Public Transport activists are often told by the local city administration/government that Public Transport is a big problem as it is a drain on the coffers of the city. "Public Transport loses money and the city can't afford to subsidize it beyond a certain extent.
A big lie, because profit and loss from public transport (transit) can't be worked out from fare (ticket ) collection alone. One must quantify the invisible benefits to the city from a well functioning public transport system. Add up the cost of air, soil and noise pollution on the city and health of its citizens, add up the cost of medication to treat respiratory diseases, hypertension, heart disease and even cancers directly or indirectly connected to automobile effluents. Add up the cost of never-ending road construction, flyovers, underpasses, accidents and stress of driving in congestion primarily caused by personal automobiles. Add to this the cost of building parking lots and other infrastructure for the automobile and you'll begin to see the real cost of automobile dominated city planning.
You will then see how much Public Transport users subsidize the city because public transport vehicles cause far less pollution, contribute far less to road congestion and accidents when compared to personal auto vehicles. If more people use public transit the city will be a much better place to live in.
But people won't get out of their personal auto vehicles unless public transit is economical and unless the city puts in place severe constraints (like expensive parking levies, congestion charging and creation of car-free areas). Free Public Transport can thus become an important step to move in this direction.