|Data source: all data are annual summaries based on the U.S. Department of Transportation's "National Transit Database (NTD)" Monthly Module Adjusted Data Release (https://www.transit.dot.gov/ntd/data-product/monthly-module-adjusted-data-release), December 2018, accessed in late February 2019. Population data are also drawn from NTD. Population for urbanized areas (UZAs)represent 2010 census estimates. Transit agency service area populations are reported by the agencies themselves—while the vast majority of agencies have updated population data with 2017 estimates, many have not (this is indicated by an astrisk in the relevant data column; for full details, see the Monthly Module Adjusted Data Release, linked above). TransitCenter takes responsibility for any misrepresentation or mistakes made in analyzing these data from the NTD. |
Citing this work: Please credit TransitCenter for this analysis if you cite it directly (i.e. without reproducing it on your own). Feel free to get in touch with any questions about this: firstname.lastname@example.org
Additional resources: The NTD Glossary is a valuable resource for anyone using these data (https://www.transit.dot.gov/ntd/national-transit-database-ntd-glossary). For more on using the NTD, see TransitCenter's February 2017 video, "Fun with the National Transit Database" (http://transitcenter.org/2017/02/13/fun-with-the-national-transit-database/).
Method: The data in this spreadsheet are sums of annual ridership (in terms of "unlinked passenger trips"), as reported by transit agencies to the Federal Transit Administration (FTA). To calculate ridership by agency, TransitCenter summed all ridership values for each agency in each year, according to one of three modes: bus, rail, or paratransit. For ridership by urbanized area (UZA) the approach is the same, but summed across each UZA. NTD modes included in the bus category include MB, CB, RB, and TB; in the rail category include LR, SR, HR, CR, MO, MG, AG, and CC; and paratransit includes only DR. Totals for agencies and UZAs represent the sum of all three modes in each agency and UZA, respectively.
Caveats: Federally reported ridership data are typically different from agency-specific data reported publicly by agencies themselves. While NTD data are the best data available to compare agencies and regional ridership trends against each other, they may not be as accurate as locally-specific datasets. Furthermore, users of this spreadsheet should exercise some caution, particularly when using the agency statistics. In New York, ridership that is today published under the heading of only two agencies (MTA New York City Transit and the MTA Bus Company) used to be published as several more. Phoenix's Valley Metro similarly continues to publish ridership information under the banner of several separate agencies. Many more such oddities exist. Combined with the fact that some regions comprise many transit agencies (e.g. San Francisco) often makes the regional UZA a simpler unit of analysis.
Questions? Feel free to reach out to TransitCenter at email@example.com with any feedback or questions.