Fairbox recovery rates [1] in the US tend to be around 15-20%. The rest is made up from public subsidies. In the most heavily utilized subway systems, the ratio can increase to around 50% (NYC). [1]

It depends how you count the revenue, but by some accounts public transit is more heavily subsidized by State and Federal government than driving. This is especially true on a per-passenger-mile basis.

[1] - https://en.wikipedia.org/wiki/Farebox_recovery_ratio