WMATA recently released the 2008 Metrorail Station Access & Capacity Study (PDF) which analyzes how the system can accommodate future growth in detail. David has a good summary of the report’s major recommendations for improvement and expansion. A table in the report caught my eye that showed the estimated number of jobs and households around a number of Metrorail stations from the year 2005. Metro’s Office of Long-Range Planning was kind enough to provide me the complete spreadsheet of the number of households and jobs within half a mile of each station, distilled from the Washington Council of Government’s transportation planning data. (I assume the numbers were calculated by summing the jobs for each traffic analysis zone whose center was half a mile from a Metro station.)

I’m using the data for a larger ridership study that should appear here sometime in the future, but in the meantime I realized it allows us to evaluate the level of transit oriented development in each jurisdiction. For Montgomery County and Prince George’s County, because the stations are spaced sufficiently far apart, we can also estimate the percentage of total jobs within half a mile of a Metro station. This relative measure takes into account the many more jobs in Montgomery County. Because the half mile radii overlap significantly in Arlington, Alexandria, and D.C. I can’t easily say what proportion of all jobs are accessible by transit for those jurisdictions.

Here’s the results after averaging the development for each station in the various jurisdictions.

The analysis confirms what we might expect: D.C. and Arlington have the most jobs near their stations, and the Prince George’s County stations have the fewest in absolute terms. The pattern holds in relative terms for the Maryland counties — according to the WMCOG data, roughly 50% of Montgomery County’s 500,293 jobs were within 1/2 mile of a Metro station, versus only 38.4% of Prince George’s County’s 358,450 jobs. While I agree there’s much Prince George’s should be doing to boost development around their stations, there are a couple important caveats. The county has seen much less real estate investment than other parts of the region, and the Metro stations are much newer. Metro made it all they way out to Shady Grove in 1984 and Glenmont in 1998, versus Greenbelt in 1993, Branch Avenue in 2001, and Largo Town Center in 2004.

For households, on average Arlington County’s stations have slightly more than D.C. stations, likely a reflection of Arlington’s aggressive development of high density housing along the Rosslyn-Ballston corridor and the low-density residential neighborhoods surrounding many D.C. stations.

Not surprisingly, some of the least-used stations I identified in my popular post on station ridership also have the least development around them. My next step is to use a regression to evaluate the relative role of jobs, housing, parking, bus lines, multi-modal access, and a variety of other variables to explain ridership.