I think one of the main arguments for free public transit is that it has large positive externalities, that is, it benefits those who do not use the system. Wh

I think one of the main arguments for free public transit is that it has large positive externalities, that is, it benefits those who do not use the system. Whenever people switch from using cars to using public transit, you get - a reduction in carbon dioxide emissions - increase in local air quality - reduced noise - less congestion, smoother traffic for those who still travel by car (and this indirectly also reduces emissions) - fewer accidents So it might be a worthwhile goal to strongly encourage people to use public transit, even if you don't use it yourself.