. Accessibility and diversity of services at destinations influence destination choice but they do not exert the same level of impact. The major destination in a trip chain tends to influence the decision more than the minor destination.
  3. The more dissimilar the two destinations in a trip chain are, the more attractive the trip chain is.
  4. Route-specific network measures such as turn index, speed discontinuity, axis of travel, and trip chains’ travel time saving ratio display statistically significant effects on destination choice.
    Our findings have implications on transportation planning for creating flourishing retail clusters and reducing the amount of vehicle travel.

After working at Valparaiso University last year, he is currently teaching at the University of Minnesota Duluth.

Urban amusement parks | streets.mn

Tivoli

Cross-posted at streets.mn  Urban amusement parks:

“All the cool cities have urban amusement parks. In fact Minneapolis-St. Paul is the largest urban agglomeration in the upper Midwest without an urban amusement park.”

Urban amusement parks

Next to the originator of a good sentence is the first quoter of it” – Ralph Waldo Emerson Quotation and Originality 

Good artists copy, great artists steal.” – Pablo Picasso (attributed but unsourced)

One of the surest tests [of the superiority or inferiority of a poet] is the way in which a poet borrows. Immature poets imitate; mature poets steal; bad poets deface what they take, and good poets make it into something better, or at least something different. The good poet welds his theft into a whole of feeling which is unique, utterly different than that from which it is torn; the bad poet throws it into something which has no cohesion. A good poet will usually borrow from authors remote in time, or alien in language, or diverse in interest.” – Eliot, T.S., “Philip Massinger,” The Sacred Wood, New York: Bartleby.com, 2000.

Good cities copy, great cities steal.” — Anonymous on Streets.MN

All the cool cities have urban amusement parks. In fact Minneapolis-St. Paul is the largest urban agglomeration in the upper Midwest without an urban amusement park.

Oh, you say, but the Greater MSP metropolis has ValleyfairNickelodeon Universe at theMall of America, the Midway and the Kidway at the State Fair, Comotown, and, coming soon, a Ferris Wheel at the old Psycho Suzi’s.

Valleyfair is suburban, the Midway and Kidway are seasonal, Como Town is in a large park fairly remote from the urban core, and the Mall of America, is, well, the Mall of America (though to be fair, it is more easily accessible by mass transit than anything but the State Fair).

2013-07-11 at 17-33-42

The history of Minneapolis and St. Paul includes many amusement areas that are no longer with us, including parks in Excelsior and Big Island on Lake Minnetonka, the short-livedWonderland in Longfellow, and Wildwood on White Bear Lake (Wildwood and Big Island were both owned by Twin City Rapid Transit as a way of better utilizing transit capacity).

Tivoli Gardens

What I am referring to are places like Chicago’s Navy Pier, Sydney’s Luna Park, the London Eye, or the best I have seen, Copenhagen’s Tivoli Gardens. They are walkable from the urban core or easily accessed by transit, and thus at least as geared to tourists as to residents. Tivoli and Navy Pier are fully programmed, so in addition to rides, there are numerous events so the sites are occupied day and evening much of the year. While Navy Pier has the scenery of Lake Michigan, Tivoli has no special natural advantage and is largely inward looking. Tivoli attracts about 4 million visitors per year. It is adjacent to a major railway station, helping attract visitors. My Tivoli photos can be seen on Flickr.

London Eye

View Map of Tivoli Gardens, Copenhagen

Where?

The site I have in mind is near Saint Anthony Main. This includes both vacant lots and industrial parcels that will eventually be reconfigured. We can start with the huge parking lot at 2nd Avenue and 2nd Street (and across the old Pillsbury Technology Center parking lot as well). I realize Metal-Matic is currently occupied by a business that employs people, but industrial sites in the city clearly have their days numbered as the value of land for other uses outweighs their use in manufacturing. We should be thinking about what comes next (without actually forcing them out). The site is adjacent to the freeway and the University, creating some built-in demand, as well as a short walk or NiceRide across the Stone Arch Bridge from downtown, catering to both the business and tourist crowd. These sites could become another 6-story stick frame apartment building, but it could be something more memorable.

Sydney - Darling Harbour Carousel

The land under the freeway could also be repurposed as part of this endeavor. There are lots of examples.

View Map of St. Anthony Main area

There are many other good sites, please identify some in the comments. The Metrodome would have been one, but it is to be reconfigured as something else.

Funding

I am trying to speak in a language public officials will understand. This does not imply an endorsement of this funding mechanism.

This lack of an urban amusement park constitutes a travesty that should be rectified with a TIF-financed economic development program as soon as possible. It has been shown bynumerous studies that urban amusement parks result in people spending money, which any macro-economist worth his salt-water will say is good for the economy.

OK, end of sarcasm. This doesn’t need to be a public facility. If it is popular, it should be able to pay for itself, like the State Fair. What it needs is to be enabled.

 

Discussion

This is of course just speculation, a Fantasy-land so to speak. But with some vision, the cities should be able to attract an amusement park builder to create an attraction (or if Minneapolis gets one, St. Paul will want one too, so make that two attractions) that appeal(s) to the masses more than 8 nights a year.