Do you have a study as a source that backs that up? I'm personally skeptical, as public transportation is weighted significantly towards ineffective demand.
This also neglects the question of positive externalities attached to public transportation systems that aren't accounted for in a profit / revenue metric, such as lower property prices, more flexible labor markets, and the quality of life improvements of mixed use zoning that high use public transportation facilitate.
This also neglects the question of positive externalities attached to public transportation systems that aren't accounted for in a profit / revenue metric, such as lower property prices, more flexible labor markets, and the quality of life improvements of mixed use zoning that high use public transportation facilitate.