L’Enfant Station, originally uploaded by plemeljr

Go and read Ryan’s comparison of D.C.’s Metrorail Fares in Context with other systems:

The D.C. Metro and San Francisco’s BART are often described as sister systems. They serve similar sized cities, were built at a similar time, and provide a similar type of service to their riders. They both also use a graduated fare system rather than a fixed fare. Like Metrorail, BART has recently adopted fare increases.

I too would be interested in see what controlling for frequency and quality of service does to the value, real or implied.
Naturally, I don’t actually need to do this comparison, but rather I can ask the lazyweb to help out.