Visualizing the Impacts of DC Transit-Oriented Development

An analysis of 10-year demographic changes to Washington D.C. through TOD.

R
Transportation
Equity
Author

Stephanie Cheng

Published

September 22, 2023

Full Analysis

Source: WMATA

Project Brief

This project is an analysis of demographic changes due to transit-oriented development using GIS data visualizations. Specifically, the analysis aims to understand the benefits and impacts of Transit-Oriented Development (TOD) in the city of Washington D.C., with consideration of spatial biases. Using open data on Washington Metropolitan Area Transit Authority’s (WMATA) transit stops and lines, the analysis centers around benefits and potentials of TOD in the city. Some key things to keep in mind about this analysis: DC’s metro lines and stops have changed between the dates of the analysis. However, due to the lack of data on the 2009 stops, this study only uses the most recently published publicly available data (May 2023) for these stops.

Exploratory Analysis

Firstly, TOD areas were identified using various spatial selections of regions relating to a half-mile buffer around exisitng WMATA transit stops. After comparing three possible spatial selections, the below “select by centroids” method was selected as a the most effective means of identifying TOD areas which each stop is likely to reach.

The project then conducted an analysis with feature engineering on a range of variables to analyze the impacts of TOD areas on those variables between 2009 to 2019. Specifically, the following census bureau variables were evaluated:

  1. Total Population
  2. Median Household Income
  3. Median Rent
  4. Percentage White
  5. Percentage with Bachelors
  6. Percentage in Poverty

These variables were then analyzed both non-spatially and in the contexts of TOD areas.

In the following selected maps, the shaded white areas are the TOD-classified areas.

TOD tracts have a significantly increasing median household income while tracts away from TOD seem to be consistent: the tracts at the top of the map continue to remain affluent ($175,000 to $250,000 on an average) while those at the bottom continue to be below $50,000 on an average. This might point to a benefit of being closer to transit.

The percentage of population in poverty seems to be going down but a small rate. Especially for the tracts near transit stops (in white), poverty percentages appear to be decreasing, marked by a shift of colors in the graph from greens/ yellow to blues.

Total population generally remained consistent across TOD areas, with the exception of a large growth of population in two areas (purple in the 2009 map and bright yellow in the 2019 map). These two points had a population of zero in 2009 to about 8000 in 2019. Overall, these maps can be interpreted as visualizing a very slow and subtle increase in population across TOD areas, with a few specific areas areas filling up and increasing in population.

In the analysis, these variables and more were visualized across TOD vs non-TOD areas by creating comparative spatial analyses across time. Ultimately, the key takeaway regarding TOD was the impact of TOD areas on attracting affluent households with higher median rents.

Project Outcome

Click the full analysis button at the top to view at full screen.

Data Sources

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