GIS Final-Blog Post

 

Introduction

The City of Omaha, Nebraska, has a population of 410,000 (American Fact Finder 2, 2010), and the metropolitan area is expected to double by 2050. Currently, the city is evaluating proposals for new community development strategies to accomodate the growth within Omaha City. Transit-Oriented Development (TOD) has been hailed as a panacea for the ills associated with sprawl because it reduces vehicle miles traveled (VMT), relieves automobile-related congestion, and reduces greenhouse gas emissions. However, it is important to critically assess the merits of TOD and the viability of placing this type of development in Omaha.

Map 1

Omaha is located in eastern Nebraska and the metropolitan area stretches between Nebraska and Iowa.

Map 2 (Source: Omaha Metro)

Omaha Metro is the public transportation authority that serves the city of Omaha and contracts with some fringe cities such as Bellevue. The map above is Metro’s service map and covers approximately 120 square miles (Omaha Metro). The city, together with Omaha Metro, have worked to develop six transit hubs to increase access and reduce the total number of transfers required to get to a desired location. In the map above, the transit centers are symbolized by yellow circles (Map 2). Noticeably, they look evenly dispersed throughout the city. However, Map 3 reveals that the transit centers are clustered toward the south-eastern portion of the city. Although some of the transit centers have been developed in to vibrant walkable areas, many still resemble traditional bus stops. For example, the Westroads Transit Center and the Metro College Transit Centers are located on the premises of a mall and college. Their facilities include little more than benches where multiple lines converge.

Map 3

Demographics

The City of Omaha ranks 42nd in the top 100 cities for population and has the highest concentration of headquarters for Fortune 500 Companies at  five (MAPA COG). The city also ranks 11th national for persons living below poverty so it is not surprising that well over half of its service miles serve low-income and minority communities (Omaha Metro)

Map 4

Overall, only 1.4% of the population in Omaha use public transit (US Census Data, 2010). This statistic is shocking when you compare the levels of transit ridership by census tract (Map 4). The above map shows how many riders pass through each transit center in comparison to the other transit centers. Not surprisingly, the transit centers located near the levels of higher transit ridership are better utilized.

Map 5

Map 5 documents residential density and transit ridership rates at the transit centers. Residential density was calculated by dividing the number of residential units in a census tract by the total area for the census tract. The more dense areas (darker green) also generally have the  higher proportion of transit riders (Map 4).

Map 6

Map 6 shows the percentage of people living below the poverty line and the transit ridership rates at each transit center. Clearly, poverty and transit ridership are highly correlated. Since the City of Omaha is very car-oriented, it intuitively makes sense that only the poorest of the poor ride public transit. In fact, when I was trying to obtain data from the City, Omaha Metro, and MAPA Council of Governments, all of the representatives were quick to admit that transit was not a strong point. One representative went so far as to say that it was only provided because of Title VI of the Civil Rights Act of 1964, which requires transit service be provided to low-income and minority populations  (FTA, 2012).

Viability of Transit-Oriented Development

TOD has been projected to reduce vehicle miles traveled (VMT) from 5% to 20%, depending on other conditions. There are two main predictors in transit ridership: socio-economic status and density. Since density of Omaha as a whole has already been mapped, I did not do this again. Instead, I decided to create 1 mile buffers around each existing transit center and look at the median income for each area. Presumably, if the City decided to pursue TOD , they would want to place the new developments near an existing transit center that already has access to a lot of bus lines.

Map 7

Map 7 documents the median income around each transit station. Since TOD is often associated with higher-income amenities, the best locations for TOD based on median incomes would be on the west side of Omaha. However, income is not the only contributing factor to TOD’s success.

Map 8

Map 8 analyzes the best location for TOD based on factors that  contribute significantly to the viability of TOD and the likelihood of decreasing VMT. The index shows that the area where TOD would optimally be located (darkest green) is no where near a transit center. The central portion of Omaha near Midtown Transit Center could be a potentially viable location.

Variables of analysis included density, the quality of the transit system, median income, and the use of other transportation modes (walking, biking, bus, etc).  For quality of the transit system, the proxy of transit center ridership levels were used. For the use of other transportation modes, Census Data for the percent of people that walk, bike, or use transit to get to work was used. Unfortunately, data is not available at a disaggregated level for rideshare of non-work trips. The following equation weighted the variables based on several meta-analysis studies (Crane, 2000; TRB, 2009; Ewing and Cervero, 2010):

Optimal Location=  .35 (Density) + .3 (Quality of Transit) + .2 (Median Income) + .15 (Use of Alternative Modes)

A critique of the successfulness of TOD is the self-selection bias, which states that people who live in TODs are predisposed to using transit and it is not the built environment that changes their travel behavior (Cervero, 2008). Therefore, the ability for TOD to significantly reduce automobile dependence and increase transit ridership is limited. Since Omaha’s population relies primarily on cars and their public transit system has not focused on widespread market saturation,  the maps suggest that TOD is not not a wise method of development.

However, changing the goals of TOD could yield dramatically different results. Since the downturn in the economy, redevelopment agencies and affordable housing programs have suffered significantly. Yet, grant money and funding is still available for TOD, especially in light of sustainability awareness. If new affordable housing complexes aimed to incorporate TOD elements, this could possibly help fund necessary improvements to housing in low-income areas.

Map 9

The analysis in Map 9 is of selected variables related to affordable housing such as: transit ridership levels,  minority vs. non-minority, median income, and percent living below the poverty line. I reclassified these variables to suggest the optimal location for affordable housing units. Not surprisingly, the index suggests that the areas with a high percent of the population living below the poverty threshold are also the locations where low-income housing is necessary. When comparing these areas to the previous maps (of poverty, transit ridership, and density), it is possible that TOD techniques could complement affordable housing programs very well.

Conclusion

Omaha, Nebraska is expecting a population surge within the next few decades. However, implementing TOD housing initiatives is not likely to be a successful means of coping with the growth. Omaha’s low transit ridership levels illustrate that only the poorest of the poor ride public transit. The car-culture that is prevalent is not likely to subside, especially since the physical environment was designed for private automobile use. Therefore, even though Omaha has policies in place to potentially encourage more compact, mixed-use development, the lack of quality transit service, low priority on increasing ridership, and relative dependence on automobiles indicate that TOD is not currently a viable option.

References

  • American FactFinder2. (2010). American Community Survey. March 9, 2012, from http://factfinder.census.gov/servlet/DatasetMainPageServlet?_program=ACS&_submenuId=datasets_1&_lang=en&_ts=
  • Businessweek (2009). http://images.businessweek.com/ss/009/10/1022_40_strongest_US_metro_economies/9.html
  • Cervero, R. (2008).  Transit-oriented development in America:  Strategies, issues, policy directions. New Urbanism and Beyond: Designing Cities for the Future, Tigran Haas, Editor.  New York:  Rizzoli.  Pages 124-129
  • Crane, R.  (2000).  The influence of urban form on travel: An interpretive review,” Journal of Planning Literature, 15(1): 3-23.  http://jpl.sagepub.com/content/15/1/3.full.pdf+html
  • ESRI
  • Ewing, R. & Robert C. (2010).  Travel and the built environment: A meta-analysis. Journal of the American Planning Association, 76(3):  265-294.
  • Federal Transit Administration (2012). Title VI regulations. http://www.fta.dot.gov/civilrights/sitemap_11706.html
  • MAPA COG. http://www.mapacog.org
  • OMAHA Metro http://ometro.com/
  • TIGER FILES. (2010). http://www.census.gov/cgi-bin/geo/shapefiles2011/main
  • TRB. 2009. Committee on the Relationships among Development Patterns, Vehicle Miles Traveled, and Energy Consumption.  Driving and the Built Environment:  The Effects of Compact Development on Motorized Travel, Energy Use, and CO2 Emissions.  Washington, DC:  National Academy of Sciences / National Research Council, August.  Pages 144, 181-186.  (http://www.nap.edu/openbook.php?record_id=12747&page=144)

Special thanks to Linda Barritt of Omaha Metro and Paul Hunt of MAPA Council of Governments

 

Skills Used

  • Models
  • Original data (transit centers and ridership data)
  • Hot spot analysis (spatial analyst)
  • Geoprocessing
  • Geocoding
  • Inset map
  • Graduated symbols
  • Aggregating attribute fields (transit use, age)
  • Creating indices (poverty, minority)
  • Custom shapefile creation (transit centers and ridership data)
  • Attribute sub-set selection
  • Extracting data from buffers

Models

Data joins

Rasters

 

Reclassification of All Possible Variables for General TOD Viability

Reclassification for Affordable Housing Analysis