Transit Information Center
Correlation of employment and fuel prices with monthly ridership (Selected urban areas.)
Data sources:
The National Transit Database > Monthly Module Adjusted data - August 2008 (http://204.68.195.57/ntdprogram/data.htm)
The Bureau of Labor Statistics (http://data.bls.gov/cgi-bin/srgate)
Energy Information Administration, Department of Energy (http://www.eia.doe.gov/oil_gas/petroleum/data_publications/wrgp/mogas_history.html)
For Miami, Seattle and New York City employment and ridership are very well correlated.
Fuel prices correlate well with ridership in New York City and Chicago.
(1) It should be noted that a high correlation between ridership and employment or fuel prices does not necessarily imply that a causal relationship should exist between them.