It doesn't need to be a cash cow (and probably shouldn't be), but public transit should be able to break even because that is the only reliable signal that a service is providing enough value to justify its cost.
Calling the police or fire department should incur service chargers.
Libraries should charge rental fees.
Schools should all charge tuition, including "public" schools.
If they're not at least breaking even, are we sure they're providing any public good?