Podcast: Colonias — Informal Housing in the U.S.

This week on Talking Headways our guest is Emily Perlmeter of the Federal Reserve Bank in Dallas. Emily discusses the half million people living in informal settlements known as Colonias, on the U.S. side of the Mexican border. Join us for a look at how these settlements are formed, who lives there, and their strengths and hardships.

Most Read from November 11th

Here are Yesterday's Top Stories from The Direct Transfer Daily

Photo-Illustration by Darrow; © Richard Cavalleri/Shutterstock

- TRB Research: Linking Transit Agencies and Land Use Decision-Making Guidebook

- Boating is cool in Venice, Not so cool in Miami Beach.

- Turns out self driving cars are a plot for robot imprisonment.  So says Scott Adams. 

Pushkarev & Zupan on Employment & Ridership

This is always a chicken and egg fight but I'm starting to believe that the residential density argument is a bit misstated in terms of its impacts on transit ridership. Specifically since you're talking about housing density and not employment density. Charlotte's Uptown development had a larger part to do in transit ridership than residential density does along the corridor. And ultimately the cycle of building housing is going to create more demand, the employment was the initial draw. The transit agency just figured out how to serve it.

Over 60% of transit trips are for work (See Commuting in America III). This is compared to just under 20% of overall trips. This means that the focus on where people work is important in monocentric cities such as Nashville. I'm not saying that residential density is ultimately unimportant. But I believe its less important for starting a transit system and more important for growing it. There are lessons on this in previous research works that we tend to ignore.

To be honest I hadn't really read Zupan in full until more recently on account of there is just too much to read in general. But when I caught up on it, the findings are quite interesting and get you wondering if we've been looking at this whole transit and development thing all wonky. In their seminal work Public Transportation and Land Use Policy (1977), Jeff Zupan and Boris Pushkarev made the following observations based on the existing data at the time:

Pushkarev & Zupan Pg 174-175:

1. Clustering or dispersing nonresidential space. Suppose 10 million square feet are to be added to a growing urban area. One option is to put the floorspace into two highway oriented non residential clusters, each 5 million square feet in size. Another is to create a new downtown of 10 million sq ft. In the second case, per capita trips by transit within a 3 to 5 mile radius will be 50 to 70 percent higher than in the first case, keeping residential density the same.

2. Enlarging downtown size or raising nearby residential density. Suppose the options are to double the size of a downtown from 10 to 20 million square feet, or to double the residential density within a few miles of it from 15 to 30 du/acre. The former will increase per capita trips by transit three to four times more than the latter.

3. Increasing residential density near downtown or farther away. Suppose the options are to double non-residential density from 5 to 10 dwelling units per acre either within one mile of a downtown of 10 million square feet or at a distance of 10 miles from it. In the first case, public transit trips per capacity in the affected area will increase seventeen times as much as the second case.

4. Scattering apartments or concentrating them near transit. Suppose a rapid transit station is located 5 miles from a downtown of 50 million square feet of nonresidential floorspace (the 1976 size of Newark). At a density of 15 du/acre, the square mile surrounding the station will send about 620 trips a day downtown by transit. Suppose speculative development scatters apartments throughout the square mile, raising its density by 20%. This will increase transit ridership at the station by about 24 percent. Yet if the apartments are clustered within 2000 feet of the station, preserving the rest of the neighborhood intact, transit ridership will increase by 34% or more; at least a car load of 62 people a day will be added not from any increase in average density within the square mile, but only from a new arrangement of the new development within it.

"Thus land use policies which will do most for public transportation are those which will help cluster nonresidential floorspace in downtowns and other compact development patterns. Downtowns of 10 million square feet of gross non residential floorspace, if confined within less than one square mile, begin to make moderately frequent bus service possible and to attract an appreciable proportion of trips by transit. By contrast, downtowns of 5 million square feet can support only meager bus service. Spread suburban clusters of nonresidential use can only occasionally support meager bus service, if they contain shopping centers, or if they are surrounded by residential densities in excess of about 7 du/acre.

Residential density is less important for transit use than residential location, ie proximity to a downtown of substantial size or proximity to a rail transit line. If greater transit use is the goal, it is more important to put housing close to a downtown than make it high density. In fact, moderate residential densities in the range of 7-15 du/acre can support moderately convenient transit service by any of the transit modes reviewed in this book. Of course, densities higher than this will support better service, as well as more trips on foot. Thus, a strongly transit-oriented city such as Montreal has an average density of 35 dwellings per acre; attached two-family houses form an important part of its newly developed neighborhoods. Evidence from New York suggests that the shift from auto to transit diminishes, and reductions in total travel per capita cease, at densities above 100 du/acre. This density can be represented by 13 story apartment houses covering 20% of their site; on transportation grounds, there appears to be no need to exceed this density. It is important to emphasize, though, that a 13 story building located amid open fields will make no contribution to transit; it will only make a contribution if embedded in existing urban fabric, close to downtown or a rail station.”

All of this says that increasing your downtown size, and putting dense housing near downtown is likely to increase transit ridership. Now this goes so far when we're talking about polycentric regions and employment clusters that we see today such as Tyson's corner etc. But ultimately I think this work has lessons for those places as well. It will be interesting to see where the next decade of TOD research heads because ultimately I think this is a part of the research that needs to be explored in greater detail.

Service Levels & Income

How about this cliche fest. The Examiner writes about how San Franciscans are tougher than the rest of the bay area when it comes to walking to transit through high crime areas. But in reading it, some of the writing made me skeptical that this was a real study or whether people didn't just take stereotypes into the paper:

In places like Oakland, Berkeley and Sunnyvale, the high-crime neighborhoods tend to scare people away from using nearby transit services, the study found. Folks had a tendency to walk less in those neighborhoods, choosing to drive instead, according to a new study from the Mineta Transportation Institute.
...
“In [San Francisco] neighborhoods where there was more crime, people were most likely to use transit,” said Dr. Christopher Ferrell, one of the study’s principal authors.
...
He added that The City’s transit services tend to be located in high-density areas, which invariably attract crime.
...
As expected, those who chose to live in suburban areas were more inclined to avoid walking in high-crime areas and using transit hubs within those areas. But even in a dense urban city such as Oakland, folks had a propensity to avoid public-transit hubs in high-crime neighborhoods.

Seems to me that this has nothing to do with crime but rather to do with transit service levels & income levels & self selection. What am I missing?

Lancaster PA, VMT Champ

I haven't been able to read the Brookings Report that just came out, but an article in the Portland DJC alerts us to something interesting. Lancaster PA is second behind New York in VMT per capita. It seems as if its partially due to its low VMT overall.

I hadn't heard much about Lancaster before the Streetcar issues that have been going on there with the FTA but the little interaction I've had is with Google Earth. The first thing you notice (if you're a nerd like me) is that the major freeways stay relatively far away from the center of town, there is a grided street pattern throughout the city, making walking, biking and transit more likely, and the Amtrak station actually serves fairly frequent trains to Philadelphia.

Eisenhower was freaked out by the idea of freeways going through our cities. It was pushed through anyways as the people who took over the Interstate program showed no mercy in cities. Perhaps this is a case study of what happens when we keep them out.

Do You Have Friends in Cul De Sacs?

They probably have lots of friends! According to a study in the UK, the less traffic you have, the more friends you have.

VMT & Foreign Oil

So watching the Pickens commercial below gave me a thought. He was discussing dependence on foreign oil and showed some percentages of how much we import. So I went to the data. In terms of foreign oil I went to the Energy Information Administration and pulled an excel chart for historic crude oil imports and production. Since its monthly I averaged 1970,1990, and 2005. T Boone uses current 2008 to say 70% but the most recent transportation data is from 2005. So foreign crude imports went from 12% to 44% to 66% of the total U.S. supply.

Then I went to the BTS and found the Vehicle Miles Traveled (VMT) charts and put the totals together. A word of caution from the last chart I put up. Correlation doesn't necessarily mean causation, but I thought this was interesting and more relative. If anything I hope it starts some discussion on how this oil dependence is related to our auto dependence.
Perhaps its also related to this: Spending on highways over transit from PIRG.

I'm going to go out on a limb here and say that our transportation policy has led us to this predicament. I believe we all knew this, but its always good to have charts right? Thoughts?

Real Density Comparisons

AC calculates real density by weighted averages of census tracks. Check it out.

More Research and Reports

APTA - The Broader Connection Between Transit and Energy/GHGs

People living in households near public transit travel 12 fewer miles per day which is 27 percent less than persons in households with no access to public transit according to the study. This equates to an individual household reduction of 223 gallons of gasoline a year.

Smart Growth America - Growing Cooler

They warn that if sprawling development continues to fuel growth in driving, the projected 59 percent increase in the total miles driven between 2005 and 2030 will overwhelm expected gains from vehicle efficiency and low-carbon fuels. Even if the most stringent fuel-efficiency proposals under consideration are enacted, notes co-author Steve Winkelman, “vehicle emissions still would be 40 percent above 1990 levels in 2030 – entirely off-track from reductions of 60-80 percent below 1990 levels by 2050 required for climate protection.“

Department of Homeland Security - Transit Threat Assessment

The Greenness of Cities - Edward Glaeser

Over the past 50 years, automobile oriented suburbs have grown much more quickly than denser urban areas, and over the past six years, the four fastest growing American metropolitan areas have been Atlanta, Dallas, Houston and Phoenix—all hot places that use an impressive amount of electricity to create a pleasant year-round climate. Cars and air conditioners both lead to signifi cant emissions of carbon dioxide, which an increasing body of evidence has linked to potentially dangerous climate change. If this evidence is correct, then there are serious social costs associated with new forms of development that tend to be extremely energy intensive.

Increasing Job Densities an Appropriate TOD Strategy

It might seem like a duh moment, but Prof. Gary Barnes paper discusses in a paper he wrote for the Journal of Public Transportation that it's not just residential density that determines transit usage, but rather where people are going.

Using regression analysis, he showed that in Minneapolis, aside from developing residential densities, transit share can be increased by building up commercial centers. In the regression, he showed that for every 1000 people per square mile that the residential density grew, the increase in transit's share to downtown increased 2.4% versus .6% increase when people went to suburban jobs. The same thing happened for increases in low income users. For every 1% increase in low income population per square mile, increases were noted. The chart that shows the results is below.



He also relates the concentration of regional jobs in major centers directly to how much transit people take. An example from the article is below.


There are a few caveats including the need for quality transit and parking regulations in these centers that encourage transit ridership. But just having a center of commerce isn't good enough. Places that have a lot of jobs like Pleasanton need to be better organized and less suburban office park.

Recently however, many people have been focused really heavily on residential densities, which are important, but I haven't seen many programs that create a regional job placement and growth strategy. This could be part of the key for increasing transit's use for work trips.

I have a feeling as well that pushing for dense commercial centers with mixes of retail and office then connecting them with high capacity transit will go a long way towards increasing transit's ability to cut congestion in the peak hours. It might also be a self-fulfilling prophecy of sorts, creating a cycle of more transit and more office development in the cores of a region.

I know that this is kind of a 'duh' post. But having numbers to quantify the effects of connecting residential areas to large employment centers is really important in moving forward with policies that promote transit ridership. Thanks Prof Barnes for this paper and for your conclusion:

Planners and policymakers hoping to manage urban traffic congestion through increased transit use are limited in the short term by the strong influence that existing land use exerts on mode choice. While this point has been widely acknowledged, most research and policy discussion on this topic has focused on increasing residential densities. However, the conclusion of this article is that the development and expansion of very large, high-density job centers is the best tool available for most cities to achieve substantial increases in transit use.

While there are many ways to improve transit use, achieving the substantial increases necessary to impact congestion levels will probably ultimately require greatly improved service frequency or higher costs of driving, such as parking charges. Higher parking charges will be politically infeasible in the absence of adequate transit service as an alternative; however, improved transit service is hard to justify in the absence of a sufficiently large market.

Creating a large market appears to reduce to two options: the well-known solution of increasing residential density and the less-considered option of focusing on the work end of the trip. While both of these tactics appear to be effective in principle as well as practice, it is, for a variety of reasons discussed in this article, very difficult to have impacts on residential density that are large enough to have regional significance.

The constraints that limit the use of residential density increases as a tool are not in force to nearly the same extent for commercial development. A gradual transition of a relatively small amount of office space from isolated or low-density settings into a few large dense centers could lead to sizable increases in regional transit use in a relatively short time.

The Twin Cities area illustrates the possibilities of this approach. There are two downtowns, but Minneapolis is much larger and is geographically in the center of the developed area. Downtown St. Paul is relatively small and close to the edge by comparison, yet still attracts a substantial transit share. This hints at the possibility that even suburban locations, if they are developed to a sufficient size and density, can become major transit attractors.

Increased densities at the work end of the trip, by making improved transit service frequency more viable, could also help to increase nonauto access to retail and other nonwork opportunities. While higher density residential development can also have an impact, the effect is much larger when the increased density occurs in or around high-density commercial areas, both because more trips will be made to these high-transit attractors and because these areas support relatively good transit service going out as well as coming in. Increased commercial densities, especially in the suburbs, may be the only tool available for inducing significant transit use from the vast suburban areas of most cities that are already developed at low densities, and which will probably stay that way forever.