Per most recent data available, here are daily ridership stats for top 3 systems of rail and bus in the U.S.
Rail-
NYC MTA subway [[not including PATH or SIRT)- 8.7333 million
DC Metro- 855.3 thousand
Chicago L- 734.9 thousand
Bus-
NYC NYCT bus [[not including MTA bus, mostly in Queens)- 2.605 million
LA MTA bus- 1.138.3 million
Chicago CTA bus- 918.3 thousand
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